Metric Lathes in the USA

[David Lewis]

Marco, care to give me a link or two of any models you're aware of? I'd prefer to have European tools over Asian tools, any day of the week.

For the rest of you, the reason behind my metric-only mission (beside the bicycle being a metric machine):

I lived in Germany for 5-1/2 years when I was in the Army (minus a 15-month tour of Afghanistan). I drove my car and rode my motorcycle (still do) to km/h, bought fuel in liters, used fuel in liters per 100 km, bought cheese in grams, bought beer by the half-liter, qualified on weapons ranges in meters, etc. I have converted to metric, and I find the U.S. machine shop a curious vestige of the past, holding on to inches for dear life while using decimal inches to try to remain relevant. When I worked at Chris King Precision Components last year, a boatload of 1980s Japanese CNC machines were all set to cut standard parts, and I had to face palm every day just keep from crying. Even one of the most respected American bicycle parts makers still uses decimal inches, but this company considers new anodizing colors to be innovation. I don't.

 

[JimDawson]

Pardon the length!

Among other reasons, I need the big bore to be able to machine braze-on headset rings from thick-wall 4130 tubing, but I'd also like to use it to make tooling for welding setups, like heat sinks and so forth, and prototype parts like hubs and drivetrain parts. I think 2" is probably enough for the tubing, and that's 50.8mm. It's far more efficient to feed the tubing through the spindle and cut off parts as they're done, but I'm sure I don't need to tell any of you that.

Jim, about an hour ago I did exactly that at ADX. I faced three 1-1/2" headtubes that were each about 6-3/4" long in a three-jaw on an ancient hobby 9-inch Clausing lathe, with decent results. I'm not saying it can't be done! However, I had to hacksaw a much longer tube and then face both ends of each part. That takes away from my beer time, which I would have more of if I could feed a six footer through the spindle and cut off headtubes in the lathe.

Ok, I see your point, a big bore it is, something with a D1-6 spindle nose. If you can't find the lathe you are looking for, I'll be happy to help convert whatever you do get to metric. With a DRO on the axis, the only things that needs to be replaced is the leadscrew, the half-nut, and the threading dial gear. Metric Acme stock is readily available.

My favorite Bier when I was in Germany, was Binding, good stuff. I had a lot of 1/2 liters of that.

 

[Marco Bernardini]

Marco, care to give me a link or two of any models you're aware of? I'd prefer to have European tools over Asian tools, any day of the week.

Here there are those I found, in a confused order:
Damato Macchine: http://www.dmitaliasrl.com/co.uk/metal_lathes_list.php
CMT: http://www.cmt.it/azienda.html (only Italian text)
EMAG: http://www.emag.com/company/brands/emag.html
OMG Zanoletti: http://www.omgzanoletti.it/torni-paralleli/
DMG merged with Mori Seiki: http://us.dmgmori.com/
GDW: http://www.gdw-drehen.de/produkte (only German text)
Weiler: http://www.weiler.de/en/start.html
Maier: http://www.maier-machines.de/cms/en/machines/
Nardini: http://www.nardinisa.com.br/ (only Portuguese text - Brazilian factory)

 

[uncle harry]

Hi David,

My $0.02 is you are setting yourself up for frustration with the requirements you've laid out. Getting an affordable lathe with the bore you've specified (also in metric) is, I suspect, nearly impossible.

I understand that facing the head tube and the bottom bracket are essential to making a quality bike frame, but I think you are going at it in a way that leads to big expense with little gain in efficiency. I'm out of my depth as a machinist here, but wouldn't it be far cheaper to cut your tubing over length on a saw, then use a relatively small lathe to face the cut using a mandrel of some kind to support the tube?

After all, the head tube, which is the longer of the head and bottom bracket, is never going to be more than about 9" long, right? Why spend thousands of dollars for a large bore that you don't need to do the job?

If you approach the job in this way, there are many talented and clever machinists on this site who will help find you a way to do the job you need at a fraction of the cost it would take to do it as you have proposed.

Walt

Another $.02 worth approach might be using a cold saw. That would afford accurate cutting of all sorts of materials with possibly acceptable tolerances.

 

[Walt]

Thanks for taking the time to clarify your requirements David. All the best in setting up your new business!

Walt

 

[David Lewis]

I still want a metric lathe, but I was quite surprised today by what a 9-inch hobby lathe can do. I made two identical parts today on it; both are aluminum heatsinks for welding headtube bearing seats.

The dials aren't worth a damn and the backlash is almost silly, but working around its shortcomings I was able to make some decent parts to very tight tolerances. Here are a few photos from the experience.

 

[JimDawson]

Nice looking job. It just goes to show that a good machinist can overcome many obstacles and still turn out good parts.

 

[Marco Bernardini]

Nice looking job. It just goes to show that a good machinist can overcome many obstacles and still turn out good parts.

The issue, then, is making things for "fun AND profit" or for "fun OR profit".
If you have to make just 10 pieces a day and you are paid per piece and not per hour, there is not really a big difference if you make them in 2 hours or in 3 hours: sure, your hourly earning will decrease working with a slower machine, but a slower machine requires less investment.
Also, I guess the market for bikes can become saturated in a short time (specially if your bikes don't break quickly :biggrin, so an expensive fast machine making thousands of pieces a day would create an overproduction leaving you with the need of finding a storage - and this one is expensive too - for parts which will be sold over a long time, if they are not obsoleted by a new design.
I know customers want things for yesterday, but also who want good things knows sometimes there is to wait (some Ferrari have a 2-yrs waiting list).
Another advantage of a less "industrialized" production is you can better fit the clients requests. You noticed it's almost impossible to find a lathe with the specs you need, but a small company making 5 lathes a day almost by hand could satisfy your requests better than a big factory making 10,000 lathes a day with CNC machines.
The ease of customization is an added value for almost every product, and a bike tailored exactly to fit the legs length of the customer is something making a big difference (I know, the one I got 2nd hand is 2 cm too high).

 

[Walt]

I still want a metric lathe, but I was quite surprised today by what a 9-inch hobby lathe can do. I made two identical parts today on it; both are aluminum heatsinks for welding headtube bearing seats.

The dials aren't worth a damn and the backlash is almost silly, but working around its shortcomings I was able to make some decent parts to very tight tolerances. Here are a few photos from the experience.

Hi David,

Nice looking work.

With regards to the backlash and hard-to-use dials, the earlier comments in this thread about adding digital readouts would go a long way toward addressing those concerns. Adding a DRO is not expensive as part of the cost of a quality lathe and doesn't take exceptional ability as a machinist to install. A DRO also reduces the mental load of cutting a part. Instead of having to translate a target dimension into a number of handle cranks plus a particular hash mark on a low contrast dial, you have a single number to shoot for on a big, high contrast display. Backlash becomes mostly irrelevant because the DRO bypasses the screw feed mechanism to read position directly from the saddle and cross feed position.

Best wishes in finding the right tool for the job.

Walt

 

[David Lewis]

Thanks guys.

Marco, I could not have said it better. Look at my Veteran Bicycle Co. Facebook page, and you'll see I just TIG welded 200+ steel tap handles, each having 32 weld beads apiece. Do the math. I got paid as an at-will employee at ADX and I worked as fast as I could because I just wanted to be done, goddamnit! I do what I love, but I won't do it if isn't a means to an end, and the end is profit! Okay, so I didn't really profit off of this, but now I know better than anyone how to make a decent weld bead, and that is what counts in the bicycle business. An air-cooled #9 torch is a pretty silly choice for 200 parts with 32 weld beads per part. Just saying! I agree hands down that wasting my time with equipment not made for production is the wrong way to go. I may not be able to find a lathe with metric dials to match the metrology my work will be, but with a DRO and a robust machine I will be able to work just as effectively. Keeping my eye on the prize!

Walt, I also agree with your assessment, especially after making these two little simple parts on a machine that was made the year my father was born. As I said, I just finished my second term in machine manufacturing technology, and I have so far worked only with manual machines. PCC just took delivery of over a dozen Chinese DRO-equipped vertical milling machines that are so silent operating it's bizarre. I chose to do my workpieces on ancient manual machines with no DRO so I could prove a point to myself that I could, and in the end I was the one with an A. Others chose to do everything according to the numbers on the screen and ended up with bunk parts. It's not because of the machine, but because their relationship to the machine is different than mine. I feel very comfortable with dials, but I appreciate DROs for their accuracy and would use one in production. Maybe it's a pipe dream to have a lathe in the United States with dials and leadscrews not based on the size of the king's toenails from the 14th century, but I still believe in my country!

To summarize, I will use DROs in production, but I will only swear by dials. I will swear AT the DRO, especially when it doesn't work because some chips screwed up the reader on the scale.