Pier designs/plan/measurements.

[Gina]

Trouble is their prices are already very high and there are usually other eplaces more than 10% cheaper.  Maybe the blue and white shop   But I've often founs local shops cheaper still.

[K3ny0n]

I do believe i have a discount pensioners cards only works on a Wednesday, well 10% is something.....when i checked on-line they only go up to 12mm, i wanted 16mm

Ah too bad, I think I will borrow mine from work

Like Gina said you will probably find it cheaper in a local type shop but its finding one thats the trouble. 

Rob.

[Sp@ce_d]

Think I got mine from Jewsons when I picked up a piece of (end damaged) discounted piping for the pier. Surely most builder merchants do them?

[opticalpath]

When I made my pier, I didn't much like the look of the bright zinc plated studding I saw at our local DIY warehouse; it was quite inexpensive but the threads looked rough and poorly formed.  For that reason I shelled out for stainless and haven't regretted it ..... but at M20 size it wasn't cheap .  Pays your money and ....  etc.  You're only going to do this once. 

Adrian

[DrRobin]

I would use stainless steel every time, but a word of warning, stainless on stainless can cease.  I have had to saw through several M8 SS studs and bolts out on site in the last few years.  What seems to happen is when you are slackening it off, the nut just starts to tighten and it just gets worse the more you turn it.

If you can catch it in time you can apply a lubricant and I have even heard that fresh water is a good lubricant, but every time it has happened to me it has always resulted in getting the hacksaw out.

I found this explanation on Wikipedia and think it is the problem...

http://en.wikipedia.org/wiki/Stainless_steel

When stainless steel parts such as nuts and bolts are forced together, the oxide layer can be scraped off, causing the parts to weld together. When disassembled, the welded material may be torn and pitted, an effect known as galling. This destructive galling can be best avoided by the use of dissimilar materials for the parts forced together, for example bronze and stainless steel, or even different types of stainless steels (martensitic against austenitic), when metal-to-metal wear is a concern, but two different alloys electrically linked in humid environment work as pile and corrode faster. Nitronic alloys reduce the tendency to gall through selective alloying with manganese and nitrogen. Additionally, threaded joints may be lubricated to prevent galling.

And the following link also explains the problem

http://stainlessautomotivefastenings.co.uk/index.php?main_page=page&id=11

I am not sure what the best 'thread lubricant' to use is, but if you concrete studs in and a nut ceases on it is a bit of a problem, you would have to hacksaw it off and put a connector nut in.  I would suggest something like copper slip or possibly WD40 might do the trick.

Robin

[Islander]

Copper slip is designed to prevent fasteners from seizing together and will work just fine.

[opticalpath]

I would use stainless steel every time, but a word of warning, stainless on stainless can cease.  I have had to saw through several M8 SS studs and bolts out on site in the last few years.  What seems to happen is when you are slackening it off, the nut just starts to tighten and it just gets worse the more you turn it.

 

If you can catch it in time you can apply a lubricant and I have even heard that fresh water is a good lubricant, but every time it has happened to me it has always resulted in getting the hacksaw out.

 

I found this explanation on Wikipedia and think it is the problem...

 

http://en.wikipedia.org/wiki/Stainless_steel

 

When stainless steel parts such as nuts and bolts are forced together, the oxide layer can be scraped off, causing the parts to weld together. When disassembled, the welded material may be torn and pitted, an effect known as galling. This destructive galling can be best avoided by the use of dissimilar materials for the parts forced together, for example bronze and stainless steel, or even different types of stainless steels (martensitic against austenitic), when metal-to-metal wear is a concern, but two different alloys electrically linked in humid environment work as pile and corrode faster. Nitronic alloys reduce the tendency to gall through selective alloying with manganese and nitrogen. Additionally, threaded joints may be lubricated to prevent galling.

 

And the following link also explains the problem

 

http://stainlessautomotivefastenings.co.uk/index.php?main_page=page&id=11

 

I am not sure what the best 'thread lubricant' to use is, but if you concrete studs in and a nut ceases on it is a bit of a problem, you would have to hacksaw it off and put a connector nut in.  I would suggest something like copper slip or possibly WD40 might do the trick.

 

Robin

Very interesting, and useful to know. Makes me think I should slacken off my top nuts every once in a while and re-lubricate the threads.

Adrian

[Gina]

I think moly grease is supposed to work too.

[Islander]

I think moly grease is supposed to work too.

It'll lubricate the thread but copper slip is specifically designed to be an anti-seize lubricant and will do a better job of it.  It puts a layer of copper between the thread surfaces and works brilliantly. 

[nytecam]

Hi - my combined steel pier and equat wedge cost ~£100 a decade and a half ago from my local steel frabricator @ http://home.freeuk.com/m.gavin/pier.htm   It amazes me that most do a pier THEN think about the wedge

[Scott]

Hi - my combined steel pier and equat wedge cost ~£100 a decade and a half ago from my local steel frabricator @ http://home.freeuk.com/m.gavin/pier.htm   It amazes me that most do a pier THEN think about the wedge

I've been wondering of late whether it's worth building my pier (for an eq6) with a partial wedge. by this I mean tilt the top mounting plate to say, 30 degrees to allow the alt bolts a better angle with the mount (closer to a straight on contact) to avoid the alt bolt from "skimming" on the mount. eq6 alt bolts have a lousy contact at 52 degrees north .

as a side note, it'll be in an obs so won't need continual P.A. so a level mount isn't critical....or is it?

[opticalpath]

........ so a level mount isn't critical....or is it?

It's not critical; it just makes PA a little less convenient.  That's because PA consists of steps involving separate adjustments of the polar axis in azimuth, and  in altitude.  If the mount base is level, small adjustments in altitude and azimuth are pretty much independent of one another.  If the base is not level, adjustment of one affects the other to some extent, so you may need a few more iterations to converge on a good alignment.  But in a permanent set up, you'll only do it infrequently.......  and an angled top plate does make a lot of sense.

The only thing about an angled top plate is that the design should perhaps include some offset so that the centre of gravity of the scope/ mount is within the footprint of the pier and not hanging out far behind it.

Adrian

[nytecam]

..  and an angled top plate does make a lot of sense.

The only thing about an angled top plate is that the design should perhaps include so me offset so that the centre of gravity of the scope/ mount is within the footprint of the pier and not hanging out far behind it.

Adrian

Any pier worthy of the name, should cope with the offset weight :-) My steel pier includes for rotation in azimuth via the base plate and adjustment of the wedge in alt-az within +/- ~10 dregs - these threads should be 'fine' for precise adjustment :-)

[K3ny0n]

My progress to far, got the tube and top plate welded together and the adapter plate on top on the top plate attached. I've got the minimum amount of spacing in between the top plate and adapter while still gaining access with a open ended spanner. Also got the azimuth pin on the plate.

Next job is to weld a base plate to the bottom then weld some strengtheners up the pipe from the base plate and I think I'm all done.

Oh I still need to drill the 65mm recess and 30mm hole for the mount to fit in to.

Rob

Sent from my iPhone using Tapatalk