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scogyrd

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Posts posted by scogyrd

  1. I think it was a case of me misunderstanding it and trying to overcomplicate things. Sorry for hijacking the thread and thanks for all the advise.

    It's still raining here so you can all blame me for causing it. If I hadn't bought the wood yesterday we'd have all been guaranteed clear skies for at least another week.:)

  2. this is certainly possible. I think it's due to the relationship between the depth of your curve and the diameter of the bearing. according to Kriege and Berry the optimum spread is 65-70 degrees although this assumes a shallow section of the curve.

    I've just got back from the woodyard and tried marking the sides up like they said and while I admit I might be doing it wrong I can't see how the teflon would be at a right angle to the bearing if the v isn't 90 degrees. I asked my Dad how he'd do it too, he designs jet engines for Rolls Royce so I think he knows a thing or two about bearings, weight distribution etc., and he said the best way to do it would be to make the cut out 90 degrees. He also thinks a V would be better than a circle because it's only got 2 very slim points of contact and they'd be much bigger, in comparison, if you used a circle.

    Did you use your router to cut out the circle in the sideboard btw? I had a go at it the other week and while the bit I cut out was perfectly circular the sideboard I wanted to use wasn't, it was wider at the edges so my bearing was a lot closer to the centre of the board than it was the edges, so if you've got any tips for cutting it out it'd be much appreciated.

    TBH I've not decided whether to make the cut out circular or a v shape yet so I'm going to do both and see which one I like best. I was going to try building it today but, typically, it's started to rain here.

  3. hi Kevin, yes, I totally agree.

    as long as the teflon pads are at about 70 (not 90) degrees apart (imagine a 70 degree piece of pie from the centre of the bearing radius) then the shape of the cut out at the top of the side bearing does not matter. effectively, be it on a curve or a V, it's in the same place. so the angle of the V would need to be 110 degrees to ensure they are 90 degrees to the alt bearing surface.

    Scogyrd did this on his thread but not sure what his angles were.

    I've just noticed this and my V was 90 degrees and the teflon pads were 90 degrees apart as well, and I'm pretty certain the alt bearing sat on the teflon at 90 degrees too. I can't tell at the minute because my scope no longer has the original side bearings on it and I've removed the teflon from my last base.

    edit: I've just checked the plans for my dob and the bearings definitely sat on the teflon at 90 degrees.

  4. You are correct. I was afraid that someone might try to center a piece on the shaft of a drill and shape it. The approach that you depict would work. The tool shown is a rotary bench sander and would be ideal - much better than a drill or a drill press (Is a 'pillar' drill the same tool?). If you have no bench sander, then perhaps a belt sander on its side and affixed to the workbench would do just as well. I've used a belt sander in this way and see no reason why it wouldn't work for the job at hand. The last tool I'd use would be a hand drill and then only as a last resort.

    I wouldn't fancy doing it with a hand drill either but I've got a drill press so I'll probably use that if I do decide to have a go. I reckon it might be easier to use that than it would be to fix my sander to my workbench too. My sander is a funny shape and I can see it being a right pain to get (and keep) everything square. TBH I don't really know though. I'll have to see what I think is best if I do decide to do it.

    Thanks for the advice btw.

  5. I might be getting confused about what a lathe does, it's been a few years since I last used one, but I was thinking more along the lines of making a jig for the circle to spin on and using the drill, with some sort of attachment, to sand the wood. Instead of attaching the wood to the drill.

    Something a bit like this but with a drill instead of whatever it is they're using.

    Sanding Jig for Circles

    I've got a router to cut the circles out. I was just thinking of using the drill as an easy way to finish them off and make sure both bearings are exactly the same.

  6. One tool I would recommend buying when building the base is a sash clamp, or two. They're not really needed, my previous two bases were made without them, but they do make constructing the box part of the base so much easier. They don't have to be expensive either, mine cost about £8 each.

    Buy Axminster Aluminium Sash Cramps from Axminster, fast delivery for the UK

    I hadn't thought about using a drill as a lathe either. It's not a bad idea really. I'll have to try it when I get round to sanding my side bearings.

    I'm sorry to read about you all being made redundant too. I've been unemployed for the last few months so I know how you all must be feeling, although I was self employed so I didn't get any redundancy pay.. In the long run it could be a good thing for us all though. I've been using the time to go back to college and gain some qualifications. I think the main thing to do is to try and keep yourself busy.

  7. ha ha

    cheers mate - I did mention somewhere that my mount was inspired by you and OOUK of course :)

    good luck with your own build!

    I don't know how I missed that bit.:icon_eek:

    Your mount does look good though, it looks a lot neater than mine.

  8. Nice looking mount! I like the piece of wood you put at the back to help keep it square, where have I seen that before?:):icon_eek:

    I plan on making a similar mount for my dob soon. I've already bought the tube rings and made the side bearings but I've just spent a fortune on my MOT and I didn't quite have enough plywood left over from my last build so it's been put on the back seat for now. One day I'll finish it though...

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