Reply with QuoteWOW, that is one wild design. Should be stout as hell though........thanks for sharing.........jb
A "Not so cost effective" Plasma Table
Hi folks,
I just thought you might want to see what ended up with our Robotic / Plasma Table. Thanks to all of your help here on the “cnczone” and the “unbeatable” customer support at Dynatorch, we were able to complete our project without a hitch!.
Brief History:
A few years ago, I purchased a couple of ABB IRB-6 Robotic arms (one was on a slide) and we built this table to accommodate one of them. After a ton of discussions and even more help on a previous thread: (http://www.cnczone.com/forums/showth...robotic+plasma),
We scrapped the robotic idea and went with a “not so conventional gantry design.
Table:
The table is 4’ x 10’. We would have went with a larger table hindsight, but at the table design stage, we were still expecting the robot to be on the back. The metal for the table is all laser cut from 3/16” plate steel with “Tabbed” assembly for accuracy. (Tabbed = legs have a dozen or so tabs that fit into the front and back and the angled front (angled for easy small parts removal) sections and are then are welded together. We ended up with a “very” accurate and square table. When we decided to go with the gantry design, we added the side rails which hold the helical rack and pinion and the 1.5” Thomson rods. One additional note on the table: there are air ram actuated levers with material handling balls that you can pop up (we even were able to program in a button to do this in the Dynatorch software) to move heavy pieces of material around on our table with one finger.
Gantry:
We choose the long sided gantry instead of the short sided type commonly built so that we could run it to the back and all three sides were free for loading and unloading. This came without its own set of problems though. For one, the gantry needed to be stout and yet light as possible. We finally choose the boxed construction design, along with the tabbed assembly design, all out of 6061 ¼” aluminum and also laser cut. The second design idea we wanted was for all of the components to be enclosed inside the boxed gantry with only the torch sticking out a slot in the bottom.
Software / Hardware:
This category should actually be at the top! Thankfully, we discovered Dynatorch. We went with their software / hardware configuration and we couldn’t be any happier. They really have a great software package. The thought behind the design is flawless including the built in arc height controls. Our system will cut a 3/8" hole that a 3/8" bolt will fit like you drilled it (they have a cool way of handling holes in the software). The smart servo motors coupled to gear boxes running on helical rack are the sweetest and quietest combination. We did pressurize the helical rack, but we accomplished this with a pair gas shocks pushing up on a linear slide mounted adaptor plate. The gear boxes (and the motors) are mounted to the adaptor plate. The linear slides eliminate side to side backlash. We did this instead of pivoting the motor on a hinge.
Short list of hardware:
X Axis (short travel) = 34 frame Smart Motors connected to 30:1 gear boxes = 800 rapids
Y Axis (long travel) = 23 frame Smart motor connected to 10:1 gear boxes = 1500 rapids.
Z axis = Dynatorch precision ball screw actuator with a crash detector installed.
X & Y axes are running Atlanta Drive helical rack and pinion
Dynatorch’s Dash auto initial pierce height sensing system
Dynatorch’s Laser Locator for finding where you are on the plate.
X & Y axis slide on 1.5” Thomson rods with twin bearings (two bearings in one housing)
Esab’s Powercut 1500 Air plasma system with a PT-21 machine torch
Final assembly:
We built the table and painted it in about 2 weeks over 4 years ago. We decided in October of this year to finish our plasma system, but this time with a gantry. It took about 30 days of “phone calls, emails, internet searching, posting to cnczone, designing/ drawing, erasing, redrawing, redesigning….until we had a final design we were happy with. We sent our cad files to our laser guy (didn’t tell him what they were for!) and got them back the first week of November. It took us another three weeks to weld up the gantry, send it to powder coating, and assemble and program the setup. Our first cut was perfect! (it wouldn’t have been if not for several years of reading cnczone!). We cut a 4”x 4” square from 3/16” steel, and it measured 4.003 X 4.003. I had just guessed at a kerf width of .050”. we cut 3/16” parts all day long now with this machine and have virtually no dross (an occasional tap with a paint scrapper along the edge is all that needed).
Final thoughts…..
To tell the truth, I am sorry the project is finished. I had such a good time designing it and building it, but now it is in our shop foreman’s hands to use. We spent around 30k, including the plasma system but not counting labor. I probably couldn’t build another for less than 40k in parts, as some of the parts were bought 4 years ago, and some were internet findings, but we think we have a plasma system that is accurate and should last us a lifetime.
"http://www.youtube.com/watch?v=47pBQBio3VE"]YouTube- DynaMax plasma system
Thanks Dynatorch and cnczone…….
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Last edited by Hi-Vac; 12-07-2009 at 02:51 PM.
WOW, that is one wild design. Should be stout as hell though........thanks for sharing.........jb
Tabs
Hi-Vac,
Job well done. I need a little help with your tab design.... the drawing you posted I believe illustrates the tabs. I wish there was a better way to enlarge them... Are these tabs a male/female design or let's say a mortise and tenon design?
I think you'll easily place first for the nicest table built on this forum to date IMO.
Thanks and good luck!
Tom
Nice looking design...but your air plasma cannot be compared to a high definition class plasma!
Jim Colt
Why? Because I didn't buy Hypertherm? or are you peeking thru our back door again.......Originally Posted by jimcolt
I personally regard you as one of the most knowledgeable people on this forum, so if you say it can't rival Hi-Def, I am sure you are right.
But what I should have said,
"I looked at hi-definition plasma system cuts on other machines, and our results are soooooo close that I don't feel we needed to spend the extra bucks to get the difference"
so, to me (maybe not you) it rivals the Hi def I saw.........I'm happy.
As for Hypertherm, I actually wish I had purchased a Hypertherm. However, I didn't 4 years ago, and so for now, I'll stick with the Esab 1500.
PS: I corrected the original post.
Last edited by Hi-Vac; 12-07-2009 at 03:03 PM.
Tom,
Attached is a close-up photo of the "mortise and tenon" of the gantry. The whole system was built like this. I would say to the guys in the shop "if the tab fits....weld it!" It takes alot of time adding these tabs and slots to our parts (and I sometimes get them wrong) but I would usually add 0.010" to the slot dimensions (.005" on each side) so if the tab was 1.00" X .250 plate, then the slot would be 1.010" x .260".
I could send you some cad drawings if you would like.
Just so every one knows.......
This was NOT cut on a Hi definition Plasma....... Sorry Jim....I had to!
Attached is the .DXF File in case anyone wants to experiment.
Very cool machine. Thanks for sharing.
Best,
BW
Try G-Wizard Machinist's Calculator for free:
http://www.cnccookbook.com/CCGWizard.html
I don't mind the comparison to high definition plasma.....the difference is not always something you can see in a picture.. Here are a few advantages:
- Cut edge angularity traceable to ISO9013 cut quality standards (as measure over the life of the consumables, based on CMM measurements...not the naked eye!
- Cut speeds. The ability to cut down to 28 gauge with close to laser accuracy.....yet the abiity to cut 1" steel at 85 inches per minute and pierce and cut 2" steel at 30 ipm.
- consumable life as compared to air plasma is incomparable. It is typical to cut over 10,000 feet of 1/2" steel (2 miles) on one nozzle...often 3 to 5 shifts of high duty cycle cutting. This results in a dramatically lower cost per part.
- Edge metalurgy.....edges are weldable, machineable, and formable. Not always the case with air plasma due to nitriding of the cut face!
- 100% duty cycle on all thicknesses and power levels.
- Less dross, less secondary work due to the oxygen high density arc.
-Full automation...no gas settings, not THC settings...just position the torch and cut.
- New technology from Hypertherm eliminates the ding/divot and taper in holes from thin plate to 1" thick. Pic attached of holes!
I have an air plasma (Hypertherm Powermax45) on my cnc machine...it cuts with quality that is amazing....I cannot afford a high def class plasma in my home shop....but the Hypertherm HPR400xd is light ears ahead of any air plasma!
Jim
-
Sweet
Awesome machine and superb craftsmanship (good choice of material on the alum. upper section)... Great design on matching up to a premade/designed table... I noticed you have many access hatches is this for maintenance or if something goes wrong or during construction? I wish you the best of luck in the cnc plasma money realm...
Dustin
Orlando, FL
where did you get the gas shocks? very nice table.
The gas shocks, the ball ends, and the ball mounts all came from McMaster Carr. The shocks I picked are listed below. They come in 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130 force lbs. I picked two 40 lbs for our system (80 lbs total).
Here is the link to the gas shocks……$11.44 each
http://www.mcmaster.com/#9416k14/=4vlwdd
The link to the gas shock ball ends….$ 1.98 each
http://www.mcmaster.com/#9416k74/=4vlx05
Link to the ball mounts……………..$ 1.96 each
http://www.mcmaster.com/#9512k63/=4vlx9g
The hatches are for access during the initial assembly of the equipment and if something fails (I hope it doesn't!) we can remove what we need for repairs. Attached is a photo of the aluminum "triangle" door support we choose for holding the "hatches" on the gantry. They were also laser cut out of 6061 aluminum with heli-coil threads added for repeat use.
Hi-Vac,
That is a work of art!
Did you go with the preload/split helical gear? I am not sure what it would look like in the picture, I assume you would see a little offset, but not sure.
Nice work!
WSS
No, we didn't go with the preloaded helical gears. Actually, I planned on it, but they (Atlanta Gear) actually talked me out of it! We went with hardened pinions and preloaded them. Thanks!
Hi-vac,
did you design the linear rail mounts for the x axis motor or did you purchase these? Can you explain how it works?
I'll Try......
1. The motor and gear box are mounted to a (moving) flat aluminum plate.
2. The Cars (4 of them) from two THK Linear Slides are bolted to the same plate.
3. The THK rails are bolted to a stationarry plate that is welded to the gantry.
4. The gas shocks push from the stationary plate to the moving plate pushing upwards.
5. The THK linear rails prevent side movement thus minimizing backlask in the motor mount assembly.
I hope this explains the design, attached is a cad file showing the different components.
....nice explanation. the gas shocks eliminate the need for pneumatic cylinders.
TP
Hi Vac,
I can only repeat WSS; A work of art!!!
It is good to see you progressed with this. I found your old thread on here one day and was wondering if any progress had been made.
Mark
Hi-Vac check your PM's please
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