Pier plate design

[Marke]

Got a question regarding pier top plate design .
Can anyone see a prob with having the top mounting plate drilled and
tapped to take threaded rod/bolt screwed in flush . The second top plate / welded pier plate drilled , slotted to allow for some rotational adjustment and leveling ? Both will be round plates .
So the leveling adjustment will be donewith the bolts protruding thru the bottom plate.

Mark

[ZeroID]

Nope, variation on a theme, that's all.
Anyway that works for you will do. As long as you can access the adjuster nuts and they don't interfere with mount\scope travel then designa dn build to your hearts content.

If I understand your description correctly it actually sounds like quite a good configuration. Adjusters available around the rim of the lower levelling plate attached to the pier. Post a drawing up so we can critique it better. Sounds also like you can keep the profile quite low, short rods thus minimising leverage and possible flex. Just keep the hardware nice and beefy.

[Marke]

Brent
The reason for going this way was so I can use 20mm bolts as short as possible and flush at the top , probably no more than a nut space apart for the pates as I dont need access underneath to attach the scope and hate seeing long bolts waving in the breeze. This will prob mean 15-20mm top plates , waiting for the quote on the pier construction now and a talk to the metal fabricator .

Mark

[I.C.D]

G' Day Mark,
I have done it the same way you talking about.I have used two 8mm plate one welded to the pier drilled and taped the other just drill and taped I have used thread bar. The thread bar is flush with the top with a nut under the top,plate to secure once you have it level and if you have a bigger gap between the two plates you can store thing their like eyepieces .I can take a pic of it if you want .

Ian C

:thumbsup:

[Marke]

Thank Ian and yes would like to see a pic if you could . I will be using
around 15mm plate and 20mm stainless rod , I thought of slotting the
fixed plate just to allow a bit of adjustment as the AP on the pier adapter has none other than the mounts own AZ adjuster.

Mark

[I.C.D]

Mark,
I would but I don't know how to send you the pic via iceinspace web site

Ian C:thumbsup:

[Marke]

Thanks Ian I sent you a PM

Mark

[ZeroID]

Go 'Advanced' and there is an 'Manage attachments' option below.

[Helo]

Hi Mark; I just put my pier in 2 days ago so I hope this helps. The M20 bolts were welded to the top plate and kept short to reduce flex but adjustable by the two bolts on the base plate. Happy New Year. Peter

[Marke]

Thanks Peter thats what I had in mind with the M20 bolts only I may get the bottom plate slotted to allow a bit of adjustment as the Mach1 cant be rotated after its attached , other than its AZ fine adjuster.

Mark

[Zaps]

As I understand it, leveling is not actually required for GEMs.

http://www.youtube.com/watch?v=AOeLnecOMeg&feature=relmfu

http://www.youtube.com/watch?v=LI3PkC0aT2E&feature=relmfu

[Marke]

Technically your right its not needed but it does simplify set up and if you ever change mounts or want a bit of extra AZ adjustment then its worth doing the double plate.

[Zaps]

It seems to me as if you're seriously compromising an otherwise good pier by including those basically useless and redundant bolts and plates.

[Terry B]

I agree.
I just turned a piece of 12mm thick steel into a disc with a hole in the middle to attach the mount. This was then bolted to the top of the pier. It is eyeball level which is plenty accurate enough. It just has to be level enough that the mount will balance on the top not causing any lateral flex.
As it will never be moved until I buy a new mount in the distant future it doesn't need to be adjustable.

[koputai]

See this older thread where I brought up this topic.

http://www.iceinspace.com.au/forum/showthread.php?t=76881&highlight=pier

Cheers,
Jason.

[Nico13]

Here is one I made up for my older Polaris mount so the top needed to be a bit different to what you want but no reason why it couldn't be kept flush for your purpose but you will see that the bottom plate is center bolted to allow for major rotational alignment and leveling is also done on the bottom plate.
For my purposes the upper plate also allowed the mount to be adjusted for fine Polar tuning.

Worked really well. Bolts could be as short or as long as needed.

Nico.

[Helo]

Hi again Mark;

The very bottom plate bolted to the slab I had slots stitch drilled to allow some rotational adjustment in my pier. Definitely needed to help me get it aligned while my wedge (Milburn) has additional rotational adjustment built into it also. Almost have my dome completed (Astrodomes) so just waiting for some clear skies now.

Peter

[Marke]

Thanks Peter , I just got the pier adapter for my mount and turns out it
is slotted to allow additional alignment. I will go with the slots in the base
not worry about doing it for the top plate . Hopefully the fabricators are back to work next week so I can get it built and installed . Now I am in the proccess of planning an obs , guess one thing leads to another :)
Mark