Milling long stock between centers

[C_Wilkes]

Thanks for the ideas.

I was just curious if anyone was doing it in any way I wasn't aware of.

At the moment the parts in question are being single point planed. I don't think grinding is a feasible option. These are made in runs of 50.

Thanks

[Harold_V]

Grinding would be one of the slowest processes to turn a round bar into a hex or an octagon. Could be done and has the potential for a better finish than milling, but might take 20 times as long (or more). Just as drilling is faster than milling, etc.

You apparently have never witnessed a large Blanchard grinder in action.

Harold

[Harold_V]

reconditionned long Cylindrical grinder tables told me that using a shaper was the only way machine long surfaces and inducing minimal stress.

A clear misunderstanding of the problem at hand. While it's possible that stresses can be introduced, what typically happens in machining is internal stresses that are introduced to the material in the manufacturing process are relieved by metal removal. If you don't think that way when material is removed, there is no end to the problems you can experience.

When movement is an issue, parts are generally fully roughed before any finish cuts are taken. The vast majority of stress is eliminated by that process, yielding relatively stable parts.

Harold

[Jose Rivera]

I think that the logical thing to do is to drill the hole first and the using the hole as center, machine the hex/octo, assuming that there is stock to spare on the outside.

[Gerald C]

I just got done making my own tapered barrel. you buy a barrel blank of the proper cal. then I put it in a four jaw chuck on my lathe and dial it in using a pin gauge in the bore. to the nearist .ooo5" then using a spyder on the other end of the spindal dial the other end in then go back and forth until both end are runing true. now turn a true to the dia. on the barrel where the breach is. ( both ends have been centers bored before they were rifled ) I then put the turned end in my dividing head and the other on the tail stock on my mill. dailed the chuck end to turn true to the turned dia. then dailed the whole lenght of barrel to be parallel to the mill . dailed the tail stock up to put the taper I wanted. then was just a matter of makeing one pass at about .010" re index make next pass. on and on till done. used jacks and clamped but It would leave marks on the barrel as I removed and re placed clamps as the mill went by. It was very time consuming but I got it done. came out perfect. I had to draw file it for final finish before I blue it (30" blank 1.3" dia. finish 1.090" taper to .950" at 28" long for 38/50 black powder remington Hepburn) Had to see if I could do it for the first time, time is nothing for me


Gerald C

[Richard_W]

Thanks for the ideas.

I was just curious if anyone was doing it in any way I wasn't aware of.

At the moment the parts in question are being single point planed. I don't think grinding is a feasible option. These are made in runs of 50.

Thanks

Actually a planer was my first thought, but I didn't think you had one to use.

Richard W.