CNC Sherline Lathe Project

[vlmarshall]

Well, I've finally managed to get a lathe at home!

To compliment my little Sherline mill, I've paired it with a Sherline lathe, which I'll be converting to a CNC machine.

For now, it's a basic "CNC Ready" lathe (thrust bearings on the leadscrews, and motor mounts already fitted from the factory), a pair of stepper motors, and a pile of goodies.

 

[vlmarshall]

One of the first troubles was this crunched power supply. The box arrived via our fine postal service, in a rather sad state. Accordion'ed for most of it's length, no single panel of the box was undamaged, and a rather large hole had been covered by some randomly-applied packing tape. Most of the contents were ok, except for the 48v power supply.

Luckily, there was a lot of crush-space between the chassis and circuit board... I never thought I'd repair a power supply with a hammer...

The supplier, KelingCNC, was ok with my disassembling it and 'repairs', and say they'll replace it if it doesn't work.

I've already smoke-tested it... it works just fine.

 

[vlmarshall]

Next up, the cute little toolpost from A2ZCNC. All aluminum and Sherline sized, this QCTP falls somewhere between building my own, and buying that Aloris I've always wanted.


Not happy with the chattery finish on the locking cam and center post, I couldn't resist cleaning up the finish on both.

Before:

After:

The locking lever is next. I should have cleaned up that off-center center hole while I was at it.

The BOTTOM of this toolpost was not machined, but left as-sawn! It also wasn't square to the dovetails, cleaning it up took almost .020"

While I was facing the 'post body, I skimmed the two non-dovetail sides, as they were both unmachined raw stock finish, and I'll be re-anodizing the body anyway, since almost every edge on the toolpost was not deburred after machining.

Skimming .020" off the bottom of the toolpost caused the tool holders to run out of adjustment when using 1/4" tools, so I skimmed a bit off of the holders, as well.

The slot for the parting tool is not cut straight, and because it's been machined in YET ANOTHER raw-stock surface, the slightly undersize material causes the slot to fade away to almost nothing at one end. Either that or the burr they left on the dovetail side caused the part to sit incorrectly for machining.

Yet another part for the anodizing bath...

 

[Tin Falcon]

vernon: nice lathe and a heap of goodies. I am planning on converting my little old Machinex to cnc. I do not plan on doing a full build just connector to motos I jut bought . Use the same PS, g540, computer etc that is hooked to the mill. i will have to figure out some sort of quick disconnect for limit switches and a motor connector if and when I hook up spindle control to the 540.
Tin

 

[zeeprogrammer]

I didn't see this when I replied in your other thread...not that I'm sorry for what I said ;D.

Excellent Vernon. You're back in business. Sorry for the troubles.
Shipping issues on the PS is one thing...quality of parts (A2Z) is another.
Good to know.

I've often wondered if I should have gone with that kind of system. There's a lot to be said about the breadth of product Sherline offers...as well as the quality. At the time I wasn't even sure if this hobby was for me....and that affected my decisions. (Having said that...I'm very happy with my decisions...for one thing...I'm enjoying the heck out of this hobby and this forum.)

Hm...wait...I remember you...this calls for a shout.

 

[ksouers]

Vernon,
Congrats on the new Sherline. You already know they are great little machines.

Really sorry to hear about the sad state of the A2Z tool post. I bought one a few years ago for my C2 and it's very well finished.

 

[steamboatmodel]

Hi Vernon,
Does the Shirline have Ball Screws or regular lead screws?
Regards,
Gerald.

 

[vlmarshall]

Hi Vernon,
Does the Shirline have Ball Screws or regular lead screws?
Regards,
Gerald.

Regular thread lead screws. Tiny, too, 1/4"-20. I've seen small Acme thread, but never a ball screw small enough to retrofit... but I'm looking.

 

[Speedy]

ooo very nice!

is it in action?

 

[vlmarshall]

ooo very nice!

is it in action?

Thanks!
It's wired and cutting air, but all of my electronics are scattered all over the desk at the moment, so I'm not about to throw metal chips!

I also need to make a slotted wheel for the spindle index, and get it onto a real stand...but I plan to be cutting parts for my Crackers by this weekend.

 

[Speedy]

sounds goooooood!
lots of videos and pictures..... okay 8) :big: serious tho ;D

 

[vlmarshall]

Here's another lathe update.

To rework that parting tool holder, I couldn't just throw it in a vise, and hack at the tool's seating surface, because none of the outer surfaces of the holder are squared up.
So, I set up the toolpost in my mill, and locked the holder into it's working position.

The first pass should give you an idea of how far out this thing was.
After a few passes, I'd gone in far enough to make the 'shelf' at the bottom the full width of the parting blade, so I cut the step at the top and called it "done".

Hopefully tomorrow, all of this stuff will be re-anodized.

 

[vlmarshall]

All of the electronics are tucked away in a plastic tub, at least for now.

It moves!

Guess I should write some code and actually CUT something... but at least I know the parting tool holder works.
Just for grins I hacked at a piece of brass hex stock with it.

I still need to set up the spindle encoder and speed control...but at least it's making chips.

 

[zeeprogrammer]

Nice.
Did you make that table the lathe is sitting on?
Kind of surprising about the tool holder...where' you get it from?
Is that fellow in back with the hat related to Chip?

Oh...and where are the Crackers?

 

[vlmarshall]

Did you make that table the lathe is sitting on?

Kind of surprising about the tool holder...where' you get it from?

Is that fellow in back with the hat related to Chip?

Oh...and where are the Crackers?

Ha, thanks. The "table" is really just a board like Sherline suggests, nothing special. It's actually louder than I'd like, kinda rumbly.

The toolholder came from A2Zcnc. I sent 'em an email, complaining but not really demanding anything, to which they never responded. No matter, eventually I'll make a steel version of the toolpost and holders.

I expected that the yellow flowery wallpaper would get more attention than the 'robot head' in the background.

Lastly, the Crackers... have their own thread.
Ok, really, they're sitting on a bookshelf off-camera.

 

[vlmarshall]

Well, I've re-anodized the tool holders, and I'm working on setting up EMC to see the spindle index pulse from one of the two currently unconnected cards in that box of electronics.


I'll probably also work on that speed controller card as well...if I feel brave. It's a card from CNC4PC, that replaces the speed control pot with a 0-10v signal under computer control. A year ago I tried using this card on my mill, missed the bit in the instructions about using an ISOLATED power supply, and burned out the motor board in the mill.

Not sure I want to play with THAT again.

 

[vlmarshall]

:big: Ha! :big: I just got the software-controlled spindle working. This task caused me much trouble a year ago when I tried it on the mill, only to burn out my mill's motor controller. Tomorrow I'll add a "Manual/Off/Computer" toggle switch to the Sherline's control box, neaten up the rest of the wiring, and calibrate the speed with a tachometer from work.

The last obstacle is the spindle index pulse...

 

[1hand]

Glad to hear your project is coming along great. I wish I wish I was there too, and have the knowledge to know what your talking about. :-\

Sooner or later this will all start making sense........I hope.

Matt

 

[vlmarshall]

Thanks!

Sooner or later this will all start making sense........I hope.

It will, you'll see. Get your Gecko, stick some steppers on the machine, everything else will come together one step at a time.

 

[zeeprogrammer]

The last obstacle is the spindle index pulse...

Last obstacle to...what? ;D

Naturally, I've been interested in knowing what the hold up is with my beer.