First off turn the dowel so that you have a length that is the same as the cylinder you want to hone, reduce the diameter after the turned diameter to allow you to pass the dowel right through the cylinder. Now you can slot the dowel and as the diameter behind the lapping part is smaller you will get the springing action you need for pressure on the internal wall of the cylinder.

the coarse and fine lapping grit will be embedded in the dowel so maybe make two dowels ffor the differnt grits.

I would advise against any cloth, close to a rotating shaft. Use paper/tissue instead for safety reasons.

I am a little surprised that one would chuck the lap & hold the cylinder. Surely, as the cylinder , often being of irregular shape would be better in a 4 jaw chuck. Then if something jammed it is just a round lap that slips in the hand & not an irregular shaped lump of metal. Worse still if one then dropped it.

Of course it should never jam, but bad luck( put that down to inexperience) happens

I only ask out of interest, having never tried.

Edited By Sam Longley 1 on 25/06/2021 16:42:49

Depends on how you cut the lap, you can do a length wise slot almost all the way through and half way axial cut then drive a long wedge into the side rather than a short one in from the end. I I mostly make metal laps and have not used a wooden one for quite some time.

That's one reason why you hold the cylinder – you can swap it end for end regularly so you get a more even lap rather than a bell mouthed end.

Holding cylinder also means you don't get any lapping past coming out the back and running all over the chuck.

I actually find it easier holding an odd shape than a round one once your hands are all oily, infact for finned round cylinders I tend to stretch a bit of inner tube over them to save your hands. Same for honing I tend to hold the cylinder and run the hone in the pillar drill most of the time then muck just drips out the end and straight down where it won't muck anything up.

My method of lapping my Lion cylinders seems to have attracted some criticism, which is fine, I'm always happy to learn from the experience of others.

While lapping my cylinders I didn't experience any significant torque applied to my cylinder, should I have let go of the cylinder there would not have been any possibility of the lap jamming or gripping the cylinder and have it flying around, the weight of the cylinder alone would just leave it hanging on the lap. In any case I was being very careful through out the process and didn't get any lapping compound in the chuck.

There are commercial honing machines where the part is held by hand, I would expect honing will be much more aggressive than lapping, at least in my case anyway, with much more torque applied to the part.

Regarding the cloth, well it was felt actually, that's a fair enough comment. The felt was packed inside the plastic tube to expend it with no real risk of it flapping around and getting caught in rotating machinery, but all the same with hindsight not recommended.

Cheers

Nigel

Jason,

what speed do you run the three legged hone? Min speed on my pillar drill is 500 rpm