Broaching Keyways with the Lathe

[olderdan]

Pneumatics is a more logical approach, I did not pursue my original idea as for my limited use it was not worth the effort.
Would still be interested in seeing your set up some time as I am sure it would make a good post.

[tonyfoale]

Pneumatics is a more logical approach, I did not pursue my original idea as for my limited use it was not worth the effort.
Would still be interested in seeing your set up some time as I am sure it would make a good post.

Alan, It is on my list to make a post, but my list is very long and seems to be growing faster than I can find the time to write them up.
Next time that I set the slotter up I'll take some pix and maybe make a video.

[ncollar]

That would not be too hard. Just make a slide valve to change the direction at the end of stroke. I kind of like the air idea.
Nelson

[marksbug]

that gives me an idea for air stroker on my sunnen rod hone to make a power stroker for my air cooled cylinders. thanks as always guys!!! different perspectives and ideas are what drives evolution forward.

[tonyfoale]

that gives me an idea for air stroker on my sunnen rod hone to make a power stroker for my air cooled cylinders. thanks as always guys!!! different perspectives and ideas are what drives evolution forward.

If you put an adjustable needle valve or similar in the air line you'll be able to change the stroke velocity and hence the helix angle of the honing marks.

[marksbug]

yes I already was thinking that when I was reading the other post.basically a regulator.and of corse a foot operated switch so it runs as the hone/machine does, so there is no over speed of the stroke when load is removed/eazed up...possiably even a 2 stage air supply.one to stroke at the right speed with no load and another to keep the same speed with the hone loaded...that shouldent be hard at all. And the direction change valve can be moved to vary the stroke length. i had already ordered some linner bearing's&shaft&mount's for this, but had more thinking to do..as always. dont know when Ill get to doing it, Im working on selling all the racecar stuff now for a lot more room in the shop.and as always, more stuff in my head that I have time to do...it's a curse.Ill be working 50 years after Im dead.

[Cascao]

Have seen this "conecting rod" one on facebook
https://www.facebook.com/merv.harris...5967129784510/

[ncollar]

Paul
Very nice work and love your set up. The thing that bothers me the most is the number of strokes and the wear on the saddle and bed.
In a pinch it works.
Nelson

[marksbug]

my new lathe ( new 2 years ago when I got it) enco 9x20. well the gear train was so noisey I skeered me...and I dont get skeered eazely. I got to checken it out and the gear bushings with built in protruding woodruf key to drive the gear so it could be swaped to positions where it could either be idler or drive a shaft. well the bushings had .014" run out....yup thats a lot. there also pretty thin.so i put them in my smaller lathe and machined the center out in the center .030 biger,I then used a thinwall phosphor bronze guide liner(Kline, for relining valve guides in engines). that worked great on all execpt for the one that was rivoted to a shaft.. so I disambled the lathe put the shaft in the chuck of my small lathe( remember it has a built in key) so I could not just turn it true...so...I used the lathe as a broach!!! and just moved the carrage back& forth and let the carbide take some shaves off ,I left some very thin strips inbetween. I then made some shim material brass stock, and shimed the low side and pressed on the gear and checked the run out...the thin uncut strips were pushed over/down so it would shape right and hold tight... it was less than .0015 run out!!!! I guess my calculating was almost dead on.I wasent about to pull it off and try to better my self and eff it up. I put the enco pos lathe all back togeather and hit the switch....holy crap!!!! it was oh so quiet!!!!! so yes lathe can also be a broach!!! most all machines cam do many more jobs than there made for, it's all in your head, just do it!! butt first.....be sure it's safe. sometimes when you strive for perfection you need to stop just short..or you may end up with a lot more work. been there done that tomany tymes so everybody keep up the great work and post some more!!!!


I have since added real ball bearings to the cross slide&compound slide screws.oh somuch better than a sloppey pos cast bracket& wobbly shafts. I tend to rework everything I buy as soon as I get it, especialy the new stuff.

[hemmjo]

The problem I see what a pneumatic cylinder to power a cylinder hone, is the lag you get at the end of each stroke. When a pneumatic cylinder changes direction in mid stroke, there is a lag with no movement. The pressure from one side has to vent, as the pressure from the other side builds enough to change direction. If this happens mid-stroke, where the cylinder has not reached a hard stop, the lag may be shorter, but cylinder travel limit is difficult to control as it is totally dependent on the loads involved. If there are are hard stops at each end of the stroke to control travel, as I imagine you would want when honing a cylinder, the lag would be longer as the pressure changes would be greater, thus the time for air to vent one side, and pressurize the opposite side will be longer.

This lag would not be a problem with a broach, but would need to be dealt with if used for a hone.

I do not want to hijack this thread, but would like to have a dialog with Tonyfoale and Marksbug, in regard to cylinder re-sleeving and honing/sizing.