Eq6 tuning, play in ra

[blinky]

I have, with a lot of help, been tuning an eq6. I now have it running smoothly buy at some points there is a little play in ra-not much, maybe a mm? Is this ok/normal? At some points there is no play and if I tighten it up so there is no play at all then the mount binds, so I'm thinking this is as good as it will get!

[gary1968]

I don't understand how it has slop only at certain points Craig, it has the uber expensive worm wheel and worm, it should be better, maybe we should strip it again and try to get the thrust washer sizing better.

Gaz

[Astro_Baby]

AI have been trying t help on this via pm , i didnt pick up on the fact it has replacement worms and ring gear.

I would incline to doubt play is down to the shim washers, anything is possible, but I was concerned that the shim washer dimensions fed to me were abnormally high.

Its devlish difficult to diagnose problems when you cant see the mount or feel it but I dis wonder about the shims as the info ai got seemed a bit confused.

The mount could exhibit slop in only a part of the cycle for a number of reasons.....

Poor worm to ring gear alignment....not square

Poor ring gear, deformed and not perfectly round or teeth miscut...factory gear is ok but its not aerospace precison

Badley set up worm end floats or duff bearings in end floats

Poor motor spur gear alignment

Tyere are probably others as well tat ai cant think of or havent faced yet.

Generally I tune these mounts with feeling and sympathy not just by the book because sometimes they need understanding and feel...and sometimes they have to be stripped and tinkered with repeatedly to get them just so. One mount I did had about ten rebuilds on the DEC axis to get it smooth, backlash free and not binding.

If tye mijnt is anywhere on the southern side of the M25 I could take a look if you want.

[blinky]

Thanks for the info, I was wondering if the problem was that I had not put the worm mounting plate back on square and that was the cause of the issue. Now that you have mentioned it would cause this problem I will take a look at it, but another day! I'm going to take a rest now and approach it again later...:-)

[t1bbbst3r]

Try rubbing some grease off, especially if you put it on moderately, this worked for me I had a similar problem so wiped grease off a few washers with a kitchen towel & now everything is tickety-boo!

[blinky]

I have been using spray silicone lube, is that the wrong stuff for this job then? I do have an old tub of thick black grease in my hut, I use it to smear on the top of my fence so nobody climbs over!! Should I use this instead for the worm and gear?

[George]

I have been using spray silicone lube, is that the wrong stuff for this job then? I do have an old tub of thick black grease in my hut, I use it to smear on the top of my fence so nobody climbs over!! Should I use this instead for the worm and gear?

I thinks there's too much rubbish wrote about what grease to use, as long as the grease has a broad temperature range (we are interested in the lower temperatures) and is relatively thin ie wont cause drag then just about any grease will be suitable.

The RPM of a EQ6 wont tax most greases lube quality's.

If you have high and low points this could indicate a slightly bent worm, if you have a lathe you could check this out.

I'd also check your worm bearings 1st tho as these are usually the culprits. I changed mine for really good quality roller blade type.

[spaceboy]

I will be watching this thread with interest. I have a very similar problem myself despite having stripped the mount twice adjusted and replaced where needed as well as taking off any high spots in the casting etc. I put it down to the fact that I had maybe made too good a job of it and now the slightest imbalance between EP changes or DSLR has a more noticeable effect where as before the thick grease and other imperfections in the mount meant the mount was all together stiffer when adjusted that any imbalance in the mount was less slick and so less noticeable ??? I mention this because I noted a similar issue with an EQ5 I had stripped re-greased etc but as it only had an RA drive I could easily re-balance the scope and have no worries of loosing alignment every time. The one thing I did note is that the tar like grease from factory remains more consistent in use if not some what stodgy (for want of a better word) where as other substituted greases can easily be displaced or more effected by temperature difference. Chinese mass produced mounts do have moving parts so it is inevitable a strip and tune is often beneficial but I think it has to be taken in to consideration if your going to fine tune some thing it has to be done whole heartedly and if there is anything that has been missed that these will become more noticeable but not always so easy to pin point. I myself have noted I have the issues when the scope is in-between the point where the worms and the gears will be between the point where the gears transfer the load bearing weight from the one side to the other if that makes any sense ??? I think I read some imagers only image one patch of sky as they know the mount and scope is perfectly balanced while others often rebalance and collimate their scope at intervals during their session due to flex in the OTA, balance, orientation of the focuser etc. Unless you are someone like Mel who has had their hands on experience with several re-grease and build projects it is a case of trial and error for the DIY'r like ourselves to get it right perfectly first time. Imaging tends to show up those tiny slips and dips that would other wise go un-noticed visually.

[Astro_Baby]

On grease will be a non starter....get some TF2 feom a bike shop or some Superlube from RS components.

The grease wont be causing the problems you have now but a soary on grease wont be up to much and will more than likley cause premature wear and dont use stiff for putting on fences. A tin of TF2 will cost about a fiver and will be enough for about tyree or four mount builds.

[blinky]

Well I took it apart again last night and regreased it with some Red Grease?? I got from Halford Bike dept and put it all back together. It is still a little tight at one point but a lot smoother and at a lot of points you cant even hear the gear, only the motor. I still have backlash at one point but I think it is time to try it out under the stars and see how it performs!