Setting up FTC (Fast Tool Change) on Desktop?

[rcnewcomb]

Has anyone set up their desktop to do fast tool change the way the yellow machines do?

If I get the ShopBot desktop unit I'd like it to behave the same way. For me this was more repeatable than using a movable zero plate.

I don't mind updating the Aspire post processor if I need to. I assume I'd also need to create a custom cut.


Workflow:
In Aspire I design the project with Z-zero set to the spoilboard.

I save out the toolpaths as though I have an automatic tool changer -- i.e. multiple tools in a single file using different tool numbers.

When a tool change is needed it pauses, I change the bit and it touches off the zero plate. The zero plate is permanently mounted just outside the spoilboard. The z-zero routine knows the offset to use between the permanently mounted zero plate and the spoilboard. (You have to update the value every time surface the spoilboard)

After touching the zero plate it resumes the file with the new bit.

[srwtlc]

Randall,

You can use TS (Tools/Shopbot setup) in SB3 to set it up for using your desired location for Z zeroing etc. You can use the ShopBot_TC_inch.pp or ShopBot_TC_mm.pp as your post processor, which will prompt for toolchanges and use your Z zeroing location. If you don't already have those in Aspire, they can be found in the SB parts folder (C:\SbParts\VCarvePro_forShopBotPosts).

If you don't already have one, you'll need a prox switch on the Z axis. You'll also need to make sure that your tool #'s are set up properly in your tool database. That format is shown in C:\SbParts\Custom\MTC\MTC.sbp, but your main concern would be... Head 1 (Z) tools are #1...#19.

[scottp55]

Randall,
All new Desktops have an upper Z prox, also any 4"Z that have had the Z-upgrade kit installed(kit about $255).
At 0,0 you only have -.5" before the prox hits at a C3.
At 24,18 I have proxs set within .125" of the hard stops, and you hit prox at about 24.375,18.375.
I suppose (depending on what you're doing) you could set your your fixed Z touch off at that corner, but might make tiling 1/4 sheets awkward.
Have you considered the Desktop Max?
It would be almost impossible for 2 people to man handle, but plenty of room at the 36,24 end for your touch off.
If you belly up to the VFD, 0,0 is at lower left(see pic of a brand new Max in ND).
All our production files are Z'd at 12,12 spoilboard as home position , and right next to the spoilboard hold down bolt(so it doesn't change much) and a bit change/Z is only 3 minute average, and not too bad.
Looked at FTC when we were considering Stinger 1 way back when.
Hope any of this helped a little. Sweet Machine:)
scott

[Kyle Stapleton]

Here you go Shopbot FTC http://www.shopbotblog.com/2016/02/new-shopbot-accessory-the-pressure-sensitive-z-zero-plate/

[scottp55]

Pretty neat Kyle!
I hadn't seen that.
You going that route with the kids?
Losing the alligator clip time isn't an issue, as on both of ours we've NEVER clipped to nut or the bit EVER in over 2 yrs:)
But then we don't use non-conductive bits either.
Got to see what overall thickness is, so maybe I could pocket one.
Wonder if you have to disable limits to get to X-1?
scott
Funny, hadn't seen this in store either:)
http://store.shopbottools.com/products/3-axis-zero-plate

[scottp55]

Sorry if this is Jacking Randall, but been talking to David Preiss the designer and just thought it might interest you?

"Hey Scott,



Glad to hear you’re interested. The plate is 0.828” from the aluminum base to the top of each of the 6 button head bolts above the blue HDPE cap. Base to the HDPE cap is 0.72.” If you don’t mind I’d be interested in hearing how height factors into your decision as we have plenty of time to make design changes and could probably accommodate what you’re after? I will get on updating the blog to include this.



We are setting the price at $150.



Also I saw from your forum post the question about disabling limit switches. There are some strange cases here but essentially on a desktop the limit switches are by default only considered homing switches, so they won’t act as true limit switches (there’s also only one per axis unlike a bigger tool). So on a desktop you can crash the tool in the X and Y without the software stopping you. This behavior is determined with a VN and then setting limits to off or on. On all of our other tools the limit switches act as true software limits (mounted ~.125 from their hard stops) and then the C3 offset covers the rest of the over-travel. So a desktop is the only place that your negative X and Y values could potentially be triggering a switch and they are by default setup to not interrupt a cut. Hope that helps and let me know if you have any other questions!"

"Hey Scott,



Sorry it’s easy to forget that there are so many custom tools out there! It seems like in your case pocketing in would work fine especially if you can sacrifice some travel. Worth noting that spoilboard adjustment is necessary for getting this setup to work on any desktop, so there is a sweet spot where you have enough –x overtravel and are just getting about 0.25” of overtravel on the +x side. Basically the –x side just starts hogging most of the extra travel by shifting your spoilboard in the +x direction.



Also I suspected and have confirmed with Ryan that you don’t actually need a Z-prox switch to use the ATC-post for an MTC (manual tool change) so this setup should work with older desktops regardless of upgrade."

Regards,
Scott

[rcnewcomb]

I appreciate the follow-up. This looks like what I would need.

[scottp55]

Actually thought about you yesterday when thinking about Demo'ing for a guy Saturday who want's a Desktop for small, fine detail.
I was looking at my slate and soapstone like a fox looking at a chicken:)
I'll blame you if I make a hash out of a 1.16 X .7 X.1" Moose.
Might as well dive in with an audience:)
Thanks for making me think of Stone.
(Doing a Bloodwood first for practice)
scott

[Kyle Stapleton]

Nope, we are just using the old zero plate.

[scottp55]

Thanks Kyle,
Have a friend in Durham now for Basic Training for his Max.
Just asked Dianne if he could meet David and maybe watch the Desktop do the Z routine with the plate so I can quiz him later:)
I can see why Randall might be interested as that was a feature on the Stinger I didn't want to give up.
Glad I did though, as moving 350 pounds vs 120 like now is SO much better in my small shop.
MIGHT be good for our production Desktop though.
scott