How do you cut metal for finished projects?

[Ted Summey]

Bikerdib, you are probably right on target with the OA torch tip. I got the torch set second hand. It was a complete set with several tips and torch attachments. I will check the tips tomorrow p.m. I am leaning toward the plasma cutter but I will give the OA torch another try. I have sufficient air with a dryer attachment that I have used to spray auto paint.

 

[Ted Summey]

The NC plasma cutter is a really cool tool! The first one I ever saw was in a shipyard where I worked in 1983. I've thought about the NC cutter as a retirement income tool.

 

[6011Artist]

woodsmith, they haven't nicknamed you "old school" have they? That's definately doing it the old school way.

Josh, I took a piece of angle iron and cut it 3" long and hammered it closed enough to cradle my torch handle. I then welded a piece of 1/4" rod into the bottom of the cradle, making a pivot point. I sharpened a point on one end while it was long, then cut it so that my torch is held up about 1/2" above the plate I am cutting. So if I want a 14" circle I measure 7" from center of my tip to center of the point on the cradle and then lock the cradle down onto the torch handle with water hose clamps. Use a center punch to make a guide hole in your material, fire up the torch and put the sharpened point in your punched guide hole and start cutting and pivoting until you get around your circle. If you don't want a blowout hole from getting started, drill a small hole to start your cutting in. There is no weaving from an unsteady hand.

So then you lay your cut out circles flat on the table and grind down the top and bottom only, getting all slag off. Drill a 1/4" (or whatever size you choose) hole in the middle of your circle in that guide hole you punched. After drilling both plates, remove your drill bit and slide it through the holes you just drilled in both (or 3-4, whatever you feel you can handle) of the plates. Clamp a pair of vise grips to each side of the plates straight onto the drill bit to use as a stop and to give you a good set of handles.

Take a big sidegrinder and clamp it in your vise. Hold the trigger down and lock into place letting it run without touching it. Now pick up your circles holding both pairs of vise grips and grind the edges on the running sidegrinder.If you hold them straight into the grinding wheel they will gain speed and turn as fast as the grinder. Twist them sideways, it makes the grinder cut better and gives you control of the speed of your circles.

By grinding them all together and letting them spin on the drill bit they will come out all exactly the same and will be perfect circles. If the hole in the center bothers you, weld it up and grind it smooth.

My buddy actually bet me 5.00 he could cut a perfect circle with a torch. I thought about it for a minute and reasoned it would be worth 5 bucks to know how to do that, I didn't doubt him, just wanted to know how to do it. It worked. So now I have done the same to several others and got my 5.00 back more than once.

To anyone that reads this, please drop 5.00 in the mail...lol.

 

[bikerdib]

6011 artist, I'm not going to send you the $5 because I've done something similar. The difference is that I made a turntable to rotate the plate which lets the torch remain stable. I rotate the plate instead of the torch. I've been thinking about adapting it to work with the plasma cutter but I really don't need to cut circular plates very often.

Ted, I'll bet that if you put a new tip in your torch you will be happy. Just remember not to go too big. You only need a tip big enough to cut the thickness you are working with. A bigger than needed tip just makes a sloppy cut.

 

[Redneck in training]

i cheat......this is the plasma unit i use. Its set up in my shop, and cant live without itView attachment 308216View attachment 308215View attachment 308214

grsthegreat

Nice set up. Did you build it by yourself or did you buy it ready made. I am considering to build a CNC plasma DIY but can't decide what where to get the parts.
There are several vendors that advertise on CNC sites but it is hard to find who is reputable and who isn't.
Advice would be appreciated.
Thanks,
Ladia.

 

[davedj1]

Don't buy a plasma cutter with built in compressor unless all you want to cut is sheet metal. I bought one thinking it would be good for 1/4" stuff, wrong! Took it right back and bought a Hypertherm Powermax 30. Now I want a bigger one. If I could only have one tool in the shop besides the welder it would be the plasma cutter. I have grinders, cut off saw, horizontal band saw and sawsall and the plasma, it's the go to tool unless I'm cutting tube or pipe.
Like stated earlier, don't forget you will need a large compressor. It's like anything, one thing always leads to another!
I don't know how I got along without the bandsaw, the thing is handy. It was used, an el-cheapo that was given to me. I put a good blade on it and have cut tons on it.
I know this thread is about how to cut but another tool I find very valuable is my homemade press brake, very handy being able to make brackets and stuff. Just the other day I bent some 3/8" x 6" for a slip on 4 way wedge.

 

[Eagleview]

My struggle is that I see the fabrication that some of you guys do and I can't seem to get parts cut consistently. For just cutoff of tubing, pipe, bar stock and angle I get consistent parts but things like gussets and flat parts it is a real bear. My parts seem to require endless grinding to get two parts to match dont mention the time involved in getting a third part to match.

It is sounding like the bandsaw maybe the better choice but I am open. My daughter, the artist, wants the plasma cutter.

Cutting sheet metal I am okay with and do okay with sheet metal fabrication. It is the heavier gauge and plate that is my greatest challenge. I don't plan on fabricating more than typical farm implements. I'm thinking about a grapple.

I appreciate your responses.

A grapple can be made using flat bar stock but will only be mild steel .

Gussets are only a matter of turning the clamp on your cut off saw or horizontal bandsaw 45* and cutting the steel on it's flat . Turn the clamp back to zero and then cut straight across . Use the stop and you will have perfect , matching gussets . It is a little slow doing this but you only need a few and it's not worth spending money on gear you may never use again ,

Use 350 grade or better for tine tips and maybe add some hard facing with an arc welder to the tips .

 

[grsthegreat]

grsthegreat

Nice set up. Did you build it by yourself or did you buy it ready made. I am considering to build a CNC plasma DIY but can't decide what where to get the parts.
There are several vendors that advertise on CNC sites but it is hard to find who is reputable and who isn't.
Advice would be appreciated.
Thanks,
Ladia.

i purchased mine complete from Dynatorch quite awhile ago...like back in 2006.

 

[Ted Summey]

Thanks for all the replies. I expect I will start with a new set of tips for the OA torch first. The current tip is giving me a real crappy cut. I will also try some different wheels for the grinder.

I may add the plasma for Fathers' Day :thumbsup: it sounds like nearly everything I would do with the band saw I can do with the plasma cutter.

 

[BukitCase]

Ted, next time you're at your local welding supply (or maybe Homeless Despot) - look for one of these

https://www.forneyind.com/store/det...rs_cylinder/7403/tip_cleaner_standard_length/

There's a size for each orifice in a cutting tip - I have a feeling this is at least PART of your problem... Steve

 

[joshuabardwell]

I may add the plasma for Fathers' Day :thumbsup: it sounds like nearly everything I would do with the band saw I can do with the plasma cutter.

You should totally get the plasma if you want it, but I don't agree with this conclusion. Plasma can cut bar stock about as good as a bandsaw, but plasma isn't great for tube or angle, because of the difficulty getting a square and even cut. You basically have to work your way around the perimeter, which introduces a lot of potential for inaccuracies. A bandsaw excels at accurate, repeatable cuts in bar, tube, and angle stock.

 

[Ted Summey]

I have a 14" abrasive cutoff saw for bar, pipe, angle etc. seems like with that AND the plasma cutter a bandsaw would be redundant.

 

[joshuabardwell]

I have a 14" abrasive cutoff saw for bar, pipe, angle etc. seems like with that AND the plasma cutter a bandsaw would be redundant.

I think you're almost right. The bandsaw makes cleaner cuts, is quieter, and is more precise. It doesn't make sparks or cutting dust either. And the metal coming off it is cool to the touch. Also, I am pretty sure bandsaw blades are a better value than abrasive wheels, in terms of number of cuts.

 

[Ted Summey]

Joshua, you are probably right on the value as far as number of cuts of the bandsaw over abrasive cutoff. I just have the cutoff saw. The cost of a stationary bandsaw AND a plasma cutter would b prohibitive. Plus space is becoming an issue. I have some other equipment in my shop besides the metal wokng tools. So whichever way I go, I have to choose one machine - bandsaw or plasma cutter.

 

[yomax4]

I like all of the above. band saw is much needed, Torch can never be totally replaced. I like the cold cut carbide teeth chop saws better than the abrasive type. Cutting circles, Bevels, Gouging etc. on Aluminum, Stainless, Rust Grease paint it's nice to have a Plasma. I'm lucky enough to have all of these and I use them all extensively. Get as many toys as possible. You will use them all.

 

[bikerdib]

I like all of the above. band saw is much needed, Torch can never be totally replaced. I like the cold cut carbide teeth chop saws better than the abrasive type. Cutting circles, Bevels, Gouging etc. on Aluminum, Stainless, Rust Grease paint it's nice to have a Plasma. I'm lucky enough to have all of these and I use them all extensively. Get as many toys as possible. You will use them all.

Wise talk that. Like I said previously, I have a plasma cutter, O/A torch with various cutting and welding tips, portable band saw, horizontal band saw, reciprocating saw, 14 inch abrasive chop saw, 8" hand grinder with cut off wheels, 4.5 inch grinder with cut off wheels, 4" air grinder with cut off wheels, 3" air driven cut off tool, air driven reciprocating saw and even a hacksaw. I use each and everyone, they all have a use and place.

 

[petes]

I used arm power and a hack saw up until just a few years ago when I built my boxblade. That wore me out, so bought a used 14" abrasive chop saw at the tail end of the build. It's great except, as stated, the mess, noise, smoke and black boogers after using it. I've also started a few fires with the sparks...

I was fortunate and got a fixer Hypertherm Powermax 800 for cheap (easy fix). I consider it paid for itself on the first project - removing a poorly built and welded on trailer hitch from a motorhome and fabricating a new one. Ability to gouge out welds precisely in tight spots is fantastic, although gouging overhead in tight spots results lots of holes in clothes and skin. I mostly use it to cut plate. Circles are easy - I make a template from 1/8" doorskin 1/4" larger or smaller), clamp in on and cut. It hardly chars the wood, and parts can be handled as they drop. I'd have a hard time justifying buying a new one, but keep using it for things that nothing else would have worked - like cutting curves and circles in 1/8 and 1/4" stainless. I hope to build a CNC table for it some day.

My next acquisition was a BIG (something like 8x12) old horizontal bandsaw (only $75!). I'm starting to use it more and really like the straight clean cuts through tube and angle. I only use the abrasive chop now for thin tube and small angle (<1/4").

A cutoff wheel on the 4-1/2" grinder is handy, too, usually for cutting through a weld or lopping something small off.

I don't have a torch - There have been a few times when I wished I did, but haven't been able to justify it.

I like to tinker and build things - tractor attachments, repairs, etc. and also building some chocolate making machinery (hence the stainless). Most is 1/4" or thinnner, but since I got a bigger tractor I'm going to have to step up to thicker more often.

In order (my opinion)
Hacksaw
Horizontal bandsaw if doing bar angle and tubing >1/8" thick
Plasma if doing plate <3/8" and curves. As stated already, also need lots of air.
Oxy/Ace torch if doing >1/2" plate but need to have a 9" grinder.
Abrasive saw is handy, quick and accurate, but I hate it most of the time. With a proper fume hood/spark catcher it'd probably be #2 on the list.

I still use my trusty hacksaw a good part of the time.