Gear Cutting Demo

Hosts:   ToolCraft & Gene Neighoff

 October 2^nd 2004

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The meeting was held at ToolCraft, special thanks to Bob and sons for having us over again. Meeting began a little after 9:00

The discussion of gears commences and started with primer on gears. 

Gene emphasizes a point.  (Why do all these demos feature a box of doughnuts on the presenter's table?)

I am amazed at the diversity and experience that we have amongst our members. Even those with no formal machining experience have a wonderful grasp of the topics at hand. The theory and discussion portion of this demo lasted about an hour.

Gene had some very informative handouts on the formulas and terms used in the process on manufacturing gears. A discussion of different types of gears and how the transmit power was spawned from a pretty technical question and answer session. 

We paused at 10:15 before proceeding onto the demonstration portion. At his time we took the opportunity to introduce ourselves and provide some background for those that are new to the group, or may have forgotten like myself.

At 10:30 most of us had gathered around one of Toolcraft’s manual mills to inspect the setup and ask questions before the gear cutting commenced. 

Bob Sanders had one of the ToolCraft guys make up a cutter on an EDM machine and had it installed on an arbor, ready to go. I believe Bob explained that the shape for the cutter was pulled of the computer. 

The Delrin blank used for the demonstration was mounted in an indexer. The indexer was mounted to the table of the mill. Bob covered the proper use of the indexer in this operation. A great deal of interest was focused on the method for choosing which plate to use and which holes in the plate are chosen. While everyone was amazed at this Bob just said “We looked up on this” and produced a sheet of paper with a table of numbers on it. The last time I saw table that big was when I filed my taxes! Indexing is something that still puzzles some of us, Bob makes it look so easy. J

By 11:10 or so we had covered as much as we could for a basic demonstration. Gene had explained earlier that gear cutting is covered in most schools over a four or five week period. We really covered a lot of material in 3 hours, now it was time for,

Show and Tell......

This RC car looks to be a bit more complex than the standard Radio Shack® variety!  

Owner  Bob Harbour provided some details: It's a small three wheeled, differential drive car that was built for developing motor controller software for a larger machine.  The big one is big enough to break things if the software wacks out, but this little one will only annoy the cat or beat up the baseboards in case of unexpected software "features".  Both motors have shaft position encoders to support closed loop motion control. It was also a good excuse to play with some little flanged ball bearings and toothed belt stuff. 

Tom Jenner brought a cutaway of a chainsaw in a wooden case. This was very nifty, I can’t believe the work that went in to making or unmaking this piece as the case may be. You could see the piston, cylinder, bearings, journals, I mean everything. This was very nice for me as I have been working on some small engines lately.

 Tom Davis brought his laptop and some software he picked up on EBay. The software was oriented for the beginning machinist. I believe the title was something like “So you bought a mill, now what !?” He also had a version for the lathe with of course a similar title. He offered anyone the opportunity to browse the cd’s and see what they thought. I found them to be pretty handy and am thinking of sticking on of my old pc’s in the shop. Being able to reference that kind of material on cd is a great benefit.

 At this point noon was fast approaching and it was time to cleanup. Thanks again to Bob and the guys at ToolCraft. It is really nice to have a large place to meet, and especially like seeing the CNC centers knocking out work. 

Unless otherwise noted, images by Neil Butterfield, the bulk of the text of the meeting was provided by Scott Brown

Updated 12/01/04