Bad vibrations ....

[imhimmelkommter (Michael Toms)]

I have encountered a problem with the telescope mount build. The pier when it is touched moves all over the place. I would like to know off any designs out there to support the pier to prevent it from moving. The pier is 165mm OD and 800mm long. How can I improve on the stability of the pier? Thank you. Michael

[iborg (Philip)]

Hi Michael

I think braces from the arms to the pier. Needs to be a triangle.

Others may have a good idea of minimum distances, but, I would go at least 1/3 out and up.

As it is, you have a huge amount of leverage of the pier against the arms.

Good luck.

Philip

[Kunama]

As Philip noted, you need to have braces going to the 'legs', but given that the legs are very thin, your braces will need to go directly above the footpad and at least 2/3 of the way up the side of the pier.....

[imhimmelkommter (Michael Toms)]

Originally Posted by iborg

Hi Michael

I think braces from the arms to the pier. Needs to be a triangle.

Others may have a good idea of minimum distances, but, I would go at least 1/3 out and up.

As it is, you have a huge amount of leverage of the pier against the arms.

Good luck.

Philip

Thanks Philip...

[imhimmelkommter (Michael Toms)]

Originally Posted by Kunama

As Philip noted, you need to have braces going to the 'legs', but given that the legs are very thin, your braces will need to go directly above the footpad and at least 2/3 of the way up the side of the pier.....

Would something like this be ideal???

[bojan]

Yes, something like this would be much better.
Maybe the braces should go directly to pads.
And make them as strong and rigid as possible since they will support the pier ans carry the whole weight.

[Kunama]

I would probably shorten the legs a little to bring the 'feet' to where your proposed braces are shown. The brace needs to resist the compression without bending or flexing.
The design also needs to ensure that the bottom of the pier does not touch the ground so that all the weight is at the three feet.

[imhimmelkommter (Michael Toms)]

Originally Posted by Kunama

I would probably shorten the legs a little to bring the 'feet' to where your proposed braces are shown. The brace needs to resist the compression without bending or flexing.
The design also needs to ensure that the bottom of the pier does not touch the ground so that all the weight is at the three feet.

I would say that's a step to take, shorten the legs. They are at 600mm at the moment. Thanks Mat.

[Wavytone]

Michael those skinny legs and rivets suggest your pier is very weak in torsion - you need to stop it rotating around the vertical axis. This is why heavy-duty legs are built like a "crutch" and fixed with a hinge to the pier with a horizontal dimension around 100-150mm.

Take a look at the tripods used by surveyors to theodolites for inspiration.

PS I bought a WILD-Heerbrugg survey tripod secondhand for $200 and I'd bet its stiffer than yours. A lot stiffer.

[imhimmelkommter (Michael Toms)]

Originally Posted by Wavytone

Michael those skinny legs and rivets suggest your pier is very weak in torsion - you need to stop it rotating around the vertical axis. This is why heavy-duty legs are built like a "crutch" and fixed with a hinge to the pier with a horizontal dimension around 100-150mm.

Take a look at the tripods used by surveyors to theodolites for inspiration.

PS I bought a WILD-Heerbrugg survey tripod secondhand for $200 and I'd bet its stiffer than yours. A lot stiffer.

I'll look into that. Thank you.

[vlazg (George)]

Hi Michael,
i agree with Matt, the legs look too thin and i assume a lot of the vibration will come from them. You really need to beef them up.
I had a pier made, thanks to Strongmanmike who allowed to copy his design.
Since the photo i have shortened the pier and repositioned the wire braces lower to allow the weights and ota to miss them when near the zenith. Doesn't move.

http://www.iceinspace.com.au/forum/a...e.php?a=203169

Cheers
George

[imhimmelkommter (Michael Toms)]

Originally Posted by vlazg

Hi Michael,
i agree with Matt, the legs look too thin and i assume a lot of the vibration will come from them. You really need to beef them up.
I had a pier made, thanks to Strongmanmike who allowed to copy his design.
Since the photo i have shortened the pier and repositioned the wire braces lower to allow the weights and ota to miss them when near the zenith. Doesn't move.

http://www.iceinspace.com.au/forum/a...e.php?a=203169

Cheers
George

Thanks for sharing that idea. I'm leaving the feet and leg design to last, and with everyone's input, will help to create the final supports.

[doppler (Rick)]

Here's a couple of variations of the portable mount design.