pipe for pier

[Daniel-K]

I agree with Olly about 'leveling top plates' - no point building a solid pier only to top it off with three flimsy 'leveling bolts' which aren't actually needed anyway.

i saw this mentioned in another thread but im finding it hard to get my head around why its not important to be level because dont you have to level your tripod when setting that up to polar align?

[laser_jock99]

i saw this mentioned in another thread but im finding it hard to get my head around why its not important to be level because dont you have to level your tripod when setting that up to polar align?

GoTo alt-az mounts mounts benefit from being level. Equatorial mounts need to be merely well polar aligned.

[fwm891]

If you think about it the RA axis points at a north or south rotation point and the telescope rotates around the RA axis. It doesn't matter what tilt angle the RA axis is supported by as long as it points its respective point in space. Alt-Az mounts however rotate around two axles one pointing to the zenith, therefore a level base is a bigger requirement.

[JamesF]

For those of you who have fixed their mount to a pier without a levelling plate, have you had a hole cut in the side of the tube to allow a bolt to be screwed into the mount to hold it in place, or have you gone for some other arrangement?

James

[ollypenrice]

When using most tripods and polar scope-fitted mounts (but not Takahashi) the leveling is useful in that it calibrates the reticle in the polar scope. It sets the top of the reticle to the top, so to speak. (Tak have a much better system.) But in a permanent installation no one is going to rely on a polar scope alignment so it ceases to matter. (Actually a level mount shows less interaction between Alt and Az mount adjustments as well but the effect is slight.) My quick explanation is just to say that the universe doesn't care where your tripod legs are pointing...

James is right to ask how you get to bolt the mount down tight on a flat topped pier and, yes, the 'Owl's Nest' method of having an aperture cut in the pipe is the usual way. I welded a set of square tubes onto mine to give me just enough extra height to get some pump pliers onto the mount head fixing nut. Equally you could just buy an Owl's Nest adapter for your mount and bolt or weld it to your piece of pipe.

On all my piers I have kept the tripod top and welded hefty, triangulated struts to connect that to the pipe. Not the best way but I'm lazy and haven't any access to a machine shop. Skywatcher have done for me though because of the internal fit of the EQ tripod legs. Curses!

Olly

[fwm891]

James, I've asked a company: http://www.projexeen...o.uk/index.html to give me a quote for a steel tube with welded top plate with a 6 or 8 inch tube. No reply yet but the sketch accompanying the letter shows a central clearance hole for the bolt and side access aperture to access the bolt and or fill the tube with sand or concrete...

Steel pier.pdf

[nightfisher]

I used to have a 3x3 concrete block into which i used a yellow gas pipe filled with concrete , it didnt move and more importantly no vibrations.

Only thing i would reccomend is not to mix the concrete by hand

The gas board have been replacing the gas mains at my home, and left a lovely of cut of yellow pipe, and im saying no more

[SlipperySquid]

Bigger the diameter the better for rigidity , I have a 6" pipe with 8mm thick steel (I think) with a 22" 12mm thick plate at the bottom held to a concrete plug by 4 18mm bolts .I wish I'd sourced an 8" pipe but I have what I have now . I know people go on a lot about vibrations etc but you're not going to be hitting the pier with a hammer or training performing elephants around the pier just to see if it wobbles. At the end of the day it's going to be more sturdy than the tripod (well hopefully

Matt.