# OpenSource LongMill Scratch Build **URL:** \ **Category:** 🧰 CNC Setup\ **Created:** [November 12, 2019, 3:23pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191 "2019-11-12T15:23:19Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 4, 2020, 8:45pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/63 "2020-04-04T20:45:32Z")
I turned them up on a lathe. I think I just made a hand sketch, but if you’re interested, I could model it in 360. You could easily get your dimensions or change it, to fit your needs. Hansi ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 4, 2020, 9:58pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/64 "2020-04-04T21:58:13Z")
Just remembered, that the simplest would be, to take a motor coupling and just Mill/grind/cut off the two dogs. Turn down a step on the one face, and there you have it. That’s where I got the idea from. I just didn’t have any spare couplings. Note: just make sure the diameter matches your design and that the clamping screw doesn’t catch the printed leg. Hansi ---
**Author:** ![frankchannel](https://forum.sienci.com/user_avatar/forum.sienci.com/frankchannel/32/364_2.png) [@frankchannel](https://forum.sienci.com/u/frankchannel)\ **Post date:** [April 4, 2020, 11:22pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/65 "2020-04-04T23:22:04Z")
I don’t have a lathe, so that’s a no-go for me 🙂 ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 5, 2020, 6:55am UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/66 "2020-04-05T06:55:41Z")
I guess instead of turning a step, you could put a thin washer onto the shaft first, up against the bearing. The idea is to have the coupling/collar only push against the inner race of the bearing. I would still try to belt sand or even hack saw the two drive dogs off the back… That could lead to a nasty situation if something would get caught on them. Hansi ---
**Author:** ![frankchannel](https://forum.sienci.com/user_avatar/forum.sienci.com/frankchannel/32/364_2.png) [@frankchannel](https://forum.sienci.com/u/frankchannel)\ **Post date:** [April 5, 2020, 10:39am UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/67 "2020-04-05T10:39:46Z")
(I was referring to the custom eccentric nut actually. Sorry for the confusion) ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 5, 2020, 12:22pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/68 "2020-04-05T12:22:05Z")
Ah, no problem. Sienci sells them, if you are in North America. [https://sienci.com/product/m5-threaded-eccentric-nut/](https://sienci.com/product/m5-threaded-eccentric-nut/) I didn’t find any long sleeved version anywhere else, so that’s why I made mine. Yes, that’s lathe work. Hansi ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 5, 2020, 12:28pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/69 "2020-04-05T12:28:19Z")
If short sleeved version suits your build, you can find them on AliExpress under search “openbuilds eccentric” ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 29, 2020, 8:15pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/70 "2020-04-29T20:15:48Z")
Corona time, helped me get ahead on a few fronts of this project… ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 29, 2020, 8:21pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/71 "2020-04-29T20:21:52Z")
Main control panel layout ![IMG_20200408_171831_HDR](https://forum.sienci.com/uploads/default/original/1X/cd5690de6c33fc8c7f251d2ea1fb44fb94f44841.jpeg) From old PC case ![IMG_20200409_135107](https://forum.sienci.com/uploads/default/original/1X/6ea157ce6386808957977b4276f64ffeb2f5668f.jpeg) ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 29, 2020, 8:25pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/72 "2020-04-29T20:25:04Z")
![IMG_20200417_182249](https://forum.sienci.com/uploads/default/original/1X/7589c2aba1c3c488ea682cbb399b23b85d505e14.jpeg) ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 29, 2020, 8:28pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/73 "2020-04-29T20:28:09Z")
![IMG_20200427_203357](https://forum.sienci.com/uploads/default/original/1X/c1985fec8f8a4a89b0a1c377f7705e1517bbdeea.jpeg) ![IMG_20200427_204828](https://forum.sienci.com/uploads/default/original/1X/eb8cee512c2cb7ef7c91a1a8c67ecdef0ac6fa09.jpeg) ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 29, 2020, 8:31pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/74 "2020-04-29T20:31:49Z")
Finally got it moved outside, after being in the living room. Much to my wife’s relief:) ![IMG-20200428-WA0014](https://forum.sienci.com/uploads/default/original/1X/dd4f5894a8984871e9cd484a2e9ac368a83e4091.jpeg) ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 29, 2020, 8:33pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/75 "2020-04-29T20:33:34Z")
Just a temporary base that you see there. I still have lots of work… But rewarding to see it this far. ---
**Author:** ![BillKorn](https://forum.sienci.com/user_avatar/forum.sienci.com/billkorn/32/40_2.png) [@BillKorn](https://forum.sienci.com/u/BillKorn)\ **Post date:** [April 30, 2020, 3:27pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/76 "2020-04-30T15:27:56Z")
You are making great progress, congrats. I see one thing in your pics that will attract a lot of attention - a 1500W air cooled spindle. I am very interested to hear how you make out with that. I really like the Makita router, but drilling at 10,000 RPM is risky at best, so the lower speeds and lower noise are really attractive. Thanks. ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 30, 2020, 8:38pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/77 "2020-04-30T20:38:38Z")
Thanks Bill! Yes, I like the spindle too, but I did not expect or think about the weight, when I ordered it. Probably not ideal for fast peck cycles but if one keeps the Z travel speed in mind, I think it will be useable. Open for suggestions though. That’s what I have… So I’ll go with it. ![IMG_20200430_224050](https://forum.sienci.com/uploads/default/original/1X/6a9779ff2f67e366446b9e9a310e99d76df1cb4c.jpeg) ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [April 30, 2020, 8:42pm UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/78 "2020-04-30T20:42:45Z")
Just to note: The round version of air cooled spindle would probably be a better option for directly replacing the Makita. With this square frame I have to add some parallels under it, so that the motor clears the Z axis top plate. ---
**Author:** ![Iguana](https://forum.sienci.com/letter_avatar_proxy/v4/letter/i/e0b2c6/32.png) [@Iguana](https://forum.sienci.com/u/Iguana)\ **Post date:** [May 1, 2020, 3:26am UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/79 "2020-05-01T03:26:06Z")
Hansi, I’ve enjoyed this thread. I like your can-do attitude. If the Z axis performance is an issue, you could move to a NEMA 23 motor with a higher torque rating. The motor Sienci provides is rated at 12.6 kgf/cm (1.24 Nm) (see [http://ldomotors.com/products/show/57mm-hybrid-stepper-series](http://ldomotors.com/products/show/57mm-hybrid-stepper-series), model LDO-57STH562804AC). You can get NEMA 23 motors in up to 3Nm torque ratings, which would certainly overcome the added weight of the spindle (approx 1.7 kg extra). I suspect that flex in the gantry would be more an issue than the motor torque, though, when doing rapid Z movements. Have you considered epoxying the two aluminum angle irons together to increase the rigidity of the gantry? ---
**Author:** ![Hansi](https://forum.sienci.com/user_avatar/forum.sienci.com/hansi/32/216_2.png) [@Hansi](https://forum.sienci.com/u/Hansi)\ **Post date:** [May 1, 2020, 4:01am UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/80 "2020-05-01T04:01:48Z")
Thanks Iguana: Actually never thought about either of those solutions. Great ideas! Ya, a high torque 23 should solve that…my drivers are good for 4A I think. I did think about a different pulley ratio. Wow. Never crossed my mind, to use epoxy on those aluminum angle irons. Would adding a lower row of cap screws help in a similar way? Hansi ---
**Author:** ![Iguana](https://forum.sienci.com/letter_avatar_proxy/v4/letter/i/e0b2c6/32.png) [@Iguana](https://forum.sienci.com/u/Iguana)\ **Post date:** [May 1, 2020, 5:23am UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/81 "2020-05-01T05:23:40Z")
Yeah, a different pulley ratio would easily work. Never thought of that. IIRC, the Z travel out of the box is limited to 1000 mm/min. Running it at up to 2000 mm/min is just an EEPROM setting, but with a 2:1 pulley will still give you 1000 mm/m travels but at twice the torque (or thereabouts, depending on the motor’s torque curve). Another row of cap screws would help with gantry stiffness, sure. Not as much as a full-contact rigid bond, but I lack the engineering background to quantify how much a difference it makes… ---
**Author:** ![Iguana](https://forum.sienci.com/letter_avatar_proxy/v4/letter/i/e0b2c6/32.png) [@Iguana](https://forum.sienci.com/u/Iguana)\ **Post date:** [May 1, 2020, 5:24am UTC](https://forum.sienci.com/t/opensource-longmill-scratch-build/191/82 "2020-05-01T05:24:43Z")
Although, you’re using different motors, right? [Previous page](https://forum.sienci.com/t/opensource-longmill-scratch-build/191.md?page=3) [Next page](https://forum.sienci.com/t/opensource-longmill-scratch-build/191.md?page=5)