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

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The washers do not rub on the rubber shield, see attached pic. But I was going to turn down some custom ones on the lathe if they did instead of using std M8 BZP washers. The bearing is a 608RS which is 22*7, the washers are 1.5mm wide and the centre of the axle is 10mm.

Hi.

Newbie here.

Thanks for posting this thread as I too am working on collecting bits for my first build, which is to be for PCB issolation milling in the main, but would like to dabble in other stuff.

I am also working to a budget and looking to 'recycle' stuff where I can. Have just bought the same motors and have spent several days checking out the threads on the same driver board and PSU that you have gone for. Will be really interested to see how yours holds up.

Thanks again for the thread and good luck.

Hi mudscience,

I've come to a bit of a stop at the moment due to various reasons. Hope to be able to kick start it again next week or so when things get back to normal, will keep posting any advances!!

Thanks for the heads up. I know you said in your original post that you were looking for comments, but I wonder if I could ask a question to help me on my quest ... you've calculated that the motors will pull 4.5A. Depending on where I look I get different advise on what the 'guesstimate' total current will be. Some indicate # motors x A x 2, which in our case with the C355-P6V's will be 3 x 1.5 x 2 = 9A or # motors x A +2A = 6.5A. Any which way I think your covered, but I was wondering what 'rule of thumb' to use, because my next acquisition will be a PSU.

Well I used the first one you mentioned, i.e. double the total amps for the 3 motors. I'm sure someone like Irving2008 will be able to tell you far more accurately! :)

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Originally Posted by njhussey

Well I used the first one you mentioned, i.e. double the total amps for the 3 motors. I'm sure someone like Irving2008 will be able to tell you far more accurately! :)

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I think to an extent it's the more the merrier!
For my 3N.m motors it's 4.2A in bipolar parallel. [bold]You need 66% of the total peak current.[/bold] So three motors, that's 4.2*3*0.66=8.3A. I used a 500VA toroidal transformer, so 10amps. The motors did work perfectly well with a 325VA toroid but I couldn't get quite as high feedrates. I think because the internal resistance of the power supply was too high.

So anyway with your motors in bipolar series it's 3*1.5*0.66=3A. Or in bipolar parallel twice that, but I don't think your driver board will cope with parallel.

Well after about 6 weeks of doing other things (scratch building a RC glider DIY etc...) I spent a couple of hours in the works on Sunday cutting up some steel for the frame and the rails, see attached pics. Just got to cut some angle for the rail supports and do some welding and things will be progressing...think it's gonna take a bit longer than I thought given the limited time I've got to put into it.

Still like British Rail....(as was!) I'm getting there :smile:

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Originally Posted by njhussey

Still like British Rail....(as was!) I'm getting there :smile:

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Hmmmm....well it's taken me a year to weld up the baseframe, did it last saturday morning. Got into RC helicopters in the last year which has taken up all my time and money (costs alot to crash, well it does when you crash like I do:naughty:) also started selling Velcro on fleabay which has recently taken over my free time and what little money I had left. Anyway....I also drilled the rail holders I'm planning on using in my lunch hour. Now hoping to crack on with this build.
Will post pics as and when I get stuff done!

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Did a bit of drilling and tapping in my lunch today...

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Been playing with Sketchup to see what my router will look like. Think I'm going to have to beef up my long (X axis?) rails as the gantry is going to be heavy...thinking about it might have to lighten it a bit else the stepper will struggle. The base is 1000mm x 500mm, box is 40x40x3 steel, plate is either 3mm or 6mm steel (all used as available from my works scrap bin!)

Comments???