Cutting 3/4 or 5/8 plate with PM45 for Modular Welding Table

[Capstone]

I'm trying to fab up a "build-pro"like modular welding table; hoping to get a a "drop" of 5/8" or 3/4" steel from my local metal supplier. I want to cut it into 6" strips and then rent a magnetic drill with an annular bit to copy the same 5/8" holes on the BuildPro® Tabletops for fast and easy clamping using the same clamping accessories.

I've researched pricing and know that I can get three brand new 38" long plates already drilled for $735 including tax + shipping, which would fit my needs for now, plus the cost of clamps etc.

I'm still assembling costs of the plate drop, along with the cost to rent a mag-drill and the annular drill bit cost but before I go too far with this I would like to know two things...

1. Is the HT PM45, assuming it's working in optimum conditions even able to handle cutting 3/4" plate?
a. If so, what cut settings have worked well for both the 5/8" or 3/4"

2. Has anyone tried this approach to creating a modular welding fixturing set-up and did you see any real cost/quality benefit versus just buying the BuildPro product?

Thanks

[acourtjester]

I would research it here there have be a few tables built and posted on this site.
http://weldingweb.com/index.php

[Capstone]

Thanks Jester... I've definitely looked at the welding table thread for ideas on size, design and features. I mainly asked here because I am hoping someone here is better able to answer my first question. I 'spose I could just test it on some a chunk of scrap.

[SeanP]

I have cut a few jobs in 15mm, it's surprising how well it does, you are supposed to edge start, but have got away with the settings below ok piercing for a few parts, I did draw the line when he wanted 8mm dia holes though, the hole marking worked superb for that job.

I can't see why you wouldn't cut them ok in 5/8'' maybe even 3/4'', trouble with edge start is it leaves it open for pulling, maybe there is a way around that.

15mm.png (32.9 KiB) Viewed 2643 times

15mm.png (32.9 KiB) Viewed 2643 times

[Capstone]

Thanks Sean. I'll definitely give your settings a run with some "scrap". The pierce delay and pierce height are definitely "off the charts" and 15mm still falls short by a mil of 5/8", so pushing 3/4" might be a stretch, but your results are superb as always.

What do you mean by "pulling"?

[SeanP]

Sorry I just mean cutting in from the edge is leaving the part loose and I find it seems to pull/move towards the end of the cut.
Even 12mm I set the pierce height to 4mm, think it was Jim Colt colts suggestion for piercing that thickness, it works, I cut a couple of sheets of 12mm yesterday with plenty holes on the same electrode/nozzle.

[jimcolt]

The Powermax45 is factory spec'd to pierce 1/2" steel. I have done 5/8" (use the cut charts for speed, run a higher pierce height than listed for 1/2" and a longer pierce delay) I don't recommend piercing 3/4" with the 45....you will eat up shields and nozzles.

Jim Colt Hypertherm

[mechanicalmongoose20]

The Powermax45 is factory spec'd to pierce 1/2" steel. I have done 5/8" (use the cut charts for speed, run a higher pierce height than listed for 1/2" and a longer pierce delay) I don't recommend piercing 3/4" with the 45....you will eat up shields and nozzles.

Jim Colt Hypertherm

Jim,
Just for conversation, what is your take on the wiggle pierce for thicker materials? Have you tried it and/or seen any improvement in consumable life by doing so? I keep meaning to give it a go but have yet to try.

[davek0974]

Hi sean, what were your full setings for the 12mm please?

I have my first job on that thickness coming up

It some 19mm holes, would they cut ok?

[SeanP]

I cut 18mm dia holes the other day Dave, well that's what I was aiming for, I used 18.5 on the drawing, top of the hole came out a close to that, and with a quick spin of the die grinder and a carbide burr the base came out around 18mm and looked tidy.



The outer cut I found it best to add that 50% slowdown near the end so the parts dropped out, worked well.

[SeanP]

The Powermax45 is factory spec'd to pierce 1/2" steel. I have done 5/8" (use the cut charts for speed, run a higher pierce height than listed for 1/2" and a longer pierce delay) I don't recommend piercing 3/4" with the 45....you will eat up shields and nozzles.

Jim Colt Hypertherm

Jim,
Just for conversation, what is your take on the wiggle pierce for thicker materials? Have you tried it and/or seen any improvement in consumable life by doing so? I keep meaning to give it a go but have yet to try.

I gave it a try once, but didn't even get to trying it with the torch on as it shook the hell out of the gantry, I'm not sure if there is a way to slow that wiggle rate down or not?

[Brand X]

I would guess (just a guess) you would be cutting thick metal using it, and you could slow the motor tuning down in mach.. (IPM) the X+Y
It must use the max speed set on the motors. Seemed like it anyway.. Maybe acceleration could be changed, and not have any issues either, being the metal so thick, and it would not hurt to do so..

My friend uses it, and likes it, but I had the same issue of wanting it to beat the table apart.. So I never tried it. I guess Les at SheetCam would be the one to ask this kind of thing.

[davek0974]

Thanks Sean, nice one

[jimcolt]

We used a variety of different "wiggle" pierce techniques about 25 or more years ago in an effort to make unshielded (exposed nozzle) plasma torches pierce thicker and without damaging the nozzle from double arcing associated with the molten metal blowback. Some of these techniques helped the non shielded torches to some extent.

With the newer shield technology on Hypertherm torches....I personally do not see an advantage to a wiggle pierce. We have put factory ratings for piercing.....and that spec allows you to pierce that thickness without an damage to the shield or nozzle, assuming of course that you follow the published pierce height and pierce delay specs. Can you pierce thicker? Yes, but expect shorter shield and nozzle life.

Two things: 1. If you need to pierce thicker than your plasma is rated for....do a separate drawing or layer in your part program that allows you to do all of your piercing.....use an older nozzle or shield, then after piercing of all holes is complete.....put in a new nozzle and shield and edge start on all of the pre-pierced holes. This will give you the best cuts on material thicker than your torch is rated for. 2. Or.....get a different plasma cutter with more pierce capacity....if you have specific thicknesses that must be pierced.

Jim Colt Hypertherm

[Brand X]

My esab 1600 had parameters for raising the torch on the pierce. That make the most sense to somewhat solve the issue.. All we have to do is get Les to add it to Sheetcam. I asked once, and got "Use the wiggle pierce.." It can be done, and the big boys use it..

So have a initial setting like .200 Pierce height at .250, and a cut height at whatever.. Just a way to add some adjustments on the start parameters.

https://youtu.be/0nSD-cCjQcA?t=1m2s

[jimcolt]

Yes that will help....we have had that function on Industrial height controls for over 20 years....allows the torch to get close enough to transfer the arc, then rises in an attempt to avoid the molten slag. Jim Colt Hypertherm

[gary42095]

i know your question was for pierce.
i question what will happen with table being built from mild and used for welding. you may wind up with boogered threads. i know the tables sold are all nitrided , which is supposed to keep spatter from sticking? maybe some sort of coating, or spray table regularly with antispatter? dont want to see you do all that drilling/tapping and wind up not being useable after some use. maybe im overthinking it

[Capstone]

i know your question was for pierce.
i question what will happen with table being built from mild and used for welding. you may wind up with boogered threads. i know the tables sold are all nitrided , which is supposed to keep spatter from sticking? maybe some sort of coating, or spray table regularly with antispatter? dont want to see you do all that drilling/tapping and wind up not being useable after some use. maybe im overthinking it

Valid point... I'm first trying to see if the PM45 is capable of cutting 5/8in. then I can determine best options for the cost and results.

1. Buy outright the BuildPro slats (plain or nitridid)
2. Buy a 5/8 in plate and bring my custom pattern for a welding table to a company with a waterjet
3. Buy a 5/8 in plate; make just the strip cuts with my PM45 and then rent a Mag-Drill for the holes.

Now it's just a cost exercise. BTW, I'm having a hard time finding a waterjet company near Wash DC.

[Gamelord]

I built my table with mild steel, works fine. YOu do get some spatter but just take it off with a grinder in seconds. I have even welded to the table for certain jigs and to tack parts for welding, works great, just grind the weld down afterwords. I don't have any taps or threads on my table though....if I needed one, I could just drill a hold and weld a bolt to the other side, grind it off when done if not needed or if it gets buggered up. My top is 5/8" plate. Used it for 7 years now and it's still working fine.

[gary42095]

Gamelord, mine is mild as well and use it the same as you. Have a 4x4 .75 thick. And a 5x10 1 inch thick. They work great when you need to straighten something, weld it right to table, port-o-power it straight and cut it off table. Fixture tables look real nice, but for most things I do, not very practical

[tnbndr]

Now it's just a cost exercise. BTW, I'm having a hard time finding a waterjet company near Wash DC.

When you do find one, you won't believe the cost!!!! Most companies that have waterjets around here don't sub out work they are too busy and the one I found that quoted some cutting for me was crazy money.
My guess is that when you crunch all the numbers you will be better off just buying the slats or just buying a pre-built table, unless you need the pleasure of building your own.

[gsi]

I've just gone down this road of doing it yourself vs buying it for a build pro style welding table. I got a quote for blanchard grinding a 4x8 of 3/4" plate and water jetting 200 5/8" holes the other day. It was $2200 to have this done including the 3/4" plate. I was still going to have to ream all 200 holes as the water jet folks could only give me a 0.030" tolerance on hole diameter. I would still have to build the table at this point. I was looking at another $1200 in parts by the time I bought all the steel and other misc stuff. Then there's all my time in building it. Remember your time isn't a tax deduction but equipment cost is. I decided to just buy one and be done with it. I figured if I was to ever need to sell it, a buildpro table would probably sell easily but a shop built table wouldn't bring nearly as much.

[Capstone]

I've just gone down this road of doing it yourself vs buying it for a build pro style welding table. I got a quote for blanchard grinding a 4x8 of 3/4" plate and water jetting 200 5/8" holes the other day. It was $2200 to have this done including the 3/4" plate. I was still going to have to ream all 200 holes as the water jet folks could only give me a 0.030" tolerance on hole diameter. I would still have to build the table at this point. I was looking at another $1200 in parts by the time I bought all the steel and other misc stuff. Then there's all my time in building it. Remember your time isn't a tax deduction but equipment cost is. I decided to just buy one and be done with it. I figured if I was to ever need to sell it, a buildpro table would probably sell easily but a shop built table wouldn't bring nearly as much.

GSI,

That's a super solid response and I really appreciate the breakdown of the costs. The bit about the tax deduction really hit's home too. Now I'm sorta leaning toward the tabandslot table kits I've seen on a few YT channels I frequent. Seems like a solid compromise of cost versus accuracy and labor for me needs. I'm just now getting proficent at MIG and hope to get more TIG under my belt. fixturing may not be super important at the moment, but I'm rattling an idea for a hybrid welding table that will eventually be used to expand my current plasma table and hopefully grow with me once I get to a real shop space. stay tuned.

[gsi]

Phil,

No problem. For some reason people seem to be secretive about the cost of having stuff done like this. Being that you have a plasma table, you could cut a table out that is kind of a copy of the miller welding table top. You may just want to look at it as I seem to remember the whole 30x60 table being about $750. I needed a bigger table for what we end up doing at the shop but it looks like a nice welding table. Our local welding shop has one on display. For general welding and just being able to clamp some stuff down it should work out good. We're doing a good bit of fixturing so I went with the buildpro. It's a lot of money but so is paying the labor to my employees to spend more time to struggle through the jobs. I keep working on big projects in the floor. I spent probably 25-30 hours in the floor in three or four days last month. I just about couldn't walk when Friday came around. Pushing the tig foot pedal with one knee gets old after a while.

Griff

[Capstone]

So as you recall I wanted to see if, under the right conditions, and on rare occassions, was the PM45 capable of cutting 5/8" or even 3/4"

Success!! 3/4" Hardened Steel cut @ 7 IPM - 140v* (see below for how that didn't happen) The angularity was very good. It's hard to tell, but there was less than 5 degrees of tilt, which was shockingly good and the dross while fairly heavy in spots, came off easy-peasy.

I am officially amazed with the build quality of Hypertherm. It's so rare that machines like these outperform their specs with such surprisingly good results.

My settings were loosely based on PM65 edge cut. It did raise one other issue with my setup and that's the MACH / CandCNC Voltage readings that control mostly the DTHC. I was looking pretty closely at it and it *never went above 52 , so maybe something is off with my divider thingy. I've adapted my DTHC II Ethercut setup to work flawlessly with all of my voltages way below book settings in MACH, and I use the 30amp consumables most of the time, so I didn't give it much thought, but what are the long term issues with running all of my different cut settings using these weird voltages?