DIY tool changer fully integrated with PathPilot

I've converted my machine from Mach 3 to PathPilot. Mostly very simple - except the ATC I built for Mach 3. Getting it to work with PathPilot required an all new controller with firmware to emulate the behaviour of the OEM ATC.
This is its first try out and there's still some fine tuning of the motion control parameters to get the best out of it, but at least the functionality's now on a par with where I was with Mach 3.
I am trying to get the controller into a manufacturable condition. Latest info on progress is at xoomspeed.com/CNC/atc/atccontr...

[@Nordic_Goon]

I'm really looking forward to this. I hope you see it through to production.

[@billstrahan4791]

Fantastic work. I'm a really good cook. Come stay at my house, build one for my 1100MX, and I promise a good meal every day! ;) Kidding aside, really nice work. Gotta be a great feeling!

[@MrJTJINX]

Spot on mate, its looking really good, a tiny nudge when the engraver got picked up but like you said its still getting tweaked. I agree with the spindle delay its a royal pain, im trying to set up the VFD on my home build and its ramp up coupled with pathpilots delay is making it a pig to set up. I dont think its a hard issue to fix just concentrating more on getting the machine running. still not designed and built the power draw bar yet, work in regress as they say. Jason Snyder has left a message aka Nerdly, that’s it man you have made the big time. we will have to get you a plug from Grimsmo and NYCCNC. Jason started a project ages ago with an Asian 5 axis trunnion, we will have to get him to go back and finish it. Still not sure how to get a 5th axis out of PP but 4 axis on a budget is a damn good start.

[@daleksw]

Good job spotting the nudge on the engraver. That's a sign of just how difficult it is to make an ATC work with TTS. To avoid tool pull out, the drawbar is always done up as tight as possible, but that means it barely opens and there's almost no clearance for the ATC to aim at to get the tool back in. That in turn means the whole carousel assembly has to be very accurate. One mistake I made was mounting the forks on the bottom of the carousel disk instead of the top. That means the parallel-ness of the disk becomes part of the tolerance build up. Correcting that would mean turning a new spindle and of course, that has to be very straight and the mounting surface true. Since it's all stepper motor driven, I could have programmable rotation and extension for each tool, but that really would be a pain to set up. All that's before you realise/discover just how important it is to have the carousel disk normal to the mill's z-axis to avoid tools getting jammed half way into the collet. Not easy at all to get it even this good, so hardly surprising how many people struggle with the oem ATC and the large amount of backlash it seems to have in the rotary motion.

[@MrJTJINX]

@@daleksw Im going to chicken out and use a rack. The spindle is like a pillar drill/Bridgeport, so i get about 10 inch of total travel. The ATC electronics/board will still get built (perhaps). but its only going to control the power drawbar for now. That should get me close. Your ATC is looking really impressive, its somthing like the fourth of fifth ive seen on youtube but looks more like the dogs doodars than the others ive seen.

[@NerdlyCNC]

great content!

[@impba3548]

;very nice work David! I like the smoothness of operation.

[@daleksw]

Glad you like it! It's the advantage of using steppers rather than pneumatics to move things. You get to control not just position and speed, but also acceleration and that's what makes the movement so smooth.

[@impba3548]

@@daleksw air is ok for some things, hydraulic or mechanical if the positioning is important, I think Tormach could use some of your expertise on their tool carousel!!

[@irish-simon]

just an idea if you put the 5th axis on the right side of the table you would then not have the clearance issue

[@Rickteg]

Nice work David, still waiting g for my mill to show up, do you have a guide for setting g up with pathpilot i have never worked with it yet so I take it your using I/O usb of some sort with relays possible a 4 relay switch

[@daleksw]

The electronics mimic the behaviour of the Tormach ATC. There's 2 x step/direction stepper outputs, opto-isolated outputs for air blast, draw bar and spindle brake and inputs for manual draw bar control, air pressure sensor, spindle motion sensor and home switches for the steppers. Connection to the controller is USB and you need to copy one small text file so it picks up the correct device name when plugged in. After that, just tell PathPilot you have an ATC and it works exactly the same as the oem ATC.

[@bradyb.3257]

Hi, I was wondering if you would be open to answering questions, as I am embarking on designing my own ATC for a path pilot tormach machine

[@CR3DT]

very nice, what probe is that on your ATC please?

[@daleksw]

The probe is one of Tormach's passive probes fitted with my wireless conversions. See xoomspeed.com/CNC/wirelessprobe.htm for more info

[@shaneclendennen1929]

So what are you using to transmit the trip signal on your probe

[@daleksw]

It's one of these shop.xoomspeed.com/collections/cnc-accessories/products/wireless-probe-kit

[@joshwarner5676]

What is keeping the tools from sliding out when the tool changer rotates?

[@daleksw]

The blue plastic parts you can see under each fork are 3d printed 'springs' They extend a few degrees around the front of the tools and have just enough tension to stop them coming out, but not enough to stall the linear motion.

[@ronincito]

Hi David, how do you automate the edge finder operation?

[@daleksw]

The probe is a Tormach passive probe converted to wireless operation see xoomspeed.com/CNC/wirelessprobe.htm and kzbin.info/www/bejne/g5rUlpaXgtmYqdE It's controlled via Fusion 360's WCS probing routines via my post-processor. See xoomspeed.com/CNC/FusionPostProcessor.htm for the download and links to various youtube tutorials on how to use.

[@ronincito]

@@daleksw That is amazing. Thanks for you answer and congrats for your work and contribution.

[@nobox1534]

About to buy a 440. Would love to buy a set of plans from you to make my own ATC and save $4K!

[@daleksw]

Thanks for the interest. I'm hoping to be able to offer fully assembled and tested electrical/electronic setups together with access to the (Fusion 360) models of how to make it. Won't save you all of the $4k, but a big chunk! The only bits you won't be able to make on a 440 are the spindle for the carousel (needs a lathe) and the panels for the sides of the box (too big for the 440's table so laser cut). I may be able to get those made at reasonable cost and if so it'll all be added to my web shop in a couple of months. Keep an eye on shop.xoomspeed.com/

[@Nordic_Goon]

@@daleksw please keep us updated. Yours appears to be so much nicer. I love that it isn't pneumatic.

[@daleksw]

I am making a determined effort to get everything into a state that can be supplied people who'd like to build one for themselves. Details are at xoomspeed.com/CNC/atc/atccontroller.htm

[@Nordic_Goon]

@@daleksw This and the wireless probe are two things I am desperately trying to get right now. Power drawbar is on the way already, just really want to build the ATC. Definitely some awesome factor to this and isn't going to rely on an air compressor. I feel like that is huge.