lathe

[hiker]

my dad gave me his old 1965 metal cutting lathe--[thanks dad]

only problem is--i need a bit that will cut eletric motor rotors..

the bits i have now are made from colbalt--they dont seem hard enough to cut

the rotors.[they do but would take forever and a day]

what type of bit should i be using???

i would ask my dad but hes down in south dakota and hard of hearing [93 years young}

lots of history on the old lathe i would like to add more to it...thanks..

[ruddycrazy]

G'day Hiker,

            For cutting hard steels etc you need to use carbide tooling as high speed steel isnt suitable unless you use heaps of coolant and a real slow rpm. You can get cheap brazed carbide tools or for more expense indexable tooling which uses multi facet tips. To sharpen the brazed shank carbides you will need a silicon carbide grinding wheel as the normal ali oxide wheels wont grind harder metals. Also a good tip to remember with grinders for soft steel you use a hard based grinding wheel, for hard steels like carbide you use a soft based wheel like silicon carbide.

If you need any other help I'll be happy to answer any questions.

Cheers Bryan

[FishbonzWV]

Hello Hiker,

I also have an old lathe that I bought http://www.otherpower.com/images/scimages/1725/Elatheshot.jpg just for turning rotors. It's a '48 craftsman 6x12.

I've turned 6 rotors so far.

This might not be totally correct from a machinists point of view, but what I've settled on using is the pointed turning tool and a lathe speed of 315 RPM with a screw feed for 8 threads per inch.

I got a box of 5 carbide bits from HF (2 left, 2 right, 1 center point) and tried them all. The cutter has lasted through 4 of them so far and is still good.

The aluminum/steel matrix is one hell of a noise maker.

Since this is just a mini lathe I can only take off about .002" at a time. I leave the aluminum ends on the rotors to help keep the magnets in place http://www.otherpower.com/images/scimages/1725/AEG2mags.jpg.

I start the cutting process with the ends, going about 1/2 the total depth and then flush up the middle with the end cuts. Then I cut the ends down to the final diameter and finish the middle. I just change the angle of the tool for all the cutting.

I make about 3 passes at .003" increments and then a fourth pass without an increase, this trues up the cut. A sheet of paper is .003".

The 8 threads per inch feed will leave a nice rough surface for the epoxy (JB Kwik) to bond to the rotor.

There were posts a while back about delaminating rotors while turning. I have had no problem with this using the pointed turning tool and taking off small increments. I had never ran a lathe before and this was all seat of the pants learning. But, I feel I've got'er down pat.

I just finished one rotor and getting ready to glue up the second row of mags on another.

Hope this makes sense.

Bonz

Oh, one other thing...how do you rename a photo link?

[FishbonzWV]

I'm not sure the 8 threads per inch is correct. I changed the gearing until the feed rate left a ridge between each turn and didn't take all day to make a pass across the rotor. It's not a quick process to turn one down.

[hiker]

thanks for all the info guys..

i found a machine shop here in town-im sure they can help me out also..

 

[hiker]

heres a few picts of the lathe....made by montgomery wards-belt drive-just a regular belt to hold your pants up

cut the ends off then sewn togeather with dental floss-works great..

when i first tried it out the darn thing ran backwards...what the ---?

checked it all out--hmm--[days later]looked at the on and off switch on the motor

flipped it down--hay easy fix--wasnt a on and off switch after all...

[bob g]

that lathe is a "logan" and rebadged and sold my montgomery wards

it is a superior lathe in many ways to the lathe the sears roebuck sold

which was a rebadged "atlas"

from what i understand most parts are still available for it, one of the sons or

grandsons of the logan family owns the rights and does support for the old machines.

there are many groups and forums for the logan lathes.

you should get many years of use from the machine, nice addition to your shop i am sure.

bob g

[FishbonzWV]

Sweet lathe there Hiker,

If you've never ran one before I suggest you get a copy of 'How to run a lathe' 1942 South Bend edition. Lots of good info.

What accessories did you get? Hopefully a 4 jaw chuck and the extra gears for the screw feed.

One of the things stressed the most is to make sure the lathe is set on a level surface. The bed will twist and it will not cut true.

Very nice lathe, Happy turning, and may the swarf not get in your eye.

[bob g]

here is an ancient pdf copy of how to run a lathe

http://www.wswells.com/data/htral/1913_htral/1913_htral.pdf

bob g

[ghurd]

My top-of-the-line lathe (Chinese $329 HF special) has issues with armatures.

Bit holder assembly is sort of wiggly.

Al, FE, AL, FE... gets it kind of vibrating.  Always chips the (HF brazed on carbide) tip off before more than a couple passes.

I gave up on using good bits.  If it still cuts, I still use it.  Sometime have to change the bit twice on a small armature.

Taking a smaller bite helps.

None of that really helps, but don't feel alone.

G-

[hiker]

fishbonzwv..

 yes i do have the 4 jaw chuck and some extra parts--

no extra gears..table is level-but i noticed their is a slight offset-just a hair..

may have been stressed in shipping...

watched my dad run the lathe years ago as a kid-he moved down to oregon when i was

21-i did make a few cannons[44 calber] on it years ago-ended up getting grounded using the lathe for awhile--not  a good idea to test fire a cannon when the shop is in range!!

[hiker]

thanks for all of the replies....

 

[hiker]

thanks for the manule bob....

[Warrior]

Congratulations on your new toy!! Once you learn to use it you'll see that a lathe is such a valuable tool!! You can do so many things on it...

Regarding the carbide cutting bits...they are a little tricky to use. If there's any vibration what so ever during cutting, a tiny, barely visible piece of the tip will chip off and although it will still cut, the surface finish will suck big time. If you decide to use cutting fluid, then it has to be cooling the bit none stop. If you interrupt the fluid and allow it to heat up, the tip might crack the next time you re-cool. Carbide bits like high speed cutting most times and on some materials cutting/cooling fluid is not recommended.

I have lots of carbide tools, both the brazed and the inserts, but I rarely use them. Just too delicate IMO, plus the griding wheel wears out really fast when you re-sharpen. You won't find that many materials that are so hard you'll need carbide...

Good Luck!