starting my build soon

[justin22885]

hello everyone.. i used to come here often in the project guitar forum.. im a luthier.... anyway, im finally starting construction on my CNC router next month

however, im having difficulty deciding on what to go for... the jgro and joes cnc machines look nice, but their forums are so flooded with crap i cant find a usable bill of materials list or much specs on the machines anymore

i need a router travel size of 24x48 inches.... ive also considered making one of my own design, but i have no idea how many pieces of plywood a machine the size i need typically uses... any ideas?

also, are skate bearings mounted to angled bars really the only inexpensive option?... im trying to keep the build, less tooling and accessories to under $500, and i have a laptop ill be using for the computer (with a serial PCMCIA card)

this will only be an initial build, when i get more profits i plan on making one strong enough to mill steel, made possibly out of welded tube/plate steel

but more on this one... i see the jgro and joes machines are made out of medium density fiberboard... so that might be the best place to start on materials

anyway, the problem with the jgro machine and joes machine is neither are fully supported rails, and using the skate bearings i see absolutely no reason why they couldnt ride on a full supported rail?

has anyone built anything similar to what im describing? or has any advice?

[ger21]

Joes 2006 is a much better machine than the JGRO, but won't give you a full 48" of travel. Best bet would be Joes 4x4 Hybrid. It's possible to narrow it down to 24" of travel.

http://joescnc.com/

All the Joes 2006 drawings can be downloaded here.
http://www.cnczone.com/forums/showpo...&postcount=156

[justin22885]

well.. why dont i use the gantry from joes CNC, but just stend the table, and thus the rails to get the 4 feet of travel desired? and wide or shorten the gantry for the 24 inches of travel?

also, do you know what the stock travel is on this machine? and a list of materials needed?

however, the way the dual rails are set up, and set in, it seems like one would already need a CNC router to accurately make this machine

just by looking at the plans.. im already thinking of cutting down on the amount of work and MDF used by supporting the bars.. and bolting into the sides of the table fully supported angle iron rails for the skate bearings to ride on, rather than the partially supported tube/bar

i figure for the travel desired... 32 feet of angle iron would allow me to use double rails on both the X and the Y axis, greatly increasing the accuracy and amount of stress and weight the machine could handle while greatly reducing the work and difficulty to build only needing to angle a table saw blade to run the side boards through to cut the angled channels for the pieces to sit into

but... i do believe two rails on each side of the X axis would greatly add stability to the supports...

for the Y axis? what is the best way to counter the weight and stress of the router motor acting against it?... perhaps increase weight on the opposite side of the supports to act as sort of a balast? or perhaps mounting the two supports for the Y axis parallel from eachother in a latteral fashion, allowing the Z axis to hang between them, adding equal force to both sides of the supports

for the Z axis.. id probably use two pieces of tube steel and two ball bushings mounted in flanges

any thoughts on these ideas?

[justin22885]

seriously.. does anyone know how many pieces of what size and thickness MDF i would need to buy for joes machine?