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Author Topic: BT30 spindle from scratch - with power drawbar and ATC of course  (Read 411008 times)

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Offline simpson36

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #350 on: December 13, 2012, 05:07:52 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

Oh my, that monster is your own personal mechanical Medusa  :o   That thing is just a freak!

I will have a lot of questions for you on the controller because that will be my next challenge after the mechanics are completed. In the mean time, I'll just ponder where Medusa keeps putting those things she's holding in her 'hands'  :P

Offline simpson36

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #351 on: December 13, 2012, 05:15:33 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

  I expect the bearings to arrive probably tomorrow,

Ray . .  you don't really think I'm falling for the old 'the bearing is in the mail' routine , do ya?

Seriosuly, what I saw from october looked very nice. I can hardly wait to find time to catch up on what you've acomplished. I'm very interested to see if and how you managed the actuation force at the ebds of the 140 degree sweep.

I really gotta fly now but I'll be participating here in the next few. 
Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #352 on: December 13, 2012, 05:29:34 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

  I expect the bearings to arrive probably tomorrow,

Ray . .  you don't really think I'm falling for the old 'the bearing is in the mail' routine , do ya?

Seriosuly, what I saw from october looked very nice. I can hardly wait to find time to catch up on what you've acomplished. I'm very interested to see if and how you managed the actuation force at the ebds of the 140 degree sweep.

I really gotta fly now but I'll be participating here in the next few. 

Steve,

It was a matter to optimizing the geometry of the arm and air cylinder to the extent I could, using flow control valves on the air cylinder to keep it from moving at 100 MPH, and rubber bump stops at the end.  Very little force is required to engage with the tool in the spindle.  I may end up adding an air damper at the "parked" end to smooth out the stop, but it's working fine as it is.

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 #353 on: December 15, 2012, 08:13:16 AM »

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

  I expect the bearings to arrive probably tomorrow,

Ray . .  you don't really think I'm falling for the old 'the bearing is in the mail' routine , do ya?

Seriosuly, what I saw from october looked very nice. I can hardly wait to find time to catch up on what you've acomplished. I'm very interested to see if and how you managed the actuation force at the ebds of the 140 degree sweep.

I really gotta fly now but I'll be participating here in the next few. 

Steve,

It was a matter to optimizing the geometry of the arm and air cylinder to the extent I could, using flow control valves on the air cylinder to keep it from moving at 100 MPH, and rubber bump stops at the end.  Very little force is required to engage with the tool in the spindle.  I may end up adding an air damper at the "parked" end to smooth out the stop, but it's working fine as it is.

Regards,
Ray L.

My first claw was a fail even though it worked, primarily because it did not have enough spring pressure to retain a heavy tool during extreme decel at the end of travel. Since I am using a servo motor to drive the arm, I will be side stepping all of the challenges of a pneumatic actuator . . albeit at a very high cost. 

I noodled over air driven arm for quite a while before abandoning that route. My design was articulated so there was no problem with the swing range or forces, but stopping the thing at exact point along the travel was something I was not able to work out to my satisfaction.  :-[

You move the entire carousel, so you don't have an intermediate stop to deal with, but it looks like you did run into the end-of-travel issues that I was concerned with. Kudos to you for getting something working!

FWIW, one method that I considered was an air operated metal band positioner. I would have needed an encoder somewhere for the intermediate stop, but it would be a simple matter for put a caliper on the metal band for a positive stop anywhere in the travel. This might eliminate the throttling and damping needed in a free swinging arm. A rack and pinion arrangement is also doable, but enclosing it is a PIA and they don't like the taste of swarf.

Anyway, I'm going to catch up on this thread now and probably have a bunch more comments and questions.
Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #354 on: December 15, 2012, 09:22:44 AM »
Steve,

At the spindle end of the travel, I provided a "hard" stop, to ensure proper positioning.  This consists of just a bolt with a rubber bumper on the end that contacts a small bracket bolted to the side of the head.  At the other end of the travel, I just allow the air cylinder to bottom out.  I agree a servo or stepper is a more elegant, if more expensive, way to do this, and would allow tuning to get constant-speed motion, or even a motion profile that should negate the need for stops, dampers, etc.  I also used prox sensors to ensure each motion fully completes before taking the next step, so if the carousel for any reason doesn't reach the fully engaged position, there;s no harm done, the toolchange simply stops until the jam is cleared manually.  Had I not needed such a wide range of travel (140 degrees), I could've certainly made this work better.  Were I doing it over again (and I still might....), I'd make the carousel fixed, and use a transfer arm.  I have an idea for that which would be quite simple, using a rotating "claw" on the end of the arm, which would articulate such that the claw was pointed towards the pivot when the arm was rotating, allowing the arm to move much faster, with no worries about the tool flying out.

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 #355 on: December 15, 2012, 10:30:46 AM »
I just measured the swing on mine.  Are you sitting down? 

213 degrees from carousel pickup to spindle. Carousel pickup to the arm 'parking pot' is another 37 degrees.

Total swing 250 degrees!  :o  I doubt I could even articulate that much swing.

140 degrees would be no problem though, if you wanted to add that. Would be very simple and give you close to full power ate each end of the swing. 

What processor are you using to control the sequence and read sensors?   ( Speaking of processing, I have a lot of questions about your Kflop project. Is there a thread going on that?)

Offline simpson36

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #356 on: December 15, 2012, 10:55:40 AM »
. . .  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 :(
Hood

It is working, but you don't have the controller yet? How does this happen?  What did I miss  ???

Offline Hood

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #357 on: December 15, 2012, 01:29:34 PM »
. . .  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 :(
Hood

It is working, but you don't have the controller yet? How does this happen?  What did I miss  ???

Mach is talking to my PLC :)
Got it fully working today, few days back I jumpered a wire to the Tool 9 coil so it will now raise and today I got the cylinder/prox's and arm fitted to Tool 10 and arm to tool 7. Only thing I have to do now is make up some doors for a couple of the holders, using tape on one at the moment ;D
Heres a vid of all 12 tools being called, http://youtu.be/oJ8KAuzgSjE
Forgot to screw the damper on the cylinder of tool 10 so it comes down with a clunk but I think I might just manage to get my hand in to damp it, if not I will drop the cylinder and get it done as I dont like it hitting the end so fast.

Hood
« Last Edit: December 15, 2012, 01:41:15 PM by Hood »

Offline BR549

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Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #358 on: December 15, 2012, 02:32:16 PM »
"DANGER Robin Hood DANGER"

(;-) TP
Re: BT30 spindle from scratch - with power drawbar and ATC of course
« Reply #359 on: December 16, 2012, 01:28:46 AM »
I just measured the swing on mine.  Are you sitting down? 

213 degrees from carousel pickup to spindle. Carousel pickup to the arm 'parking pot' is another 37 degrees.

Total swing 250 degrees!  :o  I doubt I could even articulate that much swing.

140 degrees would be no problem though, if you wanted to add that. Would be very simple and give you close to full power ate each end of the swing. 

What processor are you using to control the sequence and read sensors?   ( Speaking of processing, I have a lot of questions about your Kflop project. Is there a thread going on that?)

Steve,

Nope, you're not going to do 213 degrees without a 4-bar linkage.  I considered that approach, but it's too difficult to design to get the desired motion.

Right now, it's running entirely on the KFlop, but I'll be moving it to an Arduino shortly.  Actually, I'm moving most of my external devices (coolant, PDB, ATC, pendant, control panel) to a network of Arduinos.  It will really cut down on I/O usage on the KFlop, and the amount of wiring in the whole systems.

Ask away on the KFlop.  No thread on that topic.  Wouldn't really belong here on the ArtSoft forum, given that I'm using my own home-grown CNC controller app, rather than Mach3.

Regards,
Ray L.
Regards,
Ray L.