80/20 benchtop lathe build

[LeeWay]

For the bar puller, I really like the kind that come with the cut off tool.
Those are very pricey though. My QCTP only has 5/8" tool holders. I didn't see any that would accommodate one that small. So, leaning toward one that would operate from the gang tool setup with Z. No sure yet what all I will have to do to the head, so I will wait on that decision.
I may even decide to machine my own.

One other thing worth mentioning. All of my parts are brass or plastic. Delrin. It won't take much force to grip either well. I only use 3 different sizes of rod. 3/8", 9/16" and 3/4". That means not a lot of money spent on collets.

[LeeWay]

Something else I have been wanting to do with this lathe is tilt it. Slant it rather. Right now it works okay. The bellows catch almost all the parts and chips. Makes clean up and swapping between brass and plastic fairly easy, but this has to be done fairly often, which also adds to the cycle time.
I think with it slanted, I would remove the bellows and go with a metal bypass or sliding style between the spindle and carriage. A simple rubber sheet would be good enough on the outboard side. May even be good enough for both sides.
Removing these bellows gives a lot more room between the spindle and bed. Slanting it too will allow full runs without the worry of parts and chips filling up too much. I also intend to finally put a chip guard on it. Since we won't be opening and closing it so often, it would be beneficial. I find delrin parts all over the shop where the lathe slings them after cutoff.
Not a lot, but maybe a dozen errant parts so far. Not safe either. ;( Dodging bullets....literally.

I have been thinking about the Tormach lathe as well. I have read most of those threads here and watched most of the videos. It doesn't yet offer the auto closer, but promises it will come. I would wait until that is ironed out before I committed to one of those. They do look like nice machines.
I might sell this one later to help recover a bit of the Tormach cost. I think it would be a worthwhile investment. Especially with the turret.

[LeeWay]

Another thought. Since I get random lengths of rod delivered depending on where I buy it, (5', 6', 8' lengths) I will often have odd lengths of rod to use. I am shooting for about 3' rods to start with. Some will of course be shorter. Rather than trying to determine how many cycles to use on different parts, I would like to setup maybe an electric eye type system. Sort of like what they used to have on garage doors. Aim it right across the center of the spindle nose. That way when the bar puller pulls a remnant that is too short and clears the spindle, it will stop the cycle. I am not up on all the types of sensors there are available.
The eye type system could be spread pretty far away from the spindle itself, so would not get into any action. Just read about 1/4" or so past the spindle. Is there some other system or sensor that may work better? Thoughts and suggestions welcome here always.

Something like this one. It already has the wiring and fiber optic that would make it easy to install with the unit itself in the control cabinet.

Banner Engineering SM312FQD Mini Beam Fiber Optic Photoelectric Sensor | eBay

[jsheerin]

Another possibility could be a mechanical switch on an arm on your cross slide. You program it to go up and touch the side or front of the material after being pulled. If the switch doesn't close, there's no material - don't run the cycle. It would probably be a cheap way to go.

[LeeWay]

Another possibility could be a mechanical switch on an arm on your cross slide. You program it to go up and touch the side or front of the material after being pulled. If the switch doesn't close, there's no material - don't run the cycle. It would probably be a cheap way to go.

Thanks for that idea. That suggestion got me to thinking. This could be bad, so hang on.

It goes all the way back to the design phase of this lathe. While this setup does do what I wanted and I was able to use a bunch of stuff I had, it wasn't optimal. The slant bed is a portion that would have been nice. Another thing is the orientation of the X axis. The motor should have been on the other side. The X axis travel is also on the short side. 5". My tooling currently takes all the travel except a bit at each ends of travel for adjustment. A smaller chuck might have been better too to lessen the chance of another tool getting into it. While I have crashed a few tools on this lathe a time or two, they have always collided with the stock. Not the chuck. A chuck crash is highly undesirable.

Simply slanting the lathe will fix the part catching issue. Not the X axis. I could turn the X around with little trouble. It's all centered on the table. The bolt pattern is the same either way. That doesn't make it longer though.

To use a switch like you mentioned, I would have to have another tool position available. It would require movement each time to check the stock. That time isn't critical, but the tool position is.


I think I may have solved several issues I would be having trying to rebuild this lathe while we still need it in production.

You see, I have this milling machine that burned up last year. The X and Y axes survived in tact. The Z axis would need at least a new ball screw.
I am considering just mounting the Harding spindle to the end of the X and Y table of the Torus. This would solve many of my issues I think.

The 80/20 will no longer be a suitable base. I may have to start a new thread for this one.

Next question. I see all these nice gang tool holders on lathes. I had to make my own on this lathe. Where do I find those things? Maybe 6 or 8 positions?

[DSpeck]

Omniturn offers the gang tooling blocks, and they are pretty good. Another I have seen is http://www.artcotools.com/gang-lathe-tool-holders. Just doing a Google search for gang tooling should give several other choices as well.

For ideas on mounting the head on the mill table, you can check out the Sturges head, which does this exact thing: http://sturgesturninghead.com/

[LeeWay]

Thanks for the info. The last link did not work for me.
I actually ordered the Tormach lathe, so this machine may be decommissioned fairly soon. I will keep using it until the Tormach is 100% of course, but then this one will be on the auction block so to speak. It is a great lathe. Just cannot be easily automated with my skills.
I am sure if you can automate a big one, you can do the same on a small one. Simply not readily available. If it were, I may not have ordered the Tormach.

[LeeWay]

So guys, what we are talking about here may be an idea to promote or a small business op. Design and manufacture a small scale chuck closer for the smaller machines. Hey! They are not out there. I needed one. Any questions?

[saint_la_france]

hi there - good day dear friends, @zephyr9900 , @jsheerin and @LeeWay


well i like this thread very much!

i have bought a lathe: and now i think i need a mill. Therefore: i am after a Mini/Micro Benchtop Milling Machine - and i guess that your ideas and plans fit very well.



Lee you wrote:

Well I had such good luck building a mill using good parts with 80/20, that I have decided to go the same route for a small production lathe. I did convert a 7-12, but with less than stellar results. It is the backlash, general flexing, lack of motor power that directed me to just build new, rather than try to upgrade the 7-12. It is a much better manual lathe than it is on cnc with stock parts. Anyway, I have many of the parts already. Some parts are exactly the same as on my mill. The 3060 80/20 base, the THK rails, I will be using the spindle head from the 7/12, much the same way I used the X2 spindle head on the mill.
I will be using a treadmill motor on this but not quite as strong as the one on the mill.

this is awesome. I like your ideas very much..



to tell you some things about my interests: Would only be used for plastis soft metals (aluminium, maybe brass). I'd like to avoid spending many hundreds but accept that good, precise tools are not cheap.

so what are my plans for it: bike frame buliding see also here: https://www.bikeforums.net/framebuilders/

i am looking for a DIY Benchtop Micro Milling Machine which is modular in design and great for small parts - (metal, soft-metal etc)

Lee, well this thread is great: and the Benchtop Micro Milling Machine is an excellent example of what can be done utilizing spare parts, and a little bit of ingenuity.

well Lee - what to do - i am very very interested..

Any idea how to proceed now ?




look forward to hear from you

regards saint_le_france



btw: see A DIY BENCH-SIZED MILLING MACHINE
https://hackaday.com/2019/10/15/a-di...lling-machine/

btw: see the openbuilds-page: https://openbuilds.com/search/198750...ll&o=relevance

is this any idea we can follow!?