Wednesday, September 06, 2006
Simple Shaft Connecting Cheats - "SSCCs"
This is a 3D render I made of some real world test parts I've fabricated.
The brass item at the top is a small brass pipe into which I inserted a stiff rubber hose. In the rendering I've shown it in cut away to reveal the two shafts embeded in it. It took a fair amount of force to shove the roughly ground down end of the 1/4 inch threaded rod on the left, and the ground down cordless screwdriver bit on the right side.
Note that neither is of the same size, the rubber hose acts as a very forgiving adapter. Also, note that the hose is shorter than the pipe so it can't catch on the edges. It will then be pushed deeper into the pipe from both ends, increasing compression.
Next we see a spring wrapped around the same rubber hose, not sure how good this is, as rotation direction may affect this one. Also the spring doesn't transfer torque quite as well as a solit tube, but it sure works better than plain hose. Maybe more cheating could help, like wrapping tightly with PCV tape.
That BTW is another quick trick, just tape the hose before inserting shafts, if nothing else is available. Alternatively, tape can be used to pick up the slack between the outer diameter of the hose, and the inner diameter of the pipe if they are not a snug fit. In a real pinch, rolled up paper works well!
Lastly we see a brass pipe split down one side with a length of hose inserted. Two small offset clamps and it can now handle a massive amount of torque compared to the original rubber hose, yet still be complient enought to forgive missalignments.
Although rubber hose works, neoprene and silicon hose may work better, as they seem to grip more. Cheaper clear vinyl hose will also do in a pinch, but it tends to slack off with time, so it's not the best option. You can tell it appart from silicon hose, as silicon is usually cloudy and kinda bouncy, like neoprene. Might be good for blocking the transfer of vibration.
I'm left to wonder, however, why you didn't just take a pic with a digital cam. :-)
I used my ancient copy of Cinema 4D, version 6.5 on my ancient circa 2000 AD dual processor workstation. Leftovers from when I was freelancing 3D graphics. I love tax deductions!
I did take photos, but I'm working on a small business scheme (not so keen on freelance now) that would have me get back into 3D. My spouse is working on a degree with a major in Frrrrrench, so we could produce written material and visuals in at least two languages, maybe a third with a bit of effort.
Still working on details. ;-)
Links to this post: