Lathe Question

[mattypichu]

I have an older 6" Craftsman / Atlas lathe that is in the process of being revived. I was wondering what parts of the process a tool like this can help with. A couple that come to mind are head tube facing and relieving. What are some other creative frame building uses for this tool?

[adarn]

I had one of those for a bit. I originally got it to miter tubes on but it proved to not be rigid enough. I used it to bore some sleeves out and things like that. It could also do a good job at making binders or other small brazeons. I sold it because I think something just a bit bigger would have a lot more uses.

[Rody]

Matty,

A good lathe is indispensable in a frame shop, I honestly don't know how other builders operate without one...they must buy a lot more pre-made pieces.

Mine is used with every frame build, from creating seat tube inserts (turning, boring), facing bb shells, headtubes, creating fork crown race seats, cutting finished fork crowns, making EBB's, post weld reaming of frames, parting tubing, and making all the bits and bobs (binders, threaded Disc posts, dropout work)

If you are creating your own fixtures, a lathe is a must.

Now, all this is considering you have a lathe that is large and stable enough for this work. I'm afraid the little craftsman will be wanting in many aspects.

[Andrew R Stewart]

I've had an Atlas 6" for 30+ years. First i just made bits and tried to mill out simple slots. Then I advanced to trying to miter with hole saws. Now I've gone back to hand mitering and the lathe sits unassembled after my most recent move 4 years ago.

The lathe was too loose and small in capacity to be of real frame building help, beyond the small bits work. About 10 years ago i broke it down as far as I was comfy with and cleaned it up. Tried to tighten the gibbs and such on reassembly with no better results WRT the slop under cutting forces.

If I ever get another lathe it will be much more substantial. Andy.

[afwalker]

I have a small lathe and would love a real one with a 1.5" spindle bore. But, I use the heck out of it anyway. Facing, making jigs and tools.
I was able to make a main tube mitering jig for a Nichols horizontal mill because of my lathe.
9317648382_81011fe759_m.jpg9602161691_de2910f0f5_m.jpg
Made an Octalink 2 crank adapter for the frame jig to measure crankring and crank clearance
8550655802_18d0227bc8_m.jpg8550656892_95df0ce280_m.jpg
cheers
andy walker
Flickr: afwalker's Photostream
Walker Bicycle Company | | Walker Bicycle Company

[bencooper]

I manage fine with a little Rollo Elf, it's fine for making most bike things. For headset and BB facing, I have the proper hand facing tools, ditto for seat tube reaming. It mostly gets used for roughing the crown race seat, then that's also finished off with the proper Park crown race tool. For mitring, I have my cheapish mitring system described elsewhere on this forum.

So lathes are lovely, but I don't think they're essential for framebuilding. Then again, all those reaming and facing tools cost quite a bit more than an old lathe would cost - though they are might lighter and easier to store.

[NBC]

sell it and get a bigger one ?

spindle bore is your best friend when it comes to facing tubes etc, and thread turning would be pretty useful for being creative :)

NBC

[Tristan]

I've only got a little 7" Myford ML7 but once you have a lathe you'll wonder how you ever got by without one. What you can do with them is only limited by your imagination and tooling.

[mattypichu]

I manage fine with a little Rollo Elf, it's fine for making most bike things. For headset and BB facing, I have the proper hand facing tools, ditto for seat tube reaming. It mostly gets used for roughing the crown race seat, then that's also finished off with the proper Park crown race tool. For mitring, I have my cheapish mitring system described elsewhere on this forum.

So lathes are lovely, but I don't think they're essential for framebuilding. Then again, all those reaming and facing tools cost quite a bit more than an old lathe would cost - though they are might lighter and easier to store.

Ben,
I followed that link to the Elf. How cool that it utilizes the SA hub!

Andy,
I was thinking of the possibility to use it to cope tubes. What tooling did you use for this process? The part that is most curious for me is the holding of the tube. What went wrong?

Just for clarification, when turning the crown race seat, this is performed after the steerer is attached to the crown but before the fork blades? What benefit is there to doing it this way over using a hand tool, if any?

Thanks

[Dave Anderson]

While on the small side for sure, and you can do more with a bigger lathe, you might be surprised what you can use that Craftsman 6" for. It's not suited for mitering main tubes at all, but there are a bunch of frame building type activities that it will work for. Its amazing what I've been able to use mine for over the years. Here's just a few of the more common things:

Turning down crown race seat



Headtube reaming and facing



Making a stainless pump peg



Turning down a headtube extension



Turning down a headtube



Cutting headset keyway



Making stainless Top Eyes



Boaring out stuff



Turning down drop out plugs

[bencooper]

Just for clarification, when turning the crown race seat, this is performed after the steerer is attached to the crown but before the fork blades? What benefit is there to doing it this way over using a hand tool, if any?

With a big lathe, you can do a complete fork. But yes, I do it as you describe.

The advantage is speed - cutting the raw crown by hand is a pretty slow job, but roughing it in the lathe and finishing off with the hand tool is quick and simple.

[Mike Mcdermid]

sell it and get a bigger one ?

spindle bore is your best friend when it comes to facing tubes etc, and thread turning would be pretty useful for being creative :)

NBC

Its not essential I use a 4 jaw WAY WAY more than a 3 jaw (and yes its a large bore lathe) despite having to clock it up secondly the fixed steady means with a small bore spindle you are as capable as anything with a 4 inch bore spindle and as accurate as you need to be clocking it up, it often puzzles my why people need the biggest spindle bore they can lay their hands on and assume it guarantees some kind of precice turning , I would never dream of putting a fork in a chuck either or frame in a lathe to face it but this is for reasons where if i had suggested let alone attempted such a thing whilst doing an apprenticeship i would have been thrown down the shop and booted through the door faster than the emergency stop could have cut the power

each to their own if it gets you an end result

[afwalker]

I hadn't thought of turning down dropout plugs, how do you hold them Dave? A fixture you made?
Mike's point on the 4 jaw, I haven't put the 3 jaw back on an really like the 4 jaw, just seems easier to align.
Mattypichu, no I do not use it to cope tubes. I use a horizontal Nichol's mill with a main tube miter jig, some of the pieces I made on the lathe.
I have some fear about a more powerful lathe, just it would be nice to put a fork deeper in the bore, with clever fixturing and holding a small lathe sure can do a lot:)
cheers
andy walker

[Dave Anderson]

<snip>I hadn't thought of turning down dropout plugs, how do you hold them Dave? A fixture you made?

Yes, I got the idea from Darrell McCulloch, and its just a piece of bar stock, that has a tapered flat on the end, that the drop out bolts to and is then put in a 4 jaw chuck.

Dave

[Andrew R Stewart]

Ben,
I followed that link to the Elf. How cool that it utilizes the SA hub!

Andy,
I was thinking of the possibility to use it to cope tubes. What tooling did you use for this process? The part that is most curious for me is the holding of the tube. What went wrong?

Just for clarification, when turning the crown race seat, this is performed after the steerer is attached to the crown but before the fork blades? What benefit is there to doing it this way over using a hand tool, if any?

Thanks

I have a milling vice accessory. So the hole saw is held in the chuck (a 4 jaw so it can be best centered) and the tube is clamped in the milling vice. As this was before i better understood tubing clamping options I countered the squishing force and increased the solid (bad word with an Atlas 6") clamping by using a clamp running from the backside of the milling vice to the outer surface of the tube. I would set the angle initially by the cross slide marks, take a cut that was short then measure the resulting angle with a protractor and correct then cut to within a Mm or so to length.

I still had to do some touch up with a hand file. I found that a faster hole saw speed then the charts suggested worked better with very slow feed. Lots of cutting fluid. I would sometimes take the hole saw and grind off the outer sides of the teeth to both true it and to reduce the miter's diameter a touch. When i would do the carriage would jump on it's backlash. I would hold the tube's extended length under my arm, against my body, to reduce it's wiggling about.

All in all I found this to take a bunch of time yet still needed some fine tuning with a file after. So i went back to complete hand mitering. Now i mark my miter line best possible and hack saw out then grind to very close to the line. Then miter with a file to fit. Only the second TT miter really takes more then 15 minutes. But i am not a fast guy in my building. I've watched a couple of guys do a hand miter in under 5 minutes. Andy.

[NBC]

mike,

i'm not saying go for uber stupid silly huge spindle bore lathes, but something that's 2" is really the biggest necessary for bikes

i know a 4 jaw is pretty easy to use, and some cheaper 3 jaw chucks don't hold a great tolerance,
however if we're talking about holding great tolerance, a collet chuck really is the way to go, however they're really rather expensive for the lower amount of use you'd get from them

biggest lathe i ever used was 160" between centres and 28" swing, there's no way you could hold the tolerance you want for anything bike with that, but it was made for doing big stuff, that's where it ruled !
just be sensible with the size of machine you get, too big is just as bad as too small, possibly worse !

NBC

[Clockwork]

This Pratt & Burnerd adjustable collet chuck holds things ( 1.5" - .0625") dead straight as long as you can get about a 2" insertion. They're expensive but really nice.





Much cheaper is a 5C collet but you can't pass more than 1" through it. It'll do 1.125" but not through.

[Mike Mcdermid]

mike,

i'm not saying go for uber stupid silly huge spindle bore lathes, but something that's 2" is really the biggest necessary for bikes

i know a 4 jaw is pretty easy to use, and some cheaper 3 jaw chucks don't hold a great tolerance,
however if we're talking about holding great tolerance, a collet chuck really is the way to go, however they're really rather expensive for the lower amount of use you'd get from them

biggest lathe i ever used was 160" between centres and 28" swing, there's no way you could hold the tolerance you want for anything bike with that, but it was made for doing big stuff, that's where it ruled !
just be sensible with the size of machine you get, too big is just as bad as too small, possibly worse !

NBC

I wasnt either i was merely saying you dont need spindle capacity to turn a larger tube than your lathe can handle , many immediately who are new to machining think its got to go up the spindle to be held

[mattypichu]

This is all nice to know, I was a little bummed at first by some of the responses, but it looks like the little lathe in the right hands can do at least what I was hoping. Anyone ever make a hub? That seems like a neat project, maybe not practical...but that's not always fun.

[bencooper]

I've made custom axles and freehub bodies, and modified hub shells - I've got a little Sherline which is perfect for that kind of small but precise aluminum work.