HI I have only recently found out about the MPCNC as I was looking for a diy cnc to machine a foam plug for a project that I am working on. I figured the I could ask here if this machine(MPCNC) could be configured for my use.
I apologize if this is the wrong place, but this seemed the most suitable. I was originally going to shape a foam plug by hand, but I would much rather CNC machine it. I am building a 9.5 ft long plug for a streamlined recumbent bike to break the land speed record for a person under 18. The plug will be used to take molds from.
I would need a 4x4ft work area with the parts being 6in tall. Does anyone think this machine could be suitable for my application? I am only machining foam sheets.
When I was on FSAE we almost bought our own shop router and my idea was to machine our body plugs 1 layer at a time (our molds were all made of 3/4" MDF) by using dowel pins (or similar) to align each layer to the next. Any inaccuracies would be easily sanded out, which you’ll likely be doing anyway.
I still think this idea would work great–especially as long as the parts were designed for 3 axis machining. (IE, if you can see all machined surfaces looking at the mold from the top down)
Benefits:
machine 1 layer at a time instead of the entire plug--if you need to take a break from watching the machine it's a lot more convenient
tool length becomes a non-issue
if you make a mistake you'll lose a lot less time/material
So Tim you would recommend the MPCNC? I would definitely be doing it sheet by sheet in 2in foam board, if not 2 sheets stacked one on top of the other once I get it going.
I am leaning towards the MPCNC over the low rider because I don’t want a 4x4 machine forever, just long enough to complete this projects, then make it smaller. I know the low rider is able to do full sheet processing, but I don’t have the floor space for a 4x8 CnC.
I guess what I am really asking is will the mpcnc work OK if it is scaled up to 4x4ft work area. I may need to use mid span supports but that is OK.
I can’t speak to the foam specific question for your use (although I have a feeling it’s perfectly suited). However on the size question I’m certain you’ll be fine. Mine is 48" X 34" physical which gives me a working area of 40" X 25" give or take (I’ve never measured to be honest - as long as I got 20" X 40" I was good). I don’t see any discernible issue on the 48" span in terms of sag.
I did however build up my machine using the thick walled stainless tube. If you go this route make sure you buy thin walled tube for the z-axis as it’s more than rigid enough and makes assembly easier. Much easier. The nut traps fit and you don’t need to drill your way through as much stainless.