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JGRO CNC Router

Here is my take on the famous, Open Source JGRO Router. The plans can be downlaoded from the CNCZone forums Here. I had wanted to build a CNC Router for nearly 6 months before taking the leap and doing it. In that time I read so many posts on the net and got confused so many times as to what I should build. The best single lesson I have learnt in CNC is to do research, and just build something. Dont keep going around in circles looking for the best design, becuase there will always be new ones coming out. Find a design, stick to it and just build. Have fun along your journey into the CNC hobby.

The JGRO is a good design, but it is also Imperial. Since I am from Australia I converted most of the sizes and just rounded them out to the nearest Millimetre. The machine is adjustable enough that a little innacuracy of measurements is not really a problem. I decided to stay away from machine screws threaded into the MDF. I went with good old PVA Glue and good quality chipboard screws. This makes for an extremly strong joint, especially using the built in Dado's in the design.

I built the torsoin boxes to plan in regards to width, but I extended the bed out to 1200mm total length. I found doing this gave me a good cutting area, but also required support under the gas pipe. I used some 90x19mm Tassie Oak hardwood under each rail and tapped it with a few machine screws along its length. I can then use these screws as an adjustable support for the rails. The pipe adjustment blocks were also made out of the same 90x19mm Tassie Oak - This stuff can just be bought from Bunnings/Mitre 10 by the length. It holds a thread quite well but cut the adjustment blocks oversize as it is prone to splitting.

I went all out in the Electronics department as I orignally planned to build a Joes4x4 or Mechmate and orded my controllers and motors to suit that. Needless to say I had plenty of power, sporting 4 x 750oz Nema34's and some 80V 7A Controllers on my MDF machine. The power was driven though some 1/2" 10TPI Single Start Acme screws. I made some anti-backlash nuts out of Delrin and later upgraded to DumpsterCNC anti-backlash nuts. Quick tip for anyone just starting - Buy the Dumspter nuts straight away, worth there weight in gold.

I never did really get many more photos of the running machine after construction. I built the machine and was so eager to use it I never finished my build thread or documenting it all. It has had heaps of use though, now its just time to upgrade to a larger machine. At least I dont need to buy new electronics.










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