Help me cut a piece of sheet metal

[sherwin]

I am trying to make a simple side panel for my TC Bros battery box, I cut one side off so I can slide the battery out the side rather than out the top. I have an 18x6 piece of 16 gauge steel that I need to cut down to size. I tried using a hack saw as well as a dremel cut off wheel, the cuts were too sloppy looking for my taste. So I bought a cheap Harbor Freight chop off saw, works pretty well but the cuts have a slight bow to them. Is there a way to correct this, is it due to pushing the blade down too fast, or should I buy a better quality blade than the one that came with the saw. I know it may seem like a dumb question and it would be easier to just have somebody do it but I prefer to do it myself. I suppose the chop off saw really isn't the ideal tool for the job but it beats the other choices I had as far as doing it myself goes. Any advise is appreciated.

Thanks,
Sherwin

 

[tonyc]

I use a die grinder with a 3-inch cut off wheel and angle iron as a guide. It works great.

 

[angus67]

go back to harbor freight, get a 90 degree angle grinder(about 20$), and some cutoff wheels for metal. also get grinding pads that fit the grinder. make straight lines with a straight edge, and use the cutof wheel and take your time. there will be lots of sparks.
Use the grinding pads to smooth out your cuts.

 

[jd750ace]

A good chop saw blade (not a composite disc) that cuts steel nice and straight will run you about 85 bucks or more. If it's not cutting it into little blue chips and running virtually spark free, it's not doing it right. As far as the discs go, the thinner ones are hard to get a straight cut started with because the disc reacts to the contact by producing a wave, and a longer cut sees the wave proression cut into the metal. Usually makes it want to bind up a bit too. We use Milwaukee steel cutting blades to cut structural steel for our tooling, and we have aluminum specific blades to cut large extrusions and to chop the wing plank sections too.

 

[AceofSpades]

4 1/2inch angle grinder with metal cut-off wheels, a light touch and a steady hand.. pick up a 36 grit flap-wheel that also fits the angle grinder. Save the heavy stones for grinding heavy frame work, and then only to rough cut... then switch to the flap-disc to clean up the welds. Another good tool is the electric or air shears... great for sheetmetal cuts.

 

[hard_y_rd]

A good chop saw blade (not a composite disc) that cuts steel nice and straight will run you about 85 bucks or more. If it's not cutting it into little blue chips and running virtually spark free, it's not doing it right. As far as the discs go, the thinner ones are hard to get a straight cut started with because the disc reacts to the contact by producing a wave, and a longer cut sees the wave proression cut into the metal. Usually makes it want to bind up a bit too. We use Milwaukee steel cutting blades to cut structural steel for our tooling, and we have aluminum specific blades to cut large extrusions and to chop the wing plank sections too.

I used a good jigsaw with a steel cutting blade. I cut a seat pan out of 1/8. The metal you're cutting is a little thinner. Try clamping it to a piece of wood to control the vibrations.

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[5twins]

I rough cut using abrasive blades either in my 7 1/4" circular saw, my chop saw, cut-off wheels on a 4 1/2" grinder, 3" ones on a die grinder. One tip for you - cut your part slightly larger, like 1/8" all around, then final finish (grind, sand, file) to size. I used to do a lot of filing for the final finish to remove all the grind marks but not any more. Now I use the 2" Roloc discs in medium and coarse grits. They smooth out steel and remove all the grinder scratches in no time. They also make short work of the burned blue discoloration.

 

[essexboydave]

The golden rule of cutting with any kind of saw blade is that the pitch (distance from one tooth to the next) should be sufficiently fine as to ensure that at least two teeth are in contact with the job at any one time. I don't know what pitch you are using but if it's too course that could be part of your problem.
To get a neat finish I tend to cut the metal slightly bigger than I need and finish it the old fashioned way with a file and I normally finish with a technique called "drawfiling" where you use the file sideways, if you're not familiar with this have a search on youtube or similar to see if there are any tutorials-it's alot easier to see how it works than explain it in words

 

[scabber]

I used a good jigsaw with a steel cutting blade. I cut a seat pan out of 1/8. The metal you're cutting is a little thinner. Try clamping it to a piece of wood to control the vibrations.

Posted via Mobile

+ 1 on the Jig saw. One good saw blade will outlast 5 of those cut off wheels.

 

[jd750ace]

The golden rule of cutting with any kind of saw blade is that the pitch (distance from one tooth to the next) should be sufficiently fine as to ensure that at least two teeth are in contact with the job at any one time. I don't know what pitch you are using but if it's too course that could be part of your problem.
To get a neat finish I tend to cut the metal slightly bigger than I need and finish it the old fashioned way with a file and I normally finish with a technique called "drawfiling" where you use the file sideways, if you're not familiar with this have a search on youtube or similar to see if there are any tutorials-it's alot easier to see how it works than explain it in words

It's easier to "see" draw filing done than explain it, for sure, then the newb has to practice it for a while to get the hang of obtaining the desired results. The right file in the right hands can produce a near mirror finish on a part's edge.

 

[sherwin]

Thanks everyone for the advice, I appreciate it. When I get home in the morning I will take a stab at it. Plan is to use the chop off saw, cut it a bit bigger than needed and file/grind down to size, as one suggested. With this plan I won't have to buy anymore items than what I already have.

Some background, I originally went with the TC brothers battery box and electronics tank, but decided on an ebomb electronics tank instead. With the ebomb installed I can't take the battery in/out of the box, but I like the look of the two together. so went with this idea.

I'll post pictures when the little project is complete.

Thanks again.

 

[peanut]

don't you guys use a nibbler ?

you can cut any angle /curve perfectly without any distortion .

 

[AceofSpades]

don't you guys use a nibbler ?

you can cut any angle /curve perfectly without any distortion .

I was actually going to suggest a nibbler. But those can be a bit pricey. I haven't bought one in quite some time, but I need to pick up a new one... unless Santa is reading this.....

 

[weekendrider]

The same type of wheel used in a chop can be had for a circular saw.
Giving a bit more freedom or room to cut.

 

[plane_ben]

For flat sheet metal, an upright band saw is the best tool possible. But for people with out access, a jig saw and metal blade works OK. My favorite is my 4 1/2" angle grinder with a cutoff blade. I also use the pneumatic angle grinder with 3 1/2" cutoff wheels, then use grinding pads for smoothing edges and rounding off corners.

I've used my table saw with a carbide blade to saw aluminum down to 1/4" thick. Cuts like a hot knife through butter. Don't know if I would try it on metal in 14 guage though.

 

[peanut]

I was actually going to suggest a nibbler. But those can be a bit pricey. I haven't bought one in quite some time, but I need to pick up a new one... unless Santa is reading this.....

I thought $19 was quite cheap really ?

They cut intricate shapes so precisely and leave a nice clean burr free edge too I wouldn't use anything else now for body panels and sheet metalwork.

 

[sherwin]

I thought about a nibbler but was under the impression it wouldn't cut through 16 gauge. By the way the sheet of metal I am using says 16 gauge wld stl, is this different from 16 gauge sheet metal or the same thing.

I did cut a piece down this morning, used the cop off blade then fine tunned the edges with the 4.5 inch angle grinder, didn't have a grinding wheel so used a flap wheel. Wish I had used a grinding wheel as the flap wheel dosn't leave things perfectly straight. Will pick up a grinding wheel in the morning and have at it again. Anyway I don't mind doing it over as the metal is pretty cheap and I love adding a new tool or accessory here and there.

This battery box thing is really the only project I can afford to do on the bike at this point so, as dumb as it may sound, it's fine with me to stretch this little project out. I'll just keep doing it over until I get it exactly perfect. Besides it's a good way to learn how to use the different tools without screwing up an expensive project. I'm a neonatal intensive care nurse so it's a nice break to work with something completely different and find I want to learn more about metal working and welding. Did some reading in another thread and sounds like the Hobart Handler that runs on 115 volt is a nice unit for the beginner. This of course would take away money for the bike. But may be a good investment, also want the kids to learn welding and metal work and such.

Enough rambling, thanks again for the advice and comments.

 

[angus67]

get the welder. you wont regret it. it can handle anything you need for our650's.
endless possibilities elswere.
Exhaust on cars/bikes/trucks, framework on tractors/implaments of distruction, artsy-fartsy stuff, on and on.