1st Build, Steel, Epoxy 24"x24" for Wood

[wallyblackburn]

Wow! I was thinking it had been over a year since I last posted - but then realized the dates are DD-MM-YYYY and not MM-DD-YYYY! Anyway, got sidetracked somewhat with a surface grinder I picked up at auction. That, along with a surface plate and measuring tools pulled me into the world of tenths. A scary, but fun place. I like This Old Tony's description of his surface plate: Where dreams go to die... Anyway, gotten back to the router recently:



Now, I know it isn't pretty. Please keep in mind my goals for this are to learn and gain experience. I would like it to cut wood at a reasonable (woodworking) level of accuracy at some decent speed, but I'm mostly having fun and building skills and knowledge to make a better one after this - if I decide I want to.

I just ordered rails and ballscrews that are 50mm longer than the ones in the pics. I intend to move the existing ones to the gantry and put the new ones in their place. This should give me bit more travel and get the ends out where I can get pulleys on them. I am thinking of driving the two Y-axis screws with a single NEMA 34 and timing belt arrangement. The X- and Z-axes will be NEMA 23.

Can I get opinions on this kit: https://www.ebay.com/itm/FEEE-Ship-3....c100005.m1851

I'm leaning towards a Centroid Acorn controller.

So, given the above, I'd love some input, guidance, even criticism.

Thanks,
Wallace

[Desertboy]

Wow! I was thinking it had been over a year since I last posted - but then realized the dates are DD-MM-YYYY and not MM-DD-YYYY! Anyway, got sidetracked somewhat with a surface grinder I picked up at auction. That, along with a surface plate and measuring tools pulled me into the world of tenths. A scary, but fun place. I like This Old Tony's description of his surface plate: Where dreams go to die... Anyway, gotten back to the router recently:



Now, I know it isn't pretty. Please keep in mind my goals for this are to learn and gain experience. I would like it to cut wood at a reasonable (woodworking) level of accuracy at some decent speed, but I'm mostly having fun and building skills and knowledge to make a better one after this - if I decide I want to.

I just ordered rails and ballscrews that are 50mm longer than the ones in the pics. I intend to move the existing ones to the gantry and put the new ones in their place. This should give me bit more travel and get the ends out where I can get pulleys on them. I am thinking of driving the two Y-axis screws with a single NEMA 34 and timing belt arrangement. The X- and Z-axes will be NEMA 23.

Can I get opinions on this kit: https://www.ebay.com/itm/FEEE-Ship-3....c100005.m1851

I'm leaning towards a Centroid Acorn controller.

So, given the above, I'd love some input, guidance, even criticism.

Thanks,
Wallace

I don't care what you say she's a looker ;)

nice work, personally I'd go with 2 nema 23 for the Y and get AM882's or equiv but I'm scared of belts lol.

[Nr1madman]

Well done ;)

I looked at the kit you linked to.
Have no clue about specs for the nema34 so it might be good but the nema23 is really high inductance and will perform poorly.. the ones from zapp or cnc4you are much better!

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[wallyblackburn]

Well done ;)

I looked at the kit you linked to.
Have no clue about specs for the nema34 so it might be good but the nema23 is really high inductance and will perform poorly.. the ones from zapp or cnc4you are much better!

Thanks for the info. I quickly get overwhelmed when I start looking at motors and drivers. Especially if you throw closed loop steppers and servos in the mix! If I do go with open loop steppers, what are some guidelines for max inductance for nema23 and 34 motors?

Regards,
Wallace

[Nr1madman]

Thanks for the info. I quickly get overwhelmed when I start looking at motors and drivers. Especially if you throw closed loop steppers and servos in the mix! If I do go with open loop steppers, what are some guidelines for max inductance for nema23 and 34 motors?

Regards,
Wallace

For nema23 and 3-4nm strength then no more than 4mH. Less is better!

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[wallyblackburn]

I don't care what you say she's a looker ;)

nice work, personally I'd go with 2 nema 23 for the Y and get AM882's or equiv but I'm scared of belts lol.

Lol - and I'm scared of slaving axes! It is sounding like Centroid will have separately homed, slaved axes in an upcoming release, but I'd like to keep that 4th axis available.

Thanks,
Wallace

[Clive S]

Can I get opinions on this kit: https://www.ebay.com/itm/FEEE-Ship-3....c100005.m1851

Kits are never a good idea as the are never matched. The motors are too high in inductance, you would be better off with higher voltage drives and power supplies. The machine look bigger than 24"x24". It would be nice if you could rotate the pics.

[wallyblackburn]

Kits are never a good idea as the are never matched. The motors are too high in inductance, you would be better off with higher voltage drives and power supplies. The machine look bigger than 24"x24". It would be nice if you could rotate the pics.

I'll keep that in mind. I was thinking it might be cheaper - but if it's wrong... I still don't understand why my pics get rotated 90 degrees when uploading. I guess I'll try rotating them 90 the other way *before* I upload.

Thanks,
Wallace

[m_c]

Given you're on the other side of the pond, I would of thought Gecko drives would be a reasonable first choice, as you won't have the issue of import tax and VAT to worry about, which makes them poor value here.
However Leadshine AM/EM drives might be worth considering for the sole benefit of having stall detection, which I'd recommend for any twin screw axis (should a single screw axis stall, it's not normally a major problem machine wise, but on a twin screw axis, you risk twisting the gantry if one screw stalls and the other keeps going - even with stall detection you'll likely still get some twisting, but all motion should stop far quicker minimising or eliminating damage).

Gecko used to also sell some pretty low inductance Nema23 motors, but I see they've stopped selling them.
I'd have a search of the more American based forums to see where people are sourcing motors.

[Nr1madman]

Hmm keling is us based I think.. they have good motors! :)

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