Why two types comm lathes?

[Brian]

Someone(s) can probably explain to me why there are separate comm lathes for modified and stock motors. ( and conversion kits) Is that necessary or is it marketing? Is there one that works on both?

[hpiguy]

Stock motors used to have sealed endbells to avoid cheating.

So the stock lathes were made to cut the comm inside the motor.

Now that the stock motors can be taken apart, the stock lathes are useful only for those of us that still have dozens of sealed motors left.

[J mAn]

also, the modified lathes will work with madified and stock because now most stock motors are rebuildable like mods.

[hpiguy]

That's what I just said.