Who has a plasma table?

[cpierce18]

I have a 52” x 84” CNC plasma table.

I would be glad to work you up a quote. Email me at chris.pierce@pierceworks.net
You could check out some work at www.pierceworks.net (Sorry, website is still slowly under construction)

Please email me and include the following for each part you need.
1. A sketch if possible (or a describe the part)
2. Thickness
3. Material type (Carbon Steel, Stainless or aluminum)
4. Any tolerance requirements you need
5. Rough time frame of when you would need it
6. Ship-to location.

[SeanMurphy265]

I've got an inside track coupon for the Harbor Freight tube roller that I'm going to pick up this weekend. I have an idea that I want to try. I will get all the measurements this weekend.

[cpierce18]

For those of you who have a CNC plasma cutting table with the PP-50 cutter, here are some specs that gave me great cutting results.

A customer came to me with a job cutting (16) ¼” thick brackets, and possibly more depending on the quality of the work.

Apparently the first set of brackets came out great because he just came back for another (32) brackets.

Here are the specs. I used for cutting.

PP-50 with the hand torch.
Material- ¼” A-36 Carbon Steel
Air Pressure – 65 psi
Cutting Amps - 45
Pierce Height - 0.25”
Pierce Delay – 0.25 seconds
THC Cut voltage – 106 (around 0.7” cut height)
Hole Cutting Feed Rate – 25 IPM
Perimeter Cutting Feed Rate – 40 IPM

Edge quality turned out great and the 13/16” diameter holes for ¾” Bolts came out with a very minimal bevel & dross.

[sportbike]

Any chance you can just change belt cog ratios (if applicable) to speed up your Z axis? that is if you have a belt reduction AND you still have enough torque to lift the Z.

[cpierce18]

Any chance you can just change belt cog ratios (if applicable) to speed up your Z axis? that is if you have a belt reduction AND you still have enough torque to lift the Z.

I don’t have any belt reduction on my z-axis. I have the motor coupled directly to the lead screw. My motor takes 200 pulses to make one revolution. The driver for that motor changes that to 1,600 pulses to make one revolution, but that decreases the torque of the motor. The lead screw takes 18 turns to move 1 inch (5/15”-18). So for my Z-Axis to move 1”, my PC sends 28,800 pulses to that motor (1,600 x 18). I can’t really make it move much faster because I will lose the torque I need to power thru the grime and plasma metal dust that collects on the lead screw. I guess I’ll have to live with me inconvenience of the extra second it takes to lift up the torch.

[sportbike]

I have a 52” x 84” CNC plasma table.

I would be glad to work you up a quote. Email me at chris.pierce@pierceworks.net
You could check out some work at www.pierceworks.net (Sorry, website is still slowly under construction)

Please email me and include the following for each part you need.
1. A sketch if possible (or a describe the part)
2. Thickness
3. Material type (Carbon Steel, Stainless or aluminum)
4. Any tolerance requirements you need
5. Rough time frame of when you would need it
6. Ship-to location.

Chris,
Are you in Elizabeth PA as in near Pittsburgh on 51? I live near Johnstown, but I often use a shop in Uniontown for tuning and building my bikes. My buddy who races with me lives near Homestead.

John

[cpierce18]

John,

You are correct. I live south of Pittsburgh near Elizabeth & Rt. 51. I make it down to Homested every now and than and am pretty sure I've passed thru Johnstown on my way to State College.

What kind of bikes you build?

[sportbike]

John,

You are correct. I live south of Pittsburgh near Elizabeth & Rt. 51. I make it down to Homested every now and than and am pretty sure I've passed thru Johnstown on my way to State College.

What kind of bikes you build?

I build fast ones :-). I have a Turbocharged Suzuki Hayabusa and my buddy (from Homestead) has a Nitrous Hayabusa. The shop where I tune is mostly Harley stuff (the owner, Gregg Dahl, has a "street" harley that has gone 8.50's in the 1/4).

[cpierce18]

Here are a few pictures of the brackets.

[SeanMurphy265]

Are you using touch and go or torch height control? What are you using for you Z axis?

[cpierce18]

I'm using the LCTHC from http://www.candcnc.com. It works great. Hookup was fairly easy into the PP-50. It was just a little time consuming. Something else I'd like to add is a height senser so it will zero out before every pierce. The reason being is this. If i stick a piece of 4'x4'x1/4" plate on the table to be cut, it's not going to be perfectly flat and level. There will naturally be a bow in the material. So if I zero the Z axis at the bottom left of the plate and start piercing at .15 above the material, by the time I get to the center of the plate (at the bow) my torch is touching the plate when I pierce than the THC will take over and move to .06" or so above the material (or whatever you have the volts set at). That usually screws up my tip my blowing molten metal back into the nozzle and causes it to cut with a bevel. Right now when I cut from a 4x4 sheet, every so often I'll hit the FeedHold button and zero the z axis and keep cutting.

[cpierce18]

Oh yeah I forgot. For my Z-Axis I'm using a 5/16"-18 all-thread hooked to a 425oz/in (i think) motor. It worked on my CNC wood router, so I just carried the design over to my CNC plasma table.

[SeanMurphy265]

I've had a hard time figuring out the Z axis. I can't decide whether or not to buy one ready to go, or try to make my own. No Sleep Studio has this Z axis Who makes a good torch height sensor?

[cpierce18]

I've had a hard time figuring out the Z axis. I can't decide whether or not to buy one ready to go, or try to make my own. No Sleep Studio has this Z axis Who makes a good torch height sensor?

I hate to say this, but sometimes it is better to spend the little extra money and buy a fully assembled Z-axis. If you don’t have the tools & resources to build your own, buying one is the way to go. Remember, the overall accuracy of your machine is dependent upon the accuracy of the parts it’s made from. Now that I’ve been cutting with my machine for a while, there are things that I would do different if I were to build it again. My lead screw setup is way more accurate than you could ever get with cutting with plasma. The resolution with my Z-Axis is 0.00003”. If I were to do it again, I would go with a rack & pinion drive system. My lead screw setup is a little slower than I’d like (25 ipm).

I haven’t looked into many touch-and-go systems. I know of 2 types. 1 type is having a floating head with a home switch mounted above the floating head. Before each pierce, the z-axis will home itself by z-axis moving down until the nozzle hits the plate, the floating head would stop but the axis would continue moving until the home switch is tripped. It retracts a preset distance and zero’s the z-axis.

The other type I know of is ohmc sensing. The way this works is similar to the way a home switch works. One wire would connect to your material, and the other wire would connect to your nozzle. When the z-axis homes before each pierce, the nozzle would travel down until it hits the plate thus closing the homing circuit and zeroing the axis (like hitting a home limit switch). The only issue with this that I have not looked into yet is the resisters and stuff that you would need to prevent your drive boards from getting fried when the plasma cutter fires and sends 150+ volts through those wires up into your drive board. This is probably the way I will go when I get around to it.