Newall DRO on 14x40 lathe

[petertha]

Here are some pics of my installation. Im no expert by any stretch but happy to answer any questions. Seems like these DRO retrofits are always a series of tradeoffs & mine is no diferent. I might regret some decisions down the road, but I'll give it a go this way for now.

Travels seems accurate but I havent played with it much yet. I'm just happy I didnt have to rent some kind of lifting equipment to move the lathe away from the wall to get in from behind to install the x-axis hardware. I was able to reach in behind with a few painful contortions. The x-axis tube/encoder is Spherosyn. The y-axis & z (compound) is are Microsyn 10.

The one thing I would recommend is taking the time to make simple bar steel jigs to both drill & tap align holes in the cast iron. The only chunk I could easily remove & use a drill press was the compound bock. Everything else was hand drill action which was had me worrying at times. Mostly because some of the positions were just awkward & hard to get good aligmnent pressure wth the drill & straight in with the tap. Some holes went great & others seemed like they hit the equivalent of fir tree knots. Must have been a melted down tire rim in there! Anyway, all the holes are straight & cleanly tapped. Count myself lucky this time.

[petertha]

Here is the X-axis. I made a few wood mockups till I got it right. I used the threaded holes reserved for taper attachment. If I ever modify my lathe to allow that capability I'll have to re-think this. But some taper installations clamped onto the cross slide so maybe I will still have that option open.

[petertha]

To align the bar, I clamped up 2 jigs like picture using 123 blocks & parallels. They sit on the lathe bed & flush against the dovetail corner so that position is constant down the bedway. One jig sets height of the bar (contacting the top). The other sets setback distance (contacting the rear). The post/clamp hardware on either end allows you to set these independantly. While adjusting the end posts to their setup point, the encoder is left loose to float. I made slots in the encoder plate so they can be moved & shifted as required. This is a prerequisiste because its hard to get drilled & tapped holes bang on. You dont want to put any strain on the tubes.

[petertha]

Here is the Y-axis cross slide. Again, I poached the existing threaded holes intended for the travelling steady. I wrung my hands on this issue.

Pros
- easier installation
- putting it on the back side would cause me grief. Awkward holes to drill, deeper level carriage dissasembly, interferes with existing carriage lock bolt & cross slide lock screw (to gib)

Cons
-DRO is on the less desirable chuck side, closer to work, shavings, fluid drips
- hopefully the chip guard & fluid-proof rating + supposed good warranty will work my way

[petertha]

Here is the compound. I debated whether to even get it, but I decided to give it a go. If it all went well, thats one more set of blinky lights to keep an eyeball on. Worst case if I didnt work out, the tube was the right size for my mill z axis, which still has a jerry rigged vernier.

I ordered the shortest tube based on 5"-ish travel. The documentation says on these short length tubes its ok to only have tube end anchored on one end while the other extending through the encoder box unsupported on the other end cantilver style. After much headscratching, I arrived at this bar clamp design which & is attached by 2 drilled & tapped holes in the back of the compound block. The encoder is bolted to an aluminum block from the underside shown. Those same holes were convenient to mount the angle guard. I tried to match the dimensions carefully on these parts so everything would line up as there isn't as much adjustment latitude here.

The only thing I dont like is the tube end sticks out a bit, but only on the most extended compound position as shown. But I'm paranoid of catching it with my hand while turning the lead screw or bashing it with the tailstock if its aligned to the bed. But for the most part, it stays hidden under the guard so I'll just have to be careful. The guard travels with the compound.

[f350ca]

Nicely done. You'll like the one on the compound. I dial the compound parallel to the bed and leave it there. You can then use the compound for fine adjustment to a shoulder.

[EdK]

Peter,

Seeing those pictures, things looked vaguely familiar. Then I realized that your carriage assembly is the same as the one on my lathe which is branded as a Vectrax. I bought it in 2009 from MSC and it was also made in Taiwan.

I considered installing the cross slide scale on the left side but did not based on the same reasons you sited as the "Cons" to doing it that way. I made a new carriage lock to clear the scale but lost the use of the cross slide lock so will eventually relocate that to the left side. In hindsight, I wish I would have gotten the 3-axis DRO instead of the 2-axis. At the time, I didn't see much use for a scale on the compound. I've since been educated on that subject by the knowledgeable machinists on this forum. Oh well, live and learn.

Ed

   

   

[Highpower]

Nicely done indeed. The jigs are a

I couldn't have given up the use of my traveling steady / follower rest though. But everyone has to do what works best for their own situation.

Great post Peter. Thanks for sharing it.

[petertha]

Re the loss of traveling steady got me thinking more. I wonder of something like this would work. Instead of attaching the x-axis encoder bracket with allen bolts, I made up a fasteners like sketch. It has a threaded end to match existing casting holes. Its made of hex stock so I can wrench it down, encoder bracket stays in place once postioned. The hex has same tapped holes on chuck side to attach steady with orignal bolts.

- but I wonder loosening the the steady mount bolts to dismantle would also loosen the hex bolt & mess up DRO bracket attachment alignment?
**edit** maybe not of I can get in from behind & hold the hex with a wrench while undoing the steady bolts?

- the steady would be parked maybe an inch closer to the chuck, but no adverse issue there?

- the steady wouldnt have the face of the cross slide casting to mount flush against, but its actually a pretty crappy surface as-is (it was not machined flat & neither is the steady), so maybe no loss there?

[petertha]

A dumb usage question now that I have this thing installed. It just occurred to me.. rather than the usual take a fine feed skim cut with gib locked, measure the cut surface with a micrometer, zero the dial business...

If I were to chuck a nice, shiny piece of hardened drill pin I have handy, make tool contact to the pin, then enter the known pin diameter value into the DRO, would that not be a more accurate way of pre-setup prior to machining assuming the DRO is doing its job & measuring accurately through the range? That way I should be able to chuck up any rough stock & work my way down to (something very close to) finish OD assuming I keep the same tool in place, no? Or is it still good practice to measure prior to that last fateful cut?