DRO advice for lathe?

[skcncx]

You can install the scale and encoder on the chuck-side of the cross slide - that will free up the right side for access to the locking screw and allow the tailstock to be positioned closer to the tool post. The downside is that the DRO encoder/scale gets more exposure to chips and coolant and potentially damage by the chuck or rotating part. There are several examples of this type of install on H-M if you search around. I would always choose to do the DRO install myself - posts here (and Practical Machinist) suggest the distributor (PM, Eisen, Acra, etc.) do a pretty quick-and-dirty install.

Right... or "left" . I had seen suggestions to put it on the lefts side, just escaped from my memory. I won't use coolant, but cutting fluid for drilling/turning nonetheless is still going to drip/flung there.

Seems like most typical installs is on the right side. Out of the way of from the chuck and chips and is preferred over losing a bit on how close you can bring the tailstock up to the saddle. Do you you lose about an inch of useable quill travel that if it can't be snugged up to the saddle?

Yea, debating on OEM install... I figure it would be pretty basic. It looks pretty management as long as you are careful and take your time... plus is saves me a chunk and I'd likely just go with the Ditron DV80 or Eason EB12 with magnetic scales... so in total, I could save $400-$600 over the PM-MX200L installed by them.

Something to think about!

 

[pontiac428]

I have to cut power to the D80 on my mill when I shut down the RPC and leave the shop. It retains all configuration settings (axes, in/mm, direction, etc) but loses any location/movement settings for the session. It's no big deal. If I leave work on the table, I just touch off and get my location back.

If the mag scale placement takes an inch away from you when using the tailstock up close, just take that inch back by feeding it into the tailstock quill. You don't really "lose" anything. Maybe you could say you lose little bit of depth when drilling with the tailstock, but that's why we have so many ways to skin the cat when making parts.

 

[skcncx]

If the mag scale placement takes an inch away from you when using the tailstock up close, just take that inch back by feeding it into the tailstock quill. You don't really "lose" anything. Maybe you could say you lose little bit of depth when drilling with the tailstock, but that's why we have so many ways to skin the cat when making parts.

In my head I was thinking you might lose travel when drilling if you needed to butt up the tail stock to the saddle... but that's not likely a real scenario... I was just trying to envision what impact you have with the scales mounted on the right.

I guess, most of the time I've need to be very close to the tail stock with the saddle is when I have a live center in the tail stock and I want to reach the end of the part to turn it down, in that case, just extend the tailstock quill a bit and move on.... my current lathe, Atlas 618 has very little quill travel.

It retains all configuration settings (axes, in/mm, direction, etc) but loses any location/movement settings for the session. It's no big deal. If I leave work on the table, I just touch off and get my location back.

That makes sense... figured that's how just about every DRO (unless it was absolute), settings are retained but absolute location is not... easy to regain as you say.... My only reference is my CNC would router... I just home it... I guess, that's the aspect of getting my location back... though my controller software does remember it between powering off and on.

Going to go look at the Ditron D80 again... if I install this thing, that seems to be a great bang for your buck system.

 

[pontiac428]

I understand what you mean, I run my carriage up tight to the tailstock all the time. It's valuable space, and running your quill way out there may not produce the best accuracy and finish. Regardless, if you need to run a scale on your cross slide, run it on the operator's right hand side. The list of good reasons for putting it on the right is a whole lot longer than the one for putting it on the left.

And absolute coordinates are never needed on manual machines, because they have a real human brain keeping track of things like home.

 

[skcncx]

@mksj couple questions on your ES-12B...

• I assume you have the EH-05 scales on your (1340 or 1440?) lathe and I assume the height of the scale is shorter than the side wall of your cross slide where it's mounted.. correct? I'd think it can't be taller, otherwise there may be clearance issues swiveling the compound? My guess/hope is the PM-1236T is at least 1" inch tall, I'll have to confirm.
  
  
  
  
  
• I've gotta measure, but I believe the 1050mm (41.25" travel length) mag scale for the Easson Kit is plenty for a 1236T... I want to ensure full range on cross slide, even if tailstock is off and I don't have long extended chuck on the headstock... as in, when no chuck, I want to ensure I can take the saddle as far left as possible.
  
  
• I'm leaning toward the ES-12C (horizontal display version), same otherwise to the 12B (vertical) You previously mentioned your prefer the ergonomics of the ES-12B... do you have your unit mounted on top/above the head stock? I was actually thinking about mounting mine right out in front between centers above back splash panel... that does not seem as common for mounting but "seems" a natural position to view it, though maybe a safety issue with always reaching directly over the workpiece.

Being able to read the numbers and ergonomics is what is important for me, one reason why a I prefer the vertical screen so the axis buttons are aligned along the left side of the ES-12B. If they where horizontal or on the right side of the screen they would be more awkward to use.

I've reached out to machine-dro.co.uk and their 3 axis ES-12B/C with all reading heads upgraded to 1 micron is $910 shipped to my door. I'm really considering this option and just install myself. A small savings over the MX-200L 2 axis as well. Since I was planning to put a caliper on my tail stock quill I keep thinking it's just as easy to use the 3rd axis as I believe you and many do.

I also reached out to Ditron on their D80, for 3 mag scales with RPM is only $595, so even less... though, my perception is the Easson is higher quality... but I really like the idea of the RPM readout right on the DRO head unit as well.... too many non critical but nice to have options I guess. It just feels odd that they keep asking to send a payment link, but never provide a detailed sale order I'm paying on... and support, my guess is Machine DRO and PM wins hands down with after sales support/warranty. To bad SRM (seemingly a division of Machine DRO UK) is actually more than their UK shop for the same Easson ES-12B/C.... I digress...

 

[mksj]

The height of the cross slide on the 1236/1340GT is something like 30mm and you can also shorten the width of the magnetic aluminum carrier. I used glass GS31 slimLine glass scales on my 1340'S, thats all they had at the time. I added a magntic scale to my tailstock on my ERL-1340. The magnetic scale lengths are based on travel not overall length, so a 1000mm would be for 40" travel. More than long enough for a 1236.

I do not follow the pricing you are getting from Machine DRO, unless the shipping has gone up dramatically. The 3 axis magnetic kit is ~$500 when you remove the VAT (and current exchange rate), the 1 micron read head for the cross slide was $25, the 1000mm Z axis scale was $25. Shipping previously was ~$75. The British pound has declined significantly in value relative to the dollar. When I put in an order and checked price of the 3 axis with shipping to the US it came to £615.86, current exchange rate is £1.00 = $1.21 (put lets say 1.1 after fees) so you are at ~$600 with the scale adds. If you are paying $900+ for a DRO from Machine DRO, I would go with the MX100/200 if they have worked out the software bugs.

A tachometer is $20, if you not using a VFD then it doesn't matter, if you are then just add it at that time or use a 0-100 scale on your pot and you can workout the speed. If you went with the Baldor vector motor then the speed range at 50% is the same as the low belt speeds and at 120Hz the same as the high belt speed.

I prefer to have my DRO away from flying hot chips and oil coolant splatter, I do not want to be reaching over anything spinning to get to the keypad. In addition a lot of people mount tooling to the back splash, last place I would want a DRO to be located. It would be totally useless trying to mount mine to the splash shield. The way it is setup I use my left hand to access the X, Y Z keys and my right hand is on the carriage controls.

 

[Beckerkumm]

My 3 axis system with 1 um magnetic scales was 739 BPS in April. I also factor in some aluminum bar stock. I don't like using screws under the magnetic strip so I can't remove the scale at a later date so I mount them on a bar thick enough that I can screw to it and just attach it to the machine at the ends. I'm not sure that a glass scale on the Z axis with clips that secure it to the top extrusion wouldn't be easier and cheaper. Dave

 

[skcncx]

The height of the cross slide on the 1236/1340GT is something like 30mm

Great, no need to trim down the aluminum carrier.

I do not follow the pricing you are getting from Machine DRO, unless the shipping has gone up dramatically. The 3 axis magnetic kit is ~$500 when you remove the VAT (and current exchange rate), the 1 micron read head for the cross slide was $25, the 1000mm Z axis scale was $25. Shipping previously was ~$75.

My quote... 2nd and 3rd scales lengths are way too long, but they said it's actually cheaper because it's part of a kit. Even at $909, the MX-200-L 2 axis kit from PM is $999, so $100 less for Machine DRO and the extra scale.

I asked PM... I cannot get a 3 axis MX-200-L lathe kit, they only sell it as 2 axis.. so if I want the tail stock quill DRO... it's not an option. I can't even get their 3 Axis MX-200-M kit with scales for a lathe... kind of a bummer.

A tachometer is $20, if you not using a VFD then it doesn't matter,

No VFD to start, single phase... Just to have an RPM sensor on the spindle just seems like a nice display value, gratuitous for sure. Then I don't care what the charts say on gear selection or what pulley I would have setup... the sensor is the final truth in RPM. This feature is not something that's going to push me to Ditron.

prefer to have my DRO away from flying hot chips and oil coolant splatter, I do not want to be reaching over anything spinning to get to the keypad.

Yea, I'll put it on top of the head stock.... also thinking I would have extra tool holders above/mounted on back splash for quick access. That makes total sense for vertical display when using left hand for x/y/z access buttons.

 

[Beckerkumm]

Ask them if they have there new mounting brackets. They were sourcing new brackets when I asked in April that were to be solid on both sides rather than cast which should improve their function. Dave

 

[mksj]

Must have gotten the exchange rate backwards, oh well. see where it goes. On my 1340GT I used an Igaging Absolute scale on the tailstock and it worked fine. Batteries lasted about 6 months, others have done similar and not a big expense.