Good link for dob bearings.

[Hypernova]

Oh [removed word]!!! In the midst of putting the mount back together I have lost the lock nut for the bolt

A full report will have to wait until I find it get a new one, currently the base is in two pieces with ring of ebony star glued strongly to the rocker base and ready to go.

[spaceboy]

SORRY! I have to laugh.... everyones loosing bolts, if you were at my house all you need to do is check the vac. Got my self one of thoses magnetic trays so I don't loose any bolts or clips. I only have to search for the tray now My wife is one of those who likes to know where everything is but don't tell anyone.

May be a good time to have a go at the pivot bolt mod now Tom

[Hypernova]

May be a good time to have a go at the pivot bolt mod now Tom

I will do when I can get a drill and a tap and die set to use on the aluminium block.

[spaceboy]

I think I still have one from my 1st attempt. The thread came out as pi**t as a sailor on leave but it still worked. It is only the aluminum plate that goes on the bottom board. The nylon plate I chopped up to fix my camera tripod so you would have to find some thing to fix to the top board.

If you are happy to cover postage I can send you the alloy plate ?? Drop me a PM if you want it. As long as the pivot bolt is M10 it should do you OK.

[scogyrd]

How about you scogyrd any good??

I've had the flu so haven't got round to it yet. I'm hoping to do it at the weekend now.

Providing I find that screw.

[spaceboy]

Hope you are feeling better. Was it man flu ? woman just don't understand how bad man flu is!! Still haven't got to try my dob out since putting the LSB on DAM weather You can guarantee the only time it's clear is when I have to get up early to take the kids to school.

[Hypernova]

I have now located the runaway lock nut and re-assembled everything. The movement is very smooth but there is a lot of lateral play in the base, I guess that the bolt mod is quite necessary indeed.

[spaceboy]

Glad to hear you've got it all sorted Hypernova.

All eyes are on you now scogyrd

Did anyone take any pictures to post ?

[Hypernova]

I finally have pictures to post of the finished artical, I used a rubbish camera phone so the images or low resolution but you'll get the general idea of what I've done with the ebony star.

I have simply glued the ring onto the base with a two part adhesive and made sure to cut out notches for the bolts to sit in and allow the ring to sit flat. The laminate of the base was roughened up slightly to aid in the fixing of the ring, it was quite hard to make a mark on the base with regular sandpaper so I used a metal scouring attachment for a drill manually to get a few scratches on the base.

So far so good, the ring has dried on and has been put back together again and the improvement in the AZ movement is plain to see. There is very little stiction left in the bearings and I am very pleased with the overall swivelling movement, it is just so smooth compared to how it was before.

This mod though has shown up a lot of the inherent lateral play in the base's central bolt so I need to get up and do the required modification to bolt as shown here.

[spaceboy]

Great job Hypernova. Those cut outs don't look to bad in fact it looks a very tidy finish. I know it's not like anyone going to see it but I always say if your going to a job then it's best done right.

Although it's no shock, glad to hear it sorted out the sticksion. (dose this word even exist???)

[scogyrd]

It looks good Hypernova, and I'm pleased to hear it works well.

I should be glueing mine on tomorrow. I've just done the fixed bolt mod and it's made loads of difference, it feels so much sturdier than before and isn't half as much of an effort to get moving. I can't wait to get it all finished now.

[Hypernova]

Good to hear that the bolt mod works as intended, I plan to get that done when I can which will probably end up being sometime in the new year when the funds come back. I am so far minus the nylon sheet and a drill and tap and die set, I have the aluminium block which needs tapping first.

[scogyrd]

After spaceboy said it sticks slightly if sat for too long I decided to use teflon instead of acrylic. I don't know if it'll make any difference but I can't see that it'll hurt.

If you can get your hands on a bench drill tapping the hole is a doddle. Just put a tap where you would normally put the drill bit and turn it by hand, my thread came out spot on doing it like this. Here's a video showing how it's done: he's welded a nut to his drill so he can use a socket but you can turn them with your hand easily enough.

I wouldn't buy a cheap tap and die set either, most aren't very good. You're better of buying some decent quality m10 taps instead.

[spaceboy]

It looks good Hypernova, and I'm pleased to hear it works well.

I should be glueing mine on tomorrow. I've just done the fixed bolt mod and it's made loads of difference, it feels so much sturdier than before and isn't half as much of an effort to get moving. I can't wait to get it all finished now.

Proper job!!!! That was a good idea using Teflon. I can't see why it won't work. I think the website suggests nylon as it has a high resistants to wear but is also slick. I would imagine Teflon to have almost identical properties but maybe more slick so good thinking Scogyrd. Look forward to seeing the end result. It will be interesting to see how the ES with fixed pivot compares to ES with out. I think that SW should consider doing fixed pivot bolts as standard on all there lazy Susan bases as it goes with out saying the amount of beginners who buy a dob have no knowledge that mods are required to improve performance and have to put up with stiff AZ due to the lack of what would be a simple factory improvement.

[scogyrd]

So, I made the mistake of testing my 300mm lazy Susan bearing before gluing the ES and I've decided to use the bearing instead. Doing the fixed bolt mod has eliminated all the play and it's so easy to use that I just can't see any advantages that gluing the ES would make.

I feel like such a let down now.

[Hypernova]

Ah well I am happy with added cost of the Ebony Star and the improvements it has made to the movement of the AZ axis. I like the idea of no moving mechanical parts to maintain and worry about. I am still going to do the fixed bolt mod though to see how it reduces the stiction and that annoying lateral play.

[spaceboy]

So, I made the mistake of testing my 300mm lazy Susan bearing before gluing the ES and I've decided to use the bearing instead. Doing the fixed bolt mod has eliminated all the play and it's so easy to use that I just can't see any advantages that gluing the ES would make.

I feel like such a let down now.

Glad to hear you have sorted the dreaded sticktion problem Scogyrd. I don't think you should feel you are a let down! at the end of the day we do what we have to do to improve our viewing experience and the LSB worked for you as it did for me.

I think the key thing here is to point out how important it is the center pivot bolt is to be fixed to the base what ever method you choose.

Ah well I am happy with added cost of the Ebony Star and the improvements it has made to the movement of the AZ axis. I like the idea of no moving mechanical parts to maintain and worry about. I am still going to do the fixed bolt mod though to see how it reduces the stiction and that annoying lateral play.

Again.... this method has worked best for you and that's all that matters. Granted in actual fact the ES method comes across as more of a chore and it's not totally maintenance free as sailkot has to be applied occasionally. The advantage may again lie with the LSB as any real problems is a 4 screw & a new LSB fix where as ES is affixed to the base.

I hope you are able to do the pivot bolt fix soon Hypernova and I'm sure your mount will move like butter. I hope you can keep us updated.

Thanks everyone for your input on this thread as for me it turned out to be a very interesting read and of course a profit to my experience as I am very happy with the LSB mod. I am sure Ebony Star if more readily available and at a more respectable price would have been my first choice but I can buy 2 x 300mm LSB for the cost of 1 x Ebony star laminate disk delivered.

SPACEBOY

[sixela]

So, I made the mistake of testing my 300mm lazy Susan bearing before gluing the ES and I've decided to use the bearing instead. Doing the fixed bolt mod has eliminated all the play and it's so easy to use that I just can't see any advantages that gluing the ES would make.

Dynamic friction that increases with the speed the scope moves at. In other words, it's easier to avoid overshooting targets.

[scogyrd]

Ah well I am happy with added cost of the Ebony Star and the improvements it has made to the movement of the AZ axis. I like the idea of no moving mechanical parts to maintain and worry about. I am still going to do the fixed bolt mod though to see how it reduces the stiction and that annoying lateral play.

You should be happy too.

It's not that I don't think the ES mod is worthwhile, I had a dry run with it and it worked very well, it's simply that I've decided to opt for the lazier solution. I'm certain that had I done the ES mod I would've really liked it, it's just that now I've got the LS on it seems like a lot of work for any possible gain.

I would definitely do the fixed bolt mod if I were you though. It does make a load of difference, had I not done it I wouldn't have even contemplated trying my LS again.

[scogyrd]

I think the key thing here is to point out how important it is the center pivot bolt is to be fixed to the base what ever method you choose.

I agree, in fact you could say I found it pivotal.