I know I'm a little late, but if you use nitrile o-rings to stand off the linkage to prevent rubbing it helps make the motion feel really smooth while preventing that rubbing you mentioned in the video, it gives a nice damped feel that doesn't reduce your force feedback at all.
I might use shoulder screws for pivots. They are really convenient in that regard. Also, I find often that the dremel tool is not the right tool for the job, but rather the only tool you have that works for the job. Looking forward to seeing more.
Hey Josh, I may adapt some shoulder screws to be a little lower profile -- a lot of people seem to like them so it's probably worth a shot! I fully agree about the dremel tool -- there's the "right" tool, and the "right now" tool :P
Iv'e been thinking... Those articulated linkages look a bit 'flaccid' , I think it might be better to pivot the lever arm at the end (like the first infographic) but with the short linkage between the mid point of the lever and the end of the quill/Z arm, Set the lever in front of the linkage so it (the linkage) acts in tension. I reckon this arrangement would be more rigid and more sensitive.
How dare you call my linkages flaccid! Your name is Wobbly Bob! Just kidding. I see what you're getting at. I may try a lever setup like that on X, where space is much more limited. Good tip!
It's funny you say that, I'm a bit of a scrounger, and I have sooo many of those 3mm shafts! They are great, and they usually come with some tiny little bushings!
hlaps1990 And I'm also collect a bit . It is a pity that these bushings are extremely vulnerable. To take them out without damaging - not an easy task. I love how they mate with the bearings (installation size 3mm). Right plunger pair. Yeah, don't do the bushings, do a low-profile bearings!
I end up using shoulder screws as pivots for things like that. They are ground fairly precisely, you can thread it into the part itself so that you don't need a nut. I would then turn a bronze bushing for the bore that rides on the shoulder.
Here's a small suggestion - make a small, vertical(90deg), free-pivoting(vertically) handle for the Z actuation, so you don't have to work way down at the table level. Would also allow for much finer movements using a few fingers.
2:10 spiral lock rings, they'll at least look better then the E clips, and they're usually super entertaining watching people approach nervous breakdown while trying to install them!
If you want inspiration for linkage / mechanism ideas check out thang010146. 30-second CAD videos of every mechanism imaginable. Stuff only an enginerd could enjoy.
Its usually better to buy something that already exists instead of making one. That being said, making things is just as enjoyable as using them for me :)
You can buy pull dowel pins. They are what I was thinking about making. If needed they could be cut to required length. www.essentracomponents.com/en-us/fasteners/fastening-pins-sets-accessories/fastening-pins-sets/dowel-pins-pull-dowels/pull-dowels-smooth/pd-100
hlaps1990 you can also buy round stand-offs that are tapped on both sides. Depending on how hard you intend to push on the lathe, you could use nylon stand offs to give yourself a slightly lower friction pin. McMaster might have stainless ones, I've never looked.
Aviation standard for linkages is drilled bolts with castle nuts and cotter pins. I would recommend this over a clevis/cotter arrangement as it allows the adjustment of tension in the mechanism. If this seems like overkill (very likely is), you could use small threaded bushings at every joint with retaining screws in the ends, like what you did with the z slider. PS 3d printed handles would be super cool
CNC as a verb, forgivable (just)... FUNER! who learned you how to talk England? :-) Sholder screws for the pivots. Counter bores for the heads if you have enough metal.
Did I say "funner"? Good catch :P That's a fairly common one I think. One that I reallllly can't stand is when people use "lathe" as a verb. Latheing. Makes my blood boil.
Sailboat rigging bolts might be good and functional. The mast on modern sailingboats are secured with thin steel cable. At the deck level there is a mechanism that puts tention on the cable. You can buy the pins used in this mechanism. In my hardwear catalog (euro version of shars/ harbor freigth) they are listed from a quarter inch to half inch, and larger sailboats use pretty long ones. The exact dimensions (length) is not listed, but large ones should fit your parts. To make a nice looking clip super fast you can cut the tip (and maybe the head) off a brass nail they use in upolstery, give it a quick polish, slip it in the hole and bent the protruding end in an artistic fashion.
This is very intriguing, I'll have to look it up. This is why I love asking questions publicly, you get so many different perspectives! Sailboats hardware wasn't even on my radar!
hlaps1990 Hi! I’m glad you find my suggestion worth while looking into. I used google translate to find the english name of the rigging component, and the correct term should be a turnbuckle. The pins are of good quality, since they must resist both stress and wear in a salt water environment. The clips are too big for this use though. They are dimentioned to keep the mast secured in a hurricane or storm, and look the part (i.e. bulky and cumbersome). I think the pins themselves look really good though, and they should be available in many different sizes off the shelf in a shop.
