In that case bore the gear out, machine the shaft to fit, press on and tig the end.I'll have to turn off the boss on the new gear as the roller bearings in the apron are only 4mm from the gear edge so not sure I will be able to pin it
In that case bore the gear out, machine the shaft to fit, press on and tig the end.I'll have to turn off the boss on the new gear as the roller bearings in the apron are only 4mm from the gear edge so not sure I will be able to pin it
I think welding it may distort so loctite could be the way to goLoctite the gear on.
Design guide here if you want to calculate the torque it will resist: https://5.imimg.com/data5/AE/AX/JM/SELLER-2044578/loctite-retaining-compound-638.pdf
Look for GearDXF: http://www.forestmoon.com/software/geardxf/ It will ouput STL, and even do the keyway for you.
See also: https://www.thingiverse.com/thing:1802545 for if the gear is too big to print in one go.
@Pete. Ive found a firm online that will send me 1.25mod gears correct bore and keyway but only 24t and 30t but not cheap. Im going to see how the larger 3d printed ones work out as I can print the 96t 120t and 127t (for inches) they shouldnt be under too much strain and the test ones i did were hard to break the teeth with pliers2.You can use 20DP 20PA gears in place of 1.25MOD, they are so close to each other in pitch it makes no difference for a lathe changewheel. I think it's 3 thou difference in pitch IIRC.
I can do 'em, but I can't do them right now. Got lot on my plate at the moment and I still have a set to finish for someone else. I couldn't do the keyway until my mill is finished anyway as I don't have any metric broaches.@Pete. Ive found a firm online that will send me 1.25mod gears correct bore and keyway but only 24t and 30t but not cheap. Im going to see how the larger 3d printed ones work out as I can print the 96t 120t and 127t (for inches) they shouldnt be under too much strain and the test ones i did were hard to break the teeth with pliers2.
Did you say before you might be able to do some of the smaller gears for me ? could you bore to correct size and keyway too ? its a weird keyway for 18mm as its 4mm im sure normally its larger
@Pete. Cheers pete i just thought I would check before i ordered themI can do 'em, but I can't do them right now. Got lot on my plate at the moment and I still have a set to finish for someone else. I couldn't do the keyway until my mill is finished anyway as I don't have any metric broac
Yeah prices are really good actually I'll send him a message tomorrow to see what he can do for meAnother option is delrin. Look on eBay for you_engraving . His prices are good and the quality is excellent.
Im looking at loctite now but have calculated I should just have enough room to pin it on , I dont want to risk distortion from weldingLoctite the gear on.
Design guide here if you want to calculate the torque it will resist: https://5.imimg.com/data5/AE/AX/JM/SELLER-2044578/loctite-retaining-compound-638.pdf
Look for GearDXF: http://www.forestmoon.com/software/geardxf/ It will ouput STL, and even do the keyway for you.
See also: https://www.thingiverse.com/thing:1802545 for if the gear is too big to print in one go.
Especially if you keep the fit tight.Welding that gear to the shaft won't bother it unless you go silly. A couple of small welds will hold it forever.
Or a "French key"? Assemble gear and shaft (with loctite if you want), drill in line with the shaft, along the join between shaft and gear, knock in a Suitable Pin. Works best when gear and shaft are similar materials/hardness.Im looking at loctite now but have calculated I should just have enough room to pin it on , I dont want to risk distortion from welding
...if you decide to go loctite and taper pin...
I have thought about that too , im going to get the shaft turned to size and the gear then make a decision on how to fix itOr a "French key"? Assemble gear and shaft (with loctite if you want), drill in line with the shaft, along the join between shaft and gear, knock in a Suitable Pin. Works best when gear and shaft are similar materials/hardness.
Dave H. (the other one)
I dont think I will taper pin it as they have been such a pain to remove on this lathe so far , on 3mm pins the difference from one end to the other in some places is only 0.1mm easy to whack the wrong end.I wonder who would use a taper pin out of choice these days. A roll pin (sellock pin) is so much easier. No faff with special drills and reamers and multiple cut-and-try efforts. Dril a hole the nominal size of the pin, bash it in and walk away.
In this particular application, the pin would need to be 90 degrees to the axis of the shaft (i.e across the gear). It could not be axial as it would be going into a blind hole making removal impossible. That is why the grub screw is used in your photo as there is only access to one side of the part - you cannot get to the back to push out what you have installed.