Highly Modified Taig with R8 Spindle/PDB and DMM 750W Servo

[ThreeDJ16]

Just realized I've never posted any of my vids here. Guess because I suck at making videos, but here's my current "Work in Progress" mill. The spindle was completely DIY by a buddy including the shaft made from scratch and ground on the bearings. The power drawbar, motor mounts and various accessories designed and made by myself (and input from another buddy who also happens to make the heavy duty frames). Next up we are working on linear rails....then it will be Taig no more....all DIY. Will be adding DMM servos to the axis and finally working on our ATC project (which is still in a bit of flux on the final design and style).

Just posting a link to my channel as it shows the various stages of change with the machine and performance with the mods. Need to get back into some videos as I'd since added a direct spindle encoder and would like to see how much improvements that makes with the DMM servo motor. Also added a foot pedal finally for my PDB using a relay out originally meant for my original spindle motor with just on/off control. Glad I kept it, as now using it active low, I just plug in my foot pedal and PDB solenoid into the plug of that, no worries about stepping on it while in spindle is in operation. Also still have a manual button on the solenoid for changing tools while the system isn't up and running (tweaking spindle and such).

https://www.youtube.com/channel/UCFCKp9J-io2nqvfoKwSETFQ?view_as=subscriber

Here is one vid showing the first run of the DMM 750w servo without spindle feedback (just it's own controller feedback). I've found since adding he direct spindle encoder, analog speed mode was greatly improved. Stays within 1 RPM unloaded and haven't had much chance to mill lately to check loaded. But from past PID feedback experience with a different motor, seemed to keep it within 100 RPM loaded.

Ok, no idea why the embed code isn't working, so here is just a link https://www.youtube.com/watch?v=GfRMmgX2-38

[spumco]

Well done!

I have the exact same PDB footswitch. Could not live without it!

[ThreeDJ16]

Well done!

I have the exact same PDB footswitch. Could not live without it!

Thanks.

I love that thing....best 25 bucks spent....LOL.

We are working on the hard part tonight...dual arm ferris wheel ATC. Linear rail design is finished, we just have to build them.

[ThreeDJ16]

Most all of my build and info on the frames/spindles is located here: https://www.facebook.com/groups/524365887660604/

[spumco]

When you get the ATC done(ish) I'd love to see it. An ATC is about 4th on my list, right after a new spindle & motor, axis servos, and an upgrade from UC400 to UC300ETH (for more inputs and FRO/SRO).

Just spitballing here...

Something to consider if you're doing a dual-arm with stationary umbrella type thing. Unless you're raising the head to clear the TTS or toolholder taper you'll need - I think - some mechanism to lower the arm and rotate it. I think the ticket is a ball spline thing.

If you check prices on commercial ball spline components you'll throw up. I had very good results making my own ballspline thing by using a ball endmill to put three grooves in a shaft and making a collar with matching set-screw holes. Drop a ball bearing in the hole and preload the bearing slightly with some set screws - viola! If the collar had a series of set screw holes instead of just one per groove you could reduce preload and average the contact for smoother linear motion.

The photo is of a spring-loaded engraver I made. Took a fairly hard ER11 straight shank and grooved it, then made a close slip fit TTS holder with the bearing/set screw holes. Polished up the grooves and assembled with a spring. It has essentially zero rotational backlash and very little coaxial or angular slop. One trick I found to help smooth motion was to drill through the set screws and use a ball end mill on the ID surface so it makes circular contact with the bearing ball (instead of point contact). There's nothing very precise about it, but it appears that everything averages out to work rather well.

I wouldn't try to run a 1/4" end mill in it but the same concept could be applied to a toolchanger arm that has to move up and down while rotating with minimal angular slop.

-Ralph

[ThreeDJ16]

When you get the ATC done(ish) I'd love to see it. An ATC is about 4th on my list, right after a new spindle & motor, axis servos, and an upgrade from UC400 to UC300ETH (for more inputs and FRO/SRO).

Just spitballing here...

Something to consider if you're doing a dual-arm with stationary umbrella type thing. Unless you're raising the head to clear the TTS or toolholder taper you'll need - I think - some mechanism to lower the arm and rotate it. I think the ticket is a ball spline thing.

If you check prices on commercial ball spline components you'll throw up. I had very good results making my own ballspline thing by using a ball endmill to put three grooves in a shaft and making a collar with matching set-screw holes. Drop a ball bearing in the hole and preload the bearing slightly with some set screws - viola! If the collar had a series of set screw holes instead of just one per groove you could reduce preload and average the contact for smoother linear motion.

The photo is of a spring-loaded engraver I made. Took a fairly hard ER11 straight shank and grooved it, then made a close slip fit TTS holder with the bearing/set screw holes. Polished up the grooves and assembled with a spring. It has essentially zero rotational backlash and very little coaxial or angular slop. One trick I found to help smooth motion was to drill through the set screws and use a ball end mill on the ID surface so it makes circular contact with the bearing ball (instead of point contact). There's nothing very precise about it, but it appears that everything averages out to work rather well.

I wouldn't try to run a 1/4" end mill in it but the same concept could be applied to a toolchanger arm that has to move up and down while rotating with minimal angular slop.

-Ralph

20190309_145328.jpg

Totally with you on the UC300ETH, I love mine. When i change to DMM servos, I'll be adding a UCBB or swapping to a UB1....undecided.

FYI, might not be what you are looking for, but the spindle I'm using is being sold on the Taig facebook group (https://www.facebook.com/groups/524365887660604/) with PDB and motor mounts for DMM servos. No idea if it's heavy duty enough for your machine, but these are very nice spindles for smaller mills like mine. The unit I have is a beta unit (since I was designing the power drawbar, spindle mount and motor mounts). The production version is all black anodized except the lower bearing retainer ring, which is clear anodized.

As for the ATC, it won't be an umbrella style, we are doing a ferris wheel since space is limited and the TTS tool which is to be changed (all held with something like a collet and springs for grip and held up with a spring too) will be pushed over 90 degrees (small cylinder or solenoid plunger) and the dual arm (on a linear rail with a linear actuator and rotary actuator) will swing around, grab the two tools, pull down, spin and then pull up. Pretty much going after the design Haas uses. So the spindle will be at the top of the Z and doesn't move during tool changes, only the arm moves and the ferris wheel to the proper tool.

This is the part where I'm stuck. Most of the small rotary actuators I need are either 90, 180, 270 degrees and two position. I need 3 position, 0, 90 and 180.

And my apologies, but the spline deal totally lost me. I'm missing where that is used? We are using an R8 spindle with a 3/4" adapter and solely using TTS holders.

-=Jasen

[ThreeDJ16]

Oh, I get the ball spline deal now. Sorry, had to google it. We were just going to use a linear rail, but this idea looks cool. Thanks.

[Vmax549]

Doing teh hardware side is not too hard to do But the dual arm, Look ahead, hot swap M6 scripting can be a beast to make work in UCCNC as you cannot write to teh tool table from script. And it takes a LOT of outputs and inputs to make happen.


You may want to take a wack at teh M6 macro to run it FIRST before you commit to the hardware side.

A single arm ATC is much easier to do from the scripting side. You can still run it with a Side mount carrousel to save room.

Then later you may be able to work out a dual arm setup and convert what you have.

IF you need help I can show you what I know.

Just a thought, (;-) TP

[Vmax549]

Just to add IF you forget about using the tool table and just use the on screen dros for tools THEN it gets to be much easier to hot swap as you CAN read and write to the DROs in real time. You just will not have access to slot# assignments or any other tool data.

(;-) TP

[ThreeDJ16]

Doing teh hardware side is not too hard to do But the dual arm, Look ahead, hot swap M6 scripting can be a beast to make work in UCCNC as you cannot write to teh tool table from script. And it takes a LOT of outputs and inputs to make happen.


You may want to take a wack at teh M6 macro to run it FIRST before you commit to the hardware side.

A single arm ATC is much easier to do from the scripting side. You can still run it with a Side mount carrousel to save room.

Then later you may be able to work out a dual arm setup and convert what you have.

IF you need help I can show you what I know.

Just a thought, (;-) TP

Thanks, that's actually good advice. And I'm trying to explain that to my mech eng buddy I am working with on this.....he just sees the mechanical side as no problem. Add a solenoid here, an air cylinder there, a stepper here, sure, all fine and dandy till it comes to programming all that shit. My side is the electrical and programming and he's not getting how hard the flip side of this is going to be for me. LOL....we are at an impasse for the moment. So thinking about putting a halt on the project for a while until we can both get a mutual understanding of what all is involved.

And thanks so much for the offer too. Means a lot. My hopes are that CNCdrive will see the need to put the slot on the standard tool table. I mean we don't really need all the other additional information. Sure it's nice, but tool number, offset, diameter and slot all on the same table to read/write would really help out a lot of people. Maybe by the time we actually get moving on this ATC, some things will have changed for the better with the tool table setup.