80/20 benchtop lathe build

[ALWAY]

Congratulations on a job well done. I will be posting questions soon looking for advice and guidance. Don't want to interfere with your progress at this time.
Have a good day and keep those chips flying.
Al

[LeeWay]

Thanks, Al.
Feel free to ask away. Questions asked and answered on build threads are a great source for info for others.
I did get my stuff from Keling yesterday. No hurry to install the new motors or the BOB yet. Later on that.
My new motor controller should be here tomorrow. I will install it and the DC-06 this weekend. Gotta let Mach do it's thing. It is good at it.
I did get the code tweaked for some of my parts.
I will make a video of it running soon. I am pretty pleased with the first small run of parts coming off this. It will only get better from here.

[LeeWay]

"http://www.youtube.com/watch?v=aprdDeekio8&feature=channel_page"]YouTube - Home Made CNC Lathe

[digits]

Very nice!

[LeeWay]

I managed to get the new motor controller and DC-06 installed. No sweat really. I had a few minor glitches. Mostly mach settings I had overlooked.
It all went fairly smooth though. It is great to let Mach control the spindle.
This motor controller over the other is like a Gecko over some smaller cheap drives. This one just does so much more and the motor just acts totally different under it's control.
Absolutely worth the difference in price.
I will still keep this one around as an emergency spare, but WOW!
The little controller was a little under torqued at high speed. It wouldn't actually run top end on the Pot. It would overspeed and slow down. Therefore top working speed on the little MC was a 7 on the Pot and about 3800 RPM.
I did notice a 400 RPM slow down when this would peck the last peck on my parts. Loosing torque.

This bigger MC gets a very smooth 4200 RPM on the spindle. This is a little faster than I wanted it to run, but it handles it well. I now run my program at 3200 RPM. It does a fine job. No sign of bogging with this one. Just running on 120 VAC. This is 130 motor. 90 VDC controller. It still has to be getting around 3/4 to 7/8 HP. The multiple settings onboard this controller lets you fine tune the thing to act exactly like you want it to.
Very pleased with this.

I did remove my third Gecko from the control box and installed the C10 BOB.
As of now, I see no need to use the larger motors or PS.
Future projects may be on the horizon, though not sure what they might be.

The next thing for this will be the adjustable steady rest on the outboard side, but inside the spindle cover.
Not sure of it's design yet, but it will have ball bearing rollers.
I may look on Ebay for something instead though.

I want to be able to insert at least 2' bars into this.

[zephyr9900]

Beautiful build, Lee! When my mechanism grows up I want it to be like yours. Your anti-backlash nut mounting is especially clever.

Randy

[LeeWay]

Thanks, Randy.
I have been using the lathe for some time now and I noticed the other day, my first steps missed. It was on the Z axis after a rather deep plunge drilling.

I just shut everything down and installed the new power supply and larger motors. Tuned them up and now there is not a chance of missing a step. I must have been right on the border of available torque before with the smaller motors and PS.
Much happier now with it's preformance.

I need to install a limit switch on it for the Z axis though. I think I will make it an adjustable one that will mount on the front of the cabinet with a couple knobs. The switch would be at the end of a bracket. This would prevent my tooling from ever getting close enough to the jaws to crash. It would ease the pucker factor as well. It would let me cut my parts closer to the jaws than I do now. This has the added benefit of making the parts even more precise. The are well within tolerance now, but better is always good.

I need a charge pump for this as well.
I still get the spindle turning sometimes when it isn't supposed to. Usually upon start up. I have a switch for it, but don't want to flip it off every time I advance the part. Just really want to be on the safe side.
Anyone know of a simple stand alone charge pump circuit board available?
I have one of the older BOBs from Cand CNC with a charge pump onboard, but never could get it working. Likely my issue with Mach settings.
I really want to buy a charge pump only as the BOB's I use are all C10's and I like them.
Thanks for any suggestions.

[pminmo]

Great looking machine!

[LeeWay]

Thanks, Phil.
Still haven't had time to do the other little things to it yet, but will post more when I do.
It is running great for now.

[tootalew]

Lee,
Did you have surface the bottom of the headstock (spindle housing)?
I have a x2 housing from LMS and no way is the bottom of the housing anywhere near parallel to the spindle bore. If so how did you go about surfacing it?

[LeeWay]

I surfaced the extension in my mill. I milled off the dovetails and then face milled it. Turned out well.

My head turned out to be right inline both with the casting and the spindle bore.
I did mill the head casting some as well, but just cleanup passes to make it flat.

I used a laser pointer in the spindle. I clamped an angle plate to the table with a mark or dot inline with the laser. Then ran the Z axis back and forth. It never strayed off the dot. This was close enough for me. The way I mounted it, I had 8 different places I could have installed shims if needed. None were.

Of course, this is after the chuck was tuned, but I think you could use just the spindle bore to do this as well.

[blades]

I don't know how I missed this thread, but all I can say is WOW! Great job, Lee!!
Looks like all you need now is a power chuck with a bar feeder for nearly unattended machining.

[LeeWay]

Thanks. That would be cool, but with the spindle controlled by Mach 3, when it's done, it sits quietly ready for one of us to push new rod out and hit start. It cuts two bushings at a time and only needs to run about one day a week to keep up pace with production.
That spindle control on all three of my machines allows one guy to keep three machines running at a time when needed. A robot would give me less lip than my employee though. I doubt it could tell a joke as well.

[LeeWay]

Guys, I am considering adding a servo motor to this lathe for spindle operation.
I think the DC motor on it now has maybe 5/8 to 3/4 HP at most and it does okay.

Soo, I think maybe 750 Watts for the servo? Just now getting my feet wet with servo's. I have one running the spindle on my Novakon Pulsar and absolutely love it for the rigid tapping.
I would like to do that on the lathe as well but also regular threading with thread tools. I think a servo would be the easiest way to accomplish that.

A motor and drive like on the Pulsar would be way overkill I think. It is a 1.2 KW AC servo. Don't need all that on this.
Right now the lathe uses two Gecko 203V's for the steppers. 72 VDC PS. 12 amps. I am open to using an AC servo system, but do not know if it will work with the same BOB.

That is just unclear to me. DC servo might make more sense, but would still require another large PS, correct?

Thanks for any recommendations or information you might be able to share. I think my brushes are starting to fail in the current motor and instead of just repairing, I would rather upgrade.

[LeeWay]

Hey, Guys.
Something else that I have been spit balling is the possibility of adding an automatic 5C collet closer on this lathe. Perhaps a small bar feeder. 3' rod length would be fine. Our bar lengths currently are around 18". That is all I can use without a bunch of whipping.

I don't know that the current spindle is even big enough for a 5C. Doubtful. I do have a larger head available to me and may be able to use it instead.
Does an auto closer work similarly to a PDB in a mill?
I looked for some images of them, but could not really find any that showed much detail.
It would be easy enough to install a limit switch on the bar feed to stop it at the desired location.
Anyone have any pictures, thoughts or ideas?

[LeeWay]

No thoughts so far?
I hear ya.
I ran across a bar puller.

http://www.ebay.com/itm/CNC-LATHE-SM...05530407&rt=nc

Anyone have any experience with that? Similar?
Seems like this would be easier to implement. No air or anything needed. The way I understand is that once adjusted to material size, it bumps the left over. Then grabs it. The the collet opens. The the Z axis retracts a certain distance to put the rod at the start point. Collet closes, bar puller releases and retracts. Does that sound about right?

This will be kinda mute until I can locate a spindle capable of using a 5C collet with auto closer though.
Now I am seriously considering The Tormach.

I have one part that I need about 200 to 250 of each week. That part is a serious drain on productivity. It only takes about a minute per part, but to stop doing something else, then go to the lathe and setup again, then get back to where you were really is very time consuming. I would say maybe 3 minutes per part. That makes it at least 10 hours a week. That is crazy. That is broke and I will have to remedy that next.

[LeeWay]

Next thought.
Is there an auto chuck closer for a small chuck like might be on this size lathe? The bore on this spindle is nearly 7/8" I think. I bored the chuck out as much as I could too, which is about the same. My largest part is 3/4" dia and that works great.

[DICKEYBIRD]

Just checking in to let you know I'm watching your progress & learning from your posts. I'm nowhere near the level you've taken your machine to nor do I have intelligent suggestions for what you're doing now but just letting you know I'm enjoying the ride. Keep it coming!

[DSpeck]

Lee, you might consider buying an old Hardinge DV-59 (or one of its clones) 2nd op lathe, and taking the head off to replace the one you have here, or moving the X-Z table to the DV-59 frame. They have 5C collet heads, and you can get all kinds of different collet closers and chucks for them. The spindles are superb, and if you get one of the old split-bed designs with no tooling, you can probably get one fairly cheaply. Controls and such should be adaptable, within reason. You could also get a HSL-59, and put the table on that.

Here is a suitable candidate on ebay right now: Feeler Second Operation Ultra Precision Lathe Hardinge DV59 Copy Vari Speed | eBay

These lathes are 9" swing (4.5" center height), so I don't know how that fits with your setup. You might need to space up the head if your center height on the table is taller.

As for the bar puller, they are very useful. I used one more like this CNC-LATHE-BAR-PULLER-1-SHANK, which also works well. It speeds up production quite well, when you have a collet closer under automated control. You can get combo versions which come with a cutoff blade, so you cutoff, stop spindle and then advance to grip the material and pull it out, using only 1 tool location - handy in cramped spaces.

Doug.

[LeeWay]

Thanks, Guys.
I actually did some research today and was thing the same thinking about a spindle head. Found one suitable on Ebay and sprang for it. $399. It is the spindle head from a Hardinge DV-59.
It does not look unused. Price was right though.
It only comes with a hand closer tube thingy.
My lathe absolutely makes my parts perfectly, so I think the new head should work well. It will call for a small bit of redesign, but think I can handle that. Apparently the Hardinge motors are down below.

My current motor is a 1HP DC motor. It is running okay. I will try to keep using it first. Different belting of course.
Once I have this in hand, I should be able to see more about getting an auto chuck on it. I know they do have lever draw bars for these lathes. Anyone ever though about using an air cylinder to actuate those?
One with enough travel and strength should work.
Here is an image of this.