View Full Version here: : Wood Stain - Can you dilute it to make it lighter in colour

08-09-2007, 07:59 PM
I brought some wood stain today. After giving it a test on some wood I find
it a little to rich in colour. Is there way of toning it down?


08-09-2007, 08:07 PM
Add turpentine.

08-09-2007, 08:16 PM
What type of wood stain did you use Rob?

I use the Feast Watson brand and you can use a reducer with it.
You just keep on adding the reducer until you come up with your desired shade.

08-09-2007, 08:43 PM
Cabot's interior stain (Australian Jarrah) semi transparent - oil rich

Which I will later spray with a couple of coats of satin Estapol.

The stain is a real rich colour although i could probably get use
to it I would like to tone it down some. It kinda reminds of of
the stuff my old man use to get us to paint the fences with.
Maybe that's why lol

turpentine, i think I remember something about that.


08-09-2007, 09:06 PM
If its a spirit base stain then use mehto to thin it

cristian abarca
08-09-2007, 09:23 PM
Thin it down with turpentine. Add a little at a time and stir it very well. I would be putting some in a separate container and then adding turpentine just to be on the safe side. Don't add too much. One thing about stain is that it gets a little darker as it dries. It also tends to yellow a little with the clear Estapol.

Regards Cristian

08-09-2007, 09:50 PM

Thanks for the pointers, I'll spray the test board tomorrow and see how it
comes out. I'm going to wait until I'm in town again to get some turps an
do some test before i do the job.

Will stain keep with turps in it?


08-09-2007, 10:41 PM
Yes, definately turps. Try diluting it with different amounts using some offcuts or scrap from then same timber, thus getting an idea of different ratios of turps-to-stain.

08-09-2007, 10:47 PM
If this is Feast Watson Prooftint, then use methylated spirit or better still, the Feast Waston reducer.
Prooftint is a spirit based product so do not use turps to thin it.

cristian abarca
09-09-2007, 09:38 AM
Stain will keep with turps but the container must be sealed properly and kept in a cool place. Stain is basically turps anyway except the spirit based ones, which are metho based. We sometimes make liming stain using white oil undercoat and lots of turps.

Regards Cristian

09-09-2007, 04:47 PM
Thanks guy's for your advice and help :thumbsup:

Looking at the sample this morning in daylight. It didn't look as rich as
it appeared yesterday. I gave it a couple of coats of Estapol and it's seems
ok. My son liked the colour too and didn't want it lightened, since it will
be his scope when it's done i couldn't argue with him. Actually I really
like the colour. I so went a head with it.


09-09-2007, 06:18 PM
Beautiful Rob.

09-09-2007, 06:27 PM
I won't comment on the colour. You won't like the answer :lol:

I like DARK wood. :thumbsup:

10-09-2007, 06:24 AM

Thanks, first time I've stained something that isn't a fence paling, lol

I was originally thinking of staining it a verp deep green :eyepop::lol:

actually it looks darker in the flesh than it does in the photo, the flash
seems to lighten it up. here's a photo without using the flash but even
then it still looks more red than it really is. Still each to his own :)


10-09-2007, 07:32 AM
It will change a little when the clear is sprayed on.

10-09-2007, 06:43 PM
I'm making the truss connectors and attach them before spraying
the Estapol on it. Ordered the poles today :) i suppose i should look
at the mirror box :rolleyes:


12-09-2007, 06:10 AM
ok just for interest sake, can you double stain? I mean apply another coat
or will it just stay the same shade. I have just noticed a couple of marks
I would like to try and stain out.


cristian abarca
12-09-2007, 07:20 AM
You can double stain. The wood will look darker and the marks that you want to stain out will be a shade lighter. What you can do is stain the marks only with a slightly diluted stain (add turps). The surrounding area may become a little patchy. You have to decide what looks worse the patchy area or the marked area. Always test on a scrap sample of wood. In my experience, if the marks are really noticeable they will look worse than a bit of patchiness. Once you put Estapol on it the marks show up more than the patchiness anyway. Hope this helps


12-09-2007, 08:38 AM
Thanks Cristian


12-09-2007, 05:15 PM
btw Ed,

Here's how the focuser board turned out. I ended up clamping it for
seven days, i'm pretty happy with it. Also half done making the
wedge clamps.

posting instead of your 24" Nasmyth thread.


12-09-2007, 06:31 PM
deep green stain actually looks a lot nicer than you would first think ;)
probably a bit more fitting for a bass than a big dob though lol

12-09-2007, 07:18 PM
probably a little bit darker again, but getting close to what i had in mind.
I've seen a dark blue stained scope which was really nice (different).

btw, I'm building a weeny teeny 8" dob, called Buzz :)


13-09-2007, 07:43 PM
That's excellent Rob it looks great..:thumbsup:

18-10-2007, 07:44 PM
How is the scope coming along Rob?

19-10-2007, 03:59 AM
Seems to be ok so far. I've finished the secondary cage, it presently
has the focuser attached and spider and secondary loosely sitting
in it. I haven't aligned the focuser yet. Mirror box is built, almost
finished the side bearings. In the picture below I mounted them
temporarily so I could work out the placement of the split blocks.
Which are also semi attached by there pole locking bolt, I want to
try setting the poles into them and the secondary cage to see how
they look before I permanently fix them. I cut the truss poles last
night and also modified the side bearing with a cutout for the front
two split boxes. The bearing once the cutout bits have set just needs
a bit of filler in the odd spot and a bit of sanding. I'm going to spray
them silver and then Estapol on top.

I have been thinking of late that the mirror box can take a 10" mirror
and humming and harring about throwing one in there. But then I
would have to build another secondary cage. But then again if a cheap
one was to surface I probably would go for it.

I'm looking to have it completed by next new moon, no kids this weekend
so I will be out in the shed :D


19-10-2007, 07:35 AM
nice rob.. funny how red it looks in shot as its much darker up close
next moon eh ?...I should be pretty close by then ..maybe :whistle:

19-10-2007, 06:59 PM
It's coming along very nice Rob.

I can already see it as being a good looking sturdy telescope that will last for many years:thumbsup:

How is yours coming along Graham?

20-10-2007, 06:05 AM
Thanks guy's

Well I have made a big booboo... through a design change made between
completing the secondary cage and building the mirror box (I made the
mirror box a little bigger, wider) the truss pole connectors on the secondary
cage dont line up with the angle of the truss poles coming from the mirror
box. So I spent yesterday afternoon making a start on my parrallelogram
mount for my bino's. I was wondering how the hell I was going to remove
them without any damage to the secondary cage itself. Then it struck me
since it's all held together with glue and it is reasonbly slimline I can whack
it through the bench saw.


20-10-2007, 07:42 AM
Is there any way to modify the truss blocks to the mirror box to suit the cage?

20-10-2007, 08:09 AM
I was just typing that :).. yeah it would be a shame to have to change the top as youve pretty much got it looking good

I just have to grab a couple of sleaves(centre bolt) from my old man ed
without jacking robs thread to much I'd like to run this by you ed and see what you think
Hes also made three bearing assemblies to replace the teflon pads, basically brass inserts with a
19 mm marble soldered in each.. how well do you think it might work ?.. not that its really a problem as if it dosn't
I'll just flip the base board.

20-10-2007, 08:25 AM
Graham I replied to your 12" dob thread.

20-10-2007, 08:32 AM
Looking at the problem this morning, I've come up with a few options.

A) I could rout out the outer sides of the wedge connectors on the cage,
but the problem there is the the bolt that the wedge runs on is still at
the wrong angle. Trying to bent will damage either the connector or
possibly the cage itself, they're made of brass.

B) I can run it through the bench saw and cut them off as neat as possible,
then make wedged shaped spacer to the 2 degree angle I need and
re-glue. The wedge bolts would come with them as they dont go through
the secondary ring

C) I could just cut them off and make another variety shown in Kriege's book
which is where I scanned the image from, so I didn't have to try and
describe it.

Option C would also fix another design problem that I came across, with the
wedges permanently fixed the way they are. They get in the way while trying
to attach the secondary cage. But I'm also thinking, maybe a cross between
A and B rout out the sides and angle them.

Ed, trying to modify the mirror box is an option, but I would prefer the split
block were on the outside. But just looking at it now the outside diameter
of the secondary cage is about an in all round smaller than the mirror box.


20-10-2007, 11:05 AM
Well end result, I made a meal of removing the connectors. So it back to
building another secondary cage, managed to save the focuser board
relatively unscaved.

Oh well, we live and we learn. Any how all the design faults in the first
version can be fixed in the next version. Not that there were a great
many, more annoying to me than anyone else.


20-10-2007, 11:14 AM
That's sad to hear.
Oh well the next cage will be new and improved!

20-10-2007, 02:59 PM
Yes it will I'm determined :lol:

Well today hasn't been my day in the shed :( first I destroyed the
secondary cage. Then set about making another with some 12mm
ply I had laying around.... a bit thicker than what I wanted. So after
spending about an hour or so cleaning up the nasty side to save
me trying to do it when they are rings. I slipped up with the router
and made a mess of that, 3 hrs work gone :rolleyes:, so I humbily went
and cut another set out of the dreggs of what I had left of ply. Low
and behold my attention must of been somewhere else as one of the
panels kicked back off the bench saw and hit me square in the guts
leaving a nice big welt :doh:

So I decided to call it a day, maybe next might be a finger or something

oh well, tomorrow when I go pick up Jake. I'll drop into Bunnnings and
see if I can pick up some more 9mm ply.

off to watch Fance v Argentina with a cold brew or 2

btw, Ed your rocker box has giving me an idea for my new and improved
secondary cage :thumbsup:


20-10-2007, 03:46 PM
Yeah you gotta walk away rob .. my router got the wanders when cutting my last ring
( "possibly" somone didn't secure the pivot bolt to anything (:P) )
though I think it was still the routers fault !!!.
Had to buy another sheet of ply because of that one ..painfull as it is I find the little stuff ups that crop up all part of the process.

take care graham

20-10-2007, 08:12 PM
:lol: sorry had to laugh....it would of been a funny looking circle.:P

20-10-2007, 08:14 PM
Glad to be of help.

20-10-2007, 11:59 PM
It went wrong long before I cut a circle Ed .. I think i only got 4 or 5 inches
before noticeing the rotten thing was just heading in a straight line :D
but it was enough that i couldn't get another out of the piece i had left.

Are you going to allow for a 10 " mirror on the next one rob ?

21-10-2007, 06:11 PM
Well I went to Bunnings this afternoon, as usual most of the ply was the
usual standard. I picked through the 9mm but couldn't find a useable
piece. So I decided to go another route and got a sheet of 3mm and a
sheet of 7mm. I think I was lucky with the 3mm it doesn't appear to
have any noticable voids. The only difference is the 7mm made of pine
and the 3mm outer veneer looks like some sort of hardwood. Anyways
they're now in the press being laminated with the good sides out.

So I've rebounded and jumped back on the horse :thumbsup:. After the painful
death of my first effort with the SC :(, and the workshop disasters that
followed :rolleyes:. I'm not going to try and copy the original, I'll only make mistakes
and I have ali tube for the struts. But I'm still going with the slimeline SC
style to keep the weight down.

So I have a Q, is Shelly's exterior PVA ok to use to glue the ali tube into
the plywood rings? as they intend to be permanent. Or is there a better
alternative addhesive.


21-10-2007, 06:19 PM
Hmmmmm... I have been thinking about it since yesterday. But for me
in the end $400 is $400 not going towards a 16" maybe... hopefully... eventually...

Still it is tempting :help: too tempting :lol: no if I was going to spend a bit
of cash at present it would definately be on a 2" OIII filter:help:.


21-10-2007, 07:32 PM
You could try Mister Ply and Wood. The hoop pine is reasonably priced and good to work with.

Rob did you do some sort of drawing to calculate the angle of the truss blocks? It will be a shame to do the same mistake again.

I usually use an epoxy for the truss tube blocks but for the ply wood rings PVA will suffice.

In the future you might want to sell the telescope and it would be nice to sell it with the option to fit a bigger size mirror. If you are going to build the cage again making it 2 inches wider should'nt be a problem.

22-10-2007, 06:43 AM
Originally when I built the SC the angles were correct for the truss pole
connecter on the SC. It was later when I changed the size of the mirror
box the angle on the SC were now incorrect. The split blocks on the mirror
box look good, I had taken some measurements and calculated the angle.

We dont have a Mr Plywood up here, not that I know of. Although I have
dicovered Lismore Timber and Plywood. I haven't been there yet but intend
to next time I'm in Lismore during the week.

What about Araldite? can you use it to glue ali and wood together? I may
just go with some very thin booker rod and a couple of fancy nuts on
the ends.

Too late I didn't allow for making the SC bigger for a bigger mirror.


22-10-2007, 06:26 PM
If you want a good bond I would use the 12 hour Araldite.

22-10-2007, 06:54 PM

I have to go over to Ballina in the morning, so I'll drop back into Bunnings.
I'm tossing up whether to glue them or use threaded rod. I know there is
more weight in the threaded rod, but you can get some pretty thin stuff
and they only need to be 55mm long.

I cut the new set of rings this afternoon. I'm going to steal your lots of
holes drill around the rings look. It should counter the threaded rod maybe.
Anyways it looks kinda neat. The old focuser borad is still a perfect fit.
but I have changed it's location, and it also needs to perform another
function, supporting a spider arm. So I will probably need to make another.


22-10-2007, 07:10 PM
Remember Rob that the focuser board and the thin ply that goes around the cage will give it plenty of strength.

I don't see any reason for using the threaded rod it will only add weight.

23-10-2007, 06:30 AM
Yup I'm going to use that as an advantage. The first version was very
solid, even with a bit missing :whistle:

Dear I say it, it was/is more for cosmetic reasons than purposeful reasons.
When I counter sink the 16mm SC struts the wood drill bit breaks through
the other side leaving a hole which has to be filled. So I was thinking of
replacing the filled hole look with one of those fancy helmet looking end
bolts. I have to go over to Ballina this morning so I'll drop back into Bunnings
while I'm passing through Lismore.

Also I've been trying to track down Teflon, where can I get it? does it sell
under another name?


23-10-2007, 07:58 PM
Finished drilling the holes. At first when I was marking them out they seemed
to far apart, then when I cut the rings the markings looked to many. So I
checked back on Ed's thread and saw he has 7 per 90 degrees raidi I have 8
also my circumference is alot smaller, but since they were marked I went with
it. Now I like the look of all the holes drilled through the rings.

I'm going to paint the SC wall black and stain the rings the same as the first.
Should look ok with the ali struts, I hope.


24-10-2007, 07:38 PM
WooHoo!...Looking good.:thumbsup:

You got some sanding to do. Take your time the finish look depends on the prep. It might get a bit tedious after sanding the first five holes but it is worth it in the end.

What is the thickness of the ring?

25-10-2007, 05:51 AM
When I got to about half way through drilling those holes I realised I had
a lot of sanding to do:help:.

The ring thickness is 10mm, made from 7mm ply and 3mm ply laminated
with the good side out. To minimise sanding would you believe, shame
about all them holes :rofl:

I'm happy with the way they have turned out. They will look nice stain
and with the SC wall painted black instead of stained.


27-10-2007, 06:27 AM
Well after a couple of nights wrecking my left hand little finger sanding all
them holes, I stained the rings and then yesterday afternoon I spayed them
with clear spray. Unfortunately while leaving them to dry and taking a drive
to town last night to pick up my son. A massive storm cell developed and
hit Coombell, I could see it as I was driving home. There was hail all over
the ground when I got here. One of the rings had blown free from the hook
it was drying on and landed on the ground. I didn't realise until later that
it had snapped through one section. I was going to start over again but on
further inspection this morning it looks like I will be able to glue it and you will
never notice.

Also finished spraying the bearings they just need the formica glued on
and then they ready to bolt onto the mirror box. I've stained and sprayed
the mirror box too. The are a few wood bleamishes not of my doing and
weren't seen until the stain was applied... but it to is looking quite nice
now that it looks semi finished.

Q, for Graham,

what size teflon squares/circles? did you used for your side bearing?


27-10-2007, 06:58 AM
Did you make the bearings Rob and what color did you spray them?
Looks like 'Gunmetal Grey' one of my favorite colors.

27-10-2007, 07:03 AM
Yes I made them with a router, sprayed them gray as in the picture
posted above, to simulate forged steel lol. Each one is made from
12mm ply laminated to 24mm.


27-10-2007, 07:09 AM
You achieved that they look good.

27-10-2007, 07:32 AM
looks nice rob:)

1" round h/d felt.. not sure I'll need teflon on the alt bearings yet... its moveing nicely with just a little resistance atm
I read of a few having problems with teflon as the scopes get smaller it can be TO slippery for the small weight its carrying.

27-10-2007, 08:13 AM

The original John Dobson style mount the scope was in had teflon on PVC
bearings. I still have the teflon but they are only 1cm x 2cm x 4mm pieces.
Teflon seems to be rear as hens teeth up here.

I'm cutting the veneer for the focuser board today, I think I have just enough
veneer left over from the first one. Along with the formica for the side bearings.
I think the easiest way to cut it will be attaching it to a piece of 3mm ply and
running it through the bench saw. I tried yesterday but the formica is too thin
to run through by it self.


27-10-2007, 10:05 AM

Did you put that formica on your side bearings?
what did you use PVA or Contact, Kriege's book
say's use Contact, but would PVA be better?


27-10-2007, 10:46 AM
just ply for now rob.. If i have to i'll do change things around ..
going to mount primary this weekend with a little luck and see
how it balances

27-10-2007, 05:49 PM
Use Contact to glue the Formica.

04-11-2007, 03:11 AM

I tried to use contact glue, but the stuff I had here had been sitting on the
shelf for 4-5 years lol. Although I could still squeeze it out of the tube, trying
to spread the stuff was another story. So I went with PVA :whistle: it worked
alright just a lil tricky holding it there until it set.

Anyways here is a few pics of more things I've done. I been working on the
split block bolts in the evenings of last week I was going to leave them
square. But I thought oh well trim the corners off and make them look
hexagonal and gave myself a nice big sanding job to boot :rolleyes:. Put the rocker
box together yesterday, feels as solid as an Ox. Just filling the holes and it
will be ready for??? you guessed it more bloody sanding my poor arthritic
hands :(. I'm looking forward to those cheap GMC bench sanders to come
back into the shops... they were everywhere a couple of months back,
they should be back in stores by the end of November. I threw together a
jig to weld the tailgate together which will get done at a mates place this

Oh Yeah! pulled the new focuser board out of the press. Trimmed and poked
some holes into it and stained it. I'm really please how that has come out it
fits perfectly in thickness into the cut on the rings, not bad I thought as it
a bit of a guess. I've had to soak and bend another wall as I was just going
to tie it into the sides of the focuser board. The new wall will will lay right
across the board help secure it better plus it wont look like a piece of SC
wall is missing.


04-11-2007, 08:13 AM
:thumbsup: back on track.. looks good rob
cloudy again last night..and looking worse today

04-11-2007, 08:15 AM
Everything looks spot on!

When welding the tailgate you might want to tack one side first
then take it out of the jig turn it around with the tacks on the bottom, put it back in the jig and start welding.
Stagger your welds so that there's not to much heat in one place.

04-11-2007, 10:06 AM
Thanks guy's

Here's where I'm up to on the secondary cage with the first wall made for.
Just debating with myself whether to paint the new wall I like the black
wall look it kinda sets it off. But I also kinda like the all stained wood look.
The new wall will meet up on the inside. I'll put the join to one side of
the spider arm hole you see in the focuser board to give that arm a lil
bit of clean meat to sit in

Good points Ed, I will inform the welder, just about to head over there now.
I'm making a 6 point cell for it for stability over the 3 point design. We will
have young one playing with it.


04-11-2007, 06:10 PM
Well Ihave to say,my mate Stevo did an excellent job of the welding of the
tailgate. I'm now ready to start building the 6 point cell. I still have some
25mm x 3mm steal rail left over I'm going to use for that.

I also got Stevo to weld the nut that will lock the base plate on my tripod
for the Paralellogram mount. I'm going to copy the dobsoinian style bearing
for the base board and rocker box. Where I'll create a 8" base board, in it
counter sink 3 x 25mm SlidGlide discs, and the oposing surface another 8"
disc with formica Graham (nightstalker) gave me. The central pivot or pinion
will be a 19mm steel tubing with 6mm booker rod up the middle. The bottom
bolt and plate will be the same as you see on the base plate, welded and
permanently fixed with brass nuts and bolts. The top bolt will be adjustable.
I'm thinking this will be ok but, I might need to employ some sort of brake.
Any ideas?

The ali tube you see sticking out will be cut down and counter sunk into
the layer above. It's purpose is the stop the locating lug on the tropod from
chewing away at the wood over years of assembly and dismantle.

I have actually drawn a bit of a rough plan of this bearing I can scan
and post here to give you a better idea what I'm trying to achieve.
Just let me know.


04-11-2007, 06:33 PM
I was up 2:30am this morning although I could see a couple of stars
just to the east of north it was mostly clouded out :(, I fired up SN
and it was telling me Holmes at that time was a few degrees west
of north. Nice and muggy too, you could hear the mozzies screaming
in from every direction at the smell of fresh blood to be had. Must
of been those steak and eggs I had last night :rofl: I tell ya I had
to run for cover :help: :lol:


04-11-2007, 10:28 PM
First test to see if the tailgate fits. And I'm very happy to say it's a perfect
match. I did allow 2mm thinking it would be better to be smaller. But there
must of been some slight expansion in the welding process. Although
the jig was pretty tight. Anyways if it was half a mm bigger it wouldn't fit.
It's sitting there on it own accord. I didn't have to tap it in there. and it's
a nice square fit to the box. I'm going to give it a sanding with 400 grit to
clean the rust forming from my sweety hands, and then paint it with anti rust
primer and flat black on top of that.


06-11-2007, 08:21 AM
Metal always expands and distorts around the welding area.

The fit looks good.

06-11-2007, 08:35 AM
Rob - I've only just cottoned on to this thread - it's diverged somewhat from the original title! :)

Hey - I'm building my dual 12" bino at the moment and am tossing and turning over the bearings I'll use. I love the way you've done yours but an uncertain how you achieved the shape with your router. I've just started to use mine after owning it for a few years, and and perplexed as to just how you may have held the job and routed the angles and radii as you have. Could you briefly explain your technique for me?

PS - love the look. I'm using jarrah everwhere in the rocker box, but will need to go with something lighter in weight up top. I really like the lighter red of your stain. I, for one, love the light-red cedar look - it'd match the jarrah!

Cheers and thanks in advance :thumbsup:

06-11-2007, 03:37 PM
I'm pleased with the fit. It's currently down at an engineers workshop in
town. I'm getting three fine thread machine bolts tapped into the three
pick up points, more wood knobs to make.... more sanding :( although
I have been thinking I'll leave them along with the rest of split block knobs
cleaned but not finished and wait till I get a bench sander :whistle:. Anyways
I hope this bloke get the bolt in the tailgate in the right spots, I must
say he didn't install a lot of confidence in me.

I stained the rocker box last night. It's out there in the shed getting Estypol'ed
as I type, along with the rings, focuser board... and just remembering now I
have the split blocks ready to do.... sorry for the rave.


06-11-2007, 03:59 PM
Yeah lol, I figured I'd turn it into my project thread, since folks who have
been replying are generally building or otherwise into ATM'ing. I did have
a webpage going (still there) but I'm very lazy at updating it :whistle:

Yup! sure can. you lucky I took lots of photos of the job, show how I did
most things, but not the end part. Let me sort them out and I'll post
some up. I have to say the router is a must for any wood work shop. I
only just brought mine a couple of months back, the bearings were the
second job I did with it after my first set of rings (rip)

It's all the same stain, just fifferent types of wood. The rings are bunnings
ply, the mirror and rocker boxes are another type of ply, made from the
original dob mount. It's very nice with no voids and 18mm thick so I reused
it. After stripping the old varnish off, the split blocks and truss pole connectors
are Tassie Oak and the focuser board is Queensland Maple. All stain in Jarrah
I was thinking of leaving the split blocks and pole connectors natural to give
a different colour.... but stained and unstain together would seem like it was

Anyway I'll have some photos up on the bearings shortly, np's :thumbsup:


06-11-2007, 08:10 PM

The bearings are made from 2 sheets of 12mm ply laminated together.
Nailing a few boards to the bench to brace the panels as I cut them.
Basically I cut the design before I cut bearing surface. Starting first
with drawing the spokes on the boards, I first cut a line for the inner
rim surface using a round cutting bit, then I used a bit that cuts a 45
degree angle and worked my way down, trying to leave about 5mm of
meat at the bottom, you want the pie pieces to stay there. Unfortunately
I did a few over cuts here into the spokes, which had to be filled. I then
used a 16mm spade bit to cut the upper ends of the spokes. I then used
a length of straight pine as a stencil so to speak and cut the spokes. I
made the hub using a disc cut from 9mm ply using a hole saw, the drill bit
I use to swing the router off is the same size as the one in the hole saw,
so just tap the bit down until it does interfere with the router and cut
your half circle. I then got the dove tail bit and cut freehand, the top
layer off the spokes with the pie pieces still there giving the router
something to ride on. I then routed out the pies pieces and cut the
bearing surface. With the pie pieces removed I just nailed in the wooden
blocks to help keep everything stable on the final cut.

here are some pics of the process I did. You may find an easier way,
i just used what I had available at the time in thought and tools :lol:


06-11-2007, 08:12 PM
and another

06-11-2007, 08:21 PM
Oh yeah, then there was lots of sanding, some of which I did with a dremil
bit set I picked up for $5 at crazy clarkes lol, and whacked them the hand
drill. Actually I used the ball bit in my drill press to round off the holes in the
secondary cage.


06-11-2007, 08:58 PM
Fantastic advice Rob - thanks for putting it up. I've a much clearer picture now. I love my router, but have had no practical training on it from anyone, so I'm slowly picking up tips as I go.

I was gong to go and source aluminium bearings, but I think that you fabrication here is stiffer and quite frankly better looking.

I have two Dremels, one with a flexi-drive, so sanding tight areas is no biggie :)

Thanks again :thumbsup:

07-11-2007, 07:46 AM
There was a lot of routing there Rob.

The router does a nice job of things.

07-11-2007, 05:19 PM
Over the weekend I started on the truss clamps for the SC end. The wood
drill bit (spade style) took some nasty chunks out of the bottom edge giving
me another filling job. Anyways the filler was nice and dry/set hard. This
afternoon I sanded them down, since they were all still connected at that
stage I wrapped a length of wood in sandpaper and did the job in 5 minutes:thumbsup:

anyways here's a pic of the rough cut. As you cansee there are three
pieces to each connector. What I call the the back part of the clamp
will be glued to the base bit leaving the third bit free to clamp. The
connectors will be secured to the SC with a 2" x 3/16" brass bolts this
way I get my nice helmet nut on the end. Ed will be pleased I've bolts
in this spot not to just hold the SC struts firm. And later if one happens
to crack or break it can be renewed.


10-11-2007, 08:44 AM
they look nice rob...its good through the process you get to SEE
what is likely to go wrong and allow to make things easiier to fix.. the
downside is we have to wreck something first for the improved version to be born;).

Had the flu all week so I've been staying clear of mounting my primary
headspinning , sneezing ,coughing fits and a important piece of glass had disaster stamped all over it.

10-11-2007, 10:34 AM

It's the weather for flu's up here at present. Hot one day raining the next or
blowing a gale.

Well I thought today since I cant do any work with Hayden here. I thought
I put it together and test everything fits SC to mirror box. Except a minor
problem with one of the SC connectors it went together pretty well. I took
this picture to give you guys a look. Jake is over the moon at looking at his
new scope.

I picked up the tailgate from the engineers workshop yesterday. and I have
to say I was more than a little nervous, thinking I wont be happy with it and
will probably have to start again. But to my surprise the guy got it bang on.
So I guess you cant judge a persons ability just because their face has a
look of un-interested on it. Maybe it was me being to pedantic :lol: well ya
got know if the bloke understands what ya want done.

I glued in the SC wall last night. All in all I think I'm on the home straight
now. There a few things left to build, the floating point system and base
board being the main things. But apart from that it just fitting the split blocks,
finish cleaning up the split block knobs, make three wooden knobs for the
mirror cell and finish off the SC connectors. Then add all the hardware :)


10-11-2007, 11:01 AM
Very nice job :thumbsup:
Been following the thread for a while, you've something to be proud of there.


10-11-2007, 08:16 PM
Thanks Bill

Looking forward to being able to use it again, it's been a while lol


16-11-2007, 08:59 PM
Well I've pretty much finished the secondary cage, except for the plate
to hold the finder scope. I had to make a base plate for the focuser
because the focuser board's curve is 236mm dia and the focusers base
is set for a tube of 358mm. But you can see from the photo that I had
to raise the focuser off the focuser board by at least 5mm so the focuser
turn knob cleared the lower ring, I raised it 10mm. So the adaptor plate
performs two purposes Raise and Adapt.

The rocker box is complete with teflon bearings in place. I also used two
Eazy Glide discs 25mm dia on the inside to guide the mirror box in it's travel.
Which had to be countersunk 1.5mm either side, I used a router to do that.
I'm still to attach the base board and still to figure if I want it round or
square. Keeping it square will give a slightly better spread on the three feet.

After that it's pretty much just the mirror cell to complete. I'm going to drill
and tap a thread into each of the three bolts, as marked. In each I'm going
to thread a small flat head brass screw fitted with a locking nut which will
lock against the end of each collinmating bolt to form the pivot for the two
point plate on each point, making a 6 point cell. The image shows the top
side of the cell, I'm going to make three wooden knobs to fit to the bolt
heads (bottom side) and will be spring loaded from the bottom side. I'm
thinking I will probably go with Velcro circle for each point, I'm pretty sure
(although I haven't done the maths yet) that I'm going to be top heavy.
Doing a sling system on such a small mirror although might look a lil more
funky it isn't going to add as much weight with the extra bits to do so. Once
I get the optical system in place I can cut the truss pole to the right length.

Anyways another weekend free of kids to experiment.

18-11-2007, 09:46 AM
It looks great Rob. It's nice to see the telescope assembled after working on it for a while, you can see the work that went into it.
To make your mirror box look even better you could always change the knobs on the truss connectors from the wooden ones you have to some nice shiny brass one that you can get from your hardware store.

18-11-2007, 03:00 PM
Thanks Ed,

yeah! had been thinking of doing something with them. As you see them
there, they haven't been finished off. I'm definitely looking to change the
SC connector knobs. The wing nuts are temporary, Bunning has the Black
plastic tri-nut's that will fit the thread for those. But braas down the
bottom would look good, plus add a little bit of weight. All that's left to do
is finish the mirror cell now, need to get hold of a tap & dia set. The base
board just needs to be stained and sprayed. I stripped the varnish off the
old board and cut it down to size.

This weekend has been spent mostly building a case for my 20x80's. Using
a box I built to put the first edition SC in. The New SC has slightly wider
rings and no longer fit in the case. She's going to be a solid bino case 12mm
ply lol. Well it was intended to be a step up for the boys when needed.

Anyways looking at possibly star testing in the next week.


21-11-2007, 05:07 PM
Did the formica work out rob ?.. i 'll try and find this online store i came across .. they really had all sorts of knobs in differant threads .. worth a look

i think this is the one http://www.smallparts.com.au/cgi-bin/store/product.pl

23-11-2007, 06:33 AM

The formica worked a treat, thanks for that. All thats needed to do now
is finish the mirror cell. And with that it's just a thread and tap job, I just
have to get some little bolts to suit. Hopefully I'll grab something in town
later. I brought a little tap and dia set the other day, but it's metric.

Anyone know what the general rule of thumb is when tapping a thread,
what size hole to drill for a particular size thread???


23-11-2007, 08:11 AM
I know that in Timber and Hardware all you have to do is ask for the tap and they will give you a suitable drill bit. Anyway when you buy the tap the drill size is mentioned on the packet.

23-11-2007, 05:27 PM

I went cheap and got a set from Crazy Clarke's 40pcs set for $15.00 :lol:
They're so cheap you dont get instructions :whistle: except where it mentions
sizes it states....

Metric Sizes 3 - 0.5, 3 - 0.6, 4 - 0.7, 4 - 0.75, 5 - 0.8, 5 - 0.9...etc...etc

does that meant to tell me something?


23-11-2007, 11:00 PM
Yes.....that if you put to much pressure on them they'll snap! :lol: :P

23-11-2007, 11:21 PM
Here you are Rob, a scan fom my handy fitters reference booklet :)
I would advise some cutting oil or paste, without it you can break the expensive ones too.
Just noticed you got fine ones too.


29-11-2007, 07:57 AM
Thanks for posting the thread sheets Bill :thumbsup:

Well I had a go last night, I took Ed's advice and went and brought
a better tapping dia made of apparently "high quality carbon/chrome steal"
by P&N. It shattered on the second hole, before it had even hit the business
part of the tool. I didn't use a cutting paste, as the packet only states "For
best results use a cutting lubricant" it didn't mention any danger of the tool
shattering if a lubricant is not used. I remember years ago putting threads
into plate steal, So I used the same approach as I did then ie: cut a 1/4
turn, wind back a couple of turns then cut another 1/4 turn or there about
it was more like 1/8 turn cuts.

Anyways I'm going to return it from where I brought it and get it replaced.
Even my machanic mate who was with me when it shattered said "And they
call this carbon steal?" the thing was crumbling trying to get the piece still
stuck in the job with a pair of vicegripps.


29-11-2007, 08:26 AM
That was a bit of a nightmare Rob!

Was the hole the right size for the tap?

29-11-2007, 12:37 PM
Yup! it sure was. I brought a 3/16 tap and the packet said use a 5/32
sized drill bit, which I brought at the same time.

I'm hoping they will exchange it when I'm in town tomorrow.


29-11-2007, 12:56 PM
On another note, I finished another little project of building a case for
my 20x80's which has come out pretty good I reckon. Made from the
case I originally had built for the SC for the 8" truss dob but the second
version SC was made a little larger than the first and no longer fit.

01-12-2007, 11:06 AM
Update on the broken tap, Mitre 10 are going to replace it. But they have
to order another, which will be here next week.... things a move a slowly
out in the bush , seems a lot of drama just to tap 3 threads.

the bummer thing about it is I wanted to complete it this weekend while I
had no kids about. Oh well at least I can make a decent start on my bino


01-12-2007, 03:31 PM
Its good that they are going to replace it Rob. Especially with small taps you have to be careful not to put any sideways pressure on them as you cut the threads. Tapping close to an arc weld can be a problem too, as if it has cooled a bit too quickly it can form what we used to call "diamonds" in the metal, seen even hi speed steel taps have problems with those.

(Who has broken 3/4" taps in his time :lol:)

01-12-2007, 09:04 PM
Thanks for the tips Bill, I'll be taking it reeeeeal! easy with the next tap.

On another note, I made good head way on my bino mount today. Still
a long way to go but at least is started. With the main arm pretty much


05-12-2007, 07:57 AM
Well I finally got the mirror cell sorted out last night. Just need to make
some knobs for the colinmating bolts. and whack some velcro on the cell
and mirror and throw it in the mirror box. I still think the whole setup will
be top heavy and will have to make up some sort of counter weight. But
I should be able to start testing it over the next couple of days.


06-12-2007, 08:03 PM
Installed the mirror cell and tailgate this afternoon. Also installed the focuser
and secondary mirror in the SC, which I'm pretty happy about. The two images
below show the alignment of the first edition SC when I had first installed the
focuser (first pic). And the second edition SC (second pic). The second
editon came out bang on, if only slightly but not enough to worry about, off.
I did the alignment with a Cheshire <-typo eye piece and a card marked up
and stuck on the oppisite side of the SC.

Just need to throw the mirror in and take it outside and see if I can get a
star to focus. My estimate is my truss poles are about 25-32mm too long.
I do have a top heavy problem which I kind of figured would present itself.


06-12-2007, 08:38 PM
Here'sanother project I've been working on, my parralellogram mount for my
20x80's. At this stage it is very much incomplete and I have yet to shape,
sand, stain...etc...etc... what I have here. I just put it together to make
sure it works machanically. Also I intending to add another arm with counter
weight on the end of the main arm, like a back-hoe. the main arm has a
900mm reach, with the second arm I'm going to for an extra 400-600mm
on top. This should enable you position the bino's anywhere around your
head without having to move your seat. Also it will reach over my favourite
bino chair, our trampoline :D. Well that's the aim.


06-12-2007, 09:55 PM
On ya Rob, why buy it when you can make it!

07-12-2007, 07:57 AM
Ain't that the truth, well I try anyways.

Next week I'm starting on the Ferrari :lol:


10-12-2007, 08:12 PM
Well I finally finished it, well pretty much. Put the mirror in this afternoon
and colinmated it. Focusing on a distant tree line a few kms away I was able
to almost bring in to focus using a low powered 30mm SV. But needed more
in focus for the XW. So I have trimed poles down a little bit still trying to
leave a little extra. It looks like we might be able to give it it's first star test
tonight, as there is a patch of blue to the south. It will either be pretty close
or may need as little more trimming. Once I have that sorted I going to drill
and screw the lower truss connecter to the mirrorbox. She isn't as top heavy
as I thought it would be, but I think I'll need a 1.5-2kg counter weight in the

I'm a little surprised the weather looks like it's going to give a little piece of
sky to test with:shrug: :lol:

anyways here a couple of picture of the finished scope. Thank you to all for
the help and advice I have gotten along the way.


11-12-2007, 07:25 AM
Congratulations Rob.
A job well done.

11-12-2007, 12:26 PM
Fantastic Result after a lot of hard work Rob. You and Ed are legends!!

12-12-2007, 01:49 AM
Thanks guy's

Well it's first star test was excellent, it was nice to look through a scope
again. I've trimmed the pole too short by about 5mm for my longest FL
ep's. But no great problem there as I have a couple of fixes. I'll need
to add the counter weight to help balance things up when the finder
scope is attached. I really like it's movement compared to earlier versions
as some people say smooth as butter. Jake is pretty happy with it which
is the main thing. Just need a nice clear night and perhaps build an
adjustable observing chair.

Now I can focus on getting the parralellogram mount finished

Here's a few pics of the evolution of my scope/optics.


12-12-2007, 01:52 AM
The mirror cell turned out better than expected. I wont need to make
knobs for the colinmation bolts as you can easily turn them by hand.
I'll upload a picture of the cell soon, when I can get a picture of it lol


12-12-2007, 08:40 PM
great stuff rob .. where did you get to see a star ?.. Im thinking a wiper motor and blade down in my mirror box might be the go with this weather :).

14-12-2007, 03:59 AM
My calculations were that is was Enif in Pegasus or around that area, for
a few minutes. Been on star watch ever since :lol: I dont think we have had
as bad observing weather in a long time. Haven't even been able to check
out the sun spot group currently transiting o'l Sol with the PST either :mad2:
They're predicting better weather this weekend, which would be awesome
wont have the boy's, I'll be a free man :D for a couple of days.


14-12-2007, 10:23 PM
Ok, next step is I want to make a shroud. What material does one use. I've
seen William's and Peter Robsons big SDM's but I didn't enquire about the
material used. So I'm after the name of that stuff if anyone knows. Apart
from that anyone else have luck with a particular material? and where you
can get it from.


15-12-2007, 12:47 PM
Well, I've got my parrallelogram mount working. Just need a few tweaks here
and there, a lil striction built into the main arm would be good. Needs to have
the finishing touchs put to it. But I wanted to see if it was going to do the
job. The counter weight bar is just taped on for now, eventually you'll be
able to slide it up and down to change the setup for different bino's. The
main arm base post is removable, you simply lift it off the mount.

Actually I'm pretty happy how it works machanically.


22-12-2007, 10:45 AM
When I was over in Lismore yesterday, unfortunately most to the steel
suppliers closed for the year the day before, Doh'. But did managed to
locate one that was open. I got a 1m length of solid mild steel 25mm x
25mm. I had it cut to 250mm lengths. Each peice weigh in at 1.254 kgs,
which was quite fortunate as (according to my maths) I needed 2.5kgs
to counter weight the 8" truss dob (with my heaviest ep, 20mm t5).
The scope is nicely counter weighted now, although a lil bottom heavy
with the 59gm U/O HD Orthos near the zenith. But perfect with the XW's
and 20mm t5 which start around the 390+gms

Just need a night of clear skies and NO moon would be nice to give it
a good test. I've only managed to see one measily star so far


02-01-2008, 12:54 PM
I hate to quote myself :doh:, but I'm still waiting for that clear night :shrug:
this weather is :screwy:


03-01-2008, 02:05 PM
In the :windy::rain::cloudy:queue with ya rob :thumbsup:

This weather can't stay like this forever .."probably".

03-01-2008, 04:27 PM
I wish I had another 20 000 lt water tank, it would be full by now. The
one I have is over flowing.... what a waste :(

I believe the weather spirits are mad with us for building such beautiful
instruments... :lol::lol::lol:


05-03-2008, 05:56 PM
But I thought I give an update. Projects are never finished when you think
they are. Once you have built your project there always a lil bit of tweaking
to do.

The lil 8" truss dob works a treat, and I'm surprised that on repeated setup
you only need to tweak the collination. The only problem I really had was
mirror shift between horizon to zenith. So I installed a sling which has worked
a treat. I moved the counter weights from being cable tied to the tailgate
to bolted on the sides of the mirror box. The balance is good and is a little
bottom heavy near the zenith, I'm going to drill some holes in the counter
weights to tweak this.

I also have pretty much finished my parralellogram mount. Tweaks included
making milk bottle washers to the "L" bar on the tilt and pan axis. This has
made the action of panning around a one hand operation. I also need to
apply some sort of friction brake on the main arm since I extended it's travel
to about 80 degree, there are some weight issues at the extremes. I have an
idea how to fix this using a snatch block and cable and applying a brake to
the snatch block.

Images included of the two projects, along with the new owner Jake and
his truss dob.


05-03-2008, 09:34 PM
all looks great rob .. time to copy it :D now you have it all sorted .

I havn't seen it so green out your way for many years ..half the population
over the back fence there eh ?:)

06-03-2008, 04:47 AM
Thanks mate :thumbsup: I've still to make a light shroud for Jakes scope. I brought
some Rip-Stop Nylon from Spotlight in Lismore. Now I just got to figure out
how to work the ex's sewing machine :whistle:. On copying it I have been
thinking it might take awhile to afford a bigger mirror so my thoughts are
possibly make a 12" in the mean time to give me a bit more aperture while I
save for a 16" or 18" (or possibly a 20" :whistle:) or try and buy a 16" direct from
GSO. The GSO 16" sound ok from the reports from the Lightbridge owners.

Anyways something to think about. I'll have to start thinking about building
a shed to stick them in. My son is losing realestate in his bedroom lol


06-03-2008, 08:25 AM
Gee, you have been a busy boy :thumbsup: Your young lad looks real proud of his truss dob. Now that I have access to more tooling, might consider a go at one myself down the track.


08-03-2008, 09:52 AM
rob I found my az motion getting a little stiff the other night so much so my mirror box was trying to move inside its cradle before it would move on the base...that texteured formica we both have seems a little more abrasive on
the teflon than my old gso base .. and will likely need a clean more often imo
bit of metho and a wipe with mr sheen and its good again:thumbsup: