Cutting gears - it's surprisingly easy

I have avoided cutting gears for years. I thought it would be a complicated business and wasn't prepared to invest the time and energy. However, I decided to bite the bullet and found that although the design of gears does involve a lot of technical details and maths, you only need to know a couple of things to successfully cut a gear in the home workshop. I dived into the metric Module system and found it quite easy to define and make some small spur gears that will give a 2:1 ratio.

[@aerocam2]

Nice explanation and many thanks for taking the time to shoot, edit, and upload this content for our edification. Thank you sir

[@alanshomeworkshop]

Thanks for watching and your appreciation of the video. Cheers.

[@MattysWorkshop]

Gday Alan, cutting gears isn’t that hard once you get started, I’ve made plenty of mistakes that’s for sure but once your in the rhythm it’s quite enjoyable, great job, cheers

[@ianbertenshaw4350]

Great job Alan ! Thanks for keeping it simple ! One could make a series of videos just to explain the theory and Math involved but for the most part we only need to know a few things which you showed .

[@alanshomeworkshop]

Thanks for your comment Ian.

[@paulrayner4514]

well done, something i've never done either.

[@alanshomeworkshop]

Thank you.

[@gregwmanning]

Welldone Alan, what depth of cut did you end up using for both the 30 and 15 toothed gears?

[@alanshomeworkshop]

Thanks Greg. I cut the teeth using formula DOC = 2.25 x Module ie 2.25mm for both gears.

[@f.hababorbitz]

Any idea why the cutter is running eccentric on the arbor?

[@f.hababorbitz]

I watched the cutting of the steel gear, and it does look like the arbor runs eccentric in your mill spindle hole. I have the same Vertex RT, and also the same accessories. I think my 3 jaw has much worse runout then yours.

[@alanshomeworkshop]

@@f.hababorbitz Thanks for your comment. The arbor and gear cutter were made in China. They were bought on price and you can’t expect more quality than you pay for. Runout in this setup could creep in from several areas eg bent or eccentric spindle, dirt between spacer bushes &/or cutter, eccentric bore in the cutter or unevenly ground teeth. Loose or eccentrically bored bushes can also make any arbor runout look worse than actual cutter runout. Some cutter runout can certainly be heard in my setup but it didn’t seem too bad to me and I didn’t attempt to measure it. I think the resulting gears will be good enough for the intended purpose. As for the chuck, it is branded ToolMaster and quality is probably mid-range. I would have preferred to buy a Vertex (Taiwanese) item but this wasn’t available when I needed it. Runout varies a little depending on which pinion is used for tightening but is usually < 0.003”. You might notice at 16:17 in the video the best pinion is marked with a black cross. It’s in very different league to the Bisen chuck on my lathe which has a third of the runout (~0.001”) - but at three times the price… Cheers, Alan.

[@f.hababorbitz]

@@alanshomeworkshop I put Bison chucks on both my import lathes. I also got lucky and got a Pratt Burnerd 4 jaw 12" off eBay. Major difference in quality on the fit of the jaws. I'm also of finite resources, and as long as the tool does it's job, it does not need to be the Cadillac/Rolls-Royce perceived quality name brand. I'm trying to figure out how to fix cheap ER collets, as the seller advertise 0.005mm runout, but the ones I checked are in excess of 0.03mm. Even the chuck side has excessive runout and different at the edge near the nut and the back end of the taper, and they are not even in the same offset.

[@michaeloliver3507]

DRAFTING/CABINETMAKING/METALS/AUTOS TEACHER FOR 45 YEARS AND I KNOW YOU SAID THIS IS YOUR FIRST ATTEMPT CUTTING GEARS, BUT YOU ARE CUTTING IN THE WRONG DIRECTION(CALLED CLIMB CUTTING) - SHOULD BE CUTTING TOWARDS THE CUTTER AND NOT BACKWARDS WITH THE CUTTER - IT WORKS ON THE SOFT BRASS BUT WOULD HAVE RUINED YOUR GEAR CUTTER ON STEEL - EXAMPLE: IT'S LIKE YOU WOULD NOT INSTALL YOUR TABLE SAW BLADE BACKWARDS SO THE TEETH WOULD GRAB THE WOOD AND THRUST IT OUT OF YOUR HANDS - SAME GOES FOR ROUTING DIRECTION - BAD FOR THE CUTTERS AND BAD FOR THE CRAFTSMAN - NEXT, YOU ROTATED THE GEAR ON THE SHAFT AND SAID "SPINS NICELY" ??? - GEARS RUN THE SHAFT AND ARE FIXED WITH A SET SCREW SO THEY DO NOT SPIN ON THE SHAFT - FOR YOUR NOVICE VIEWER'S IT'S CONFUSING INFORMATION

[@alanshomeworkshop]

Thanks for your comment Michael. My thinking for that setup was to direct the cutting force at the tail stock centre to prevent any possibility of the workpiece moving into the 3 jaw chuck. However, I wasn't aware that climb milling was bad for an involute cutter and I will take that advice on board. You might be interested to note that in a later project to machine a steel gear I did advance the workpiece into the cutter: kzbin.info/www/bejne/qX_En5ato5ersKcsi=TRPOvVAKa7TKZ1J9&t=199 Cheers.