Quite an Unusual one

[Bongo]

Hi Boyan. Inspiring. After reading this thread I had to join the forum, just to say how cool your machine is and how impressed with your work I am. Thanks so much for sharing. I am partway through building a beast-sh 1.2 x 2.4m steel and epoxy machine, which I plan to run with similar Samsung servos to you. I am just debating whether to spin the 2 long ballscrews or their ball nuts to eliminate the potential problem of whipping.
Like you I am aiming at snappy ;)
Anyway, I wonder if you would be able to share some of the details of how you designed / constructed that area where the servos, belt drive the ballnuts and attach to the gantry ends?
Thanks again for your inspiring work!

[Boyan Silyavski]

I am partway through building a beast-sh 1.2 x 2.4m steel and epoxy machine, which I plan to run with similar Samsung servos to you. I am just debating whether to spin the 2 long ballscrews or their ball nuts to eliminate the potential problem of whipping.
Like you I am aiming at snappy ;)
Anyway, I wonder if you would be able to share some of the details of how you designed / constructed that area where the servos, belt drive the ballnuts and attach to the gantry ends?
Thanks again for your inspiring work!

Hi,
will take photos

Definitely go rotating nuts. Normally i run it at 8000 mm/min for wood as faster wood will chip. But for foam or 3d jobs i run it 16.000 or faster. And being snappy means no slowing in corners. Especially important if doing deep trochoidal toolpaths. Meaning a very serious difference in time. Not that a 10.000 mm min max speed machine is not enough for a normal work, but if you have an order of say 100 doors or something the difference will be like 4 or 5 more days to do the job. And talking about profiling the panels only. Not 3d job

[Bongo]

Hi,
will take photos

Definitely go rotating nuts. Normally i run it at 8000 mm/min for wood as faster wood will chip. But for foam or 3d jobs i run it 16.000 or faster. And being snappy means no slowing in corners. Especially important if doing deep trochoidal toolpaths. Meaning a very serious difference in time. Not that a 10.000 mm min max speed machine is not enough for a normal work, but if you have an order of say 100 doors or something the difference will be like 4 or 5 more days to do the job. And talking about profiling the panels only. Not 3d job

Hi Boyan, thank you for the good information. Yes I want to aim for some of those speeds without it being a disaster if I don't achieve - This is mainly ambitious hobby stuff, but would like to have the option to put it to work for money.

I guess you are not a fan of ballscrew damper type things like this - https://www.youtube.com/watch?v=NWB6FAJCPhA ?
Even if I ddn't have a problem with whipping, I would be a bit concerned about the rotating inertia of the ballscrews if I went the driven screw rout.
The two long ballscrews I have are 32mm dia. 5mm pitch and 2300mm stroke. They are only rolled c7 accuracy (claimed) ones from China, but will hopefully work for what I want. Maybe I would have gone 15 or even 20mm pitch if I was doing over, but I started this a long time ago... I bough end supports with them - only cheap ones though so not worried if I don't end up using them...

I look forward to seeing the photos of your machine's design in this area. Am almost certain I will copy it quite closely. What size belts did you go for? Any leads on best place to get belts and pulleys?
Thanks again for your guidance on this - priceless info from an experienced builder!

PS.
I just pulled the trigger and bought 4 of the 400W AC Samsung servos and drivers, similar to the ones you use, from dy-global. Fingers crossed they get here ok.

[Boyan Silyavski]

Hi Boyan, thank you for the good information. Yes I want to aim for some of those speeds without it being a disaster if I don't achieve - This is mainly ambitious hobby stuff, but would like to have the option to put it to work for money.

I guess you are not a fan of ballscrew damper type things like this - https://www.youtube.com/watch?v=NWB6FAJCPhA ?
Even if I ddn't have a problem with whipping, I would be a bit concerned about the rotating inertia of the ballscrews if I went the driven screw rout.
The two long ballscrews I have are 32mm dia. 5mm pitch and 2300mm stroke. They are only rolled c7 accuracy (claimed) ones from China, but will hopefully work for what I want. Maybe I would have gone 15 or even 20mm pitch if I was doing over, but I started this a long time ago... I bough end supports with them - only cheap ones though so not worried if I don't end up using them...

I look forward to seeing the photos of your machine's design in this area. Am almost certain I will copy it quite closely. What size belts did you go for? Any leads on best place to get belts and pulleys?
Thanks again for your guidance on this - priceless info from an experienced builder!

PS.
I just pulled the trigger and bought 4 of the 400W AC Samsung servos and drivers, similar to the ones you use, from dy-global. Fingers crossed they get here ok.

There is a rotating ball nut thread in the forum, most info is there including free designs from me and other people


15mm HDT 5 belts

I use Belting online for belts and pulleys. Once bought 20 crappy chinese pulleys so -never again


i use this calculator for the centre to centre distances and other stuff


I can send you the CAD files if needed for the rotating nut , ball screw is 25 size, screw should be manually greased well as it heats when things get faster

[Boyan Silyavski]

I guess you are not a fan of ballscrew damper type things like this - https://www.youtube.com/watch?v=NWB6FAJCPhA ?

If you see a 250kg gantry moving at 20k mm min at 3000mm/sec you would laugh at the speed shown on the video.