antlu65 EDU

Activity

• 
  drjoe_johnson → antlu65

  Hi,

  Your gear lab FS is amazing in 10,000 ways. It is ALMOST what I need but not quite.

  I almost always modify my gears to make them better. We are printing or waterjet cutting or laser cutting gears now. There is no reason to stick to standard gear profiles in most cases. We have other things we desire more than the ability to mate with a standard off the shelf gear on a standard center distance.

  So… I typically play with the addendum, dedendum, and tooth thickness to give myself a gear pair that are better for the purposes I desire (of course I also play with pressure angle and other parameters but your FS and most other gear FS do just fine monkeying with those parameters). You latest Gear Lab FS ALMOST gives me what I want. Up to a point I can modify the Addendem and Dedendem but it is a bit clunky to do so. I could live with the clunk but then you limit the shifts such that I can't QUITE modify the gears as I want. BUT "root clearance" and "tip extension" (the clunky ways I modify Addendem and Dedendem) inputs are limited to +/-0.5 (modules) There are a lot of times where I need more modification than that (to make "equal strength" teeth or to have a silly small number of teeth on a drive pinion).
  
  So… my 1st request (and I know you are not asking for work to do but I am trying to find an acceptable custom involute gear designer for Onshape and your Gear Lab is the closest to what I want so I am starting with a request to you for these features) is to remove these limits to the existing parameters. Bonus points would be if you could go into a mode to make modifying the addendum & dedendum more direct. Maybe you can keep the root clearance but then have an OD and "working depth" parameters. There are 10,000 ways to skin a cat. I don't really need it to be exactly as I want it. But I do need to produce large changes from "standard" addendum & dedendum parameters.
  
  Request #2 is that I am not sure that the "side reduction" feature is really doing what I want it to do. In my past work, I had a script in Solidworks or other CAD package that effectively thickened or thinned the tooth while keeping the involute unchanged. Specifically it would still be an INVOLUTE and that involute would have the SAME BASE CIRCLE as the unmodified gear. In effect the entire involute curve that defined the "business end" of the gear profile would be rotated about the rotational axis of the gear I was designing to thicken or thin the gear. I am not sure exactly what your "side reduction" parameter does. Maybe it does the right thing or maybe it just offsets the involute face a constant amount which I am not sure is even an involute any more and even it if is an involute, it may not have the same base circle as the unmodified gear profile so then we are mucking with the pressure angles and that way lies madness. So… request my request would be to have a way to modify the tooth thickness that keeps the involute shape and the same base circle as the unmodified gear profile.

  Request #3 is not a huge thing but I really prefer to work in transverse plane when designing my gears. I know that there are some advantages to working in Normal Planes but I think a lot of that had to do with historically gear designers trying to using standard hob cutters to cut helical gears. We are not hobbing gears. The "rolling" of the gears is actually in the transverse plane. I can use trig to get the numbers to work out regardless of how you happen to paramaterize your gear generation but for me it makes more sense to work in the transverse plane. Potato - potato. But I would love it if there was a way to switch to traverse or if you simply switch to doing it my way (aka the correct way ;-)
  
  Request #4 I think there was something with the root radius that wasn't working for me and when I use unmodified gears, I would just default to Spur Gear FS because it handled them correctly and with your Gear Lab I would have to put the root radii on "by hand" I am sorry that I don't recall the exact situation. If you are interested in more on this bug, I will do some work to duplicate it for you and give you details.

  Thank you for reading this long message. Love your FS. Thank you for making it available.

  
  Cheers,

  Joe J.

  —

  Retired Gear Guy

  0

  July 27
• 
  antlu65 earned the Third Anniversary badge.

  Thanks for sticking with us for 3 years.

  July 3