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Hardinge TM Mill DRO Recommendations

techymechy

Aluminum
Joined
Oct 24, 2018
I just bought a Hardinge TM mill for my hobby shop and am working on adding a VFD right now. After I add the VFD, I would like to look for a DRO. The real limiter with Hardinge TM mill is that the Y axis only has about 5 1/2 inches of travel and the front of the mill is used for controlling the table feed along with oiling the ways, etc. I am hoping to place the scale between the column and the table, but there is only about 3/4" clearance when the table is fully traveled to the column.

Does anyone have any good pictures of the DRO conversion and have a recommendation for where to purchase the DRO box/scales?

DROPro's have a system made by Electronica and they also have the MG232 scales that look like they will *barely* fit on the X axis (between the column and the table, they are like 18 mm thick and 46 mm tall). The only problem is that DROPro's seem to take a real hefty mark up for the devices that they sell.

I see these Chinese DRO's seem really inexpensive and people say that they are sufficient for most hobbiest. I don't know what are the good ones and if they have the scales that will fit my mill.

Looking forward for advice on a good hobbiest DRO that will fit my Hardinge w/o limiting my Y axis travel.

Thanks,

Dave
 
I am in the process of mounting my DRO Pros magnetic scales to my UM. Their scales seem to be the skinniest of the ones that I have seen and was the reason I went with them. and most important, you can cut the scales to length. It is a challenge to mount the Y -front to back axis ( always get these confused) and Z axis. I mounted the Y on the left side as there is a knee access port on the RHS, and the scale would interfere with that. I cut the scale and fabricated mounts to suit. My mill is completely apart which made it easier to set up on my other mill(nice to have) to drill and mill mounting reliefs. The X axis was a straight forward install and I mounted it on the back of table. After alot of eyeballing, I did not think the scale would limit Y axis travel too much. The 5C snout sticks out quite a bit, and you can cut down the supplied chip guard to get even more travel. Again custom mounts made a more compact install. Because of the way the front of the table is used, (stops and oiling ports) mounting the scale on the front was out of the question, although I have seen it done. Also I have done away the original table feed and gone with the late Servo type feed and all of the controls and stop rods are mounted on the front of the table. Z is still being figured out , but it will be mounted on the LHS as I didn't want to obscure the switch gear adjustment screws. I think that the additional Z axis scale is almost essential on a horizontal type mill like these.
 
Hi Daryl,

Thanks for the reply.

How thick is the X axis scale? Does it reduce your Y axis travel?

I wrote an email to DROPro's and they said that they can get the MG232 scales in 19" length. This is plenty long for the X axis on the Hardinge (travel length ~ 14 "). One can also shorten the scale to the length they want.

I'm just in the noodling stage of a DRO conversion. I was considering to place the X axis scale on the column side of the table, the Y axis on the left hand side of the knee and the Z axis scale on the right hand side of the knee. I'm pretty sure that I'll have to machine my own brackets. Did you have to reduce your Y axis travel with your set-up?

This is my first and only mill. I'll have to carefully plan/design my brackets so I can drill/tap my holes on the mill. I really don't want to screw up and place a hole in the wrong spot.

Please take some pictures of your process and post. There really isn't very many reasonable photo's for a DRO on a Hardinge TM.

Thanks!
 
Lemme get some pics and I will post them. A good pic of the scale on the X will show how much space it takes up. I haven't got that one done yet, but will cob something up. I have finished the Y setup, and it is quite tidy if I do say so myself. The Z is tough. The plan is to mount the scale inside of some square alum tubing, and mill out a channel for the read head and bracket. I milled a flat and tapped some holes on the LHS of the rounded edge of the knee casting to mount a L bracket assy. for the reader head. The bottom of the square tubing is attached to a clamp bar that uses the column dovetail to clamp to. The top bracket..still a work in progress. There are a few pics out there of installations, one that I remember uses a Newall. I think the main reason you don't see many install, is that it is really hard mill to do this on. I also suggest [email protected]. You should get a good response there.
 
Hi Daryl,

I am active on the .io group and really haven't had any comprehensive responses for mounting a DRO.

I've been looking at the pictures of the other installations, and they are helpful. Most of them are using scales that are much larger than the DROPro's magnetic scales. I'm trying to come up with a design that will minimally affect my current working space.

I look forward to seeing pictures of your install. I'm sure I'll have more questions after you post them.

Thanks again,

Dave
 
I tried to look up the Microsyn scales. They are SUPER expensive. I also think that the reading head and scale is too big for the gap I have between my table and my mill column.

I've been looking at the Chinese DRO's. I just need to find out the sizes of the reading heads, etc.

Dave
 
I think for magnetic systems you can get away with plain magnetic tape stuck to the table. Then if you can place the X axis read head off to one side of the knee so that it clears the column but still gives you full X travel then you should lose very little Y axis travel.

Not done it myself and you'll have to do a DIY bitsandpieces buy, but it's one option. I think the install I saw used Ditron read heads, mag tape and head unit.
 
OK, no pics yet, but I went and measured a couple of things. The gap between the column and the table when the Y leadscrew nut holder butts into the knee casting is about 1.250". The DRO pros scale and reader head w/o the chip guard is about 1.250" . The chip guard is about .053" thick. The way the bracket mounts to the reader head will not add any thickness to the assy. The chip guard should have alittle air gap , lets say .100. The 5C spindle nose , no collet ,sticks out from the column 2.250" . This is a 1965? UM . So what am I missing here?
 
I’m interested in seeing how the scales work out; thanks for posting this.

I would suggest rethinking the VFD solution and just install a small rotary phase converter. You would save a lot of time reworking the controls, and for recreational use you’re not going to gain much from the variable speeds.

I tried a static phase converter on my Hardinge lathe and it didn’t work well. Wound up with a rotary converter and have no issues with it.

In my opinion VFDs are a good way to go in many situations except for running these Hardinge machines with their highly balanced two speed motors.


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IMG-2680.jpg

Here is a picture of the distance from my table to my column. When the table is fully moved to the column, it's about 3/4" on my 1967 mill.

IMG-2681.jpg

Here is a picture of the amount of table left on both the right hand side and the left hand side when the table is fully moved in each direction. I don't think that there is sufficient distance here for a DRO head, hence the head needs to be able to fit in the space between the table and the column.

IMG-2685.jpg

Here is a picture of the table, facing the column. There is an oil port there which requires access - about 3" above the Y axis way.

I think that the only way to place a DRO on this mill is to shoe horn the X axis scale between the table and the column.

I find it very interesting that Daryl's mill table-to-column distance is so different from mine and they are about the same age. I'm pretty sure my mill has the original nuts on all axis. Daryl, is your mill all original?

Daryl, I have a vertical head and horizontal arm for my mill. I want to keep as much Y (and X and Z) movement as possible when installing the DRO.

I have the VFD figured out. It is pretty straight forward. I know I can use the existing switches for the change from FWD/REV and I'm trying to use the Hi/Low to control the VFD pot for spindle speed control. It looks like it should work, but I need to install the VFD and try out the ideas I have to insure that everything works.

Dave
 
Mine is a very original UM not a TM like yours, universal ,which allows the table to swivel, and to get a useable range close to the spindle, that is most likely the reason for the larger gap. You are going to be hard pressed to find something that will not limit the travel somewhat. I will still get some pics this weekend.
 
Right! You did state that you have a UM mill.

There seems to be two scales that will work. Ditron makes a magnetic scale DC10F (5 um)and DC11F (1 um) scale that is roughly 18mm (.71") thick and 39 mm (1.54") tall. This would work on these mills, but it would be a tight fit.

Electronica also has a scale that is 18 mm thick by 46 mm (1.81") tall. I'm not sure if you need to go through DRO Pro's for the purchase.

So, it looks like there are some choices!

Dave
 
...
I would suggest rethinking the VFD solution and just install a small rotary phase converter. You would save a lot of time reworking the controls, and for recreational use you’re not going to gain much from the variable speeds.
...

Honestly I would not think he'd gain much from a DRO on that machine. Mine has the older steel dials and I've never had any trouble
hitting a number with them. But I'd sure like to see the finished result when it's done!
 
Well I have to admit I am an idiot. Never drink wine before you make measurements. Both your mill and mine Y travel is the same. Seems I had allowed the width of the scale/reader into the equation which gave the 1.250 + dimension. Without this, the column to table gap is about .750..doh! Sorry about that.
 
Thanks for the pictures of your Y axis modification. I see that you removed your table. Do you think that it is necessary to remove the table to install the DRO?

I contacted DROPro's and Electronica. The guy who answered the phone from DROPro's really couldn't answer any questions but asked me to call back and talk to the guy who's in all of the videos. I contacted Electronica and eventually they replied and asked me to work with:

CARL STAEHLE CORPORATION,

77 McMillen Rd. Unit 103,

Antioch, Il 60002

U.S.A.

Phone : (847) 573-8200

Contact Person : Mr. Carl Staehle

Email ID : [email protected]

I talked to a guy named Mike (extension 0). Staehle sells the MG232 scales that are 18 mm thick for production applications, etc. I'm supposed to be getting back together with Mike to discuss recommendations/costs/etc. Of course, Electronica does not sell a "kit" that will fit the Hardinge TM mill. Mike recommended the EL403 readout and said it had a port for an edge finder, etc.

I haven't heard anything back from Ditron.
 
I would suggest removing the table. I sorta don't know how you could drill and tap the holes without doing it. For mine, it was just manageable smallish slabs of cast iron that I could jig up on my other mill, but you might not have that luxury.
 








 
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