Let the fun begin !!! ???

**PAULRO** · 05-02-2015

Latest pics.... i clocked the bed top get it as true as possible . i will still M/C it when i get it powered up . i want to minimize the dust as much as possible. i have 2 nema 23 s , 4 NM for the x axis . i'm not sure if 1 motor would be enough and go with a belt drive for both ballscrews. i have read up on the different opinions here on this forum and on 1 versus 2 motors . the gantry with brackets , cables and spindle come in at 65 KGs .
i'm going to move on to the electrics next and spec the various drivers, power supplies and other miscellaneous parts that will be required to get this baby up and running
i would like to start on the electrics next so i'm hoping that someone here will give my nema 23s the thumbs up or down because i don't want to buy drivers for a motor configuration that is inadequate. i have pumped the numbers into Irvings spreadsheet ( what a piece of work , by the way) and they look good . i have read Eddys build a few times and hope to get my electrics as close as possible to his. Eddys ganrty is not as wide as mine and that why i'm curious about the 1 motor versus 2 on the x axis of my build and more to the point should i go with a nema 34 motor? any thoughts on the subject would surely nudge me on.
my build changed as it went on due to extrusion being extrusion. it all looked great in the CAD model but when i went to assemble it in the designed configuration ( L shape bolting 2 pieces together at 90 degrees) it kicked up and played havoc with the brackets supporting it so i had design around the headache. this in turn lead to a change in the z axis configuration. i have left scope for a revisit to mechanical build but for the time being i want to get it running and discover if it needs a revisit. Paulro

**PAULRO** · 05-02-2015

more pics .the motor config. is repeated on the far side .

**JAZZCNC** · 06-02-2015

Originally Posted by PAULRO

more pics .the motor config. is repeated on the far side .

Why do you have what looks like a 3:1 ratio on the screws.? Even with a 10mm pitch screw 2:1 is bad idea if your planning on using as wood router.
2:1 ratio will slow you down to around 5 or 6mtr/min max rapids and for woods you'll want to be cutting at that. 3:1 would be even worse.!!
Stay with a 1:1 ratio is my advise if your cutting woods.

Regards the motors then it's preference thing mostly 2 x 3 or 4Nm 23's will easily handle 65Kg. I prefer single motor with belt for accurecy and piece of mind reasons but I'm equaly happy to use slaved motors provided the correct drives and precautions are used. Slaved motors work ok but I would only use them provided you have Digital drives that can detect stalled motors or have fault output so you can E-stop the system.
Digital drives have made slaved motors much safer in my opion with less stalling as they handle current so much better and can easily detect for stalls. They also dont loose steps as much as the old drives did.

**PAULRO** · 06-02-2015

it's a 2:1 ratio. 18 tooth on the motor and 36 on the screw. i read a post in one of the blogs here that 2;1 ratio would be good for detail work but i can change to 1:1 if i could still achieve the required detail. thanks for the advice on the digital drives though.

**JAZZCNC** · 06-02-2015

Originally Posted by PAULRO

it's a 2:1 ratio. 18 tooth on the motor and 36 on the screw. i read a post in one of the blogs here that 2;1 ratio would be good for detail work but i can change to 1:1 if i could still achieve the required detail. thanks for the advice on the digital drives though.

What kind of detailed work.? 1:1 ratio on 10mm pitch will get you this kind of detail.

**PAULRO** · 06-02-2015

that will do it for me so . i'll go with the 1:1 . i could replace the 18 tooth pulley for a 36 tooth pulley to create a 1:1 ratio or replace the 36 tooth pulley for 18 tooth pulley . i suppose it wouldn't matter either way , or would it? i'll replace the 36 tooth pulleys and be done with it.
excellent work on the calender. if i can reproduce that detail i'll be more than happy. i might get some more details on the M/Cing of that when the time comes , if you don't mind.

**PAULRO** · 06-02-2015

By the way Jazz , i just had a look at the u tube video of leadshine closed loop stepper(https://www.youtube.com/watch?v=ZMZdCcLQc4M) you posted and i have a couple of queries.( great video, by the way) would it be worth my while to attach encoders to my nema 23s?. i had planned on using AM882 drivers but i don't think they take feedback signals. i know they have stall detect ( you mentioned that previously).i would like to get as much info. as possible before i decide to press the BUY button. the closed loop system is a more attractive option in terms of constant feedback but that's as much as i know at this point.

**PAULRO** · 06-02-2015

i had some play in the fixed bearing blocks (0.3 mm) . stripped them down and set them up again and still had end play. had to make some shims to eliminate it .

**PAULRO** · 06-02-2015

i have gathered power supplies over the years and i'm, hoping to use some of these.i will have to either make a power supply for the drivers or buy one . i haven't decided yet .