# My homemade bar puller for my CNC lathe.



## rgray (Apr 1, 2019)

I made this "bar puller" from a scrap piece of 1" exhaust tubing.
I still push the "go" button for every part. I haven't gotten brave enough to program it to continuously work.
Mostly because it's not super reliable. It's not spring steel so after some parts I had to adjust the diameter when it failed to pull the bar the entire distance.
I'm no programer so it took me some doing to get this to run.

Initially I programed a G1 for the puller to go to the bar as I thought that way I could control speed.  That doesn't work as the spindle is stopped so tool is also stopped.

Then I fought the lathe just stopping at some point and I guess it was it didn't have a rotational speed command. This lathe has speed commands under turret 2 program so confusing sometimes. I put speed commands everywhere trying to get it to work and that rev right before the first bar pull seemed to be what made it cooperate.  Odd as later it pulls the bar without that same "rev" beforehand.

I had to add a chamfer to the cut off at the end as the bar puller would move in and run into the bar and push it into the collet. (only did that once that was enough).

The view isn't great. my waterproof Gopro housing deteriorated in a matter of months inside the lathe cabinet. Guess it couldn't handle the coolant. So video was shot through the door window.


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## JimDawson (Apr 1, 2019)

Is that one just spring loaded ''jaws'', or does it work off of turret coolant pressure?  You can't feed in a tool with the spindle at zero speed?

I bought an Easy-Puller for mine, seems to work well.


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## rgray (Apr 1, 2019)

JimDawson said:


> Is that one just spring loaded ''jaws'', or does it work off of turret coolant pressure? You can't feed in a tool with the spindle at zero speed?



It's exhaust tubing from an old race snowmobile I had in the 90's.
Karl T said months ago (in your cnc thread) just build it from scrap. So that's what I did.

Two cuts across the end and squeezed down to have some grip on 1" bar stock.

The part has a chamfer so it just pushes on. Had to add the chamfer for the cut off piece to make that work.

Goes on not rotating. But when writing the program the lathe would just stop. No alarm no clue. So adding the speed command made the program continue on, the rev then M5 to stop spindle and then it continues on.

I'll have to mess with it and see if I can make it work without the rev up. Seems silly, but I'm happy it works, I spent all day yesterday figuring it out.


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## rgray (Apr 1, 2019)

JimDawson said:


> You can't feed in a tool with the spindle at zero speed?



Yes it will rapid a tool to position with the spindle stopped. I have had it do that before and stop and do nothing until I pressed the coolant button, then continue on and stop again waiting for me to release the coolant button.
Somehow when hitting the emergency stop button it can get the relay activation backwards or command backwards.
I learned this by chance. Lathe would stop, I'd look at the screen and M8 was next line, so I pushed the coolant button and off it goes (surprise).

Once the machine has been completely shut down it goes back to normal, but as a new user with my first cnc I spent some time figuring that one out.

Thought something like that was my stoppage when commanding the bar puller, but I don't think it was. I'm really just stumbling along here.


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## JimDawson (Apr 1, 2019)

That is a bit strange.  Sorry, I can't help you with this one, I've never seen a Mori before.


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## rgray (Apr 1, 2019)

JimDawson said:


> Sorry, I can't help you with this one, I've never seen a Mori before.



Fanuc 6TC   from 1983. That probably doesn't help either, but I thought I'd throw it out there.


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## JimDawson (Apr 1, 2019)

rgray said:


> Fanuc 6TC   from 1983. That probably doesn't help either, but I thought I'd throw it out there.



Nope, doesn't help much.    That's a real antique.


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## rgray (Apr 1, 2019)

I'm always amazed that it still works!!!


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## rgray (Apr 2, 2019)

Little update. I swore the turret was moving away to fast outrunning the collet closing and pulling extra length bar out.
I slowed the video down and could see that that wasn't happening. Not in the piece in the video anyway.
Thing is that by chance was the last of the bar, so it was light.
After the video I put another 6 foot bar in and started again. The quick movement of the axis (start/stop) causes the bar to slide farther into the puller
making a longer part, and leaving a to long starting length for the facing op of the next cycle.(no sure of this???)

I fixed that with a few G4 dwell lines giving the collet time to clamp before the puller pulls away.
Not entirely sure my theory on that length variance is correct. Originally thought  the puller was pulling more length as the turret speed out ran the collet closing, but then it should have been better with the full lenght bar as it would be heavier and harder to move, but it was then worse.
Leading me to think the inertia sliding it deeper into the puller. Sounds a little far fetched. I don't know.

Somehow the dwell make the length come out right very consistently (so far). It is a pullback collet so maybe the dwell makes it's clamping more consistent. Bar got pulled out .315 to far after first part was machined (a little much for the facing) I hit the E-stop, added the dwell codes and it has been good.


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## JimDawson (Apr 2, 2019)

I have seen inertia change the position of the bar.  If the puller does not grip the bar tight, that could be a problem.

You might slow down the pull cycle, I think mine is at 50 IPM.  I also use a positioning stop in the turret which pushes the bar to where I want it before closing the collet.  I final position this at 20 IPM so the inertia is not a factor.


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## rgray (Apr 2, 2019)

JimDawson said:


> You might slow down the pull cycle, I think mine is at 50 IPM.



I'll have to "hit the books" as I don't know how to slow it down.
I wanted it slower and thought I could G1 feed rate control it, but no dice....no feed rate when spindle is not turning.

I'm having a duh moment....It's as simple as turning this dial isn't it?

But that would slow the whole program right?
I use the 25,50,100 selector when testing programs, but have left the large dial where it is.


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## JimDawson (Apr 2, 2019)

That is a problem, I forgot about your G1 issue.  Not sure how you can fix that one, maybe there is a way to override it someway.  I guess you can do what I did and rip out everything that said Fanuc on it.


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## JimDawson (Apr 6, 2019)

I just had another thought, try issuing a G98 (inches/min) after the G5.  This might allow the X and Z to move when the spindle is stopped.  Then issue a G99 (feed/rev) again after the bar pull.


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## mmcmdl (Apr 6, 2019)

That brings back memories . I still have a bar puller sitting down the basement from 1999 . Used it on a Makino Slant bed with a Funuc 6MB ? Or TC ?  My memory isn't that good to remember , but , I guess I can safely say I dodn't need the puller any longer .


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## rgray (Apr 6, 2019)

JimDawson said:


> I just had another thought, try issuing a G98 (inches/min) after the G5. This might allow the X and Z to move when the spindle is stopped. Then issue a G99 (feed/rev) again after the bar pull.



Thank you. That looks like it will work. I'll report back after I try it. I've switched programs to machine the opposite end of the part so it will be a couple of days before I have them all run.

Little tidbit about the machine approaching the work and waiting for me to hit the coolant switch.
It did that again on my program for the opposing end of these parts. I wrote the program and then run the first part and everything was normal.
Then running second part turret 2 approaches the work and stops and won't proceed until I push the coolant button.
I had not used the E-stop, so my theory of that being the cause was not it.

I shut the machine down and restart. Run another part and it runs all normal. Second part turret 2 again stops and waits for coolant button.
My programs were not self resetting and by fixing the end of the codes so they rewind/reset then everything worked normal.
I had put the M30 at the end of turret 2 as it is the last turret to run. Putting M30 at the end of each turrets program fixed that.

I'm learning and I'm having fun with it, and that's what counts.


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## rgray (Apr 6, 2019)

mmcmdl said:


> That brings back memories . I still have a bar puller sitting down the basement from 1999 . Used it on a Makino Slant bed with a Funuc 6MB ? Or TC ?  My memory isn't that good to remember , but , I guess I can safely say I dodn't need the puller any longer .



For sale?
My 29 cent puller worked flawlessly for about 100 parts (200 pulls) so I can't complain. But and official puller might be nice also.


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## mmcmdl (Apr 6, 2019)

rgray said:


> For sale?
> My 29 cent puller worked flawlessly for about 100 parts (200 pulls) so I can't complain. But and official puller might be nice also.



If it'll fit your turret , sure . I'll never use it again . It has the round shaft with the grooves cut in for mounting in the turret ( forgot the name of the mounting system )   , got a couple sets of jaws for different pulls etc . I'll post a picture of it on this thread when I can .


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## mmcmdl (Apr 10, 2019)

Found the puller all as well as some other goodies for other folks with Atlas lathes . Im finding things I my scrap buckets !

Anyway , it's a Berg puller that mounts in your turret . Wanna pic ?


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## rgray (Apr 10, 2019)

mmcmdl said:


> Wanna pic ?



Yes, please


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## mmcmdl (Apr 10, 2019)

Heavy duty bar puller . The shank is interchangeable if your turret is different . 1/8"-3.750 or so . Not sure if you need one this big .


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## rgray (Apr 11, 2019)

Bigger than my capacity but would probably work fine. My draw tube is 1.7 I.D.
How much you want for it?


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## rgray (Apr 11, 2019)

Here is the second side machining of the tap holder from the first video.
I ran all these last weekend, but saved 3 for the video. I was waiting for that waterproof GoPro housing. It came in and I made a video and it was
terrible. The coolant was spraying the camera so bad you couldn't see much.
So I changed the camera location to the opposite end of the cabinet and it is better.


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## rgray (Apr 12, 2019)

JimDawson said:


> I just had another thought, try issuing a G98 (inches/min) after the G5. This might allow the X and Z to move when the spindle is stopped. Then issue a G99 (feed/rev) again after the bar pull.



So I reloaded the program and put some G98 & G99s in and all works great once I figured out where to put them.
Like the speed commands when I was lacking them to make my turret move I've probably entered more than I need.
Now that it works I'll have to delete some and see what is actually needed.

I got some alarm codes I'd never seen before.

One odd thing I can't figure out is the lathe will run the program through and reset so all I need to do is push cycle start to run another part. 
This is same as was before.
But the second time you push cycle start it proceeds as normal till the first tool I'm calling on turret 2 (spot drill)  G1 X0. Z-.07 F.004; the lathe puts the tool in place and them stops and turret 2 has a 011 alarm (the feed rate was not specified for cutting feed or the feed rate was inadequate)
Originally I had the feed at .002 changing this number makes no difference as far as I can tell.

This makes no sense to me as it does not alarm on the first run.
Hitting  the E-stop and then shutting down the display power and then rehoming will make it proceed into spot drilling with the tool offset missing.
Another E-stop as it tries to spot drill the side of the part.
Shutting completely down and restarting makes it work perfect for another part and then same thing.
Any ideas?


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## JimDawson (Apr 12, 2019)

Maybe add a G99 after (before?) the tool change


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## rgray (Apr 13, 2019)

JimDawson said:


> Maybe add a G99 after (before?) the tool change



That was it. Thanks so much for the help. I actually struggled with that when setting up the bar pulls. After the first pull is the cutoff and the tool would advance and stop at the no-turning rod and I had to add the G99 to cancel the G98 so the spindle could run and make the cut off.
What I didn't do was cancel the G98 from the second bar pull.
What is odd to me is how it would machine the first feature (turret 1) switch to turret 2 advance the turret to the work and then alarm and stop.
If G98 was active the spindle should not have turned for the first feature.
Oh well works great now. This machine is smarter than I am. Tells me what is wrong and all. Gives clues anyway (feed rate wrong) yep spindle not turning feed rate is wrong.LOL
Did an updated video. Moved the camera to the back cause the coolant spray was so bad where it was. Unfortunately that makes it harder to see the bar pulling/collet action. There is a light in the way so to get the needed height I moved the camera right and up. To see the bar pulling better I should have moved left of the light.


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## JimDawson (Apr 13, 2019)

I'm happy to hear that worked.  

It is a real pain to try to get good videos in a lathe.  Looks pretty good.


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## mmcmdl (Apr 13, 2019)

Russ , just got your message . Does your number start with 406 ? Your number didn't come thru but you can give me a yell anytime tonight , I'm here at work till 7am my time . Dave .


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## rgray (May 8, 2019)

I needed to run some brass bushings and being spoiled by the 1" bar puller I just had to make another.
5/8" this time. I made it from a truck leaf spring so it is spring steel. it's way to heavy to be very springy but works great anyway.
if I make more sizes I will remove more material so they might actually spring.

Here's my raw material.




And here it is on the lathe. My intention was to pin and dowel it to the shaft. I did that but when the turret rotates it ran into the 
way covers. I had to redrill a hole to shorten its reach. I didn't bother with the dowel hole the second time, there wasn't room for it between the two holes.
It is bolted to an unhardened piece of O-1 drill rod.




And a video of it in action.
Even turned the coolant off. Figured I could get away with that on brass for 1 bushing.


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## rgray (Jun 5, 2019)

Made another bar puller. This time a 1/2" and 3/8" double ended puller.





Worked great but gripped a 1/2" rod to deep in it's throat for my latest project.
So I built another that is extended out farther and grips the bar closer to the end (of the puller) so my latest
project had clearance to clear the tool holder. Here it is installed.




Works great here's a vid of it working.






These are handles with a 5/16-18 thread. 4130 and here's a pic of them after heat treat and temper.


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## rgray (Jun 19, 2019)

So I got some W1 and was running a few more of those handles tonight, tweaking offsetts, sharpening carbides, changing feed rates, and all that fun stuff. 
Had things working good, but I was still messing with offset on the threading tool. The thread was just a little loose and I figured I'd tighten it up a little. Actually I was changing the value of the cut ....not the offset, and forward slashing / the original figures so I could run the new numbers and have the machine ignore the originals by switching on "block delete". 

So I was watching this particular handle and the program was at the knurling part, and I hear a clunk like something fell down into the chip conveyor.
It finishes knurling, cutting off, and pulling the bar. and I find this.






I haven't been very good about stopping before the stock runs out. and so the collet is closed on nothing every time I use up a bar.
I've been running 3' and 4' bars.
I had decided I would get better at that and I knew I could only get 5 handles out of the 3' bars I was running.
But I guess that was a little to late. My abused collet gave up on me.


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## macardoso (Jul 10, 2019)

Whoops


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