Any thoughts on CNC machines?

[SONICJK]

Well my post got deleted. Damn.

I have a cncrp 4x8 pro that I use in a production environment. It's served me faithfully for 5+ years without much complaining. It's a good machine.
The rigidity is ok, not great but it does well on wood.

For my money I'd probably get JD2's new table.
I have a plasma table from them and dollar for dollar you're not going to get a better machine, even at twice the price. They went absolutely nuts gearing up to make these. I went to the factory and hung out with Bob the owner for a day and he showed me all around. They spent millions and millions setting up to make their tables. The result is a machine that competes easily with 100k+ machines for 15k. Their routers start at 9k.
They make every piece in house down to the circuit boards, it's insane but they do it. One piece aluminum machined gantry, real industrial bearings, servo motors on all axes etc.

https://www.jd2.com/pvd-multiplatform-cnc-table
Beside the JD2 the cncrp looks feels and performs like a toy, and the price is about the same.

 

[sav0r]

Here's my G0704 conversion. It's been a labor of love but also one of profit. It has a 10 spot tool changer and power draw bar, automatically oiled ways, 2hp 6k spindle. I also installed a spindle encoder so I can rigid tap up to m10 threads. For a G0704 it's fairly tricked out. The enclosure and tool changer are pretty sought after. It is in no way cutting edge, but I can make some nice stuff with it. The best part is that it is 25 feet from my kitchen.

 

[3DogNate]

Here's my G0704 conversion. It's been a labor of love but also one of profit. It has a 10 spot tool changer and power draw bar, automatically oiled ways, 2hp 6k spindle. I also installed a spindle encoder so I can rigid tap up to m10 threads. For a G0704 it's fairly tricked out. The enclosure and tool changer are pretty sought after. It is in no way cutting edge, but I can make some nice stuff with it. The best part is that it is 25 feet from my kitchen.

Impressive. I also did a G0704 Conversion a couple of years ago. I stopped after the Stepper/Ball screw conversion and a DC Belt driven Spindle conversion with a Tormach TTS. The tool changer is certainly ambitious... Nice job.

 

[SONICJK]

YES!
Love the ATC, very cool.
Build thread anywhere?

 

[sav0r]

I never did a build thread. It took me years to get it to where you see here. That said, it's been CNC for at lest five years. One of the first mods after converting it to CNC was a 6k spindle motor and belt drive, that has evolved since then. The current brushless motor is fairly large on the head, but it fits.

I machine all sorts of motorcycle stuff as well as race car stuff. It took me a bit to get accustomed to the machine, a G0704 isn't exactly rigid in the scheme of things, but with some practice the results can be great. It's similar to a Tormach 770, but with better rapids, more horsepower, and like 60% of the price for the features.

 

[SONICJK]

I'd love to see a video of the ATC in action. I've been wanting to build one for my dyna but haven't taken the time to do so.

 

[sav0r]

I'll get a video up once I get the power draw bar back together. I was hoping to finish machining those parts today but I also promised my wife I'd get the bar top on our new bar before the in-law onslaught in the coming weeks. So the bar top happened... I've been working on different belleville arrangements with the PDB, the Tormach Tool System holders (and potential for tool pullout) can be a bit finicky in my experience.

The ATC took some adjustment to get it all working right, from there the magic is in the M6 Macro. Luckily, I didn't have to write that M6 macro myself.

I didn't build the ATC, I actually bought it as a kit. The guy who builds them, as far as I can tell, copied another guys basic home brew ATC design but built it so it's pretty easy to retrofit to a wide variety of machines. The brackets and mounting are all made so they can be moved and adjusted. Once I figured it all out, it's been pretty reliable for me. The price isn't too bad either, certainly less expensive than designing, machining, proofing it on my own would have been. I believe he charges in the $2500 neighborhood, but I've had mine for a long time so it could be more these days. I can send you his contact if interested.

 

[sav0r]

I'd love to see a video of the ATC in action. I've been wanting to build one for my dyna but haven't taken the time to do so.

It took me a while to get this all back together. Between having loads of work to run, pure laziness, my day job, family, and a bunch of other nonsense, I always just ended up running the thing sans PDB and tool changer. But it's back together and working reliably again. I ended up reworking the spindle and making some adjustments on the PDB. Tuning this thing is like tuning a race car, it's never ending, and it's only as good as it is on the day you need it.

 

[SONICJK]

Very cool! I need to make one for the dyna, but it almost never gets used anymore with the haas around.
Any reason to run it so hard on the pneumatic cylinder? Seems to be slamming around unnecessarily? A needle valve on the air inlet would slow that down to a more reasonable speed. I'm just thinking it could easily get knocked out of alignment or rattle some bolts loose under heavy use at that speed.

 

[sav0r]

I have valves on it, the problem is that I run my shop pressure at 90 psi, which is perfect for the drawbar but too much for the carousel slide. If I turn the valves down it will move slower initially, but it still hits quite hard. The cylinder is cushioned as well, which actually complicates things, because that cushion inconsistently stops the carriage, meaning sometimes the carousel ins't fully inserted, and that leads to a bad time. So higher pressure and more action helps prevent that. What I need is a separate pneumatic solenoid that's regulated down to like 60psi. When I put this all together I just purchased a triple bank pneumatic solenoid, that let me run the ATC, drawbar, and I figured I could eventually add air-blast inside the carousel to clean the tool shanks, and maybe even airblast on a tool height setter if I put one on the table permanently. It was a good plan, except I didn't anticipate needing to run the PDB and the carousel carriage on two different line pressures. The pitfalls of being a DIYer I suppose.

All of that said, the mechanism that controls the umbrella door is spring loaded on each end of its travel, and that tends to really dampen the carriage because the movement of the carriage that activates the door. It's a cable operated system. That system is disconnected currently, so maybe when I get it back in place I won't need the lower line pressure... Only time will tell.

 

[sav0r]

Here you go Sonic, you got me thinking about this and I just couldn't move on until i worked on it. The door mechanism that I mentioned is indeed a great help. Check out this video.

The problem is that the door was a relatively new addition, and I've only run it for maybe 200 tool changes, then the PDB broke. But now that the PDB is looking rock solid, I think I need to run with the door for a while. I like to stand test these things out for at least 100 tool changes. So there's testing to go... I did 60 tool changes tonight before I had to pull the carousel down and adjust the bolt for the door hinge. I guess I need some thread lock on that bolt.

I've run this machine lights off a number of times, but unlike (some) professionally built machines, there can be surprises. I do have a plugin that emails and texts me when faults are encountered. So that's cool.

 

[SONICJK]

Ha ! sorry to put that seed in your brain!
Looks less violent now, I hadn't though about needing two pressures.
What about one of these guys, I use them on several machines I've built as dampers. They are hydraulic so you cna slam into it with whatever pressure you want and it will slow ya down gradually but shouldn't impede movement.

That's what's on this guy, but adjustable so you can control the final lead in speed. Let me know if the video doesn't work.
https://photos.google.com/share/AF1...?key=RUhYcV9zc0hxa2hIdVNrZ20yeld4a3hUZjItcmhR

 

[sav0r]

I was looking at those dampers on McMaster yesterday. I may go that way if I can't get this all a bit more fine tuned. As is, it seems to be working much better, and I'll keep tweaking it.

I don't know what I just saw in that video, but I liked it! My system is setup with the same push to connect fittings and valves. Space is limited on my machine, getting a damper to fit might be the issue.