CNC update

I have successfully purchased all the linear rails i'll need for the CNC. They all are THK brand, the Z-axis has HSR20 carriage blocks for the moment load. The x and y axis are on SR20 and SR25's. We'll use the SR25's on the X-axis to take the weight of the Y-axis. The lengths for each axis are:

x-axis = 32.25"
y-axis = 29-7/8"
z-axis = 20"

Now these linear rail length's are the total length not the travel length, because the carriages when bolted up to the table mounting plate will be taking something like 8" off the total travel. So a rough guess of our work envelope will be something like:

x-axis = 24"
y-axis = 22"
z-axis = 12"

We now are working on locating screws and purchasing screws. I also purchased http://www.hobbycnc.com/products/hobbycnc-ez-driver-board-kit/ for 64$. We are holding off on the steppers for just a bit to finalize our torque requirements. Troy has been busy on the spindle design. He sucessfully modeled it up in SW, and he is performing FEA calculations on it. While I did find him some angular contact bearings that dimensionally work, and financially work, they did not have specifications on the tolerances. Troy has been working on some equations he can apply to ensure everything falls into our safety factors.



I have been keeping a spreadsheet on expenditures... Oh man it's starting to add up. I alone have purchased 450$ worth of parts specifically for our CNC alone. Troy special ordered some 4340 for his spindle for 50$. He also needs to make a tool post grinder, take a safety milling class, and buy angular contact bearings, and a VFD (300$) all for the spindle. This is going to hurt our pockets. This is really going to start being the "test" on us, we are on a tight budget (our own pocket money no less.) Our wits, our ability to scrounge, our courage, and our vigor are all going to be necessary to get through this project. The last project that i have taken part in that is of this magnitude was the 2008 HPV project. That said back to research!