Building a Gear Shaper 

Thanks! The only thing I'm slightly concerned about is that the rack and pinion gears on the quill are not that big and probably not designed for this type of use. That's why I used the shear pin. I'm probably being over cautious though and it will outlast all the use I'll ever need from it.

@@AndysMachines I agree. The rack and pinion gears will probably wear out first (after a LOT of gear cutting). Maybe a bell-crank arrangement at the top of the spindle driven from your new reciprocating arm could drive the spindle up and down directly?

@@chrisarmstrong8198 Good point. Not sure how the bellcrank would be fitted, but I was thinking of a piston. Could you elaborate?

funny you said this. I could watch this all day. a 15 part series sounds fantastic :D. Andy always delivers!!! TIA, Greg

I never actually went anywhere, but time flies!

Thanks! Yes I am. In fact I need this machine to make some of the T-800's gears.

It is! The problem is it needs a specific cutter for each number of teeth, and the geometry is much more complicated. A shaping cutter (which looks very similar) will cut any number of teeth, like a hob.

Yes, that method would be similar to using a regular gear cutter on a milling machine and indexing the blank, whereas the pinion cutter is more like cutting a gear with a hob. The pinion cutter is more complicated to make, but has the advantage that it will cut any number of teeth. The one-tooth cutter might be better for larger module sizes, as only one tooth is being cut producing less force on the cutter compared to multiple teeth being cut at once.

@@AndysMachines ja Yes!That idea you are moving to now is way more professional. It ticks a lot of boxes. One is practical setting up the gear for runout before starting. You only have to deal with one plane instead of milling which has three. Two, overall rigidity. Instead of cutting something on a abour you are cutting into the table. 3, by setting feed rate slower (more cuts per tooth) equal less force and better accuracy. 4, cutter runout becomes neglectable for generating with 1 tooth cutter. 5, you will always get close to perfect involute profile instead of form cutters that's involute is only correct for 1 count tooth for that specific range. That alone in itself is why one doesn't cut professional gears on milling machines. 6 form cutters involute profiles typically vary from standard generated gears so it's not a good idea to mesh milled gears with 99% of all gears found in a gearbox. 7. now you can start experimenting with complex internal generating profiles like internal square with almost no radius. You're making the gear cutters jealous now. Actually generating with a mill wow!!! Cant wait to see more

I have made and generated with single point cutters if you are interested to see how good the results are? Its totally worth it for various reasons.

Yes, I did think about doing something like that and other people have mentioned this too. But for now at least it's unlikely I'll need to change the stroke for the gears I want to make.

I chose a stroke length to suit the type of gears I want to make, I probably won't need to change it, if I do the only way is to shorten or lengthen one of the lever arms.

That's an interesting opinion, most people tell me to give up with skiving as I'll never get good results with home-made equipment! The main problem I have with skiving is making the cutters to the correct geometry, there's much more to it than a hob or shaper cutter, plus with skiving you need a different cutter for each tooth count whereas with hobbing/shaping it only takes one cutter. So far the results I've got from shaping are much better, though the cuts I'm taking seem to be consistently shallower than expected, due to rigidity/ deflection issues.

@@AndysMachines Yeah, i can understand the issue with grinding your own skiving cutters. I've just never had an easy going experience with gear shaping so i would rather put in the time to research, reverse engineer and calculate a parametric formula for the geometry to make my own skiving cutters than to work anymore than i absolutely have to with a gear shaper

I usually make a broad plan to start, but it often evolves as I build it. Usually it's steered by the parts and materials I have available. You'll see in part 2 how the control system evolved.

Thanks! It's actually capable of applying a downward force on the cutter of around 6000N (~600Kg) in the middle of the stroke. This would possibly be enough to strip the quill gears but hopefully the shear pin would go first. I don't know how much force it actually takes to make a cut, but considerably less, even when cutting steel the motor doesn't appear to be under much load at all. Using the Z motor (Nema 34 stepper) would be much slower, have less force, and also there would be more backlash as when using the quill I lock the head to the column.

Yes, I did make sure it was all well lubricated when I reassembled it. The quill is easy to lubricate in use, but the rack and pinion gears are not so easy to get to without pulling out the gear shaft.

@@AndysMachines ah yeah. Maybe a little oil dripper above the pinion?