Constructing a gear (with more improvements).

Post by **FixitMike** » Tue Sep 15, 2015 5:22 pm

This is the same as I've posted before, except that the radii representing the tooth surface are constructed in a more elegant manner.

These instructions are for a 14 1/2 degree pressure angle gear. If you want a tooth shape that is stronger use a 20 degree pressure angle and an addendum factor of .8.

Drawing a gear in Aspire or VCarve Pro.pdf: (302.29 KiB) Downloaded 265 times

The following file describes various gear racks. The outlines shown are for a 1 DP rack. Copy and reduce the size by 1/DP to use for other pitches.

various gear racks.crv: (396.5 KiB) Downloaded 263 times

Post by **dhellew2** » Wed Sep 16, 2015 6:47 am

Thanks Mike.

Every bit of information helps.

I recently started working on gears and at my age it has been a real mental challenge, not so much the gears themselves but with the applications... tickers, clocks, etc.

In addition to the gear gadget there are a few gear programs out there, some free, some at a modest cost. So far the best one I've found is Gearotic2. This is written by the same man that wrote Mach3 [Art Fenerty] and has the same licensing as Mach3... you buy it once then get all the updates, video tutorials, etc. forever free.

Art Fenerty and Bob Landry are very responsive to questions and like Mike, very knowledgeable and helpful.

Gearotic2 creates gear trains, outputs the gears and shafts to several formats.

I am importing the output dxf files into Aspire, making them ready for laser engraver cutting and CNC

Dale

Post by **mikeacg** » Wed Sep 16, 2015 1:03 pm

Thank you Mike and Dale! I need all the help I can get with this!

Mike

Post by **FixitMike** » Wed Sep 16, 2015 3:57 pm

As I have pointed out before, the gear gadget draws gears with sharp corners at the bottom of the tooth profile. This doesn't work well with CNC routing because profiling leaves a radius in the corner that can interfere with the mating teeth.

Post by **dhellew2** » Thu Sep 17, 2015 6:17 am

Mike is correct but there are ways to compenste for the tooth mating problem... backlash allowance, smaller bits, cutting deeper corners, etc... use a laser.. and if you are real serious about learning look into gearotic2 video tutorials
http://www.gearotic.com/GUItutorial.html
Dale

Post by **garylmast** » Thu Sep 17, 2015 12:42 pm

Dale is right about compensation. When I modeled my gear mechanism, I planned on using 6mm mills when I drew it, but when I started calculating the tool paths in Aspire, it was off enough that I had to use 3mm mills which took twice as long. In Aspire, a 6mm mill won't fit in a 6mm slot, it has to be a fraction larger. http://forum.vectric.com/viewtopic.php?f=29&t=23170 Gary

Vectric Customer

Constructing a gear (with more improvements).

Constructing a gear (with more improvements).

Re: Constructing a gear (with more improvements).

Re: Constructing a gear (with more improvements).

Re: Constructing a gear (with more improvements).

Re: Constructing a gear (with more improvements).

Re: Constructing a gear (with more improvements).