$100 screw cutting 12" lathe design

[rohart]

This is a superb project.

I used a belt driven Lorch with no screw cutting for years, and turned out a lot of useable work.

You don't need the best precision in the world to make replacement Landrover parts.

When I was travelling through Kenya I saw trucks being fixed in the open. The mechanics would wipe the sand off the valve gear before putting the cam covers back on. Things work like that. They have poor roads, so they don't ask for silent rides.

This kind of project could help a mechanic in a developing country get a useable workshop going at the kind of prices he could afford. Don't knock it.

[rigmatch]

Who it is for?

The original Yeomans lathes made millions of cannon shells that were accurate enough to hit the right trench when fired from up to 15 miles away.

All I did was make 4 small changes that would allow it to be made in Developing Countries by people who make just a few bucks a day.

What is it to be used for?
To resurface brakes and flywheels with an angle grinder attached
To turn down shafts that have been welded up
To make things fit together (like putting car engines in boats)
To repair Chinese equipment where new parts are not available

Much of my experience has been repairing heavy equipment in the field and I Have had to "make do" many times with lesser equipment.

[oldtiffie]

Morale boosting

Note that mention of "Tool Room" and "Metrology" etc. are conspicuous by their absence so far - as will apply to many jobs in HSM and small rural? (= "red-neck"?) shops here as well.

I suspect that some are embarrassed by their so-called "inferior" "old American iron" and "Chinese" stuff and tools.

Don't be - there is no need to be - just use it and if needs be show the job off to some who may not believe that you and you machines/tools are capable of such work.

It can be very morale boosting and satisfying - and the smug self-satified smile (smirk?) will last quite a while.

[macona]

The original Yeomans lathes made millions of cannon shells that were accurate enough to hit the right trench when fired from up to 15 miles away.

All I did was make 4 small changes that would allow it to be made in Developing Countries by people who make just a few bucks a day.

What is it to be used for?
To resurface brakes and flywheels with an angle grinder attached
To turn down shafts that have been welded up
To make things fit together (like putting car engines in boats)
To repair Chinese equipment where new parts are not available

Much of my experience has been repairing heavy equipment in the field and I Have had to "make do" many times with lesser equipment.

Have you built one and done these things? If so I want to see video.

[John Stevenson]

What a piece of crap.

Sorry, it just is. Looks like it was designed by someone who heard the description of a lathe and designed it from there.

Sorry but I found this reply to be immensely negative.

Not everyone in the world has been blessed with the same chances as you have.

Room for improvement ? Yes but I dare say you could make a 10EE better.

[GadgetBuilder]

Have you built a "proof of concept" machine or is this a "blue sky" concept, sort of a marketing proposal?

Lots of practical questions arise when looking at this design:
How long does the concrete have to cure, and does it need to be kept wet for the duration so it develops full strength? What minimum quality of concrete is needed for a successful build and how is this quality ensured in the envisioned 3rd world location?

In the large WW1 example shown the bed looks like it was cast along with the supports. What type of support is needed for the thinner bed in your design? Does it need to be full length? The bottom of the bed may have some roughness if cast as shown; will this roughness affect mating with the supports? Might irregularities between the bed and supports cause stress cracking of the concrete?

How will the bed be raised onto the supports? If twisted in the process might it crack?

Without a working model, I'd be hesitant to suggest others build one, especially if they're very poor.

[gzig5]

Looks like it has the potential to be stiffer than my Atlas 6x18. Didn't Evan build a lathe with a wood frame and get some good use out of it? I haven't seen anything on it in a while but my impression is that it was stiffer than a wet noodle.

[Iraiam]

Note that mention of "Tool Room" and "Metrology" etc. are conspicuous by their absence so far - as will apply to many jobs in HSM and small rural? (= "red-neck"?) shops here as well.

I suspect that some are embarrassed by their so-called "inferior" "old American iron" and "Chinese" stuff and tools.

Don't be - there is no need to be - just use it and if needs be show the job off to some who may believe that you and you machines/tools are capable of such work.

It can be very morale boosting and satisfying - and the smug self-satified smile (smirk?) will last quite a while.

I'm not the least bit embarrassed about my little Chinese machine shop, I can regularly make pieces within less than .001" tolerance.

And you are absolutely correct, I do get a certain amount of satisfaction putting out quality work on my "Chinese junk"

[J Tiers]

I have an ENTIRELY DIFFERENT criticism to make about this machine....

It is entirely too high tech.... No I am not kidding.

In many of the areas where this might be useful, all sort of the parts required (which don't look too bad to us), are totally unavailable.

Basic concrete probably IS available many places, but certainly now all places, it is heavy, and requires a fairly complex plant to make it...... And forget tile grout, cement would be used for that anywhere.

Scrap metal? WHAT IS THAT? Scrap metal is valuable and would not be laying around.... let alone ground rod of any sort.

Skid wood is likewise valuable, and would already be used in housing, etc.

Given the fact (and it is one) that many materials would not be available....... the most practical way to deal with this is to kit up the essential parts..... and rely on the local area only for the most basic materials...

I didn't go through every page, I skimmed looking for essentials.... not bad, really, I missed the power source... hopefully it can be minimal....

[rigmatch]

original design

My original design had 2+" ways 12" on center, a 225 pound carriage and full length way support. This small version was designed to be shipped to Maker
Faire in Cairo Egypt in October. Once the drawings were made, I felt I could not ask Tyler Disney to revert to the original size since he was a volunteer and had already put hundreds of hours in modeling.

I cannot build the lathe (I can barely walk) so I tried to stick to the proportions in the 2 Machinery magazine articles. The only actual dimensions that I can find are for a 16" 10 ton short bed lathe that made 3200 pound projectiles. It had a weighted carriage and ways supported at the center. The only problem the lathe seemed to have was the long time it took for the spindle to warm up when the machine was started. Yeomans had a subsequent patent about a lever operated wooden block that was used to slightly lift the spindle while the friction from the wood warmed it.

[Tony Ennis]

It is entirely too high tech.... No I am not kidding.

Are you positing simpler purpose-built machines?

[J Tiers]

Are you positing simpler purpose-built machines?

I am suggesting that any device of this type has to be made with materials actually existing, or they must be brought in.

I suppose that on the other hand, an area having a lack of materials might also not really need a lathe.........

I read over some of the material at the beginning of the blurb on the machine, but I still wonder to some extent whether this is not a solution in search of a problem. Exactly WHERE does the correct combination of need and lack exist? Are these materials available THERE?

[oldtiffie]

Contrarian

JT.

Perhaps is was a contrarian response to a need and a "can be done".

The sceptics and knockers may well have been proved wrong and had the self-satified smirks wiped right off.

Irrespective of the "ifs and buts" and "rights and wrongs" and feasability and usefulness of it, it was a great outcome.

[Arthur.Marks]

I agree that the design has reached the stage where a prototype must be built. I also disagree that the purpose is unwarranted. I applaud pat for his work. I have seen too many co-ops where unconcerned people say it is pointless---but the work is appreciated and necessary to those that need it. Unfortunately for the project, it sounds as if the initiator has reached the end of his ability at the moment. Another member is needed to step in and build one... perhaps adapt to what is found from such a prototype. I find----particularly Macona----very disconcerting You never know... what goes from design to physical reality can just as often surprise the heck out of you with what works as doesn't. Time for a practical test of the theory.

[macona]

My choice of lathe at home has little bearing on the subject. I have had many lathes from a sherline up to my monarch.

Im sorry, I guess I have seen too many peoples recipes on how to help out people in needs buy providing simple plans on how to build "xxx" and add catch worlds like "open-source" to catch attention. Turns out these entire plans are often built on pure conjecture from someone surfing the internet. I find it highly irresponsible to peddle plans that have never been tested in the real world.

rigmatch, things like this do not scale from the big machines. Yes, the big machines could do what they did and did it well. Concrete type construction is still used today in cast machine bases. But the machine ways and spindle is too flimsy for a machine of the swing. With 1" way bars and the minimal support I can guarantee I could deflect the carriage with my own weight. This means you won't be able to turn a cylinder true down the length and chatter will be horrendous.

You would have a better chance of making something that worked using thick beams of hardwood, maybe something like ironwood which grows in many places around the world.