Uh oh… I bought a lathe today, since I’ve been taking too darn long to design my “MPCNC Lathe Edition”. I lost a tip on my break cue last week and wanted to be able to clean up the new tip, so lathe time! This guy is pretty simple, it’s an old Craftsman 12" Wood Lathe that has actually never been used. Looks like almost all parts are there and he swears he’ll be able to find the cutting tools.
Anyway, it comes with an add-on four jaw chuck that I can use to hold the shaft, but I really need a steady rest to hold the tip end centered while I shave away the excess glue and tip sides, then polish and shape. I can’t just push the tip up against the live center after all. A quick search on Thingiverse doesn’t come up with anything that looks workable. Anyway, it looks like RMWoodCo makes something like what I think I want, for about triple the cost of the lathe:
[attachment file=78607]
Anyone with actual CAD skills want to mock one up that I can cut out on my MPCNC? It looks like skateboard wheels, but I need to pull the center down to 10-12mm, so they might be too big. Our 608 bearings might work, especially with a rubber band glued to the outside to give a little give. Even better would to tweak the design so when you moved one leg the other two would move with it…
Hello Bill,
I might be able to help you, I would need dimensions, I would find it difficult working “remotely” but willing to give it a go, maybe better off forum, PM me, we could post final drawings when finished.
I took up wood turning in 2010 but had to give it up, could not find a way of managing dust, respirators don’t work when you have a full beard.
Attached it one I made earlier for a mini wood lathe.
I don’t normally feel the need to show off my work but as the goblet is in the picture of the steady here’s the finished goblet, I tell people that the rings were soaked in Polish Vodka for two weeks before stretching over the base (-:
Frank Howarth had a video last week where he used and made one like that. It was about his carving mallets.
(About 9:50).
That one you posted almost looks like you can get the arms from inside the hole. That always seems useful. Maybe instead of designing the whole thing for 608 bearings, you just add another small piece for fine work, but use wheels most of the time?
Ah, didn’t realize there was no PM facility, no problem.
Two things to consider Bill.
What is the diameter of those wheels, it may restrict you holding the thin end of a cue, post the dims and I will draw them see what we end up with. (Imperial or metric)
Do we have a problem with copyright, the steady does not appear to be available anymore but the triangular parts are used on another steady on their web site, if this was done privately it wouldn’t bother me in the least.
At the very least we could do with Ryan’s input on this as it’s on his forum.
I’m not a lawyer, but if you draw the design in cad from looking at this image, that’s not infringing on copyright. Posting the image here technically is, but I don’t think anyone will care. If they have a patent on the design, then they could argue that your work is similar enough to sue, but open source it makes that hard. If you copy their logo, or use their name, then they could argue you’re infringing on their trademark. Copyright is really the only danger here, and it would only cover things like their plans or that image.
There used to be, and some bot got a username and pmed everyone. There was some backlash so Ryan had to turn it off. You can mention someone in your personal feed, but anyone could read it.
I really have no advanced knowledge of any of this stuff. If you are going to make something posting it here is kind of burying it, thingiverse or something similar would be a much better options.
So, my current visualization has two feet at the base, wide enough to give a nice stable support. Finger joints to the upper portion should be good enough since I don’t see much side load on it. The three triangle pieces should have arms that make it so pivoting one pivots all three. That means (I think) that all three need to pivot in the same direction, as opposed to the example. The center need to dial down to no more than 11mm (typical cue diameters are 12-13mm at the smallest point), hence the thought about switching from the wheels to bearings.
The lathe is a Craftsman 113.228162, 12x37". The tube that forms the long base is 2 1/4" (actual measurement is 2.22" with my vernier). Height from table to center line is 9". That means the feet need to be at least 2.25" apart, so maybe 60mm? Height to center of bearings needs to be right on 9", 229.6mm. Widest piece theoretically could be 12", but realistically 3-6", maybe 100mm or so? As stated above the smallest needs to be no more than 11mm, the bearings can’t touch at center or else they’d bind, and it’d be nice to put a wide rubber band around each bearing.
My quick calc says that 40mm diameter bearings touch when the center shaft is just over 11.5mm, so the bearings need to be no more then 40mm in diameter, including a bit for the rubber band. Looks like this size might be doable at 35mm or maybe these at 37mm.
Hi Bill, sorry for the delay, sometimes every thing happens at once, had a busy couple of days.
A few thoughts,
Glad you decided against the skate board bearings, not only diameter but the rad on the perimeter would put a concentrated pressure on the cue marking it.
An opposite thought to the above has come to mind, a cue has a slight taper so the edges of steel bearings would put more pressure on the cue, (can’t win).
But you would need a fair bit of pressure on the cue or you could get chatter which may lead to splitting the cue.
I don;t think I have ever seen a steady rest auto center if I have understood you right, a normal way of setting up would be to hold the work piece with the tail stock while the fingers were adjusted.
Although I am quite happy to draw the parts, I think the end of the cue would be better dressed on a disk sander, a small jig taking taper into account.
I had a quick draw the other day pdf attached, the three circles are 60mm, the triangle/quadrant is just to see how things worked out, started with a 100mm triangle.
I have set up a temporary email that will be deleted at the weekend should you wish to contact me.
If you go back to the original image and turn that lower right side triangle plate around so they all pivot in the same direction you can place another pivot on the outer corners such that when you move one arm in all three arms are constrained to move the same amount. It ties in the the properties of a Reuleaux triangle. I’ve seen this used in other things and I believe it can be done with gears as well. I’ll look for examples, though this Youtube video is similar
How strong does it need to be? I guess if you where making the one from the original picture, could you do it with 1/4 cheap ply or does it need to be stronger? I really have no sense of the kind of loads this would experience.
You need an iris, use a three blade with small urethane wheels. I threw this one together in about an hour for a class my daughter was giving on photography.
Dang, lost my message by accidentally clicking on Josh’s picture.
Ryan, I believe the strength requirements are fairly small, 1/4" plywood would likely be fine. There should be next to no force acting lengthwise on the work piece, it’s end is fixed at the chuck. There should similarly be little force side the side since the pieces of the cue are already pretty well balanced and round. There is quite a bit of spinning force when you start or stop the lathe, but it should spin at a constant speed once it’s going. Ideally the bearings (wheels) would have very little stiction as you get things spinning so it would put as little load on the wood surface as possible.
Josh, that’s exactly the direction I’ve been going, though it took me a while to come up with the word ‘iris’ in my searches without having to wade though page after page of flowers. The design would either need to be clamped into position after running it in to the wood surface or be spring loaded to do the same thing, yet be easily pulled back open to allow the next piece getting inserted. When I make my MPCNC based CNC lathe I’ll revamp it to fit there instead, but for now I need it to work with what I have. Maybe when that’s done I’ll try to make a cue or two from scratch, but right now I need to fix the tip on my break cue…
Mechanical Iris is the term you are looking for. The spring loaded part wouldn’t be hard I’m just not sure what to use as a roller. I have a 113. Lathe as well and If a guy had a 3D printer I dont think a mount would be hard to come up with. I am currently traversing Montana for a V.A. appointment but if you still need something when I get home I would be happy to help.
I’ll just mention, because I don’t want to rain on your parade, that the arms moving in unison is going to create backlash. It will get you close, but you’ll still want to lock each one individually and adjust them each a bit. Once you do that, is it worth it for them to move together? Seems like the original design with three individual arms makes it a ton simpler.
I think you can still do this with skate wheels. Put the two bottom wheels side by side, and almost touching. They can be on the same mount. Make this part moveable up and down to center your work piece. Have the third bearing on a hinged lever arm above, and outboard of the bottom wheels. Can be held down with a bungie, or threaded rod. Probably easier than an iris. Save that for bigger pieces.
is similar, but older than mine.
