3D Printed DRO Mount for Lathe

STL's and links: fpfdesigns.com/
Black PLA: amzn.to/3T9afnk
920MM 5UM Scale for Carriage: amzn.to/3TE6XHR
170MM 1UM Scale for Cross Slide: www.ebay.com/itm/163206330524...
DRO Mounts for the milling machine: • 3D Printed DRO Scale M...
Outro music is "Quantum" by "Vapora", used with explicit permission from the artist. • Quantum
Other music used is "Monolith" by "Vapora", used with explicit permission from the artist. • Monolith
New videos published every Friday, featuring a new 3D printed functional object, how I use it, and design considerations.
The design depicted in this video is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License or other non-commercial license.
functional
print
fpf
lathe
cross slide
SINO
glass scales
PM1440GT
precision matthew
1440
touchdro

[@pdxminecraft]

Drill out one of the wrong threaded holes. Turn an aluminum rod to be a press fit. Fit the pin with green locktite. Drill and thread a hole in the correct place.

[@FunctionalPrintFriday]

another great option

[@vcedge9466]

This is exactly what I was thinking but I'm used to doing this on aircraft parts. There are some things to watch out for, such as making sure you have at least .030" wall thickness when you're done. I love 3d prints but for something like this I'd rather have the more solid mount even if they both work.

[@noanyobiseniss7462]

@@vcedge9466 And putting bolts in the doors.

[@charlesK001]

my suggestion is 3d additive metal printing (mig/tig...2 seconds done)...and drill and retap.

[@j.hankinson7803]

I’m in the suggestion camp of fixing one of the the ‘wrong holes’, notwithstanding the 3d printing theme of the channel. Whether you put a piece of aluminum in one of the mounting holes with Locktite, or fill one with metal epoxy for a new mounting hole doesn’t matter. KIS principle.

[@joell439]

I’m in the camp of repairing (drill-out/plug/redrill/tap) the aluminum plate. Good luck.

[@jSan1776]

My thought is to use the printed mount. If it turns out not to be strong enough, you can mill a new aluminum mount later.

[@lv_woodturner3899]

The piece is just a spacer. It has minimal load. If you are concerned about strength, then make a new piece from aluminium bar. You have a milling machine so easy to make a new bar. I think a 3D printed bar will be strong enough and will hold up well. I have a DRO scale covering the gib locking screw on my carriage. I have had a few occasions when I wanted to lock the gib. I may make a 3D printed spacer for my gib.

[@PaulBohn]

It took a long time to figure out how to mount the carriage scale on my lathe. At the end of the day, they pulled a fast one on me because the scale should have been 2x higher counts, exactly like you said. Even so, It's been a huge advantage to have it, especially for marking exact lengths more than 12". The DRO on the cross slide gets me close enough, then I default to the graduated wheels, and a sharpie mark if I'm doing multiple parts.

[@mikecirrincione9895]

Have you thought of milling a new aluminum mounting plate with all the features of your 3d printed plate?

[@badjuju6563]

This would be my preferred option, 3d print a tpu bung for the cross slide bolt access notch.

[@1point3liter]

3d printing creeps into every project!

[@FunctionalPrintFriday]

it's true!

[@haydenc2742]

Rapid prototyping ;) Imagine how much time/material wasted if all the iterations of a production testing run were machined out of physical material...

[@mkegadgets4380]

You can coat your 3-D printed part with CA glue. That will make it waterproof in a little bit more durable.

[@bwselectronic]

I'd see how you like it at this point. You can always change it later. This way you haven't drilled the holes yet so no damage that causes more work later

[@Rob_65]

I like the suggestion to enlarge one of the mounting holes and put an aluminum rod in there. Green loctite for sure (638 or 648). The PLA part is nice for testing but plastics can be attacked by different types of coolant/oil so I would not use any 3D printed part as a final solution. I did initial testing on my lathe by just gluing the scale in place with some superglue. After 6 months or so - when the thing fell off - I realized I should drill holes and fix it permanentely 🤫

[@rickdiego5]

PLA is the easiest to print with and is good in some circumstances but if you're using a water-based coolant on your lathe the PLA will disintegrate over time since it's biodegradable. I'm printing most things using PETG. To move the holes I would TIG weld aluminum in one hole and then relocate it and drill it tap it. I was a tool and die maker for over 20 years never once needed to lock the cross slide. By the way, that's a beautiful lathe.

[@kevd7212]

You could print it using ABS or PETG maybe put a thin layer of resin on it and cure it to make it a bit more water resistant

[@bootstrappyworkshop8367]

Take the partial refund, go with the PLA for now and reprint in something like acetal if need be later on, although I expect PLA will hold up just fine in this application. I'm in the middle of cleaning up and upgrading a vintage lathe and am planning something similar to this. Thanks for the ideas!

[@future-matze-35]

love your channel ❤ thank you!

[@PaulMillhouse7]

Cut the mounting rail in half right down the middle and take a section out of it as large as you need to turn the wrench and attach the two halves on either side of your custom grub screw so that the two holes are the correct distance apart to mount the linear encoder. In fact you don't need most of that mounting rail you just need the parts that have features. Since you're mounting it to something rigid the rest is unnecessary as long as you attach the needed parts correctly. Why do you need the mounting plate anyway? Just use a spacer at each end and attach it using mounting tape. How are you attaching the mounting plate? Are you drilling and tapping holes into the lathe? If so just don't use the mounting plate at all, attach the encoder directly to the lathe with screws with a few washers in between. The more I think into it the less I feel the mounting plate is necessary at all.

[@noanyobiseniss7462]

Seems to me the simplest way to address the issue is to measure the offset and drill out the holes to a size diameter one half that offset size and retap. Can't get a vid out of that though. ;)

[@kmccontube]

If you are going the 3d printer path, consider incorporating the dust shield into your mounting bracket with the wrench notch incorporated. If you go with somehow fixing the aluminum then you could machine or print up a couple spacer blocks to fit between the cross slide and the aluminum bracket then install everything as is. This gives you the space needed to use your wrench. Doing spacers you can slot the scale mounting hole(s) and attach them with nuts. In the end you are just needing to hold the scale in one place. Unless something is wrong there should not be any real force/stress. Since the scale is relative and not absolute location just isn’t that critical.

[@Jeff-zc3wl]

PLA tends to creep when it's under tension or compression, which could cause problems down the road.

[@andrewmalaty8]

couldn't you cut a section out of the aluminum bracket. essentially , making it into two pieces so you can space them out that extra millimeter. This would also allow you to make some room for the locking bolt. only downside is that you would need four holes into the casting instead of two.

[@haydenc2742]

he would have to add 2 holes to the separated part...then have to align them Doable...but adds ALOT of measuring/frustration/pucker factor because he has to double the holes for drilling/tapping for mounting it

[@rickdiego5]

Probably the best reason to not use PLA is it gets soft at elevated temperature.

[@kippie80]

Use the aluminum one. Oil on the plastic will wreak havoc.

[@billdoodson4232]

I would drill and tap out one of the holes to say M6 Fine, machine an alloy screwed plug with a tight thread and Loctite in , drill the new hole in the correct position. But then, I'm not a a 3D printer based channel, I don't even have a 3D printer; yet!

[@ryanpeterson5239]

My DRO didn't come with any mounting hardware (or if it did it was worthless and I threw it away). I got a strip of 1/2 aluminum and tapped the holes in the ends and then glued it to the cross slide because I didn't like the idea of drilling that close to the gibs. It does block the screw to lock the cross slide but that has never bothered me

[@AlAmantea]

I don't think PLA is the right material in this case. I think Nylon or ABS would be better suited for this application due to the cutting oils and chemicals used on and around the lathe during mill operations. Additionally, a lot of operations machining on the lathe require or generate heat which will instantly ruin that 3d printed part if something goes awry. I personally would go with a replacement piece in aluminum and forego the printed piece, keeping the mounting bosses in the standard configuration. I do like the idea of the cutout for wrench access to the locking bolt that you made. That is a great addition, even though it won't get used much. I might lock the cross slide once a year if I'm lucky, but knowing that the capability is there when I need it is a comfort. I would leave the dust cover as it is and remove it when you need to lock the slide. The advantage of using PLA to create a test piece will certainly allow you to easily duplicate that from aluminum in the mill because you use the 3d printed part for setups and have already verified proper fitment and operation!

[@GordLamb]

I also would stay away from PLA due to its tendency to creep over time, but I definitely wouldn't choose ABS. It has poor chemical resistance to solvents, especially acetone. PA6-CF, PETG-CF, or PC-CF would be my go to.

[@RB-yq7qv]

I'm sure the PLA will not hold up to oils or coolant. Maybe carbon type filament. Why not drill a hole in the cross slide bolt and silver solder a small locking handle as the pressure required is small. This will do away with a spanner.

[@MrTrollHunter]

I haven't seen the other side of the cross slide, but couldn't either the scale or the cross slide lock screw be on the other side of the cross slide so that they don't interfere with each other?

[@martinathome296]

Did you consider cutting the mounting rail in half and joining the two halves together with a 1 mm gap by milling it down to half its thickness for the length of a joiner?

[@matthiastieben5761]

I definately would go the route with 3D printing. BUT avoid PLA as it will creep under the pressure of your mounting screws! Prefer PETG or PETG-CF or even better PC-CF!

[@fliplmb]

Recently bought some IKEA flat packed crap, and it came with a crap spanner (wrench) which was just a thin stamped piece of steel. Wonder if you that could be used for the slide locking bolt rather than a proper spanner. Would need less depth in the v-slot.

[@niaimack]

Why do you need extra holes in the spacer? Could you just drill and tap holes in the slide to mount using the DROs holes?

[@haydenc2742]

Very cool...I don't think it will be an issue...unless PLA get's softened/dissolved like ABS can with petroleum based cleaners/solvents (I would go with PETG, or other exotic all metal hot end filaments though) I do like the idea of the plug you can just drop in to cover the cutout for the dust cover needed for the lock bolt (chips will find their way in there almost guaranteed) How many shells/top/bottom did you print it in...for strength I usually go 4-5 shells, there was a YT'er that did strength tests and he found that weight to strength the optimum was 3 shells 20% infill...anything less makes it weaker, anything more increases strength but uses more filament (also by printing the design at 45 degrees it eliminates the layer splitting weakness because the layer lines are no longer parallel with one of the faces of the axis of movement) Keep em coming!!!!

[@PaulBohn]

I get your idea of locking the carriage, but that's a bad place to do it. Every chip will want to fall down that cavity and possibly get jammed and damage the glass scale. I don't have a better solution right now, and I have the same lathe. I just haven't used the lock since I installed the DRO a couple of years ago. The carriage doesn't move if your taking reasonable cuts. You can see that with the DRO.

[@gregoryselin9680]

What if you cut the aluminum mounting bracket in half or with enough clearance on the middle for your wrench I think you can also take the scale apart and shorten the housing. Hopefully, the glass piece is the right length

[@gregoryselin9680]

Could also drill and tap two new holes, It'll be a bit off center but that's fine

[@gregoryselin9680]

More to add, I'm an 4th year apprentice machinist and when we are doing high precision (less than .002 or so) we use a mag back dial on the cross slide

[@stuartwyre4742]

I look forward to your videos every week. This is an interesting problem. However, why try to fix a poorly engineered cheap bracket when you have the advantage of being able to 3D print a much better solution. Way back when DRO scales were retrofitted to old manual machine tools the brackets were multiple steel or aluminium flat or angle pieces bolted together to attach the glass (or earlier metal) scales to sometimes rough castings, not ground surfaces as on your lathe. With your knowledge and ability why not design and print bespoke end brackets that attached to the front and rear of the cross slide. Hopefully, you could take advantage of any existing tapped holes. This would avoid drilling and tapping the side face of the cross slide. The “dust cover” you refer to, performs a more important task, by protecting the fragile glass scale, if you accidentally run the carriage into the tail stock or drop something. An elegantly designed 3D printed bracket arrangement and integrated protection, which completely enclosed the glass scale could offer many advantages than the simple solution that comes with the scale. This would also be good content for your videos. I have spent my working life around conventional and CNC machine tools, been 3D printing for 4 years and learning CAD to enable me to make useful functional things. Usually way over engineered, because I can!

[@rwa7856]

How much is the pla going to expand and contract due to temperature. I tried pla ( no carbon fiber or glass filler added ) as home switch mounts on a cnc lathe and they varied 8 thou of an inch from a start on a cold day in the shop to my shop with the heater on an hour later . I even put the pla mounts in the fridge to make sure that was what was happening.

[@FunctionalPrintFriday]

wow! thx for sharing

[@kobemaui9983]

I would make a bit of aluminum all thread, lightly counter bore each side of the hole in the aluminum plate, cut the all thread slightly longer than the aluminum plate and peen the all thread end into the counter bore repeat on ther other side, file, and drill and re-tap.... I like 3d printing but for this application when talking microns stick with aluminum.

[@75keg75]

The little sharp leg to hang the scale on - extend to get more beef it could be the thickness of the scale. So your plastic would be an equal angle. It would be super rigid in both directions Print in abs/ asa or some higher level material than PLA. temps in may cause creep in PLA. As fixed each end may not be a issue but why do it twice. Print solid. Don’t scrimp a few grams of plastic and compromise the part. With China ask for all you money back!! Invariably they won’t ask for their “junk” part back, or after resolved give 1 star. They probably have a factory with a couple thousand of factory defects that they are flogging off at full price in hope someone will just bend over and take it. Remember China isn’t number one!

[@Speedgaming802]

make it in asa or abs

[@FelheartX]

If you're going with 3D printing, print the thing out of carbon fiber nylon (PA6-CF)

[@GordLamb]

PC-CF might also be a good choice as it's quite a bit more rigid than PA6-CF, and toughness probably doesn't really matter in this application. Definitely would stay away from PLA has it tends to creep over time.

[@haydenc2742]

@@GordLamb at the minimum PET-G, but it is more stringy

[@sypernova6969]

I`d go for it. worse come to worse you can try a print that has carbon fiber in it or something.

[@michaelgleason4791]

Why wouldn't you just use a threadsert? Use the original part, drill out the hole where it goes, put in a threadsert, done.

[@torchmd]

Don’t get me wrong, I I like your process, and your video’s, but…. I fear you are really overthinking this one…. 1) I don’t think I would have worried about 10 thou on each side. 2) I am uncertain you could measure 5 micron’s diameter difference in your garage, let alone actually cut it on the lathe, and 3) As far as rigidity, there should be _no_ forces on the scales, they are scales after all. I 3D printed my mounts in PLA for my lathe, used a magnetic scale. I can’t detect any variance in the scales with moderate forces on them. Again, fun to watch, interesting thought process, but…. Maybe more intellectual investment than it’s worth?

[@BobCollins42]

Maybe you could start your videos by defining terminology. What is a DRO?

[@FunctionalPrintFriday]

digital readout