PDA

View Full Version : Build Thread Was going to build, but took a MAJOR shortcut instead!



panozeng
12-02-2010, 08:50 PM
Ok, ya'll may remember my post earlier this year about a build that resulted from a killer junkyard find. I was able to score an 18" x 18" x 4" cartesian coordinate industrial robot from a junkyard in awesome condition for scrap steel by the pound pricing. It was made up of ballslides and screws, and only took about 2 hours to fit stepper motors in place of the original servos. Here is a picture:
http://tubularfab.com/upload/cnc/cncxyz.jpg

At the time I had been scrounging up materials to build a bigger table, but figured I'd get this little 18" machine going first to figure out stepper drives and Mach. I was able to get it going very quickly, and was soon making useful parts! Here it is in action:

http://www.youtube.com/v/Z7FURzJPJcc?fs=1&hl=en_US

So, that was a great, inexpensive way to dive into cnc control, and I learned a lot from it. Before that i had never looked at Gcode and had no idea how to get from a dxf to runnable Gcode.

So, lately I decided it was time to start on the big table again, and started looking for materials. I wanted to have at least a 4' x 8' cutting area this time around. So, I was searching on Ebay for cnc parts and came across a 1993 Advance Cutting Systems 60" x 120" cnc plasma cutter listed by a shop that went to laser and no longer needed it. It was in good condition, but had a really outdated Koike Hybrid analog servo control (same as a linatrol picopath). Well, I was able to buy it for practically nothing, oh - and did I mention it came with Hypertherm Max100D dual gas plasma cutter and machine torch? Since my spare time is non-existant I figured this would be a good way to go. After taking delivery I had it all hooked up and cutting shapes in about 2 hours. I quickly decided that the old control system HAD to go!

So, I stripped off the control, driver box, and servo motors. I re-used the high quality shielded motor wires and mounted some big 1125 ozin steppers I already had. This machine is rack and pinion drive and had 3 to 1 timing belt reductions on both axes. All I had to do was make 2 simple motor plates that fit the stepper bolt patterns, and bore the motor pulleys out from 1/2" to 5/8".

I'm currently using the microkinetics 80v 10 amp microstepping drivers and power supply with an ebay breakout board and have great performance. The gantry is rather heavy, but I'm still getting good accelerations (77 milligees on X, and twice that on Y) with reliable rapids at 1600 ipm. I am really thinking hard about cutting a bunch of lightening holes in the gantry beam to help out, but haven't done so yet.

Here is a video of it simply moving through a big test pattern at 1250 ipm and 1600 ipm rapids:

http://www.youtube.com/v/LPb6bsgPLqg?fs=1&hl=en_USA

As you can see in the background I have a long way to go on getting the computer tidied up and in a cabinet. But, I've already put it to work making usable parts. Here are some videos of cutting 10ga steel at 170ipm:

http://www.youtube.com/v/I_1fo0pQq44?fs=1&hl=en_US

http://www.youtube.com/v/MtEMgk9fSgY?fs=1&hl=en_US

More to come on the plasma soon...

PS - what's the secret to embedding youtube vids?

panozeng
12-02-2010, 10:14 PM
Ok, I have to talk about the Hypertherm plasma cutter now. Throughout the years I've used about all brands of plasma cutters - starting with a 1980's Thermal Dynamics, later a stakpak, a Pakmaster 50XL, a couple of Lincolns, and a couple of Millers. I was impressed 3 times - obviously the first time I ever used one, much much later when I was on monster garage and used an Esab, and finally by this 20 year old obsolete Hypertherm. As of a few years ago the Esab was the best I'd come across, to the point that I went and bought a Powercut 1500 not long after with ideas of a cnc table in the back of my mind. I have never been impressed with either a Miller or Lincoln offering! The TD stuff was pretty good, but were all low power units.

So, obviously I had no idea about what was ideal for CNC when I bought the Esab. It has no cnc interface or capability and HF start. And, while it's got plenty of power it's also got a seriously tapered cut and very expensive consumables.

This plasma table came with a really old (1993?) Hypertherm Max100D cutter. This has been an impressive unit. I have asked Jim from Hypertherm a lot of questions about it, and he keeps talking about how outdated the machine is. However, I'm getting the best cut quality I've ever had from a plasma out of this thing. It's way better than the much newer Esab. And, the best part is Hypertherm's manual is DEAD ON with it's setting chart. I hate to think what a new Hypertherm would be like if this is so far out of date! As you can see I'm definitely a convert - never buy another brand again!

mcphill
12-03-2010, 03:54 AM
What Monster Garage episode were you on?

jimcolt
12-03-2010, 09:07 AM
Glad you like that old Max100D. The 100D was very similar to our popular Max100.....the "D" stands for dual gas, meaning you can have a different plasma and shield gas. Often, for cutting stainless and aluminum users would use nitrogen for plasma gas and CO2 for the shield gas to get an oxide free cut. If you are cutting steel, you simply use air as both the plasma and shield gas for best results with this type of torch.

It is true that the 100D is old technology by Hypertherms standards, in fact our new Powermax85 cuts way thicker, way faster, and with about 4 to 6 times the consumable life as compared to the 100. We have developed a lot of technology in both the torches and the power supplies that improve cut quality, reliability, size, and exspecially consumable life.

I like to see those older systems still cutting steel. Reminds me of a day with no gray hair! I was managing the assembly department at Hypertherm back then. Most likely I tightened a few screws on that system!

Jim Colt

panozeng
12-03-2010, 10:45 PM
It was the 2 part "Flying Car" episode...

As you can see in the videos I am currently using the old ball transfer floating torch set-up. It works fairly well at keeping the torch height over the material constant, but is not good for controlling pierces and you have to clamp the material down so it doesn't drag it around. I am only using the floating head as a temporary measure...

I got an email from Candcnc yesterday saying my MP3000 builder's kit should be shipping today! I am really anxious to get it on the machine - should fix most of the nagging issues with the table.

There is one other issue with the table that's a little disappointing - although not surprising. The single side drive on the gantry allows a little racking, specially when the carriage is towards the opposite side of the table. There's no play in anything, and it takes a lot of force to make it deflect, but acceleration forces will bring out a wiggle in the cut. I'm debating strategies for connecting that other side now.

Another better resolution video is now on youtube:
YouTube - MVI_1986.AVI

panozeng
12-08-2010, 07:52 AM
Just seeing if I figured out how to embed one of the videos above...



Well, that didn't seem to work either, and it was taken straight from another post on here that showed a youtube video embedded. Weird...

m230042
12-21-2010, 12:13 PM
Ok, I have to talk about the Hypertherm plasma cutter now. Throughout the years I've used about all brands of plasma cutters - starting with a 1980's Thermal Dynamics, later a stakpak, a Pakmaster 50XL, a couple of Lincolns, and a couple of Millers. I was impressed 3 times - obviously the first time I ever used one, much much later when I was on monster garage and used an Esab, and finally by this 20 year old obsolete Hypertherm. As of a few years ago the Esab was the best I'd come across, to the point that I went and bought a Powercut 1500 not long after with ideas of a cnc table in the back of my mind. I have never been impressed with either a Miller or Lincoln offering! The TD stuff was pretty good, but were all low power units.

So, obviously I had no idea about what was ideal for CNC when I bought the Esab. It has no cnc interface or capability and HF start. And, while it's got plenty of power it's also got a seriously tapered cut and very expensive consumables.

This plasma table came with a really old (1993?) Hypertherm Max100D cutter. This has been an impressive unit. I have asked Jim from Hypertherm a lot of questions about it, and he keeps talking about how outdated the machine is. However, I'm getting the best cut quality I've ever had from a plasma out of this thing. It's way better than the much newer Esab. And, the best part is Hypertherm's manual is DEAD ON with it's setting chart. I hate to think what a new Hypertherm would be like if this is so far out of date! As you can see I'm definitely a convert - never buy another brand again!
smart man !!!! hypertherm rules