[pupdogg]

As per title. Take a look. Love these servos! Skip to 2:32 to see motion.

https://youtu.be/AY-i5pnaJ1Y

[pupdogg]

Here's the router shaving 1/16" of the back of the art piece shown in the original video. Video was sped up to fit 1min.

https://youtu.be/i1aYV9acC2g

[wizard]

Here's the router shaving 1/16" of the back of the art piece shown in the original video. Video was sped up to fit 1min.

Nice work!

A word of advice, keep your hands out of the work area of an operating machine tool. I've worked industrial maintenance, in one form or another, all my life and the people that loose body parts invariably have those parts where they don't belong. It isn't the type of call the department ever wants to get. Be careful so that you can enjoy your work for years to come.

- - - Updated - - -

Here's the router shaving 1/16" of the back of the art piece shown in the original video. Video was sped up to fit 1min.

Nice work!

A word of advice, keep your hands out of the work area of an operating machine tool. I've worked industrial maintenance, in one form or another, all my life and the people that loose body parts invariably have those parts where they don't belong. It isn't the type of call the department ever wants to get. Be careful so that you can enjoy your work for years to come.

[pupdogg]

@wizard, thank you and good call on the safety...I normally do try to take calculated risks but I agree, there’s no excuse for proper safety.

Anyhow, here’s another video of an artwork I shot today:

https://youtu.be/xDT8n5cKs54

[OlfCNC]

Nicely built machine, congrats!

[ger21]

I'd prefer to see videos at normal speed, even if it's shorter.

Does that gearbox have any noticeable backlash?

I bought some chinese gearboxes for my DMM 400watt servos, that I'll be using with helical R&P.

[pupdogg]

Hi Ger21, sorry for the delay in my response. To answer your questions:
1. Normal speed video: I will most likely get some time this coming week to re-render the video in realtime...in the meantime, I just uploaded a video of milling ALU with 3F 1/2" HSS endmill, 0.03" DOC @ 100IPM, 25% step-over all in a single pass. You can see the video below.
2. Gearbox backlash: Not that I can notice visually on any finished pieces. I have yet to put hard factual data around that conclusion...however, I don't see myself doing that anytime soon as we are swamped with existing projects and the overall cut quality is acceptable. Note: I did open up each gearbox and cleaned/re-greased the sun/planetary gears with Kluber Isoflex grease for my sanity (available here: https://amzn.to/2leSfHH). Our 4.4kW swiss laser came with plenty of cartridges of this grease for its geared components so we had it on hand.

We're using this machine commercially for our signs business and so far it has served us well. When things do slow down a little, I do plan on making a few more changes to the overall setup:
1. New Gantry: Existing gantry is a weak one...need to design a weld a new/more heavy duty gantry. I could go with aluminum but plan on adding some weight to offset higher acceleration. Btw, I do have brake resistors installed on each of the 3 DYN4 servo drives.
2. Helical Gear Rack: Replace the existing straight gear rack on X & Y axis helical MOD2 with a split pinion 0 backlash, gear reducer
3. Spindle upgrade/ATC: Upgrade to a 9 or 10hp ATC capable spindle

https://youtu.be/_T2glOFVlCA

[fretman_2]

Sweet machine!

[andrewwong2000]

Thanks for the vids.. I’m looking to order 750w NEMA34 Servos with DYN4 drives.

Any issues with holding torque on your z axis ?


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[pupdogg]

@fretman_2: thank you!
@andrewwong2000: Our z-axis uses DMM 400W servo with DYN2 drive and I would say that it's a workhorse. I see no issues with the motor holding torque. With that said, I have a spare DYN4 servo drive and might upgrade the z-axis motor to 750W to have a consistent servo/drive combination throughout the system. If I was to do it all over again, I would be careful in choosing the appropriate 750W motor from DMM as they have 2 different versions with 1 having a 14mm shaft and the other with 12.7mm (1/2") shaft. I ended up getting the 14mm version, which was cheaper....but in the long run, it cost me a lot of time and research to the find appropriate gearbox and pinions to fit this style. If I were you, I'd go for the 1/2" shaft version: 86N-DHT-A6MD1. I hope this helps.

[andrewwong2000]

Thanks - yes DMM advised me on the 1/2” D cut shaft model as it will be running a CNCRP4896.


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[automationtechinc]

Hi Gerry

We have the Gearbox, the backlash is less than 7 arcmin, it works very good.

https://www.automationtechnologiesin...etary-gearbox/

[ger21]

2. Gearbox backlash: Not that I can notice visually on any finished pieces. I have yet to put hard factual data around that conclusion...however, I don't see myself doing that anytime soon as we are swamped with existing projects and the overall cut quality is acceptable. Note: I did open up each gearbox and cleaned/re-greased the sun/planetary gears with Kluber Isoflex grease for my sanity (available here: https://amzn.to/2leSfHH). Our 4.4kW swiss laser came with plenty of cartridges of this grease for its geared components so we had it on hand.

Thanks.
I actually have a $400 tub of the Isoflex grease at work. But I'm a little afraid to open up the gearbox, lol.

[mactec54]

@fretman_2: thank you!
@andrewwong2000: Our z-axis uses DMM 400W servo with DYN2 drive and I would say that it's a workhorse. I see no issues with the motor holding torque. With that said, I have a spare DYN4 servo drive and might upgrade the z-axis motor to 750W to have a consistent servo/drive combination throughout the system. If I was to do it all over again, I would be careful in choosing the appropriate 750W motor from DMM as they have 2 different versions with 1 having a 14mm shaft and the other with 12.7mm (1/2") shaft. I ended up getting the 14mm version, which was cheaper....but in the long run, it cost me a lot of time and research to the find appropriate gearbox and pinions to fit this style. If I were you, I'd go for the 1/2" shaft version: 86N-DHT-A6MD1. I hope this helps.

14mm shaft is ISO standard throughout all manufactures so not sure why you had a problem, all normal gear boxes for that size motor use 14mm shaft, so using a motor with a 1/2" shaft motor you would have just the same problem or may be even worse, as you would have to be a custom made drive gear that fits the motor shaft

[ger21]

I think the 1/2" shaft version is designed as a replacement for a Nema 34 stepper motor.

[pupdogg]

@mactec54: The shaft size was just 1 issue. The 750W motors that I have, 86M-DHT-A6MK1, are NEMA34-Metric and have a gearbox mating rabbet size of 80mm OD and mounting screw pattern spacing of 70.71mm. This deviates from the standard NEMA34 (I am guessing Imperial?) rabbet size of 73mm and screw pattern spacing of approx. 69.5mm. When I was looking, eBay had a lot more standard NEMA34 gearboxes supporting 73mm rabbet, 69.5mm screw spacing and 1/2" input shafts than NEMA34-Metric available. Even the manufacturer, DMM, recommended going the belt reduction route as they could not recommend a viable gearbox manufacturer for this motor. This just dragged my decision making process until I was able to find an eBay seller who was willing to make small modification to their existing gearbox to adequately fit this motor.

[andrewwong2000]

Sounds interesting pupdog - who did the mods for your gearboxes ?


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[pupdogg]

@andrewwong2000: Try this link https://www.ebay.com/itm/263268452071. It's been a while but I believe I had the guy customize servo-to-gearbox screw hole locations and size. If I was to redo it all again, I would still get the 1/2" shaft servos and gearboxes to match BUT with helical planetary/sun gears...these are generally rated for backlash of <= 3arcmin. Will I notice the difference in end-result for what we do? Probably not becuase I'm building upon someone else's frame...but it will just feel good in the back of my mind.

@ger21: Looking back at that listing, the backlash is listed as <= 7arcmin

Wanna see something cool? Here's a hollow motor winding of the gantry servo of our laser with the ballscrew nut press fitted inside...all the green spatter is lithium grease! This thing can haul ass at around 5000IPM. Pretty insane!!

https://youtu.be/GNDJbZL-LMo

[pupdogg]

@ger21: here's a quick view inside the gearbox...there's no grease present in this one yet

https://youtu.be/q3KusUDDM3w

[mactec54]

@mactec54: The shaft size was just 1 issue. The 750W motors that I have, 86M-DHT-A6MK1, are NEMA34-Metric and have a gearbox mating rabbet size of 80mm OD and mounting screw pattern spacing of 70.71mm. This deviates from the standard NEMA34 (I am guessing Imperial?) rabbet size of 73mm and screw pattern spacing of approx. 69.5mm. When I was looking, eBay had a lot more standard NEMA34 gearboxes supporting 73mm rabbet, 69.5mm screw spacing and 1/2" input shafts than NEMA34-Metric available. Even the manufacturer, DMM, recommended going the belt reduction route as they could not recommend a viable gearbox manufacturer for this motor. This just dragged my decision making process until I was able to find an eBay seller who was willing to make small modification to their existing gearbox to adequately fit this motor.

If you had of brought the 86N-DHT-A6MD1 motor it would of fitted straight to the gearbox the motor is the same 750W with the 73mm locating spigot and a .5 shaft size and mounting holes are also correct for the gearbox you are using