easy way to remove low speed dross
Been back from the sunny south for about two weeks and got the shop up and running for the summer. Took awhile to get everything running but it's all working now. Great to be back and burning stuff up.
I obtained the new fine cut charts from Jim Colt that are about half the speed of the regular charts. They work great if you are going in a relatively straight line and can maintain the cut speed. For the metal art stuff that I do, there are way too many twists and turns. What you end up with is a blend of high and low speed dross and some areas with no dross. The fine high speed stuff is really tough to remove and the low speed is a PITA.
I was at my buddy's body shop and noticed one of the body men removing rust scale from a frame with an air tool. It was a needle scaler and did a great job. I left with one of his spares in my pocket (just borrowed). I found that if you hold it at a 45 deg angle and perpendicular to the line of the dross, it just vibrates it right off. Don't press too hard against the dross, just hold it loosely and let it do it's thing. It's much better on low speed than high speed dross so I've reduced the cut speed by 30 IPM to avoid high speed stuff. One caveat is that it will leave very slight marks in the metal. I finish both sides of my work so the sanding, primer, and topcoats cover them right up.What used to take 5-10 minutes to clean up is now done in 1-2 and the sanding is much quicker.
One problem is that the scaler is noisier than hell. Wear ear protection and you should be OK but your neighbors may object.
Happy cutting!!
Willy
Another season come and gone !
Another summer has come and gone. We did very well with the metal art business both on-line and at shows. Generated lots of custom sign and metal art work.
The machine continues to run very well but as Millman said a while back, you find out the design problems after you've been running for a while. We probably ran for 3-4 hours per day this past season and this puts a lot of strain on the machine.
I've decided to make some changes.
The current gantry is a 2 rail design and is slightly top heavy. It's fine when running at slower speeds (less than 100 IPM) but has a slight wobble when reversing directions above that speed. It's not that a great a problem with the metal art but it bothers me when it happens and adds extra clean up work on the pieces. Another problem with the old gantry is the linear rails. With the extra usage the machine is getting, it is taking more time for maintenance, cleaning the rails and slag screens.
I've designed a single rail gantry with a single V rail guide with a sealed bearing torch carriage. I am also going to re-do the floating head to incorporate bias springs to reduce the amount of pressure required to zero the torch height on thin material.
I am also going to enlarge the slag screens to reduce the amount of cleaning required. Although it doesn't take much time, it's a pain when you have to stop cutting to clean in the middle of a run.
The last thing is to reduce the belt reduction ratio. The current ration is 4:1 and this accuracy is not required for a plasma table: I am going to try a 3:1 or 2.5:1. It should give me better acceleration, especially with the lower gantry weight.
I'm just starting to order parts and I'll post pics as I get started on the project.
Happy Holidays to all.
Willy
Re: A Different Machine - Downdraft/water table
Been a while since I've posted anything about the machine. It is still running beautifully. Haven't had to do anything except adjust the belt tension once in a while. The downdraft system is still sucking everything out that the water table doesn't collect. The LCTHC from Candcnc is running great and maintaining 1 volt (plus or minus) and the G540 is rock solid. The PMAX65 now has 45.1 arc hours and hasn't skipped a beat. 90% of the cutting is done at 40A and consumable life is really long ( I do metal art so I probably use them longer than most people would) and is mostly fine cut consumables. After several years of use, I've found that my primary settings for 16 GA steel (my primary material) are 150 IPM with 40A on fine cut consumables. It gives me the quality I need with very little dross and long consumable life.
The only addition is a backup computer. My PC died this year (hard drive failure). I've added two machines with one backing up the other automatically. One machine is in the shop running the table and the other is in the office and connected over a wireless network. It also backs up my PC that I do the drawing designs on. I also put in a external hard drive (western digital) that backs up files on all 3 machines. Spent many hours trying to recover files when the table PC died and I don't want to do that again.
The new gantry is still unfinished. Too much work, not enough time. Getting ready to shut down for the winter and head south , so it will have to wait until next year (again). Building this machine was a lot of fun and a lot of work but it was well worth it.
Willy
Re: A Different Machine - Downdraft/water table
Hey WILLY! If you like the LCTHC you would pass out from joy :cool: with the new MP3100-DTHCIV plugged into that G540 and running the advanced posts we have for SheetCAM. You now have a full Electronic Cut Chart for the 65 in our Posts for SheetCAM (toolset) with all of the settings (including preset volts) that auto-load it to MACH and the DTHC. No more knobs to twist. It even reminds you to check your AMPS setting and the consumables for proper size. If you get rich and want the ultimate, you can upgrade that Hypertherm 65 with their RS485 port and our HyT-Connect RS485 SIM Kit. Now you don't even have to remember to change the AMPS because it does it for you!. The MP3500-DTHCIV is our new Ether-Cut product that runs off a CAT5 to the PC Ethernet port (no more parallel port). You can run it off a laptop and WIN 7. You can have the Ethernet for the control and a separate wireless channel to talk to your network or another PC.
TOMcaudle
www.CandCNC.com
Re: A Different Machine - Downdraft/water table
Tom:
Your new unit looks great but I don't need all the bells and whistles. I haven't changed the settings on the Pmax or LCTHC in 2 months and the cuts are plenty good for the stuff I do.You built the LCTHC too good. It just runs perfectly. If it ain't broke, don't fix it.
The only way I would consider the upgrade is if the LCTHC craps out or when I finish the new gantry and I have to rewire the machine but that's way out the way I've been going with that upgrade.
Good luck with your new products.
Willy
Re: A Different Machine - Downdraft/water table
I don't NEED the power steering, power brakes, cruise control, GPS or bluetooth on my new truck but they sure are NICE! :banana:
Of course if all I do is drive to the barn and back my old Ford truck is just fine.
Re: A Different Machine - Downdraft/water table
The winter is moving along and it's time to start planning for the new summer art season. Plans are to complete the new gantry (been planning that for several years) , start on a new (aka larger) table, and upgrade the air system. Don't know how much we can accomplish with the projected workload but it's good to plan ahead.
For the air system, I just purchased a Speedaire / Dayton 15 SCFM refrigerated air dryer off Craigslist for $50.00 and it actually works well. The plan is to use both the dryer and my desiccant dryer in series with a bypass(s) around each unit. I am also going to install water drops with auto drains at the outlets. The plasma will get along fine with either but when we are using the plasma and spray painting during the summer, the compressors generate a ton of water and overpower the desiccant dryer by itself. So the air system will look like this:
Compressors ----Air Radiator ----- Refrigerated Dryer ------M60 -------- Dessicant Dryer ------ Water Traps / Outlets
| | |
|-----------Bypass-----------|------- Bypass -------------------------|
That's the plan. If anybody has any suggestions, be glad to hear them.
Willy
Re: A Different Machine - Downdraft/water table
Hi Flyinwilly,
You mention that you still have a few "stuck consumables" and that doing a complete cleaning of the torch could resolve this. What type of cleaning are you doing? I too have stuck consumables (Pmax 85) more often than I think I should. We use to have serious problems until we installed a refrigerated air dryer. The problem is about 1/10th of what it was but it still exists. It tends to happen more towards the end of life on the consumables but it can happen fairly early too. When our torch was new we didn't have a single issue with stuck consumables.