Proxxon MF70 Upgrade - Brushless Motor

As I've upgraded my MF70 spindle to ER11 collet, a potential risk is the torque and power of the original motor (as it is only a 100W motor). So I've upgraded it to a high power brushless motor. The new motor is a 3650 kv2300 motor. Although the highest voltage can be 22V and the max. power can reach to 900W at 50,000 rpm, I'm a bit concern about the heating risk. Thus I only use 12V power supply thus the highest speed will be a bit more than 25,000. Comparing to the original motor, this is far more than enough.
Furthermore, my pinciple of upgrading the machine is try to make as less structural change as possible, so that I can easily restore it back to the manufacture status if needed. To achieve this, I've 3D printed 2 parts which almost identical to the original one (only with some adaptation to my new motor). And it works perfectly well.
By now I think it has almost reached the ultimate potential of this MF70 and would be my final upgrade to it. In case I need bigger and more precise CNC machine in future, I'm thinking to build one by myself.

[@PaulFalder-g7b]

Hi Eddie, continuing with your upgrade having purchased all the necessary components. However having great difficulty removing parts shown at 0:39 seconds from end of original motor spindle? Is that the reason you re-made these components because the originals were unusable after attempted disassembly?

[@eddiejiang6789]

Yes, you are right. I also found it very difficult to remove the motor-side coupler. And I don't want to risk destroying it by using strong force. So I just left it with the original motor and made the coupler myself. Fortunately, the one I made is even better then the original.🤭

[@GazelleCreativeStudio]

Hello Eddie, I saw your KZbin channel. I have a Proxxon MF70 and I would like to be able to use Larger Drill Bits. Do you know where I can get one? or guidance as how to make one? (I don't think I have the tools to make one, but let me know) Do you have an Instagram account?

[@eddiejiang6789]

Hi, I have tried 2 approaches to upgrade the spindle to Er11 collet. You can search "Er11 extension" on Amazon, and find either an adapter or a extension rode (100mm or 150mm). For the adapter, you'll have to make M8*0.75 thread so that it can directly replace the original collet. But this approach may create additional spindle runout. The other approach is to make a whole spindle shank with a lathe using the extension rode. I have video for both solutions and prefer the 2nd one. One thing to remind is that if you want to use extension rode, make sure it's solid rode as most ones are hollow. Or you may have to think of how to install the adapter for connecting the motor. Hope this can be of help. Sorry I don't have Instagram account.

[@PaulFalder-g7b]

Hi Eddie, perfectly easy to see model number of motor, but what about controller and power supply part numbers which you wrote is 12v. do you use an external rectifier to step down from 240V (in UK)?

[@eddiejiang6789]

Hi, for the controller, you can easily found one on Amazon by just look for "servo tester". For power supply, I used an adjustable DC power supply (0-30v, 0-10A), which was also bought from Amazon. Of course you can select other less expensive solutions

[@marcosiccardi7956]

HI, how did you interfaced the er11 collet with the shaft of the kv2300? mine is really small in diameter compared to the er11 bore. Thanks

[@eddiejiang6789]

Hi, MF70 has a mechanism to connect the spindle with the motor shaft. It includes 2 connectors, one on spindle and one on motor shaft. Theoretically I can directly use the original connector on motor shaft by selecting the same diameter motor shaft KV2300. But given that I wasn't able to take out the original connector on motor shaft, I 3D-printed one (ref. 2'27''). Also later on I've made another connector with aluminum+3d printing parts, which is much more durable and effective (ref. my other video). Hope this answers your questions.

[@TRUCKAMIONES]

Your talent is impressive, I tried to remove the motor coupling and it broke, could you share the stl and print measurements? I appreciate any help blessings

[@eddiejiang6789]

Yes. I can share the coupler in solidworks format. As some part was made with aluminum. Could you let me know your e:mail? Or any other ways to send you the file?

[@eddiejiang6789]

Hi, I have uploaded my motor coupling kit to a 3D object sharing website. Unfortunately it does not accept Solidworks format so I only uploaded STL format, thus you might not be able to easily modify it. Please pay attention to my notes, hope it can help. Please try the link: www.myminifactory.com/object/3d-print-proxxon-mf70-motor-upgrade-kit-377309

[@TRUCKAMIONES]

@@eddiejiang6789 thank you very much... thanks... thanks

[@lucasaju8712]

the problem with this milling machine is not the maximum speed that can be reached but the minimum one. To work metal, many cutters have a maximum rotation allowed ranging from 1000 to 6000 rpm, in fact they sell a mechanical speed reducer. If you don't work metals, its motor is sufficient also because the structure is not very stable and the cross table is not easily adjustable

[@eddiejiang6789]

Thanks for your comments. I use this machine to work on metal like aluminum and brass, etc. (ref. my other video using this machine to make a propeller). And when working on aluminum, I normally set speed @ around 18000RPM. It works perfectly well. I also tried it on cast iron which also proven quite good (ref. my video about upgrading my lathe tailstock). Never tried it on steel.

[@lucasaju8712]

Indeed, aluminum can also be worked at higher speeds but it depends on the type of cutter. Normally finishing requires one speed while material removal requires another. As for harder metals, if you don't use a cutting liquid and a low speed the cutters don't last very long. What type of cutters did you use? the standard proxxon ones?

[@eddiejiang6789]

@@lucasaju8712 No, I use cutters bought from Taobao(Alibaba Chinese part). 'Cause there are a lot of variances are not available at Proxxon. Also that's why I upgraded the spindle to Er11 - to give me much more choices.

[@isidoromaich7226]

Awesome upgrade! Nobody can guess there is inside a more powerful motor. The printed part files are available in Thingiverse or another repository?

[@eddiejiang6789]

Thank you very much for your recognition! Sorry I didn't publisize the files for printed parts. I never had shared my files on internet. Will try later. Furthermore, I found that the printed parts may have some issues on durability. Also it won't help in cooling the motor. I'm making a further upgrade to make aluminum parts with redesigned cooling fans to replace them. Will upload another video soon.

[@pamintangwasak]

@@eddiejiang6789 Nice upgrade. How's the redesigned alu 3650 motor coupler going?

[@eddiejiang6789]

@@pamintangwasak The coupler in this video was a 3D printed one. It works Ok when the motor runs in lower RPM. However, it was not strong enough especially in high RPM and high load. So I made a further upgrade and changed some of the parts with aluminum. Then it works perfectly fine.

[@pamintangwasak]

@@eddiejiang6789 Noice! I'd like to give that DC motor upgrade a try. Got a spare aluminum coupler (and its supporting parts) for s@le? :D

[@eddiejiang6789]

@@pamintangwasak Thanks! I regret to say that I don't have spare parts for sale at the moment. You can see my other video clip about enhancing the motor coupler for reference.

[@AveryKoff]

LOVE the upgrade! Can you recommend a specific 3560 motor? How is yours holding up and, if it's done well, what model did you go with?

[@eddiejiang6789]

Hi, thank you very much!! Re the motor, I bought it on Taobao (Alibaba's Chinese branch). You can see the detailed model @ 0'45'' of the video. Re the assembling, you'll need to pay special attention that the shape of 3650 motor is a bit different than the original one, so you'll have to make 2 notches on the motor (see 1'19''~1'33'' in the video) so that the screw can be fit in. One more thing is that actually the coupler/connector of the motor in this video was fully 3D printed with resin, which is not strong and durable enough. So I made a further upgrade (pls ref my other video "Proxxon MF70 - Motor connector enhancement"). Re the final result of the machine, I used it to work on aluminum and it's quite satisfiable. There are 2 things may take into consideration: 1. although the power of the motor was stated to be 900W, but it will not be reachable until it runs at 22V and 50,000RPM. However, the torque might be a bit insufficient, especially when working on metals. To solve this, you may consider using synchronous pulley to reduce the RPM while increase torque. But that would be much more complicated. I even saw someone using A2212 motor+ER11 spindle which has much less power but also workable. 2. The motor is "soft" coupled with the spindle with a rubber gasket (ref 2'35'' in this video), if you set the motor at too high speed, the gasket might have a chance to mulfunction. To solve this, you make need to redesign the coupler and make the teeth wider. So that it becomes "hard" coupled. But if so, I think the coupler on the spindle side needs to be upgraded to metal as well (I've upgraded the motor-side coupler to metal already, ref my other video). To sum-up, I'd say after the upgrade, it works well on soft metal like aluminum, copper, etc. as long as you control the feedrate and cut depth carefully. Anyway, given MF70's XYZ travel limitation, I've built a CNC of my own which is much bigger, so not much experiences on this MF70 anymore. Hope this helps.