Clint's Lathe + Mill Combo Touch DRO Install

[ClintNZ]

Hi All, a thread to share some info on my DRO setup & hopefully get some pointers on the finer details of the electronics & getting the most out of this system.

My machine is an Optimum Optiturn TU3008G lathe (12x28" benchtop machine) With an Optimill BF20V milling head bolted on the back. I bought all this new a couple of months ago. (a long awaited upgrade after many years with a worn old 10" Atlas)

So I'm quite looking forward to the upcoming V3 of TouchDRO after reading about how it is better configurable for combo machines (if you need a beta tester @ycroosh please get in touch!) I got the deluxe 4 axis kit which made it's way slowly but surely to NZ.

For scales I am using the magnetic type as both these machines come with slots pre-milled for stick-on magnetic strips. I ordered 3x Ditron DMR200 0.001mm from the 'Ditron Official Store' on Aliexpress, these were delivered in good time but they only sent 1m of '2+2' strip not the 2m ordered. After a few messages they are now hopefully sending me more strip. Fortunately the 1m is just enough to do the lathe axes for now.

The first problem was the discovery that the '10mm' groove in the back of the lathe bed was actually 9.85mm so the strip didn't fit. The cross slide slot which I did measure is 10mm+ but it looks like the mill column slot may be a little marginal too. So a bodgy shaper setup was devised to widen the lathe bed groove. Worked great, could do about 0.05mm per pass.

Next the magnetic strip was installed, it had a self adhesive strip on the back but that didn't want to hold in the groove despite a thorough clean, I had to use some spray adhesive which stuck it on well. The separate stainless steel cover strip stuck itself on fine.

Very carefully wired up the connectors. The Ditron wire colours in the plug matched their pin-out list & they seemed to power up fine. 5V, 0V, A, B, A', B' were all wired into the board leaving Z, Z' & Shield pins disconnected. Is it worth grounding the shield line? It's probably earthed at the read head?

Then made some mounts, part of this will be re-made so there is a one piece wiper holder/ read head mount / protective cover. And it works!

Calibration was fairly straightforward, had to tweak the cpi a bit after the first try but she's pretty close now. I got 25404.83 which I just realised will be 1 pulse per micron, 25400 is probably the correct number. Will re-check all this once all 3 axes are installed.

Cross slide next. Waiting on the cross slide to be ground to fix the shonky Z-axis level of the saddle vs lathe bed. Mount is mostly done though. 50x6mm alu angle was hacked up for the lower brackets then 8mm alu plate for the cross beam put the read head at just the right level. Will also mill out a burly cover for the read head. Unfortunately there was no way to get the read head outboard of where the tailstock comes in. May even dowel the mounting brackets so the top section can be lifted out if it's in the way then dropped back in right on line.

Cheers
Clint

 

[ycroosh]

Clint,
Looks sharp. I'm installing TouchDRO on my new (40+ year old) Rockwell lathe, and ended up going with a magnetic scale as well for the cross slide. I went with a fancy EMS 1um scale, but I'm curious how yours holds up in the long run. I have a few of those (not sure if mine are the same mode, but the head looks identical) and so far they are doing pretty good after 5 years in service.

Also, for a combo machine you will like the V3 of the app. I added a way to re-map scale inputs and switch between different "configurations" with two clicks, so you will be able to have a conventional axis setup in lathe and mill mode.

Regards
Yuriy

 

[ClintNZ]

I tried to get a price on EMS scales after reading up all the great info on the Touch DRO site but after I mentioned it was for a hobby machine the New Zealand EMS agent stopped returning my emails. I know they'd be more expensive than the Ditron, could have stretched the budget a little but I'm still in the dark about what they'd actually cost. I suspect they do not stock them in NZ anyway so I'd likely still be waiting if I had gone that route. The local Vevor agent quoted a price just a small premium over the Ditron but then wanted $270 shipping which ruled them out.

I have attempted to sign up to the Yuriy's Toys TouchDRO forum, same username as here. I am still waiting on the authorisation email.

Cheers
Clint

 

[ycroosh]

Clint,
My forum is "in a bit of a state". last year some "marketing" company in India got a hold of the address, so I've been getting hundreds of spam account registrations. Those are human accounts, so standard bot traps don't work. I have to go through the list daily and fish out legitimate users and approve them manually, but it's really easy to miss real accounts.
I activated your account a moment ago, so you should have access.

I'm surprised that Vevor was more expensive than Ditron. I see them for much less than Ditron. I can't keep track of Chinese "brands" anymore, but in general Ditron, Easson and Sino are real manufacturers of at least some parts of the scales. I know that Sino, for example, made/sourced their own reading heads last time I checked. Ditron seems to be the manufacturer of several different magnetic reading heads, etc.
The two Vevor scales I ran into were generic non-name stuff...

I got my EMS scale from DRO Pros in the states. They (for some reason) treat me as a competitor, so I don't want to do too good of a job endorsing them, but so far my experience with the company has been very positive. The guys on the phone knew their stuff and were very helpful. I suspect shipping to NZ would suck, though.
I've heard from several people that EMS doesn't want to deal with one-off stuff. I had a bit of experience with then on the other side - a few years ago they wanted to use TouchDRO as a "white label" system, and after I sent them a sample boards, several calls, dozens of emails back and forth, one day they just stopped responding... It might be their company policy

Regards
Yuriy

 

[ClintNZ]

Thanks Yuriy for getting me set up with the V3 beta!

Last week I got my cross slide back from being ground flat so the X axis is now operational. The magnetic strip has a stainless steel backing & adhesive behind that. Also supplied is a stick-on stainless cover strip. Plenty of room in the groove for this one. I filled around the strip with some neutral cure silicone sealant so there are less crevices for swarf to gather in. May add another layer of that to fill it right up flush.

The Ditron read heads are quite tolerant of variable angles or spacing off the strip.

The new scale calibration wizard in V3 worked nicely to set that up & I have started to get the app programmed with the two different configurations for lathe & milling modes.

Next I'll be refitting the milling column with a custom shim to set the mill spindle centre right on the lathe centreline, & using my new threading tool for the first time making a stud to mount the new QCTP on the compound, then I'll work through setting up the QC tooling & report back.

Cheers
Clint

 

[ClintNZ]

On the good news front my tablet holder is done & really nice to use:

On the down side the 'Ditron Official Store' on Aliexpress have now stopped replying to my messages about my missing scale strip & it is nowhere to be seen. Frustrating but things always seem to be a bit of a gamble on Aliexpress. Further bad news is I have manged to fry one of the read heads when welding too close. It seems having the scale cables running up next to the TIG welding bench as below was a Very Bad Idea:

At the time the lathe was also plugged into the same circuit as the welder which I wouldn't do normally but I'd swapped it over for some reason & forgot. I certainly wasn't welding on the lathe or any metal connected to it. The read heads & their shielding were earthed to the lathe which is also properly earthed but that wasn't enough to protect the cross slide read head which started incrementing up endlessly. Unbolting it & turning it on & off got it working intermittently but not reliably. Fortunately I had the other read head for the mill column, unused as it's waiting on the magnetic strip, which I could swap on & keep the lathe axes going. I may even just get a glass scale for the column as there is plenty of space there. So now the DRO box has been moved to the other end of the lathe & the cables tucked in out of the way, further away from the TIG & mostly horizontal so not going across the field so much. The lathe power cable has been shortened right up & given a dedicated outlet on a different circuit to the welder. Now the readings don't even flicker when the welder starts. Expensive lesson that one.

After that debacle it was time to try setting up the tool library. I got some 123 blocks set up in the 4-jaw so I could easily do 'both sides of the line' My 16mm RH turning tool was zeroed out as 'tool zero' & everything else was compared to that.

I used a feeler gauge to touch off to a similar slip then added twice that thickness to the offset if going to the other side.

The Touch DRO manual is still a work in progress & tool offset is not covered in that yet. So I was just going off Yuriy's blog post. Things were initially very confusing until I realised I needed to set the DRO x axis to radius mode & switch the +/- sign of the offset sometimes. Then good progress was made.

(should figure out a quick way to get a screen grab off this....)

Now all my indexable lathe tools are loaded up I need to try them out on a few test cuts. I'm guessing a little fettling of the offsets may be required to account for deflection etc. Realistically even if the offsets are getting in the ballpark they'll be useful but it will be handy to have commonly used things like the LH turning tool well dialled in vs the RH cutter.

Cheers
Clint

 

[ClintNZ]

More progress this week, mentioning the 'dispute' button got some action from the Aliexpress Ditron store so hopefully the makings of my mill Z axis scale are now not far away. Also hacked up a chunk of aluminum for the cross slide read head cover.

Starting to get the hang of using sub datums, cutter offsets & guidelines. The graphical display on the app sure makes it easy to keep track of where you're at.

With mount and cover the scale adds 27mm to the back of the carriage. Tail stock quill travel on this lathe is fairly decent so it shouldn't be a problem.

Cheers
Clint

 

[ClintNZ]

Re-made the bodgy lathe Z read head mount, Using 6mm alu angle, incorporating the original bed wiper plus a flap of silicone rubber to keep swarf off the read head. Not quite as elegant as it could be but tidy enough for me & well protected.

My missing strip finally arrived from the Aliexpress Ditron store, along with another DMR200 read head so now I have the mill Z-axis operational. My measurements of the factory groove for the magnetic strip must have been a little off as it wasn't 10mm either. Managed to tin snip off a tiny sliver down the length of the stainless steel backing strip where it extended out from the magnetic material & then it fitted in. The groove in the mill column isn't quite as deep as the strip so the cover stainless strip went straight on. As with the other strips I filled in around any gaps with silicone. With this one I also extended the stainless cover off the ends a bit as now I have some to spare. Pro tip: scrape all the crappy paint out of the groove first otherwise the strip adhesive will just lift it off.

As with the lathe mount I may make eventually a burlier version of this now I've got the dimensions sorted. Now I am looking at the integrated capacitive scale/display on the quill & wondering if I could graft a magnetic scale in it's place & have Z-axis summing... Probably not worth another $200 just to avoid some math occasionally though!

Meanwhile I am continuing to get more skilled at the basics of using the V3 Touch DRO app, haven't found any more glitches, it definitely contributes a lot of speed & accuracy to machining jobs & really adds to the enjoyment of using the machines too. The ability to quickly switch between lathe & mill modes really does make it the 'killer app' for a combo machine like this.

Cheers
Clint