Comments sought on new build: A CNC Router for RC Gliders and Planes

[njhussey]

New development on my build is that my work has just bought my router off me (well kit of parts so far) as they want to have one for cutting Delrin rings and other bits...I'll have use of it whenever I want (as well as the lathe and milling machine) so a bit of a win win situation for me as I can use this as a learning curve for building my own (probably larger one) later. Plus I'll be able to build this one in works time now legitimately

[JAZZCNC]

Plus I'll be able to build this one in works time now legitimately

Well make sure you put Servo's and all best gear on it so then if they go PoP you can buy it back cheap knowing it's got quality gear on it.

[njhussey]

Well make sure you put Servo's and all best gear on it so then if they go PoP you can buy it back cheap knowing it's got quality gear on it.

I was wondering whether to get a Nema 34 motor for the X axis as I'm going to drive both ballscrews with a belt. will I need one or will a Nema 23 3Nm one be ok or should I get another driver and stepper and do a slaved setup?

[JAZZCNC]

I was wondering whether to get a Nema 34 motor for the X axis as I'm going to drive both ballscrews with a belt. will I need one or will a Nema 23 3Nm one be ok or should I get another driver and stepper and do a slaved setup?

If your driving both with single motor then yes you'll need Nema34 about 6 to 8Nm but make sure you use high power drives for best performance.
My personal preferance is screws connected with belts but if you run slaved motors well within there capabiltys then you shouldn't have any troubles. The only thing I would recommend and will only Use with slaved setup's is Digital drives that have stall detect and provide a Fault signal which you can use to E-stop the system. If you do this then your safe with minimal risk of damage to screws when things go wrong.

What will the main use be.? and what size/pitchscrews are you using.?

[njhussey]

If your driving both with single motor then yes you'll need Nema34 about 6 to 8Nm but make sure you use high power drives for best performance.
My personal preferance is screws connected with belts but if you run slaved motors well within there capabiltys then you shouldn't have any troubles. The only thing I would recommend and will only Use with slaved setup's is Digital drives that have stall detect and provide a Fault signal which you can use to E-stop the system. If you do this then your safe with minimal risk of damage to screws when things go wrong.

What will the main use be.? and what size/pitchscrews are you using.?

I'm using RM1610 screws....main use will be plastics a bit of aluminium and possibly light cast iron work (spot facing cast iron couplings etc.) with a bit of balsa and lite ply cutting. I've got AM882's at the moment, they do up to 8.2A so a SY85STH118-6004B Nema 34 rated at 6A should be OK to drive?

[JAZZCNC]

I'm using RM1610 screws....main use will be plastics a bit of aluminium and possibly light cast iron work (spot facing cast iron couplings etc.) with a bit of balsa and lite ply cutting. I've got AM882's at the moment, they do up to 8.2A so a SY85STH118-6004B Nema 34 rated at 6A should be OK to drive?

Neil it's the 70-75Vdc limit of the drives that causes the problem with Nema34 motors. Larger motors need 100V+ to get decent speed out of them and that's why High power 240 Drives are best. Now with 10mm pitch screws and 75Vdc you'll get approx 8mtr/min of usable speed with a decent weight gantry. You'll possibly get higher speeds but they won't be reliable and could stall if pushed hard. That is more than enough for cutting most soft materials so again personally I'd go with single motor setup for reliabilty issues and to remove all doubt.!

That said AM882 are good drives for slaving has they have stall detect and can be used to stop system so either setup would work. You'll possibly get slightly higher rapid feeds from Twin motor setups as motors spin faster but that doesn't mean you'll get higher cutting feeds as the 34's tend to have more torque higher the RPM scale then drop off quickly.!

[njhussey]

Cheers Dean, I'll probably go single Nema 34 and 240V drive!!

[njhussey]

I presume that the below is some sort of tapping head? I've just dug it out of a box of large drill bits...anyone know exactly what it is and how it works?

[EddyCurrent]

New development on my build is that my work has just bought my router off me (well kit of parts so far) as they want to have one for cutting Delrin rings and other bits...I'll have use of it whenever I want (as well as the lathe and milling machine) so a bit of a win win situation for me as I can use this as a learning curve for building my own (probably larger one) later. Plus I'll be able to build this one in works time now legitimately

Congratulations, great result.

[njhussey]

Congratulations, great result.

Cheers...got some more epoxy and some MDF for the weirs so just have to find some time to get the rest of the epoxy off the rails (its coming off really easily luckily) but there's other works stuff taking priority at the moment.