I know this has come up from time to time on the forums but wanted to bring it up again since I have a couple of NEMA 23 steppers and controllers just laying around. The main factor with being able to run the machines faster is cutting power (mix between the steppers and the router/spindle) and the rigidity of the machine. It seems that with the 76 oz-in stepper motors, the machine is limited to about 10-15 mm/s and about a 1-3 mm DOC (highly dependent upon the material). Anything more and you are at risk of losing steps. For a large machine like the LowRider, it would be advantageous to boost up the cutting power if the rigidity allows for it. I imagine the Dewalt 611 has enough cutting power to allow for faster speeds so that leaves the size of the steppers.
I would place NEMA 23s on the X and Dual Y axis. Dual Z Axis will remain NEMA 17 (it seems more than enough power there).
Has anyone started a mod for installing NEMA 23 stepper motors on the LowRider? I have started some initial designs for the plates and am working to fit a NEMA 23. I mainly wanted to see what people think about it and if there has been any work on the subject.
Ryan, I am sure there is a reason why you chose the NEMA 17 in place of the NEMA 23s. I would love to hear your thoughts on the matter.
Well you know where I stand on 23’s but I feel the need to chime in about your numbers. I regularly cut MDF at 9mm/s 6mm DOC Slotting, Just did some aluminum at 3.mmm DOC @ 3.5mm/s slotting, and just touched some steel. I strongly feel chip evacuation is limiting me. When adaptive pocketing I am easily getting full depth 9.5mm @ 10mm/s. I use those numbers as I have videos for them all. I am also not the guy that likes to push my cuts to the limit, I am too busy for that. I prefer things to work the first time I don’t care if it takes an extra 2 minutes.
CAM is the limiting factor for most people. As you learn and can get more aggressive, chip clearing on a 1/8" bit starts to limit you.
If you get to that point, rigidity comes into play. As most people here are building giant machines that is an even larger factor. I think you will find a skipped step is never an issue. If you want speed move to a 20T pulley. With a 16T I limit the firmware to 120mm/s and I feel a max usable speed is 30mm/s before power drops off to a level that is not ideal. So you can choose lots of shallow passes really fast and dull the first few mm of your tool or do one slower pass and evenly wear the bit.
Thanks, Ryan for the comments. I have seen your comments on NEMA 23 steppers in the past, and I appreciate the insight. I am going to try some deeper and slower cuts to see how my machine performs. Hopefully, I will get some of the same results. I am also going to try the Trochoidal milling feature is EstlCam (I like how your number look). Slowing down the machine 33% to get 3x cut depth is a great trade off.
With all that said, I am really interested in pushing this machine and really find out what the limitations are (Fail/Design/Improve) – while keeping costs low. Granted, I understand that one NEMA 23 stepper motor is the same price as three NEMA 17 steppers motors (it is nice to have a couple on hand).
You have designed an amazing machine for the price.
I am also interested in NEMA 23 steppers for the lowrider. I just got mine built and am doing some cutting now. A friend and I are milling aluminum plates for the flat parts for fun on his tormach mill, and I think some NEMA23 steppers would compliment that nicely. I’m new to the CAD side of things too for that kind of part, so if someone made some STL’s that made NEMA23’s fit the existing frame I’d be all over that. If not, I’ll work on some when I have some more time.
I am using the ones that came with the lowrider v2 kit I purchased from you. There is some added weight by using aluminum plate for the Y plates and the 611, but they are extremely rigid. The NEMA17 motors you provide in your kit definitely work well and you have a brilliant design. I have a full sheet table I built, and for my needs I will be cutting large parts a lot. I’d like to be able to rough in slotting significantly faster. With 1/4" bits deflection is not an issue for me for my purposes. I also just like more margin. With the NEMA17 setup, which is extremely affordable and easy to set up, it’s very easy to run right on the edge of what they can handle. A hard knot or anything could miss a bunch of steps unless you are in the very conservative range.
Please don’t get me wrong, what you have designed is brilliant. I just would like to see what the machine can do with NEMA23, and I will probably switch to linuxCNC and a MESA card as well in the future.
The steppers I sell and the boards that match are shipped under volted, feel free to turn it up for more free power. If you want faster, move up to 20Tooth pulleys, 20% faster.
Try a 1/8" bit you should be able to cut faster since it is about 4x less load on the machine. Mass of aluminum plates vs MDF should not be huge. If you think you have an issue just turn down the acceleration and turn up the feedrates, mass only matters when changing directions.
I can easily help you get your desired results but tell me exactly what you want. I feel very strongly that a 23 size stepper is nothing special. You can get much bigger 17’s that your current board can push easily, if we can’t solve all your other wants.
I push a 1/8" bit as fast as I think the machine can handle rigidity wise, nothing else seems to be holding me back. I see a 1/4" being so much more foce teh X gantry would flex far before I would worry abou tanything else.
What are you’re cuts specs? DOC, bit type, bit size, feed rate, material. Deeper per pass is faster that feedrate.
Bigger pulley’s would make it faster, but lose torque. So you can move faster but lose DOC, so doesn’t really change anything no?
I have skipped steps, yes. There aren’t much stronger NEMA17’s than what you provide in the kit to my knowledge. (Yours are 76oz, I believe 92 is the strongest I could find in the NEMA17 frame size.
In my mind, with a NEMA23 I would not need to worry about missed steps, that is totally out of the equation unless you do something crazy. My focus for this machine is on cutting out parts, so endless slotting. Not doing peel operations and such. There is more cost without a doubt. And it works brilliantly, but I believe I could cut out a bunch of large parts a lot faster with NEMA23 then with any NEMA17 configuration I can imagine. I believe I could get to better chip loading with them. I could be wrong. Wouldn’t hurt to try.
What are your cut specs, that just doesn’t seem right to me?
I have a small build (2’x4’-extremly rigid for a lowrider build) and I can still overwhelm the rigidity with an 1/8", in MDF. I run bone stock, 6mmDOC, 9mm/s, MDF, single flute, low 611 RPM (might be a little more but I can’t double check this right now).
I can’t see you using a full sheet sized build and not overwhelming it in aluminum with a 1/4" bit…the differences are gigantic.
I really appreciate all of your input Ryan, thank you. I’m happy to try your suggestions and work along those lines.
Regarding bit size. I did some manual testing on forces, and the 1/4" endmill required FAR less force (virtually no resistance) for cutting about 5mm of depth. Where the 1/8 bit required multiple times more at only 2 mm depth. However, that just shows the 1/8 bits I got (ordered two types from amazon) are crap. My local supply store does not carry 1/8 end mills. The 1/4 they have are razor sharp and cheap. So I need to get some better 1/8 endmills. I’ll have to order some from you I think. I’m in Canada so for small stuff it’s not practical normally, but I have to find something better. I’ll need to use 1/4 until I can get some better ones.
What I found with this new bit (4 flute 1/4, all I could get right now) I tried 6.5mm DOC at 15mm/s and it worked fine for the first 25 minute cut. I was at 3mm at first. I don’t think I can push DOC much further with a 1/4 bit as it is. This is cutting red cedar 5/8 thick.
I would be curious to do some test cuts at different speeds and see how far away I am from when it doesn’t work properly, as I would not want to be running near the edge and I don’t know where the edge is at the moment. Lots of learning of this machine to do.
I am going to recompile the firmware with the eeprom enabled so I can make changes to stepper voltage and save it to play with that aspect as well. I don’t think you sell 20 tooth pulleys right?
I put the cut specs in a reply before I saw your new question. I am not cutting aluminum however, at this point I’m cutting red cedar. (I’ve cut MDF as well). I would either build a smaller lowrider or mpcnc for cutting aluminum with, this thing is way to big for aluminum except at extremely conservative numbers I would think.
You must have had bad bits. 1/8 removes less material, and has much less resistance because of it. 1/8 of equal quality removes 4X less material.
4 flute on a larger diameter is all bad, we use extremely high rpm routers, single flute is good on a 1/8" it is hard t push a 2 flute in an 1/8 to its limits, a four flute is more than 2x out of its specs. Check a cut calc. a four flute at 30K should be starting a fire.
6.5mm@15mm/s in cedar is almost doable with a single 1/8 but your tolerances must be all over the place with a 4 flute 1/4. With my specs it is good enough to not be measurable with a tape. Are your circles circles or ovals, corners sharp? Your numbers are just vastly different than any other I have ever heard or seen.
I could be wrong, if you are getting good cuts don’t listen to me, just buy a few 20T pulleys and enjoy 20% faster, turn up the power a tiny bit. Shoot, who knows now I am doubting everything.
Shoot, If you can put up a few short videos of that, I will buy the same bit and try it myself. If I can triple my output I would not keep running out of flat parts.
The flutes are also spinning faster so you need to feed them faster. I will have to check a calc for theoretical load ratings.
In my head it almost makes sense faster blades, thinner cuts, less load, but we know we can’t go too low or it will start a fire. So this might be a sweet spot and I could jut be babying my cuts. I mean I was shocked when I ran through 9mmDOC cuts…then steel…I am wrong all the time but this feels off.
1/4" 4fl = wants 142mm/s to keep it fed at the same load
[attachment file=“4er 4.JPG”]
1/4" single = more direct comparison same speed 5x load 8kg
[attachment file=“4er 1.JPG”]
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So running the four flute at 15mm/s I can’t see how it isn’t starting a fire, but at the same time the load is probably very close to zero. Have we been doing this wrong all these years??? DUDE
Direct comparison though is a 1/4 same flutes is 5x the load.
[attachment file=82904]
Adjust speed and sure as sh%t it is 9.kg vs 1/8’s 1.7…OMG
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So lesson for today, adjust accelerations to allow for higher federates and use the calc more often. I have to the 1/4" I have siting in the drawer and another two flute 1/8"
haha, I hear you. A lot of what I tried is totally against what any of my research has said to be true. I used some very unscientific methods to test the bits (this was done by hand feeling the force required to move through material, being red cedar in this case). The 4 flute 1/4 should be totally wrong at the speeds this machine operates. However it worked, no signs of even getting hot. After a 25 minute cut, the bit was warm to the touch afterwards. No signs of burning on the wood at all. The 1/8 bit was brutal. I am assuming the two separate brands of 1/8 1 flute upcut bits I got suck, so I want to order one of yours to try and compare.
I did an oval test cut at the 6.5mmdoc and 15mm/s and it looked perfect. Im going to go out at lunch and do a circle and a quick video so I can post it. Curious to see your thoughts. Sorry to through insanity in to the mix, but it’s now becoming interesting to me.
I keep waiting for them to figure out the physics is wrong for the lift of a plane and they can’t actually fly and see if they all suddenly fall from sky… (Bernoulli who?)
