CNC Sherline Lathe Project

[vlmarshall]

Last obstacle to...what? ;D
Naturally, I've been interested in knowing what the hold up is with my beer.

Arrrgghhhh....

 

[vlmarshall]

Well, yesterday I got the spindle tuned to within 10rpm of commanded no-load speed, through the 0-3000RPM range. This assembly is going so much better than my mill did years ago. The boards from CNC4PC (breakout board, spindle speed, and spindle index cards) and Gecko stepper-motor drivers are in a completely different class from the old Xylotex system.

 

[1hand]

and Gecko stepper-motor drivers are in a completely different class from the old Xylotex system.

Better?

 

[vlmarshall]

Absolutely better. Not only does the higher voltage (48 vs 24) give more power and speed, but the Gecko has some internal programming called "midband resonance dampening" which kills the high-speed stalls common with other drives. Look on YouTube for Stepper Dampener or such, or I'll post a link here later, and you'll see a Xylotex machine locking up without "harmonic balancers" added to the stepper motors.
I've got 'em on my mill, and it does help some, but it's nothing like this lathe system.

 

[Tin Falcon]

When I forst looked into cnc I was very tempted by the xlotech and it does get used sucessfully but I was wisely steered toward the gecko. The xloteck has a rep of being over or maginaly rated and easily gives up its magic smoke. It is rated for 24 volts not 25. IIRC I am running 36 in my gecko .
Tin

 

[vlmarshall]

Xylotex has also made a revision, and refuses service (not just warranty, but SERVICE) on older boards like mine. needless to say, I don't have much faith in the thing now. I've been helping my parents build a CNC router for woodwork, and when they got that Gecko 540 I was just plain speechless.

Speaking of service, each axis in that G540 is a separate card, actually using the a variant of 251's like I now have, so burning out something doesn't mean you've ruined the whole system.

 

[Tin Falcon]

Speaking of service, each axis in that G540 is a separate card, actually using the a variant of 251's like I now have, so burning out something doesn't mean you've ruined the whole system.

That is one of the things that sold me on the 540 and in the unlikely event one does go bad just put the a axis driver in the slot of the offending driver and order a new one .
Tin

 

[1hand]

That is one of the things that sold me on the 540 and in the unlikely event one does go bad just put the a axis driver in the slot of the offending driver and order a new one .
Tin

That is a great Idea if something where ever to happen.

Matt

 

[vlmarshall]

I've done that drive swap at work, on the Haas mills. It's great for getting a job out the door in a pinch. Even better at home, where time is more valuable than money. ;D

 

[vlmarshall]

Well, it works. After two weeks of struggling with it, I can finally singlepoint threads with this lathe.

The Sample threading program that comes with EMC was pretty rough with mismatched speed and feed, relying on the encoder to sort things out, but by matching the spindle speed and feedrate I was able to get good performance out of it.
Here's a (long, boring) video of my first singlepoint threadcutting with this lathe. After I got it set up, I decided that, good or bad, I was getting it on video. ;D

[ame]http://www.youtube.com/watch?v=C8zwXztmpEc[/ame]

 

[Maryak]

Vernon,

Great, I'm very impressed. :bow: :bow: Now if only the NC between my ears would drive my hands like that, as it is, if the breath in breath out tape stops............. I've got a problem.

Best Regards
Bob

 

[90LX_Notch]

Vernon,

That's very cool. I love stuff like that. I wish I had the funds.
Also, great job with the credits! :big:

Bob

 

[zeeprogrammer]

I enjoyed the video.
And I appreciated the 'thank you' at the end. ;D

But seeing as it was you...I should have known.
Since you owe me beer, I've tried to be nice in hopes you'd actually pay up...but now...

"Of course you realize, this means war."

 

[bearcar1]

[quote

"Of course you realize, this means war."


[/quote]


Isn't that what Daffy Duck said to Bugs when he was getting his arse kicked? ;D



Great vid Vern', In time I may have to break down and get mechanized, but for now I;ll have to make due with what I have, *sigh*


BC1
Jim

 

[1hand]

Very nice, and fast too. Great job! Thm:

Looking forward to this even more now!

Matt

 

[steamboatmodel]

A great job.
If I may make one suggestion, some thing I learned running commercial CNC. You need to move the start point over from the end of the work so that you are cutting air for about three or four thread pitched before it starts cutting metal. this allows everything to come up to speed and synchronize at the start of each cut.
regards,
Gerald.

 

[vlmarshall]

If I may make one suggestion, some thing I learned running commercial CNC. You need to move the start point over from the end of the work so that you are cutting air for about three or four thread pitched before it starts cutting metal. this allows everything to come up to speed and synchronize at the start of each cut.

Thanks, yeah, I know... This was running a sample threading routine that comes with EMC, and the zero point was...at the bottom of the thread if I remember correctly. Onscreen, it looked like it was going to start threading out where the cutter started chamfering air. ;D I can't wait to start using this thing for real!

 

[wongster]

Hello,

I'm in the process of wiring up the G540 VFD to my Sherline's speed control. Kinda of lacking in confidence to do the job though the KBLC board has now been taken out of the box.

Do you have some pics showing how you wire them up?

Appreciate any help.

Regards,
Wong

 

[ttrikalin]

very impressive!

t

 

[kvom]

Does EMC use a canned cycle for threading?

It looks as if it is increasing the cut depth the same amount each time through. which can be a problem if threading harder material like steel. Optimally you want the cut depth to decrease as more of the tool engages the stock.

Looks like a good system you have there.