Honing cylinders

Interested in details. Jim W. responded on thread

Details and/or pointers to info. would be of interest.

When I was a youth there was L.H.Sparry's "The Amateur's Lathe" and it did mention honing - but I never got anything like that far. If I recall the mention was copper and fine grinding paste.

[I am used to using fine diamond paste on a felt nap to polish metallurgical cross-section samples to a mirror finish before micro-etching to reveal the internal structure]

Point about hydraulics - need to be very smooth but seals can take up some out-of-round and slightly varying size is interesting point...

Rich S

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I posted the little that I know, from being shown and told rather than hands-on experience, I simply use fine auto body sandpaper of up to 1000 grit. I do have experience with polishing and etching metal samples from college. They gave much hands-on training in technique, such as glass-blowing to make custom equipment. Then the Army officially taught me shooting and electronic soldering.

I grew up on the edge of town next to an area still sufficiently rural to practice with a BB and .22. In Basic they started by observing how good a shot we were already. The man to my right was a "hick" who didn't understand running water but sure could shoot, so after he rapidly knocked down all the

300 yard targets the Sergeant silently moved behind me to watch. I more or less repeated his performance and the Sergeant just remarked "You damn hillbillies" and moved on. That was my entire rifle training though we fired over 2000 rounds at reactive targets with only safety supervision. Under stateside conditions the M16 was 100% reliable. Later I was issued a .45 pistol with absolutely zero training.

When I was a youth there was L.H.Sparry's "The Amateur's Lathe" and it did mention honing - but I never got anything like that far. If I recall the mention was copper and fine grinding paste.

------------------------- Lead works too, and can be cast to an exact fit to a difficult surface such as a rifled gun bore. In general the grit is pressed into a relatively soft material which can be cast iron or mild steel, and the harder material will be cut faster. The grit is sorted by size by mixing in thick oil, shaking and letting it slowly settle.

The standard advice is to avoid grinding or honing on a decent lathe because their exposed ways are too vulnerable to abrasion by stray grit. On a surface or tool grinder the ways are covered which limits the motions they are capable of compared to a lathe.

The first small cheap used lathe I bought had up to 0.025" of wear on the ways near the chuck, which varies tool height more than cutting diameter. I used a machine shop night class to mill them straight and flat again which lowered the half nuts out of good engagement, and reserve that Sears AA lathe for cutter grinding, polishing and drilling small deep oil holes as it's more easily stripped apart to clean and spins much faster than my 10" South Bend. I could maybe shim the carriage back up to original height with brass stock but the South Bend with collets is so much better for threading and even very small work like custom 0-80 screws for optics. I needed slotted fillister heads to recess and 1-1/4" length.

With a Dremel the AA cut the teeth on the hollow circular counterbore that opened up space around the broken-off-flush M3.5 case screws in plastic bosses on the battery pack of the scooter, allowing me to heat the now protruding screws with a soldering iron to soften the plastic and enable unscrewing then with needlenose pliers. That job alone may have repaid the lathe's cost.

.45 auto has some kick, as I experienced. Doesn't hurt your hand, but comes way up on the recoil? Given one with zero training - would have been an interesting first practice session?

.45 auto has some kick, as I experienced. Doesn't hurt your hand, but comes way up on the recoil? Given one with zero training - would have been an interesting first practice session?

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I never fired it. I have later, accompanying my boss at his invitation to the class for his MA pistol permit, and grouped well enough with it to unintentionally embarrass him when he ran out of white target bullet hole pasters, asked to swap sheets, and noticed that I had run out of black ones.

There are hones that theoretically can be adjusted to hone to a specific size. I do not know how straight they hone over a long distances, but I would assume they are only intended to grind a few tenths. I have one I used to hone the bore on my KMB1 mill when I bought a new quill/spindle that was tight in the bore. I had no access to a cylinder grinder which I assumed would have been the correct way to size the quill.

I can't imagine trying to remove more than a few tenths with one of these adjustable hones, but it did resize the sleeve inside the head. I think I wound up a tiny bit over sized in the end, but it worked well enough. It didn't result in out of spec parts for the machine. To be fair the manuals for the machine says it should hold .003 or better, but until I had mechanical failures in the ballscrews it tended to hold about .001 over its length of travel as long as I kept parts cool.

Since the stones do wear away your mileage may vary. I just went slow and checked fit as I went. I cleaned out all the grit and relubbed it a dozen times probably before I was done.

I can't imagine trying to remove more than a few tenths with one of these adjustable hones, but it did resize the sleeve inside the head. I think I wound up a tiny bit over sized in the end, but it worked well enough. It didn't result in out of spec parts for the machine. To be fair the manuals for the machine says it should hold .003 or better, but until I had mechanical failures in the ballscrews it tended to hold about .001 over its length of travel as long as I kept parts cool.

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When reconditioning a hydraulic pump to the tightest tolerances I could manage I found that raising the table instead of extending the quill held bore diameter better.

Of course it does. Less stick out and less flex. Same thing on a lathe. Heck its the same principal as using a screw machine drill instead of an air craft drill. Its shorter and stiffer. I wasn't talking about that. I was talking about that there are hones that ARE designed to hone to a consistent diameter. There is one in the bottom drawer of my big roll-a-way right now. One I actually used to hone a cylinder to an "exact" tolerance fit with a "piston" (the quill).

Another advantage to using the table instead of the quill is if the head isn't in perfect tram your oval bore will still be straight from top to bottom.

The entire team were total incapacitated one early weekend morning, simultaneously falling about the place laughing...

Radio message: "Butts to firing point; we are running out of white stickers".

[the implication is that our shooting is hopeless (the middle of the target where you are supposed to hit is black - after identifying the shot you cover it with a little round black sticker - so the next shot is obvious as being the only hole in the target. Obviously if the shot hits the white surrounding the target you have to put a white sticker on it - so the next shot makes the only hole in the target (you shouldn't need many white stickers))]

My own personal best, butts to firing point radio message: "It didn't hit the target, but we know it went between the target and the mantlet" (berm, earth bank, whatever you want to call it). So that's under the target. How did they know that? I soon found out. When in the butts a round going past supersonic half a metre above your head is unmissable with that supersonic "crack" :-)

The entire team were total incapacitated one early weekend morning, simultaneously falling about the place laughing...

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Was that British Army training? I've lost track of what you used after the Lee-Enfield.

Was a club - target shooting. NATO 7.62mm To be honest I improved a lot using an air rifle, where at less than a penny a shot you can do a lot of refining your technique and trying to get groupings first. Then adjust your sights so you are on target.

22LR is common here for "small bore". Also very cheap per round.

Problem is in crowded country - not many ranges where can use 7.62mm. Power to go through brick walls, enormous distances if "negligent discharge" and high likelyhood of landing in a residential area, etc.

NATO 7.62mm and Lee-Enfield .303 are about equivalent I believe. Funnily enough, never tried .303 In US tried a hunting rifle with .300 (?). Because of being a hunting rifle you have to carry long distances it is light. So the "kick" - wow! Heavy target rifle softens the recoil using the just about equivalent (?) NATO 7.62mm