Need a piece of rack gear, may be 5" long, curved to be a section of say 16" OD circle - so that the teeth are on the inside of the arc.
Do they sell something like this in US ? I reckon bending regular straight rack gear into something like this is not possible .
May be 6 teeth per inch, 1/4 tall.
Not as a stock item.
It'll work just fine for large radii. I've done it on a much larger scale for a punch press feed that needed a powered angular axis. Two identical pieces of rack will mate face to face if you want to roll the arc and don't mind sacrificing a piece of rack. O O
Standard 24 DP (about 7.6 teeth/linear inch) rack is 1/4 x
1/4.Ned Simmons
Try
don't you need some kind of internal gear? how about gluing some kind of tooth belt to the arc and driving it with a tooth belt gear? what is this used on?
Cut a starter ring gear of of an automotive flex plate and heat it up to make the bend you want. You can use the starter bendix gear to drive the new gear you are creating. I have used starter ring gears for several rack and pinion projects .... cheap , quick and nasty!
Pete
Cheapest way to go is to thoroughly degrease some bicycle chain, then weld that on the inside of your ring. Use bicycle pinions to match it, of course ..
GWE
Would you believe
Most interesting idea indeed !
What it is used for is a shear used to cut blue steel, in making of accorion reeds. It has a L-shaped stationary RC58 bottom with moving straight upper blade - this way one can cut both the length of the reed (.4-3") AND the shoulder (typically
1/32-1/16 wide), in one cut, outta strip of blue steel_____________________________________i--------| _____________________________________ o |
i--------|
Now. to drive the upper blade, some kind of (hand) power transfer system is used. Typically a long handle drives either a gear or an eccentric. One needs some power to cut .032 blue steel - especially the shoulder.
When a gear is used, it drives a curved rack (attached to the upper blade) - thus the original question. Typically the distance from pivot point to the driving gear's outer edge is 8", so the rack would need to be curved with 16" OD.
Use of eccentric makes the whole thing much more compact - at the cost of friction-induced tear/wear on the apparatus :)
Any relation to Spacely Sprockets?
Interestingly enough, none of the links on that site seem to work for me in NN7, IE6. They work only in Firefox.
- - Let Exxon send their own troops -
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I guess I should learn to type with more than 3 f> > Try
It may not help but a cheap source of internal gears and matching pinions might be your local automatic transmission shop. Lots of planetary gearing that might be modified and adapted. Bigger ones from truck transmissions. Don Young
Brilliant!
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