Bit wobbly, lazy Susan to the rescue ???

[OneEyedSam]

At high magnification my lightbridge gets a little wobbly. Now this might be an inherent problem in the overall design, but am wondering if the lazy Susan mod 12" bearing would improve the stability between the upper and lower halves of the base.

didnt get in until late last night, but will look tonight whether there is movement in the swivel part of my base, but would appreciate info from anyone who's done the lazy Susan mod. Ie the top half of the swivel would be better supported by a large 12" bearing over the smaller Teflon bearing that it came with, right ??

[Moonshane]

when you say wobbly, is it a physical wobble/insecurity or vibration through the eyepiece? settling for a second or so at high magnification is normal but can be sorted to a large extent by smooth bearings but it's important to establish what's causing the wobble.

[jetstream]

when you say wobbly, is it a physical wobble/insecurity or vibration through the eyepiece? settling for a second or so at high magnification is normal but can be sorted to a large extent by smooth bearings but it's important to establish what's causing the wobble.

Moonshane,I understand you build excellent Dobs,and smooth bearings & stable mount must be crucial for observing....so what type of azimuth bearings do you use?Hope its not a trade secret!lol!

[Moonshane]

hi Gerry - I don't do many but the ones I do I try to get right . I use only teflon pads and kitchen laminate sheet (0.8mm thick) and then treat the latter with turtle was (hard wax) polish. works a treat - nice and silky.

[knobby]

Not sure about the light bridge base but my 250px improved massively by securing the centre bolt and fitting a lazy suzan.

I feel that the centre bolt causes a lot of problems on the budget bases. Its too slack and allows lateral movement which doesn't help with the smoothness of movement or the rigidity of the base.

[jetstream]

Does it matter the type of laminate?I'm just curious,I can buy Ebonystar bearing kit for the planned Dob for about $80.00 US.I often wondered what other laminate a guy could use however,I suppose the texture matters.I like to plan ahead...

[Moonshane]

I think it matters a little less than is usually stated. the texture on the one I normally use is very lightly textured. the price you state would make about 4-6 scopes in the materials I buy.

[OneEyedSam]

i suspect its play inthe two halves of the mount. The scope is otherwise rigid and I don't get sticktion or suffer from an overly slack bearing bolt

[Moonshane]

try packing around the central bolt with teflon if you can get it or milk bottle washers (or other nylon washers) to give just enough support. you can then tighten the bolt a bit more and it should solve the issue I think.

[jetstream]

I think it matters a little less than is usually stated. the texture on the one I normally use is very lightly textured. the price you state would make about 4-6 scopes in the materials I buy.

I was kinda wondering about the cost($80.00) but I guess it is the price of convenience.I'm going to check some different laminates out...I like your cost a bit better!lol!BUT,I know the learning curve can be $$$.Thanks for the info.And my guess is as you say supporting the base(on center bolt) with plastic washers may help with the sticktion the stock Dobs suffer from.

[LeeB]

My home made dob has a home made lazy susan, 15 inch 1/4 inch steel ball bearing and I find a hard wax in the channel prior to assemble makes it super smooth.

[OneEyedSam]

try packing around the central bolt with teflon if you can get it or milk bottle washers (or other nylon washers) to give just enough support. you can then tighten the bolt a bit more and it should solve the issue I think.

Thanks, ill take a look when I get time. It was bugging me last night in the small hours, need to look into it further during the day. I do fancy the lazy Susan mod, so might give it a go anyway and see how it pans out.

[astronymonkey]

My LB16 came with a lazy susan bearing and is very smooth. I didnt know the LB12 didt have one ..... Id say fit one though !

[OneEyedSam]

My LB16 came with a lazy susan bearing and is very smooth. I didnt know the LB12 didt have one ..... Id say fit one though !

do you detect any wobbliness betwen the upper and lower halves of the mount ? I dont get much, but at high mag there is some movement....maybe not very much but I'm sure I can improve it

[knobby]

This firms things up no end

[astronymonkey]

do you detect any wobbliness betwen the upper and lower halves of the mount ? I dont get much, but at high mag there is some movement....maybe not very much but I'm sure I can improve it

To be honest its rock solid even when nudging to follow Saturn for example at 276x.

The bearing fills the gap between the two base boards allowing the nut and bolt to do the job of squeezing the whole lot together so no room for wobble as the bearing is wide enough and flat enough to not create any fulcrum for it to rock about on. I was expecting to have to do some mods to the base to make it steadier so I was really suprised at how smooth it was straight out of the box.

Cheers

[OneEyedSam]

Looking at a 16 or 18" bearing...got to be a winner I think