just another plasma build and then some :)

i just wanted to explain the aluminum plates in a little detail. the cross section of my gantry is 15 series extrusion. the T slot extrusion has a draft angle around the T slots which doubles as a built in lock washer. i actually bolted two aluminum flats to the cross section before mounting the rails to the add aluminum flat bar. the reason for this was to give me material to machine the bosses that lock the rails down into the flat bar and then add the tapped holes to the flat bar. The reason is to have the rails sit at the exact same height and be locked into a perfectly parallel race to use as a datum point to transfer squareness from axis to axis.

when i machine my parts i am working to +/- .001 the aluminum plate for the uprights on the gantry are the same way and are identical to about .001 as well. You have a right and left hand side with those but in the plate i machined -.100 deep pockets to locate and transfer squareness so when the parts are bolted together they are square to each axis. same approach is done with the Z axis and on a transfer of axis the bearing blocks are locked in and that part is doweled into place to transfer the squareness.

no matter what the process starting with a square machine frame takes that part out of the guessing and adds to cut quality over all. SO if you spend all this time on torch height control to hold +/-.005 or better to keep your cuts straight on the sides it makes sense to have a square bed of machine to the same specs or better as well.

just my 2 cents

was thinking about leveling casters for the table and came across these on amazon. does anybody use this type of caster and if so how do they work out? i think the specs are off on four of them since the ones rated for 550 lbs are listed for 2200 lbs as a set of four.

Never seen that type before. If you buy them make sure to let us know how they go.

i would think i would need at least 6 of them as something in the middle is probably going to be helpful. i'm not sure how many gallons of water a trey will hold for a 4' x 8 table? i can see some serious weight adding up there at 8 lbs per gallon they come in 4 packs not much of a price difference between the those and the ones rated at half the weight either.

My table weights in at around 2300kg, And my tank hold about 1900 liters. When full the total weight it closer to 4200kg without including the weight of the steel its cutting.

But it is a big machine, 4000x2500 cutting area.

How deep is your water tray? Its easy enough to calculate the volume it holds. Are you going to have a tank? It really helps when you need to drain the pan to clean out the mess inside.

Just make sure your tank is over the volume specs for the pan. I made that mistake my on my first tanks assuming I could get 100% of the water out and into the pan.

just found a calculator and a 4 ft x 8 ft tray 3" deep is 80 gallons so about 640 lbs of water. That's lighter than i was thinking.

yeah i have a cheap option as i can pick up a used 200 gallon plastic tank for 50 or 75 dollars. i see them all the time in the classified adds. figured i would just get a utility pump to control water height and let gravity do it's thing to drain it out. simple but good enough for now.

just now did some conversions and yes your machine is pretty big compared to my tinker toy

Letting gravity empty the pan is what I do and it works well, I use all 2inch piping but I can empty my pan in about 10 minutes.

I have a diverter valve that I use when draining the pan to stop steel particles going through the pump, and its much faster to drain as well.

+1 on this. I use a 100gal stock tank under my table for water storage. The water table is filled using a cheap HF sump pump. Gravity drain. Simple and quick.

John