Harmonic Rotary Drive

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msimpson
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Harmonic Rotary Drive

Post by msimpson » Wed Feb 06, 2019 1:24 am

I recently purchased a harmonic rotary drive.
_MG_2404.jpg
I paid $430 delivered. It has a 50:1 reduction and is rock solid. So far I have been very happy with it. I did some runout tests here:


I purchased from Amazon here:
https://www.amazon.com/gp/product/B07B2 ... 1b31592686

Once I get it hooked up to some of my CNC machines, I will do a full write-up.

mbonadio
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Re: Harmonic Rotary Drive

Post by mbonadio » Wed Feb 06, 2019 10:04 am

That's awesome, I've been looking to add the 4th axis to my machine for ages, can't wait for the writeup and get it working.

Thanks so much
Cheers
Michael

MarkVa1
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Re: Harmonic Rotary Drive

Post by MarkVa1 » Wed Feb 06, 2019 10:54 am

That's very cool! Look forward to the write up.

msimpson
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Re: Harmonic Rotary Drive

Post by msimpson » Wed Feb 06, 2019 11:43 am

I have been playing with rotaries for a little while. I have tried a couple that used worm gears, and one of those 6:1 belt driven drives.

The worm gear ones just have too much backlash. The belt driven ones have no backlash, but lack the holding power for any serious machining.

One area I plan on putting it to the test, is on the plasma CNC. I want to make a fixture that will hold steel angle. This would allow me to drop in a piece and cut both sides in one operation.

mbonadio
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Re: Harmonic Rotary Drive

Post by mbonadio » Wed Feb 06, 2019 4:00 pm

That's so awesome, I didn't even think of that for cutting angle iron, but it makes total sense. Are you thinking of manually writing the gcode or doing it through a CAM program?

msimpson
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Re: Harmonic Rotary Drive

Post by msimpson » Wed Feb 06, 2019 9:26 pm

Heavens no, manual gcode is only good for simple things like my breakin loops. For plasma, Sheetcam is a must. Sheetcam has all the plasma provisions needed. Even if I have to run two sperate jobs, it still beats removing the part and reinstalling it.

msimpson
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Re: Harmonic Rotary Drive

Post by msimpson » Wed Feb 06, 2019 9:29 pm

I will probably look at doing some milling of aluminum angle and square on the KRMx02 or CNC Construction Set. You can plasma cut aluminum, but the finish wont be as good. For plasma, I only need to support the part by one end. For milling both ends will need to be supported.

Bobtail Farm
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Re: Harmonic Rotary Drive

Post by Bobtail Farm » Thu Feb 07, 2019 4:06 pm

thanks for the continued innovation. i look forward to reading your write-up on the harmonic drive for the 4th axis (eventhough I purchased and use one of those <$150 units).

mbonadio
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Re: Harmonic Rotary Drive

Post by mbonadio » Mon Feb 18, 2019 1:11 pm

Can the UC300eth and another breakout board like the SainSmart 5 Axis Breakout Board, with the Stepper Motor Driver CNC Controller, Stepper Motor Driver Nema tb6600 be used to control the A axis in Mach3. I understand the the UC300eth breakout board allows two ports, would this work or I've been reading about the UC400eth and its ability to support multiple ports.

Thanks
Michael

msimpson
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Re: Harmonic Rotary Drive

Post by msimpson » Mon Feb 18, 2019 2:03 pm

KRMx02
For the KRMx02 you can swap out one of the drives but in order to have full axis to all drives you will need a driver and breakout board and a way to interface it to your PC. I doubt you have a second parallel port so unless you want to add a PCIe card to your PC, you will have to look-in to moving to a motion controller like the UC100, UC300ETH, or the Smooth-steppers. All but the UC100 will allow you to add a additional breakout boards and drivers.



CNC Construction Set
You can add a breakout board and driver to the Advanced layout build (UC300ETH). This will allow you to set up a B axis. The A axis is being used to help drive the Y axis.

You will also need CAM software that will allow you to translate drives, IE X to B in our case. With both Vectric and SheetCam, this involves some new post processors. The first one I will probably work on is the post processors for Vectric software (Vcarve, Aspire, Cut3D). The plasma stuff will be using Sheetcam so once I get some plasma upgrades tested and posted, I will start on those.

I have pretty much chosen the driver and the breakout board and will be posting links when I am ready to start writing things up on the drive.

msimpson
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Re: Harmonic Rotary Drive

Post by msimpson » Thu Feb 21, 2019 10:56 pm

I got my K12-100 4 jaw chuck to day.
_MG_2595.jpg
Honestly I doubt I will ever remove it as it can still hold round stock but gives me a much better way of holding square stock.

Build 3 of the CNC Construction Set is now undergoing the plasma upgrades so all my milling will be done on this machine.
_MG_2597.jpg
This is a fixture table I am working on. I will be adding several Rivnuts for the headstock and tailstock.

msimpson
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Re: Harmonic Rotary Drive

Post by msimpson » Thu Feb 21, 2019 11:04 pm

@mbonadio
You can not use the driver you linked to as it does not support our 48v power supply.

mbonadio
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Re: Harmonic Rotary Drive

Post by mbonadio » Fri Feb 22, 2019 1:24 pm

Which driver board are you evaluating?

msimpson
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Re: Harmonic Rotary Drive

Post by msimpson » Sat Feb 23, 2019 11:15 pm

I will be starting a web blog on the harmonic drive after I get a couple more chapters on the CNCCS Plasma table completed ( couple days). I will post links to all the components I will be using.

Note that this will be for the CNCCS as, the write-up for the KRMx02 will be a more involved.

mbonadio
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Re: Harmonic Rotary Drive

Post by mbonadio » Sun Feb 24, 2019 2:10 am

Ok, cool. Looking forward to it, I've been waiting for a 4th axis for a long time.

Thanks
Michael

msimpson
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Re: Harmonic Rotary Drive

Post by msimpson » Fri Mar 01, 2019 6:35 pm

I just started my harmonic rotary drive write-up. Its going to take me a while as I don't want to stray to far from the plasma books I am working on. Also I dont want to commit to any electronic parts until I have a chance to do some more testing on both the KRMx02 and CNCCS.

I did create an 8020, 1030 aluminum table for my CNCCS which I will be using to mount the rotary. This is the same kind of table that's on most of the KRMx02 machines so the mounting and alignment will be identical on both machines.

Here I just mounted a vise so I could machine some small aluminum clamps.
_MG_2834.jpg
This setup would be almost identical on the KRMx02.

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