Flexure? No: bus! Now what?

[Joel Shepherd]

Last night, after working up the nerve to try for 2-minute lights, I got some evidence that some occasional flexure-like movement I get in my lights might not be flexure but is actually vibration caused by city buses running down the street in front of our house (~80 feet from the telescope). The timing is suspicious enough.

I can't stop the buses, so what is the best way to deal with it?

I did have vibration suppression pads under the (AVX) tripod legs but now I'm suspecting they may have made things worse by slowing the rate at which the mount returned to its original position. Possible?

Is this one of things that could be best addressed with strategically applied sand (in the tripod legs or hanging off the mount)?

Thanks -- Joel.

[lensman57]

Last night, after working up the nerve to try for 2-minute lights, I got some evidence that some occasional flexure-like movement I get in my lights might not be flexure but is actually vibration caused by city buses running down the street in front of our house (~80 feet from the telescope). The timing is suspicious enough.

I can't stop the buses, so what is the best way to deal with it?

I did have vibration suppression pads under the (AVX) tripod legs but now I'm suspecting they may have made things worse by slowing the rate at which the mount returned to its original position. Possible?

Is this one of things that could be best addressed with strategically applied sand (in the tripod legs or hanging off the mount)?

Thanks -- Joel.

I too have this problem. I live less than 20 Meters away from a main road out of the city what we call a dual carriage way here in the UK. When heavy lorries usually carrying construction waste pass by and hit the drain grids or the pot holes I feel the house shakes. Mercifully they do not pass very often in the late evening while imaging is happening but they do pass at times and this has an effect on the guiding if the scope is set up on the tarmac. It is not so bad when I set up on the grass as it cushions the vibration to some extent. The other problem that I have noticed recently is the flashing blue lights of the police or emergency vehicles that seem to light up the night sky for a considerable period.

A.G

[kalasinman]

Hang 5K or so from the EP tray.

[wxsatuser]

My obsy is about 80 feet from the road and I can feel the vibs the buses cause as they go by.

It's slightly better since they repaired the joints in the road but I can still feel it.

Have checked subs and I cannot see any difference between vibration or clean ones

so now I don't bother checking.

[theghettostylus]

I use some old cast iron dumbbell weights and sit them on the accessorie tray.

About 10kg I think. It really does help take away some wobble.

[Uranium235]

Set up on grass if poss, it will dampen the vibrations. Also as mentioned - add extra weight and back away from the telescope (remote trigger if you can) - helps to be light-footed around the mount while its taking snaps as well.