Topic: Accurate beveling on plate with cutting torch.

[754]

 This job came into the shop where my brother works..  Approx 8 x 30 ft piece of 3 inch plate, need a beveled edge.  Approx 1.5 deep on 3 inch edge and in about 8 or ten inches.. The scrap part being removed looks like a wedge.

 Is this possible with a torch on the straight sides ? How about following a radius  on the ends , do you think it can be torch cut?

The ends have a radius, another company quoted over 50 k to do this job..

[Bailgang]

 Is this possible with a torch on the straight sides ?

Do you mean free hand? Well I guess if you were exceptionally good with a torch and had rock steady hands you could but it would be tough to do it on 1 pass. At work we use a track torch setup for long bevels or thick bevels in thick steel but the key to a smooth cut regardless if free hand or track torch is preheat, preheat, preheat, the thicker the bevel the more time needed to preheat. You probably already know that but I' just sayin. I cut bevels free hand all the time unfortunately I don't have steady hands so I don't bother trying to do it perfect on the first pass. What I usually do is take the bulk off with my first pass then grind to the finish with a 7" grinder mounted with a stone wheel. I should point out though that I don't free hand bevels any longer than 12"

[Bailgang]

I just got to thinking that doing it freehand would be risky if not impractical and a track torch setup can be pricey, an alternative might be to make up a DIY jig that would keep the torch at a set angle and distance yet allow straight lateral movement for you to cut the length of the bevel. As long as you can keep the torch moving at a consistent speed and the area well preheated I think it's doable, not necessarily easy but doable and you would probably have to make some test passes on some scrap material to make sure you have it set up right. I hope this helps.

[Retro Rocket]

This job came into the shop where my brother works..  Approx 8 x 30 ft piece of 3 inch plate, need a beveled edge.  Approx 1.5 deep on 3 inch edge and in about 8 or ten inches.. The scrap part being removed looks like a wedge.

 Is this possible with a torch on the straight sides ? How about following a radius  on the ends , do you think it can be torch cut?

The ends have a radius, another company quoted over 50 k to do this job..

There are specific machines to do this, a good friend of mine does this work every day making equipment for mining companies, i think its called a Plasma profile cutter, i'll give him a ring and find out for you...

[Retro Rocket]

Ok, just talked to Danny, He said that they do this all the time but with not as much depth, he said his machines , which are very good, can not cut anything with a torch {oxy profile cutter} more than 150-160mm {6inches}, he said that when they have to do a bevel as  big as the one you mentioned, they out source to a guy that has a huge mill, he puts the plate on the mill and does the bevel that way, very time consuming and very expensive. The torch doesn't have enough power, pressure to cut any deeper and struggles at 160mm. Danny also said that when they do the 150mm bevels at his work that the oxy or torch profile cutter leaves a very  rough surface and all bevels have to be hand finished which is very time consuming, he said that the 50K quoted was within reason for that type of job....
He does these bevels on drag line buckets and massive dozer blades and other large mining machinery.

[Don R]

Dang, 50K  maybe we could jig it up and cut it with a portaband! How about one of those wire feed cutters? Put a bridgeport on railroad tracks? What's the tolerance?

[754]

 He did use a trackcutter, it came out very nice..will try..to get pics....
.in case you read it wrong the. Piece is roughly. 30 feet x 8 feet with rounded ends..  By 3 inches thick  or more.
.They work on pretty big stuff, the can roll 3inch plate in that shop.
 If i get the pics  I will post them..pretty nice cutting.

[faux fiddy]

Heck of a job in my mind's eye, just to move the thing around.

Not sure what water jets can do,  or how big they make them or can roll a piece across.

[754]

I am trying to get the pics. I guess he had done this a few years ago.first tried it on a scrap piece, the cutting depth wasabout 8 inches. On the big piece he said it was more like 6 w 1/2..and cutting upward at about an 18 degree angle.
 Another thing he would do there was cut a hole into tank ends,for fittings. This use to involve at timeshoisting up a radial drill and boring/drilling the center hole, then air gouging, and sanding and grinding till the cows came home. He would do it in a single. Bevelled cone shaped circle....less than 1/4 the time..

[Retro Rocket]

Cool, see if you can get some pics Frank, my mate is very interested in having a look...