[FineLineAuto]

Ray,

We have cut a fair bit of UHMW with the O-Flute bits from Onsrud. They have them specifically for plastics. Leaves a clean finish on the top and bottom and doesn't string out. We use a router and spin them at 8,000 RPMs which is a little fast for them and the finish is still golden. Well worth the money.


Nate
Fine Line Automation
Home - Fine Line Automation

[SCzEngrgGroup]

This was a pretty good day - I finally have something that's starting to LOOK like a toolchanger:

For anyone who is unclear on the concept of a "chain" tool changer, this picture should make it clear:

Attachment 228118

Connect the two free ends, and it reduces to a carousel, which is the base configuration of my ATC:

Attachment 228120

Now wrap it around a wheel, to make the 12-tool carousel.



In the 18- and 24-tool configurations, we simply "break" the chain, and insert 6 or 12 more links, and add a second wheel, with the chain wrapping around both.

I'll likely have the rest of the parts to finish this tomorrow, but it will be several days before I have the hardware to actually assemble it.

Regards,
Ray L.

[AiR_GuNNeR]

Beautiful job Ray. Very impressive.
What cutter are you using for the chamfers?
Eric

[SCzEngrgGroup]

Beautiful job Ray. Very impressive.
What cutter are you using for the chamfers?
Eric

Eric,

Just a 90-degree spotting drill.

Regards,
Ray L.

[bozidar22]

Nice design is there going to be a way to compensate for wear in the chain. Just thinking if .001" develops at each pin on a 24 tool chain that would throw things off by .048"

[SCzEngrgGroup]

Nice design is there going to be a way to compensate for wear in the chain. Just thinking if .001" develops at each pin on a 24 tool chain that would throw things off by .048"

That actually would not matter....

Regards,
Ray L.

[Hirudin]

It's looking great!

This was a pretty good day - I finally have something that's starting to LOOK like a toolchanger:

For anyone who is unclear on the concept of a "chain" tool changer, this picture should make it clear:

Attachment 228118

Connect the two free ends, and it reduces to a carousel, which is the base configuration of my ATC:

Attachment 228120

Now wrap it around a wheel, to make the 12-tool carousel.



In the 18- and 24-tool configurations, we simply "break" the chain, and insert 6 or 12 more links, and add a second wheel, with the chain wrapping around both.

I'll likely have the rest of the parts to finish this tomorrow, but it will be several days before I have the hardware to actually assemble it.

Regards,
Ray L.

[SCzEngrgGroup]

Guys,

Good call on using a straight-flute tool to cut the UHMW. I ran down to the local Ace Hardware, and picked up a Freud 1/2" 2-flute carbide Rabbeting router bit for $19.95. Cuts beautifully, with zero string/fuzz/flash. Very good surface finish as well - better than I could get with the endmills.

Regards,
Ray L.

[MichaelHenry]

Mike,

Cool! Thanks!

But how does HDPE compare to UHMW in terms of stiffness and hardness? Isn't it considerably less flexible than UHMW?

Regards,
Ray L.

Sorry, but I can't help with that. For my few applications, I've used them almost interchangeably but never enough to figure out to eliminate those nasty birds nest burrs. They will be a mess on one piece and almost non-existemt on the next.

You might be best off buying stock in each and compare for yourself.

Mike

Mike

[LeeWay]

Here is a link to compare basic characteristics of common plastics.
McMaster-Carr

I have bought black 1" thick Seaboard from Norva plastics and I know I have seen them list thicker stuff. That stuff really machines well.
I use it as jigs on my router that I cut polycarbonate pieces on. The white stuff can get pretty dirty, but the black always looks great.

[AUSTINMACHINING]

Same here. Trying to chamfer/debur is a PITA. I ended up deburring by hand with a razor blade. I used a heat gun which helped, but my material was white. The only color they stock locally. Heat gun with black may look fine.

[SCzEngrgGroup]

More progress today - Got all the remaining parts for the first 12 tool receivers made. As soon as my McMaster-Carr order shows up, hopefully tomorrow, I can assemble them all. The plastic parts came out just beautiful, using the carbide router bit instead of an endmill, and absolutely no string or flash anywhere.

Attachment 228232 Attachment 228234

Todays parts were interesting to make, because they were so fast - nothing over 2 minutes machining time per part, with as many as 6 tool changes per part. Some tools were only used for as little as 5 seconds. I REALLY could have used an ATC today!

Now on to the carousel/chain drive assembly, then the transfer arm assembly.

Regards,
Ray L.

[rlockwood]

They also sell swivel debur blades specifically for plastics and they work quite well.

Sent from my Nexus 5 using Tapatalk

[SCzEngrgGroup]

Got my McMaster-Carr order today, so I was able to assemble the carousel. It went together really beautifully - everything fits and functions perfectly!

Attachment 228378 Attachment 228380

I hope in the next few days to have the servo motors for rotating the carousel and operating the tool receiver locks mounted and operational.

Regards,
Ray L.

[AUSTINMACHINING]

Great progress Ray, nice work !.

[AUSTINMACHINING]

Great progress Ray, nice work !.

[Tkamsker]

Looks nice i See the Locking mechanic but how does the achine get the holder Out ? Is There a Swing Arm ?


Gesendet von meinem iPad mit Tapatalk

[SCzEngrgGroup]

Great progress today! I've got both servo motors mounted and working, and temporary brackets to make a "stand" so I can use the carousel on the table top for firmware development. What's been really nice is the combination of Solidworks and HSMXpress has made the design and CAM development so much easier, and more reliable, that I almost always get good parts on the first try, and so far have only a handful of VERY minor tweaks to be made to create a production design. Everything has come together really nicely, and with minimal effort. At this rate, I might just have a complete ATC to displayat Cabin Fever next month!!

Attachment 228516

Now on to building up electronics for the development system. I should easily have both servos operating under firmware control in the next day or two. Still need to add the sensors and the tool "lock" coupling - both very small, simple parts.

Regards,
Ray L.

[SCzEngrgGroup]

More good progress today! I now have the carousel rotating under closed-loop firmware control. I need to do some PID tuning, but it's already clear I will be able to position the carousel faster than I had expected, so I expect worst-case tool-to-tool seek time will be on the order of 1/2 second, which should yield a chip-to-chip toolchange time of under 10 seconds. I'll post a video in a few days, once I have the sensors in place, and more of the firmware working.

I'm going to re-design the coupling between the drive motor and the carousel, to allow slight misalignment, to ensure I don't stress the gearbox. I'll probably use a custom Oldham coupling, or possible a flex coupling, if I can find suitable material. I'm also ordering a number of different motors and gearboxes to test. What I have seems to work ok, but I think I can do better. Rather disappointingly, one of the motors I have here for testing was incorrectly built - it's missing one of the sensors in the quadrature encoder, rendering it useless.

Regards,
Ray L.

[keithmcelhinney]

Ray you need to come to my house. It took me 4 days to do my jig system and I still am not done! Haha!