Cutting tread plate with tread down advice?

[Deezl Smoke]

Got a call to cut .5" tread plate, but the customer needs to use a mag drill to drill holes through it that he wants me to center punch with the plasma. Ok on everything, except with the tread plate upside down on the table, how will the dthc work? I need torch height control as there is some dross build up on the slats, so the plate will be close to plumb with the gantry, but not as good as it should be. Cuts are long, like 72".
I personally think the magnets on most reasonable quality drills should stick well enough to the tread bumps for small holes like he will drill. But he's hoping I can cut with the tread down.
I'm thinking I should be able to pierce a locator hole for him to locate his drill on the flat side. A pierce through .5" a36 shouldn't have but a couple thou deflection should it? Thinking 85 amp, or would 65 amp be better through .5" to pierce?

[weldguy]

I would go 85 amp But take i to account the added thickness of the material the treads add. You wanna make sure your going slow enough that it can cut through that extra material and not blow back at you. As for marking the holes for the mag drill I would use an easyscriber or pen marker, i have never been happy trying to mark holes with plasma. Let us know what you decide and how it goes.

[Deezl Smoke]

I've always had real good luck using the plasma to mark out holes for drilling or stud location etc.
So I talk to the customer, and told him another down side to cutting with the tread down was that the tread may get gouged if the plate slide on the table at all either squaring it up to cut, and/or removing from the table post cutting. So he agreed to just have my cut the plate tread up and he will lay out the drill holes at his place with the tread down as the plates will be manageable size after cutting. So....
Thank you for the reply.

[Joe Jones]

The tread plate is 1/2" THICK?!?

Joe

[Deezl Smoke]

The tread plate is 1/2" THICK?!?

Joe

Yes. Hefty bit of tread plate. Supposed to carry vehicle traffic I think.

[Deezl Smoke]

I think it did a good job. 85 amp.

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[tinspark]

Looks real good. I would be very happy with that !

[adbuch]

Those are some nice looking cuts!
David

[SegoMan DeSigns]

I like watching the THC while cutting tread plate it, it certainly has its ups and downs
I don't know how many of these you did but an option would be to make a marking template out of some 1/8" or thinner material.

Generally speaking the thicker the material the stronger the attraction from the magnet, depending on the hole layout I could see where they might want to drill from the flat side to prevent drill bit drift when hitting the edge of a tread.

[adbuch]

Steve - I agree it would probably be best to drill from the smooth side if using a mag drill. Or another option would be to clamp a piece of steel on top of the diamond plate for the mag drill to attach to. If he goes slow using an annular cutter he should be fine.

David

[Deezl Smoke]

Thank you for the replies.
I only had to cut 4 pieces, and there are just 4 holes per. It's one of those things where I can tell the customer what I have done in the past with a mag drill and had good luck, but the customer may have differing experiences, so..... And the customer pays the bill, so I made sure I removed as much risk of failure as I could and he is very happy with the result.

[adbuch]

Thank you for the replies.
I only had to cut 4 pieces, and there are just 4 holes per. It's one of those things where I can tell the customer what I have done in the past with a mag drill and had good luck, but the customer may have differing experiences, so..... And the customer pays the bill, so I made sure I removed as much risk of failure as I could and he is very happy with the result.

[SegoMan DeSigns]

Steve - I agree it would probably be best to drill from the smooth side if using a mag drill. Or another option would be to clamp a piece of steel on top of the diamond plate for the mag drill to attach to. If he goes slow using an annular cutter he should be fine.

David

David,

Annular cutters are nice and compared to bigger bits they are cheaper to buy, I bought the right adapter to match my drill press arbor and used them on all of my pivot holes on the press brake build. They do a clean drill, just keep them cutting and oil cooled.

IMG_20201025_145545407.jpg

On occasions I use the vinyl cutter with poster board paper to make drill templates, I call it my CAD system (Cardboard Aided Designs)

Drill Guide (1).jpg

Deezl Smoke,

I'm glad the paying customer is happy. That is what keeps you in electrodes..

Steve

[adbuch]

Steve - I agree it would probably be best to drill from the smooth side if using a mag drill. Or another option would be to clamp a piece of steel on top of the diamond plate for the mag drill to attach to. If he goes slow using an annular cutter he should be fine.

David

David,

Annular cutters are nice and compared to bigger bits they are cheaper to buy, I bought the right adapter to match my drill press arbor and used them on all of my pivot holes on the press brake build. They do a clean drill, just keep them cutting and oil cooled.



IMG_20201025_145545407.jpg


On occasions I use the vinyl cutter with poster board paper to make drill templates, I call it my CAD system (Cardboard Aided Designs)




Drill Guide (1).jpg


Deezl Smoke,

I'm glad the paying customer is happy. That is what keeps you in electrodes..

Steve

Steve - I have an R8 adapter to use them on my Bridgeport as well.

David

[Deezl Smoke]

Same here, an R8 to 3/4" weldon. Love it. Super handy for small stuff that fits on the table. Otherwise I don't think I'd be very happy without my Hougen.
Rotabroach annulars are available close to me. I've bought a few chinezium cutters from amazon with hit and miss luck. What other brands do you guys use?

[adbuch]

I like Hougen. Top quality drills, cutters, and tooling. That's what I use.
David

[Rockchucker]

If you have the ability to cut with O2 plasma gas ive had good success with making the holes .020 undersize then just chasing(reaming??)them with annular cutter after. Do NOT attempt this with air plasma... ask me how i know

[weldguy]

Wow, cuts came out awesome! Very nicely done