3D Printed Tachometer for Lathe Spindle - Part 3

STL's and links: fpfdesigns.com/
Hall Effect Sensors: amzn.to/3WG9ogi
Magnets: amzn.to/4bpq2VT
Loctite 222: amzn.to/45jeyRM
Transparent PLA: amzn.to/3RhtSbG
White PLA: amzn.to/4aYxvu2
Black PLA: amzn.to/3KAwqhk
M8x30 bolt: amzn.to/4bNpqty
M2.5x4 bolts: amzn.to/3VAL7HG
M3x16 bolts: amzn.to/4bUVDz1
Part 1: • 3D Printed Tachometer ...
Part 2: • 3D Printed Tachometer ...
Part 3: • 3D Printed Tachometer ...
• 3D Printed Cordless To...
Outro music is "Quantum" by "Vapora", used with explicit permission from the artist. • Quantum
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.
diy
finished
touchdro
tach
rpm
revs
feed rate
pm1440
1440gt
pm1340
precision matthews
lathe
magnets
hall effect
reluctor
functional
print
fpf
PLA
clear

[@JernD]

Great video! Haha, I was about to shout at the screen that you needed a window for the LED on the part for troubleshooting -- and then you did it! For translucent windows in 3D prints I often just smudge a bit of hot glue in the hole.

[@heidi5942]

That's a great idea. I don't have an AMS, so I'll keep the hot glue option in mind.

[@kenjay3490]

IF the clear PLA does not meet your goal… Try making a hole for pressing in a button of Lucite rod, with the ends polished. Ken.

[@DrFiero]

Or a perfect solution if you don't have the luxury of multi filament!

[@sosa99999]

What I like to do for a small PCB mount is the studslike you made but taller than the board. Then melt the studs with a soldering iron and that will hold the PCB down.

[@badjuju6563]

or china build it and use a gob of hot glue to glue the board in AND seal/hold the actual sensor in place AND seal the bare wires in the joint to the cable. bigger the gob the better the job.

[@philipershler420]

The problem with the melting the studs would be if the board ever needed to be replaced. Unlikely, but possibly.

[@KallePihlajasaari]

Having the pins MUCH longer with matching holes in the lid would provide alignment during lid fitting and have the PCB locked in place with the lid in place.

[@Roobotics]

I'm really glad you redid the design to have screws to hold the board to the base, everything else looked finicky as heck. In this case you really want the wire and sensor to just stay-put if you ever need to pop the cover off to troubleshoot or adjust things.. speaking of which, that soldering could really use a re-do and some heatshrink between strands if there's time.

[@rlschow]

I appreciate the sharing of your design process. Really good problem solving, and I love the led window. Also an inspiring example of the power and usefulness of affordable 3D printing. I’m in the process of installing a TouchDRO system on an 80’s Graziano SAG12s lathe and, though the fit-up is quite different, I have benefited greatly from following your series.

[@FunctionalPrintFriday]

Glad it was helpful!

[@tomruxton6546]

'Please Stay in There' loving the subtle/sarcastic humour. Thanks for your content.

[@FunctionalPrintFriday]

and thank you for watching it

[@dwp6x9e42]

I like your final design. I think I would of mounted the sensor to the cover instead of the base. Maybe adding a snap/slide on feature between the base and cover to reduce screws.

[@davidmcdaniel4322]

I bought an A1 with the AMS during the Bambu Lab sale. Wasn't sure if I needed the AMS or not. Your comment about the multi materials in a production part reinforced my decision.

[@v4lgrind]

It's worth it just for one material, one colour. Having the AMS switch to the next roll when the old one runs out is one of my favorite features.

[@davidmcdaniel4322]

@@v4lgrindbit of a step up from a run out sensor

[@FunctionalPrintFriday]

for sure!

[@JackPinesBlacksmithing]

My mind was silently screaming, “Strain relief!” As a BambuLabs A1 owner, we all got an education on same recently. This was a great series.

[@FunctionalPrintFriday]

thx! yeh I still need to replace the bed cable on my A1

[@NimblyJimbly]

I definitely want one! My problem is that I’ve got the 3D printer and the build hardware… I just need the lathe. 😑 lol. Thanks for the awesome video. Love seeing your process and all the tips, tricks and tools along the way!

[@FunctionalPrintFriday]

Ha! I saved for a long time to get that lathe, but zero regrets. Thx for your comment

[@DmitriyKhazansky]

Just something to consider for next time: make a custom PCB so that you can land those relatively large wires to the three pin sensor. It just needs a terminal block and the three holes for the sensor with three traces

[@FunctionalPrintFriday]

all the different places reaching out to me that make custom PCB's wanting to sponsor the channel would love this :P

[@andyb7754]

Very nice work, excellent outcome. Thank you for the videos.

[@FunctionalPrintFriday]

Thanks for watching!

[@danieljosefsson7007]

I didn’t realise translucent PLA was a thing, for some reason I’ve just assumed you have to switch to PETG for that. Thanks!

[@63huggybear]

I’m very impressed on how you solve challenges. Great work. Thank you.

[@TerryPullen]

I would like to see fewer parts in the final design. A base, and a parts box with a cover. The base bolts to the machine, the box snaps to the base, and the cover snaps to the box. The base and box would share a stress-relief feature that held the cable and allowed for a tie wrap to do double duty securing the box to the base. The cover would just snap to the box. - Rotate the box a few degrees from the mounting bolt so the cable doesn't interfere with the bolt. - Print the cover and box in one print job and connect them with a flexible hinge P.S. Easy for me to say. 🙂

[@DrFiero]

As for board protection - a simple solution is conformal coating. Spray the crap outta it to make it really thick... done! While not applicable here, beware using Loctite on plastic. Years ago, I'd made a switch panel for a car. Didn't want the lock rings for the switches to vibrate off so.. used a drop of blue on them! Bad idea. Every one of the rings split, and the switch bodies had broken the next day! :O

[@DrFiero]

BTW - your cap/lid is fantastic! I was just thinking 'simplistic'.

[@joell439]

That was super fun. 👍😎👍

[@Todestelzer]

11:35 hot glue. Every maker should have it 😊

[@FunctionalPrintFriday]

lol, friend of mine joked the same thing

[@LucasHartmann]

Your could have made your life easier by keeping the base-cover interface flat, placing the main bolt deep in a pocket, and maybe flipping the PCB upside down. Loving the videos, though

[@Grivooga]

An easier way to have the window for the LED without using multi-filament is to put a 1.8mm hole in your model directly above the LED then after it's all assembled push a piece of clear filament into the hole (the squarer the end the better the result) then cut it almost flush then use a junk soldering iron on low temp to make it flush. The clear filament acts like a poor fiber optic light tube. Then for the white dot, paint pen. I have an X1C with AMS but I try to avoid prints that have filament changes only for cosmetic purposes.

[@jimdaniels71]

Great series! I have a PM-1236T that I hope be able to use this on. It seems like much of your trouble was with the wire exit. Is there a reason you didn't run the wire out at the cap level instead of pushing it down to the bottom of the well?

[@FunctionalPrintFriday]

just wanted it as much out of the way of moving parts in there as possible

[@mp-xt2rg]

Great video

[@DavidCousins]

Well done. You have many talents. I enjoyed the design journey. Your last iteration was an amazing improvement.

[@FunctionalPrintFriday]

thx!

[@devilvortex1]

For what purpose do you need the tachometer if you don't have the speed adjustable with a potentiometer ?

[@75keg75]

Print 20 times, measure once.

[@evugar]

Next: ELS! 🙂

[@Streetduck]

Ich hätte das Kabel mit Stecker von unten herangeführt, vom PCB die Anschlüsse nach unten gelötet, so wäre alles aus dem Weg und man könnte den Sensor einfach stecken 😉👍🏻 Aber gute Idee und tolles Video …..

[@zerker2000]

how annoying would it be to move the wire exit down a bit, and leave a counter-bore to be able to assemble the part first and bolt it to the machine second? would make the bend in the cable gentler too

[@ianmcpherson2301]

I would have mounted the board in the cap along with a socket for the wires. No wire retension required within the case. Just my thoughts not a criticism.

[@UnCoolDad]

I was in your way of thinking with regards to the AMS - I don't need it. But after seeing this print, if I buy a printer with an AMS option, I may well get it just for the elegance of adding a window, or some contrasting text. Looks so much more professional. Am I correct in s saying that the AMS needs to do a purge for every layer of a different color? How many layers of the clear filament did you use in this model?

[@FunctionalPrintFriday]

about 8 layers I think. Yes, it does purge between changes. It's less than ideal, but really only a pain if you're doing a huge trinket with 4 colors throughout.

[@UnCoolDad]

@@FunctionalPrintFriday is the slicer smart enough to print the same color it printed after a layer change to minimise purges?

[@FunctionalPrintFriday]

@@UnCoolDad yes

[@kippie80]

Following up on some further talk about using Sketchup. Yes, I've tried it a few times and it is working OK. Really have to be careful with your operations to keep the geometry good. The tool is very free-form but that is what is good about it, especially for one-offs. The one sadness though is curves/circles. It does not generate nice curves. :( It seems to come right from the implementation of curves, they are only ever modelled in segments. That is a real shame. Too bad there is no post-processor that could even identify simple curves and switch them up.

[@FunctionalPrintFriday]

you can specify the number of "sides" for the curves by selecting the tool and typing a number followed by "S" to denote sides. For example: "128s" will give you 128 sides for the curve.

[@derbuechsenmacher]

Use only a small drop of loctite. More is not better

[@FunctionalPrintFriday]

Appreciate the heads up. I used a bit more than I usually do, but sounds like I was still going way overboard.

[@yuvaltal6417]

Definitely consider putting some insulation on the wire ends soldered to the board.

[@tat2joeelliott]

I dig this whole idea except for the fact it’s not Apple compatible

[@FunctionalPrintFriday]

I initially had the same thought, BUT you want a dedicated device for it, and cheap (new) android phones can be had as low as $35.

[@ToddRafferty]

You're spending way too much time trying to design something to get the board attached to the part on the machine and fiddling with the cap too much when it should be the other way around. IMO, I would have attached the sensor to the cap, and created a cable channel on the cap as well. The part that stays on the machine would just receive the cap and hold everything against the machine. Just .02 cents.

[@derbuechsenmacher]

You are using way to much loctite. All you need is a small dot

[@FunctionalPrintFriday]

Appreciate the heads up. I used a bit more than I usually do, but sounds like I was still going way overboard.