Steve B published a new build:

Read more about this build...

 

Attached are the changes to the original OX gantry plate.

 

Plates from Chris Laidlaw - My custom gantry sides and standard X and Z Axis plates. Also got a standard mount for Dewalt Router.

 

Making the Y axis motor plates. I cut a template from my laser cutter and used to drill 5mm holes in 1/4 6061. Then cut them out on a band saw. The leadscrew bearing ends got drilled in the wrong spot. I'll first use these plates for initial fit, and remake them once I know the geometry is right.

 

Change of plans on the OX PPR... considering a rename due to some recent discoveries. Most importantly, based on the CNC Jr. build, I determined that the structure here does not support portability. It needs to be fixed to the base. Also, since I am more interested in plasma than milling on this machine, I've decided on some changes to favor plasma cutting over milling. The biggest change is that the machine will be built upon a portable 4'x2' downdraft table. The table is started, a picture is below. Due to the changes, the leadscrew design is also looking less favorable. Considering reverting back to belt design. Though my geometry is different than a standard OX, I think the looped belt method will still work. 3D model will be updated soon....

 

Today I worked on motor/belt placement alignment. First picture shows geometry I am planning, second picture shows how the motor will actually be situated on the gantry plate. I think this should give me 25" cutting width and around 40-42" cutting length. The Y-Axis 80x20 v-slots will be oriented so that the bottom is level with the top of my cutting area. This should provide 2-3" clearance between the torch and the cutting surface, plenty for plasma. For routing, I think that if I remove the slats on my table (they are removable) and put a downdraft spoilboard down, I should have 4-5" clearance. In both modes, with the X axis low, the machine should keep rigid.

 

Update with a little more progress. Downdraft cart is all welded up with Y-axis rails in place. The gantry is being built and wired up on the workbench. The electronics box is also coming along....

 

It's been a few months since I've worked on the PPR... but it's alive and kickin'. Today, all linear motion was checkout out and working and all the limit switches and homing procedure. I will still need to wire the LCTHC into it before I can start burning. Photos attached of the current progress.

 

BUD Industries NBB-10271


http://www.amazon.com/gp/aw/d/B005T...+NBB-10271&dpPl=1&dpID=41TR3FHGoJL&ref=plSrch

 

I agree, 100%. I only paid about $45 for the box, but still a lot more expensive than I would have liked. Next time, I'll probably just laser cut a box.

 

A quick test video:

 

Here it is, the first actual cuts with the machine. There are still some serious issues to work out. The THC isn't working and if you watch closely on the video, the RF noise causes a considerable amount of USB noise, effecting the PC. It even zapped my video card on the last cut (which came back ok, thankfully!!). Thinking I need to fully isolate the PC from the cutting system.

 

Thanks for the honest words, Prauk. I knew going into this that, especially with Plasma, that I might run into difficulty with the CNCUSB board. So far, though, none of the issues I'm having are related to his board.

My biggest turn-off, based on experience a few years ago, to using Mach 3, was that I couldn't run it from a laptop. It just didn't work. I really don't want to invest in a PC JUST for the machine. I think now there's a good alternative with the Ethernet Smooth stepper and the Mach 3 combination. That's my alternative route, if this doesn't work out. It'd be about $400 to switch, which puts me out a little bit, but I can probably make use of the M3/4 board on another machine, or sell it.

But, as mentioned, if this works, I'll stick with it, and the problems I am having don't appear related to the board. My biggest concern right now is that it seems that electrical noise is getting to my PC and keeping the LCTHC from working. I need to isolate that all out before anything else.

 

Well, a lot has happened since I last posted. The plasma HF start causes major havoc on my electronics. The USB based control board was the first go - I quickly discovered I needed complete isolation to the computer. So, I got an Ethernet SmoothStepper and switched to Mach 3. I also tried different bread board and drivers, but they didn't do well with the HF noise, either. So, long story and several iterations later, I'm now at:
- Ethernet SmoothStepper & Mach 3/Sheetcam (really nice, but added $$$)
- Gecko G540 - Plasma HF was causing noise in the motor drivers I was using. G540 is metal cased and good quality. Haven't tested yet.
- Extra BOB for e-stop and THC signals
- Changed CANDCNC THC out for a Proma 150

Mechanical changes - The belt drive system wasn't going to cut it. It caused many problems. The biggest of which is that the steps per unit on the belt drive system is way too low. But, I also had problems with belts and the gear adapter staying tight enough. I went back to my ORITINAL plan to use leadscrew drive. The X/Y axis are 1/2-10 10 TPI. The G540 is fixed at 10 microsteps, so that will be 20,000 steps per inch!

Pictures are below. I haven't had a chance to run the system yet, but it's looking good. Hopefully this weekend I'll get a chance to start testing the new configuration out.

FYI - The PlanetCNC M3/4 I have is FOR SALE, as well as 9 TB6600 based motor drivers and the CANDCNC THC that I have. PM me if you are interested. I think these are still VERY good for milling operations. Just not as good for plasma. I may keep the Planet CNC board for my mini-mill, we'll see.