For ball bearings, a "suitably large hole" would have a tolerance on the order of .0002", not something you get with a drill. The holes are drilled undersize and then bored to size. You can increase this tolerance a bit, if you Loctite the bearings in, instead of pressing them. But anything over .001" could lead to sloppy gear mesh. As Art points out, the most important thing is the center distance between two gears. Too close and they bind; too far, and they get ratty. A 32 pitch is pretty good for any indoor winding. Class of gears also is important, but you don't need super gears. Most nylon or Delrin gears are molded and fit in one of the lower classes. They still should be fine and are what A2Z uses. Phenolic gears are machined and are quiet like nylon.
If you make a winder, it would be best to mock it up using a milling machine with a digital readout and fiddling with center distances until the mesh feels good (just outside of binding). Two plates on standoffs works fine.
Ray
--- In Indoor_Construction_at_yahoogroups.com, Tapio Linkosalo <tapio.linkosalo@...> wrote:
>
> On 14.3.2011 15:28, art wrote:
>
> > The 32 and 48 refer to teeth per inch (pitch).
>
> teeth per inch of the gear wheel circumference?
>
> > I use nylon inserts in polycarbonate (Lexan)frames, but I'm using chains
> > and sprockets, not gears, so if any wear does occur in the bushings it
> > will have no effect on the mesh...I'll still have 5 or 6 teeth engaged
> ...
> > ball bearings. K&P use bronze bushings and coarse tooth gears to counter
> > the inevitable wear, but that's why they get ratchety under load after a
> > while.
>
> Actually ball bearings are maybe even easier to use, just drill a
> suitably large hole and drop in the bearing.
>
> > We know you're capable of precision machining, and if you are going to
> > make a top grade geared winder you'll need all your skills.
>
> I was simply planning of using a press drill (is that the English word
> for the machine that makes vertical drilling?) and make the body of the
> winder from either two plates bolted together, as you have done with
> your winders, or if that turns out to be to unstable, use a piece of
> aluminum square tubing for the body.
>
>
>
>
> -Tapio
>
Received on Mon Mar 14 2011 - 11:00:45 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:46 CET