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Author Topic: BT30 spindle from scratch - with power drawbar and ATC of course  (Read 400237 times)

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #340 on: December 03, 2012, 12:04:59 AM »
"You're creating solutions in search of problems."

Might just be... You are not the first person to tell me that... lol...
Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #341 on: December 03, 2012, 12:23:00 AM »
having studied how you did your stepper/planitary gearbox PDB, I will now eat crow and tell you that it is genius. I now get the relay selecting the current limiting resistor and that is really smart.

Does it tighten at 25ftlbs by rotating a set number of degrees/rotations, and if the motor stalls (stall point set by current limiting resistors) then it is tight?

Opening is at 75ftlbs, rotating a set number of degrees/rotations and it does not stall, just rotates a certain amt to effect release?

Am I getting this right?

I use G203V's, and if I were to do this, I would have to make sure the motor did not hard stop, as this would fault the drive (red light) and require a reset. Now I do resets by de-powering, It does not look as if the 203V's have the ability to be reset except for by de-powering...

is the air cyllinders down force suficcient to lock the air cylinder in position on the loosen stage, so that the R8 toolholder is forced into the fully loose position? if not, how did you accomplish the downward hammering motion to effect loosening of the collet?
Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #342 on: December 03, 2012, 01:11:43 AM »
You've got it basically correct.  Current limiting in the Gecko determines torque.  I limit torque during tightening, and run full torque for loosening.  I loosen 1-1/4 turns, and on tightening I go 1-1/2 turns, stop, the go an additional 1/4 turn.  In most cases, the first move will stall near the end, and the second is just ensuring full tightening torque is reached reliably.

There is no reason this would not work just fine with a G203V.  When the drawbar stops, the Gecko will limit current, and should not fault.  It will only fault if the motor outputs are shorted.

Yes, the air cylinders provide enough down-force to pop the collet free of the spindle.  Wouldn't be a workable PDB if it didn't.  There is no "hammering" motion, it is simply about 300# of down-force.

Regards,
Ray L.
Regards,
Ray L.

Offline simpson36

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #343 on: December 13, 2012, 04:39:57 PM »

I could, of course, also go with a more complex linkage, but I really don't want to go there unless I have no choice. 

Oops! I was going to suggest you articulate as that is what I decided I would need to do when I was considering and actuator similar to what you have . . .  but  . . uh . . never mind.

Hey, is that friggin' thing done or WHAT??!!

My 60 day project is completed. I have another project that will be wrapped up in about a week and I have material on its way to finish my ATC.

Tick Tick Tick  . . do I smell Chili Beer?   :D

Online Hood

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #344 on: December 13, 2012, 04:44:13 PM »
Hey Steve, not sure if you saw it or not but heres the Chirons changer working :)
http://www.youtube.com/watch?v=pILjZ-JXCRQ
Hood

Offline simpson36

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #345 on: December 13, 2012, 04:51:49 PM »
OK sports fans, I am almost to the point of working on this ATC again.

Here is the feeble sum total of my progress over the last 70 days or so . . a couple of mounts. I included an older shot (second photo) of the arm actuator to show the air cylinder that will drop the arm vertically.

I had some other weling to do to make a new ficxture, so I made up the carousel mounting arm while I had everything dragged out for welding. Then I was doing some surfacing, so I grabbed the arm off the shelf and cut the mounting pad. I was doing some boring, so I grabbed the swing arm transmission mount . .  etc etc. Little bit here little bit there.

However, sometime towards the end of next week, I will be spending about half of my time finishing this thing up. I have some material coming to partially build the new mill head so that I can mock up the final assembly and and start testing.

Oh and incidentally, I have a big fat die spring for the next drawbar and I'll be showing that coming up pretty soon. Bye Bye belleville










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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #346 on: December 13, 2012, 04:57:51 PM »
Hey Steve, not sure if you saw it or not but heres the Chirons changer working :)
http://www.youtube.com/watch?v=pILjZ-JXCRQ
Hood

Yes I saw this thing before so I guess you posted it somewhere. This is the coolest example of mechanical intercourse I have seen in many moons. The tool 'pods' on my carousel are modelled after a setup you showed . . I think it was on a machine you were thinking about aquiring. Does that sound right? This does not appear to be the same machine.

Online Hood

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #347 on: December 13, 2012, 05:02:22 PM »
Unless you saw it in the last few days that was not my Chiron but just a vid pulled off of youtube, I just got the Chiron changer working from Mach a few days ago, still not ordered the controller yet, that will have to wait until the new year :(

The one you modelled your pots on was a Beaver VC5 that was at the same place I bought the Chiron from.
Hood

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #348 on: December 13, 2012, 05:02:28 PM »
Oops. my bad . . . I jumped back into this thread where I left of not realizing there was a ton more stuff that happened after that!

Ignore everything I said, RAY . . until I can catch up on the rest of the progress between October and now. Should make an interesting read, but can't do it just now. Busy busy . . .
Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #349 on: December 13, 2012, 05:06:01 PM »

I could, of course, also go with a more complex linkage, but I really don't want to go there unless I have no choice. 

Oops! I was going to suggest you articulate as that is what I decided I would need to do when I was considering and actuator similar to what you have . . .  but  . . uh . . never mind.

Hey, is that friggin' thing done or WHAT??!!

My 60 day project is completed. I have another project that will be wrapped up in about a week and I have material on its way to finish my ATC.

Tick Tick Tick  . . do I smell Chili Beer?   :D

Steve,

Actually, the ATC is working just fine, I just can't prove it right now....  But it has run literally thousands of toolchanges in testing without a single error.  I went out a few days ago to cut the very first parts using the ATC (the little brackets to hold the "skirt" on the carousel), and ran face-first into an unrelated failure, and I now have the spindle out, and almost the entire head disassembled, waiting for some new bearings and a few other parts to show up.  I expect the bearings to arrive probably tomorrow, but I'll be out of town for a few days, so won't get to work on it again until at least Tuesday.  But, I am hoping that this will *finally* resolve my long-standing "rattly head" problem.  Well, the one on the mill anyway.  I'm pretty sure the other one is beyond hope at this point....

I'm also thinking seriously about buying a Novakon Torus Pro/Servo bed mill....

Regards,
Ray L.
Regards,
Ray L.