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+--- Thread: Fixed Steady from Pipe Flanges? (/thread-2594.html)
Fixed Steady from Pipe Flanges? - Hopefuldave - 03-21-2015
Well, although the last skip-dive wasn't one of the best, it provided a piece of pipe with sturdy flanges, beats dragging quarter-ton hydraulic accumulators out on my own...
Anyway, I *need* a fixed steady for my lathe, it's quite short between centres when I want to cut longer parts, if my welding's up to the job this is what I hope will materialise out of thin air - well, thick steel... Sadly not cast iron, so it may sing a bit :(
The bolts-for-scale in the Crap-O-CAD are M12 x 75, so approximately 1/2" x 3", centre hole is a touch over 200mm/8" (just slightly bigger than I can swing over the cross-slide, perhaps and inch or so), weight is, errr... just about liftable! Can't weigh much more than a 10" steel Pratt-Burnerd 4-jaw, can it? The ring section is about 50mm/2" x 45mm/1-3/4" but there will be three 1" threaded holes through it for the steady fingers...
I saw an interesting video by a shade-tree machinist where he was impressed with the fingers on a big fixed steady - inside the screw-down right-hand thread caps were left-hand threaded rods which pushed the fingers out, so f'rinstance a 10tpi in the cap also pushed down a 12 tpi l/h screw into the moving finger - giving I guess about 6tpi of movement? I may have to try that... but with roller bearings in various sizes and bronze/brass pads that can interchange?
As the pipe flanges already have nicely matched holes, I thought after bevelling the weld lines I'd bolt 'em together then weld the two flanges tgether and the hinge bosses plus locking bosses on in some kiind of jig (lowly stick welder), then cut the two halves apart through two of the holes, which could have a pair of dowel pins to help repeatably locate everything square once in use...
I'm sure there's something there that can't/won't/shouldn't work, Constructive Criticism always welcome! Tell me why I'm an idiot! Tell me how to improve it! I won't be starting for a few weeks, so plenty of time to Get It Right...
RE: Fixed Steady from Pipe Flanges? - f350ca - 03-21-2015
I don't think the steel construction will be a problem Dave, I made one years ago, actually a hollow section out of steel and it worked quite well. Didn't bother to have mine open. saved a lot of work and it wasn't that big a disadvantage. I don't like roller ends on the fingers, the one on my big lathe has them, if any cuttings get back there they want to go under the roller with not pretty results. That one probably weighs a hundred pounds, goes on with the crane, it had what I thought was a chinsy plastic knobed bolt to hold it closed. One day while using it a large cutting got back there and tried to go under the roller, it couldn't so that plastic head shattered allowing the steady to open, sort of a safety valve. If it couldn't probably would have twisted the long shaft. Brass pads are a bit of a pain but fool proof.
RE: Fixed Steady from Pipe Flanges? - Hopefuldave - 03-21-2015
Thanks Greg, useful info :)
I hadn't though about a "safety valve" on it - perhaps the "nut" for the closing bolt could be a delrin/ally/crappy-Mazak cylinder with the bolt thread tapped through it, perhaps not full depth, ready to strip threads? Or I could do what I did when I rode a Really Skinny Tyre bike (glued-on tubulars) and set up a scraper to clear the way for the rollers, a bit like a cow-catcher :)
RE: Fixed Steady from Pipe Flanges? - f350ca - 03-21-2015
Might work, I now cut a hole in a margarine container lid and jam it over the shaft.