Just thought I would put up a post about a semi-portable pier design tha I am currently fabricating.
I say semi portable as it will be fairly chunky. It will basically be transported permanently to a dark sky location and stay there; however I need for it to be mobile to certain degree.
Material used:
Pier: 168 OD (14.3 mm) Wall thickness high carbon steel pipe.
Legs: 75 x 50 mm RHS (5 mm) wall thickness
Brackets: 10 mm + 12mm Steel flat bar cut to shape and welded.
Wheels: Heavy duty Castor wheels (Capacity 60 kg each)
The top of the pier will be machined on a lathe to allow an insert that will have the ability to rotate 360 degrees. It will be locked down with three bolts through the top side of the mount. (See Top Pier Cross Section diagram).
The legs will be on a 19 degree angle, and adjustment bolts will used to raise the rig off the wheels and enable accurate level adjustment.
I will keep this thread up to date as progress continues for any one who is interested. I will also include progress images.
The pier section is now complete, so all is left now is to fabricate the legs.
I have also included my version of an EQ6 saddle plate, I have already got one of these made for my obs, I will need another made for this pier.
I forgot to mention, feel free to use the plans as you wish. I have learnt many things from many of you on this forum, so what goes around comes around.
Mark excellent work here mate, just the kind of thing i need made. I have been kicking the bucket over it for some time but I think i need to get a move on and your plans will come in very handy.
I wish I could do the lathe work myself, I just dont have the skills.
Its something I had to outsource.
But the remainder of the work will be done by me, as I do have some fabrication and welding experience.
You don't know if your machinist who's doing your lathework has more of the big round he is using to make the cap do you ?
Is it aluminium or steel ?
I don't fancy having to buy a whole 170mm diam steel round (cap it with aluminium ?) or a whole 152.4mm diam aluminium round .... will work out very expensive unless I can buy an offcut of suitable depth. (about 3")).
I am looking for something similar (probably a blank undrilled (no predrilled bolt holes (usually at this size it's 4 bolt holes) and no central hole) flange but I can't locate a standard one thick enough in steel (would prefer aluminium (this way it wount have any redox reactions with the base of my Altux (which is finely machined aluminium)).
Looks good but the only weak point I can see in that design is the way you want fo fiz the cap into the tube.
It does not matter how tight you press the screws against that cap the danger is there that it does have some movement after mounting your telescope on it.
Why not use a V groove, make the end of the fixing screws in a slightly different angle and so it will be forced downward unto the tube and there is no danger that anything will lift up.
Looks good but the only weak point I can see in that design is the way you want fo fiz the cap into the tube.
It does not matter how tight you press the screws against that cap the danger is there that it does have some movement after mounting your telescope on it.
Why not use a V groove, make the end of the fixing screws in a slightly different angle and so it will be forced downward unto the tube and there is no danger that anything will lift up.
Its funny you should say that, I had the same recommendation made to me by a close mate, but by the time I could alter the drawings the work was already done. So I am stuck with this.
The top of the pier will be tapped for M8 grub screws that have teeth at the end, not sure what they called but I manged to source some from universal fasteners. They should dig in nicely and be out of sight. So that is the compromise
I would assume that it would take quite a bit of force to try and rotate the top with all three nuts tightened.
I am looking for something similar (probably a blank undrilled (no predrilled bolt holes (usually at this size it's 4 bolt holes) and no central hole) flange but I can't locate a standard one thick enough in steel (would prefer aluminium (this way it wount have any redox reactions with the base of my Altux (which is finely machined aluminium)).
Ian,
Its steel, and I'm sure I could get you an offcut of the same size. Just tell me the size you want and if you are in Adelaide you can pick it up.
I have a similar "rolling pier" already, works a treat, and with three "spots" painted onto the ground I have repeatable polar alignment each time.
My imaging PC is fixed to the base as well, so it is "roll it out, fix the wheels, plug it in and go".
I need to shoot a picture and will do so. Great concept.
Gary
Last edited by gbeal; 27-11-2008 at 06:39 PM.
Reason: Attached picture
that setup looks mint. great idea for me Ide love to put a permanent peir out the back of my house but i would have to carry all the gear out all the time, only problem to having something like that i would have to put rubber wheel barrow wheels because ide have to travel over the lawn ... hairy!
I have a similar "rolling pier" already, works a treat, and with three "spots" painted onto the ground I have repeatable polar alignment each time.
My imaging PC is fixed to the base as well, so it is "roll it out, fix the wheels, plug it in and go".
I need to shoot a picture and will do so. Great concept.
Gary
Nice setup Gary, I was also thinking of making a laptop platform for it. Might add that on later.
that setup looks mint. great idea for me Ide love to put a permanent peir out the back of my house but i would have to carry all the gear out all the time, only problem to having something like that i would have to put rubber wheel barrow wheels because ide have to travel over the lawn ... hairy!
Yeah, grass can be a bit of bugger, especially if your pier is heavy. You could always use a sack trolley to get the bugger out.
.... why cant i finish university so i can stop being so poor.... I was talking to my partner today as she was saying how much some gear costs. I then reminded her of my younger days. I used to be a car fanatic and then i really put it into perspective when i told her my best friend sold his VRSS commodore for 45k (mind you it has 500bhp). Imagine the setup you could have for close to 50k..... ide drop 10k on the OTA another 10K on the mount 10-15K for guiding and camera and misc bits then build a nice obs to cover it all in. ahhhhhh. hhahaaaaaahh...
Well yet another day of progress. Got up at 6:30 this morning and was in the workshop by seven.
I forgot how slow it is working with steel, just cutting a single piece takes forever.
Today I plasma cut the 10mm steel ends into moon shapes so that it fits snuggly around the circumference of the pier then finished them off with a grinding wheel.
Then I had to grind V grooves on all edges that were going to be welded. I did this to strenghen the weld and allow deeper penetration, as I grinded off the welds for a smooth finish.
Welding was the easiest part, the grinding took ages to get that smooth finish.
The finishing of the surfacees will take the longest, I'm not being too careful as the base primer should fill out all the imperfections nicely before it goes in the oven once painted.
4 Hours and I only managed to finish one mounting, two to go. Need a few more saturdays to finish this job off.
... steel normally isn't that hard to work with. unless your working with 10mm steel hehehe, thats some good fab work, though keep this in mind, the few saturdays you take it easy get it right will be a shining example for everybody later on and the pride when people go where did you buy that from. now thats the gold part.! Top job
I decided to scrap the two mounting brackets that I made, I just was not happy with the finish.
So I made some new ones from scratch and used a belt sander to do the final finishing, using 80 grit and then 120 grit paper.
After the initial welding of the parts, used a grinder with a sanding disk to grind off as much of the weld as possible. Then used the belt sander to do the final touches. For the brackets to follow the pipe nicely, I scribed a line using the pipe and the removed the material using a grinder with a very coarse sanding disk. This was much easier than I thought and definitely quicker then using the plasma cutter and then a grinding wheel.
So in total I have made five mounting brackets, the last 3 being the final ones.
I have included some pics of before and after and also a pic of the first mounting bracket in place for welding to the pier.
I was talking to my partner today as she was saying how much some gear costs. I then reminded her of my younger days. I used to be a car fanatic and then i really put it into perspective when i told her my best friend sold his VRSS commodore for 45k (mind you it has 500bhp). Imagine the setup you could have for close to 50k..... ide drop 10k on the OTA another 10K on the mount 10-15K for guiding and camera and misc bits then build a nice obs to cover it all in. ahhhhhh. hhahaaaaaahh... 
