Skymax 127 vibration

[Mez7000]

Hi All

After a bit of advise!

Have a Skymax 127 on an AZ mount and haven't really used it much over the past year and decided to start using it again.

Have noticed that there is a lot of vibration and the slight touch and the view through the eyepiece just bounces.

I've moved the scope from the patio to grass and that didn't solve it, tightened all bolts and knobs, undone and repositioned the one which holds the scope to the AZ mount arm but all to no avail.  I've even tried using the scope without the legs extended but that hasn't helped.

Am getting this issue at all magnifications too.

I'm hoping it's just me and that since I've not used it for a while I've forgot that this happens, would expect higher sensitivity at high mag but not all the time.

Reassurance required please or how to solve it!

Thanks

Mark

 

[Art Gecko]

It's normal... The focal length of a Mak is much longer than the tube length... For instance, if you put a 20mm eyepiece in your Skywatcher 130 which has a FL of 900mm you will get X45 magnification... However the same eyepiece in your Skymax 127 (FL 1500mm) will give a X75 magnification, with that higher level of magnification comes greater sensitivity to knocks and vibrations... Simply take a little extra care not to nudge it while observing and the sky is your oyster!

HTH, Art.

[Louis D]

Try putting Sorbothane pads under each tripod foot.  I bought new old stock 100% Sorbothane insoles for cheap off of ebay and cut them into squares to place under each foot.  You can also buy Sorbothane pads already cut to various sizes and shapes off of ebay for a neater look.  You can also pay a bit more and try vibration suppression pads.  They may work well, but I've never tried them.  With my 127mm Mak, vibration dropped from 2-3 seconds to about 0.5 seconds to dampen out with the Sorbothane pads.

[kilix]

I did 3 modifications -

1) I poured epoxy resin into the gaps on the plastic leg holders, where the plastic connects to the steel leg. One rivet on each side of the leg is not sturdy enough and pouring epoxy there helps a tiny bit.

2) I poured concrete into the lower, extending part of the tripod legs. This helps to bring the center of gravity a bit lower. First you need to drill out the rivets on the locknut holders, then the bottom part of the leg pops out. You can then pour concrete into the lower legs. After the concrete solidified, I also made an epoxy "stopper" on top of the solidified concrete in the tripod leg, so in case the concrete starts to crumble, there is no possibility that it will leave the lower legs, and any concrete dust or small particles are held there by the epoxy stopper. The tripod now feels a lot less flimsy and seems solid (but that is just an illusion, the quality of the plastic parts is crappy).

3) I made a modification to the leg spreader - as I've seen here:

synscan tripod mod

Basically, you make an extension to the center tray holders, so the center tray can be mounted as low as possible. This also helps to stabilise the legs a bit more lower, which helps to reduce the oscillation a tiny bit.

all this helped a bit, but not by much. Overall, the vibration seemed to go from ~3secs to ~1sec.

There seems to be a lot of members who claim that hanging a weight (about 1kg) from the center tray also helps a bit. But I did not try it, I am relatively happy with the state of the tripod as it is now. Still, that tripod is by far the weakest/cheapest link of the telescope. During winter all three locknut holders cracked and I had to repair them. First one cracked, because I overtightened the locknut a bit, but the other two cracked by themselves. The cheap ABS plastic of this tripod is very sensitive to cold temperatures. At least most of the money went into optics, that's what I keep telling myself

 

EDIT: the scope must not shake when you are not touching it. Mine does not shake at all, only when I touch the focuser, or when I touch the eyepiece by mistake. Also, it did not shake before I made all those modifications, it only vibrated for a few seconds when I touched it or when I was focusing it. Those modifications helped minimize the time it needed to settle down.

[Mez7000]

Thanks everyone for the help and advise!

Lots of things to consider here.  I agree the tripod itself is not the best and I think I may consider investing in another tripod, or another scope! ?

The vibration does last only a few seconds as described by you all, I just couldn't remember how bad it was, but once it stops and I'm not touching the scope, all is well but I will need to consider some mods to reduce the vibration.

Once again, thanks everyone for your help!

[Louis D]

If you're considering a new tripod, go with a Berlebach or other wood type.  Wood naturally dampens vibrations.  Any metal tripod, no matter how sturdy, will ring like a bell if not dampened in some manner.

[Cosmic Geoff]

The tripod with the above-mentioned kit (as it's an alt-azimuth I assume it's either the GoTo or an AZ-3) is inherently wobbly, being designed to be low cost, and portable.

IMHO it's not worth trying to modify it - either use it for what it is, (with or without a suspended damper weight) or get something else. If this is a GoTo, a really solid alternative will include the electronic mount and be rather expensive. (The budget GoTo mounts do not mate with standard tripods).  If it's a cheap manual alt-az, there is more hope - an AZ-4 will be far more solid and costs around £200.

The more solid mounts (e.g. AZ4-2, EQ5 and upward with matching tripods), are in a totally different class of stability, like comparing a cheap camera tripod with scaffolding poles. So if you require extreme stability, get a better class of mount.

[Mez7000]

On 2017-5-27 at 12:39, Cosmic Geoff said:

The tripod with the above-mentioned kit (as it's an alt-azimuth I assume it's either the GoTo or an AZ-3) is inherently wobbly, being designed to be low cost, and portable.

IMHO it's not worth trying to modify it - either use it for what it is, (with or without a suspended damper weight) or get something else. If this is a GoTo, a really solid alternative will include the electronic mount and be rather expensive. (The budget GoTo mounts do not mate with standard tripods).  If it's a cheap manual alt-az, there is more hope - an AZ-4 will be far more solid and costs around £200.

The more solid mounts (e.g. AZ4-2, EQ5 and upward with matching tripods), are in a totally different class of stability, like comparing a cheap camera tripod with scaffolding poles. So if you require extreme stability, get a better class of mount.

Yes it's the cheapo tubular tripod that they supply with the skymax, with the goto attaching to the top, never been to sure of it and even less sure how the scope itself is just attached to the goto arm with the one adjustable screw, always worry it'll fall off!  My old Skywatcher Newt seems a lot sturdier on the EQ3 mount!

[Cosmic Geoff]

2 hours ago, Mez7000 said:

and even less sure how the scope itself is just attached to the goto arm with the one adjustable screw,

A one-screw attachment is standard. I have that on my 6/8SE GoTo mount and my EQ-5 which mounts a 9Kg Newtonian. Don't worry.