Woodworking Bandsaw to cut steel
dfletcher
| Posted in Power Tools and Machinery on
Hi,
I own a Delta 28-682 18″ steel frame band saw that I am interested in using to cut some steel for a non-woodworking project I have.
My knowledge of cutting steel on a band saw is limited, but do know the following:
- My band saw has 2 speeds: 2300 RPM and 3250 RPM.
- To achieve these two speeds, the pulleys on the motor shaft are 2″ and 3″, the pulleys on the bandsaw wheel are 8″ and 9″; 2″ + 9″ = 2300 RPM, 3″ + 8″ = 3250.
- I know that in order to cut mild steel, the speed of the saw needs to be down around 250 RPM or slower.
- Based on what I know, in order to slow my saw down, I need to have a 16.4 to 1 ratio of the pulley sizes in order to get the saw to a slow enough speed to cut steel.
- Also, I would need a bimetal saw blade with 10 to 14 tpi.
Does anyone have any experience with something like this? Has anyone gone though the process of gearing down this particular saw, and if so, what did you do to achieve the slower speed?
Thanks
-David
Replies
Hi David,
You might want to research "friction cutting". I recall seeing a recent article in some wood mag I browsed through at a newsstand. I do not recall all of the details.
Steel cutting is usually done with a coolant, and if done dry will present a fire hazard if any saw dust or chips are nearby. It also creates a mess.
The subject has been discussed here in the past a few times and the general recommendation was against doing it with a machine that would be returned to woodworking use.
John White, Shop Manager, Fine Woodworking Magazine
David-
Don't know what your financial situation is but I would look into buying (or renting) a portable metal bandsaw. HD sells the Milwaukee, which I have used, for about $300. Pricey but a great tool. Grizzly sells one as well, for about $140 if I remember correctly. And Harbor Freight sells one for about $70.
Not sure what you are cutting, but a jigsaw works well for quick cuts-like cutting metal balusters and such. A grinder with an abrasive blade makes nice cuts too. (BTW what are you cutting?)
I would personally avoid messing around with cutting metal on the woodworking saw.
Maybe someday I'll know a little something.
http://www.grizzly.com/products/mach-specs.aspx?key=410000
Not enough info in your question. Do you need the bandsaw to cut curves? A gear box would be required to slow it down enough and you could buy a cheap metal cutting bandsaw for that price. Plus as pointed out once you cut metal it's messy to cut wood from the coolant oil. You don't need a bimetal blade. Metal was being cut long before bimetal blades. Bimetal blades last twice as long but cost twice as much as a regular blade.
Abrasive cut off wheels are old school. For straight cuts...$45...
http://www.coastaltool.com/cgi-bin/SoftCart.exe/a/accessories/saw/circular-saw-8.htm?L+coastest+xjpf5236ffed82ed+1172285087
I've cut 1/2" thick steel on a regular saw with that blade. Almost no sparks.
Hi All,
Thanks for the information. I really hadn't thought of the fire potential, but agree with you that there is this potential. Obviously, I would not have used my dust collector, but now also realize that I will then have a bunch of metal dust to clean up too that could contaminate my shop I use 99% of the time for woodworking. My thinking was that if I could slow the saw down, I would avoid having to use a coolant.
Regarding the other options of buying a metal cutting saw, I think that might be the way to go for me. It sounds like I can pick up something cheap enough, and because I'm not going production, speed is not an issue. But then again, I like the idea of using my existing jig saw - I probably should try that first.
My project is a wood splitter using 1/2" and 3/8" flat stock, angle iron, and square tubing. I'm planning to use an oxyacetylene torch to weld things together (outside on my driveway).
Thanks everyone for your help! You all have helped me...
-David
Cut it with the torch. Clean it up with a grinder. Fast and effective. Right tool. Right job.
Good luck,
I totally concur with your solution.
Just for the record, as a rule of thumb, for cutting mild steel and steels like O1 in the annealed state , the blade needs to move at a speed of around 50 to 80 feet per minute.
Contrary to what I have just read, I can assure you that coolant is not needed for that application at those speeds-only lubricant which extends blade life and makes a mess. Bi-metal blades are good for production purposes and the price is then justified, otherwise high carbon steel blades for cutting steels are cheap and cut well. The chippings produced under these conditions are not even warm, let alone hot, so no question of fire hazard. (that friction cutting method is sheer lunacy and is a short route to machine destruction, fire hazards and high blade consumption).
It seems to me that for what you wish to do the hassle of modifying a wood saw to cut metal is not justified- I would use more conventional means.
If you are dead set on modifying your saw I can show and discuss pictures of what I have successfully used to cut a heap of O1, D2, Brass,Bronze Etc for making knives and planes etc. The bandsaw is a Startrite (light British) and in no worse condition than it would have been had it only had a diet wood- and there has never been and will not be any danger of fire.I prefer to cut all these dry, with an air stream to blow the chips away from the kerf-that extends blade life.Philip Marcou
Here's another opinion, just for the record. I've modified my 14" Delta bandsaw to cut metal. I use it exclusively for this purpose. I got it down to just less than 300 ft. per min. Too fast really for steel, but it still works fine. I think I get slightly less blade life with it this fast. I use good bi-metal blades, they last at least three times longer than carbon steel. You have to break them in. The chips are warm, not hot. The chips stick into the tires. The chips get into the adjustment devices on the saw.... all these work stiffly now on my 14". The table has had the crap beat out of it. The cast iron is a lot softer than steel and a sheet of sharp edge steel is gonna scratch it. I wouldn't treat my nice wood saw like this. I slowed the thing down using two auxillary jack shafts, not a gearbox. My mod cost about $40. I wanted a metal bandsaw so doing this was/is worth it to me. And, I have two other bandsaws to use. It sounds to me like you're going to be cutting bar and angle stock. A hot saw, cuttoff type, will serve you well. Get one with a 14" blade. Milwaukee makes a blade that's 3/32" thick. It cuts far faster than the more common 1/8" blade. These saws do not cost much at all. If you plan on doing any amount of cutting of 3/8 to 1/2" steel, this will be money well spent. A horizontal bandsaw is nicer, I think. But they cost quite a bit more. I have a small 6" model that I bought used. Since getting it I hardly use my hot saw any more. I use my bosch jig saw to cut thin sheet steel, but it's a drudge with anything of thickness. Definitely use bi-metal blades on that. And protect the base plate. The steel will eat it's lunch.Or you can really go to town and get a plasma torch. Mine is rated at 3/8" but will still cut up to 5/8", although raggy. A plasma is great fun on thin stuff. You can write your name into sheet steel. I've done the friction cutting thing. Now that's some excitement! You can cut very fast doing this but I couldn't get the hang of it to be able to cut consistently. Every steel worker ought to try it once. But DO NOT do this with your good wood saw.
You might consider a metal cutting blade in a chop saw. The blade was like a thin grinding wheel. It's easier to clean-up, and you can take it to another area outside your shop. A few years back I rented one for something like $30 a day.
Be very cautious in using a metal cutting abrasive blade in a woodworker chop saw. The very fine grit produced will get into the working parts. This will gum up the swinging action for making miter cuts. It can be cleaned out but is a hassle and who knows what kind of wear has occurred. Saws meant for steel cutting generally have an adjustable stop with a screw-clamp. These simple devices are easy to keep clean.Another way to go may be using a carbide blade designed for cutting steel. I have a steel cutting "skill saw" made by Evolution that uses a carbide blade. It is a very smooth cutting and fast cutting machine. So perhaps these blades are now available for a regular chop saw. Be mindful about rpm ratings for the blade and machine.
Hi All,
Again, very educational for me - thank you!
Regarding the hot metal chips from cutting at 50 - 80 or even 300 RPM, I recall from metal shop in the 7th grade using a horizontal bandsaw and didn't use any coolant, but it's been so long since then that I was not really sure anymore.
Regarding "gearing" my saw down, I don't have the requirement at this point to go through the effort or expense in figuring that out. I was just asking and if someone had a cost effective solution, I would have used it, but...
As I mentioned, I plan to build a wood splitter using 1/2" steel. To do this, I will buy a torch and just learn to use it (there's a one day clinic available to me.) I already have a 25 gal air compressor, so picking up an inexpensive grinder should be all that I need. Regarding the Plasma - isn't that expensive?
Thanks again for all the great information. I don't know about anyone else, but it really helps me to think through these projects before getting started; I feel it just ensures a higher degree of success for me.
Regards,
-David
You are correct that the horizontal bandsaw doesn't give off any sparks and you can get a perfectly servicable one for $200. You will need the larger size tip to weld that thick steel with oxy-acetylene. It's going to take more than a day clinic to oearn that as well. You should look at some of the many welding and fabrication forums out there.
25 gallon compressor?? It's more useful to talk about hp and cfm for compressor. 25 gallon doesn't really do much in describing the capabilities of the machine. What does the compressor have to do with the project. You certainly can't run an air grinder off it. Get a 4-1/2" angle grinder with 5/8" -11 shaft. The most common size to use with most accessories.
Hi,
You're right in that it will take me more then a day to learn to weld, no problem for me. My expectation of the clinic is to provide me the knowledge to feel safe operating the torch as safety is a big component of the coarse. In the end, if my project looks like crap but functions, then I will be happy knowing that I was able to learn something new and have some fun in the process.
My compressor will provide 2.5 HP, 4.5 CFM or 6 CFM peak. It won't run an air grinder huh? Probably the CFM for that is more like 7 to 9 CFM? (Honestly I haven't looked at air grinders to see what they can and can't do.) I'm sure then an electrical one would be cheap enough?
One final question before I get going on this project (this spring). I don't have a shop or garage to do this project in and was thinking that I could build it out on the tar driveway at my house. Can you think of any issues with that? Aside from keeping the torch away from flammables, the house, dry grass, etc.? I will also be setting up a couple of saw horses with a steel top for the welding.
Thanks again!
-David
One thing you don't realize about welding is that it will distort from heat. For example if you weld a 90 degree angle by the time it cools it won't be 90 degrees and it especially problematic with a torch because it takes a long time the heat the metal for weld penetration. A MIG would do the job quicker would cost a lot more. You can't the hobby migs as they are rated for 1/4" and run about $500 to $700. I think you are in for more a learning curve than you expect. With the pressure from a hydraulic cylinder to split wood you will probably have pieces fall off your project. Far cheaper to buy one from the catalogs or find a used one in the spring.
You should get some fire bricks to support your work. You risk distrorting your steel top from the heat and it acts as a heat sink and draws heat from the steel you are welding. Often we put things together with welding or silver braze and have to bend it to where we really want it to be. Sometimes we need a hydraulic press. If you try to clamp it in position the heat will expand and distort it anyway.
You should be reading books on welding or going to the welding forums. Not a wood forum project. Learning to do metal is a good thing for a woodworker as you can make better jigs and hardware. I ended up becoming a Metalsmith and it was the best thing for my work.
Edited 2/26/2007 11:22 am ET by RickL
First a disclaimer: I'm not a welder..... I'm a furniture maker who welds. Welders are in a class by themselves and I don't pretend to know that much.It seems to me that you are going into this project with a load of desire, expectations, excitement, and with your eyes open. This is good. Do not be discouraged by anything you've been told here. Go to this clinic and continue to keep your eyes and ears open. Welding with oxy-acetylene is a wonderful experience but it can be fraught with danger. If the clinic instructor doesn't stress safety from the beginning, then find another clinic and instructor. You may learn that welding with gas isn't going to be applicable to this project and if you do, then that's OK. Simply shift gears and take an arc welding clinic. Working with real steel is fun, it's hard work, but fun! Work safe.To put things into some perspective, I learned to arc weld in an evening "class" at a local high school back when high schools had tech classes. The teacher was the usual school metal shop teacher, used to teaching kids. His instruction was about five minutes long, consisting of showing how to turn on the machine, how to strike an arc, and what to watch in the puddle. Then he said go for it. Out of a dozen guys there, I was the only one who returned to the second class. He always kept a watchful eye out for my safety, and his minimal instruction made me learn. After all, the process is like cutting dovetails, it's all about hand-eye coordination. Gas welding and cutting, is much the same although the learning curve is much steeper. It took a real class that met two nights a week for 10 weeks to teach me to gas weld. PS Gas welding is not like riding a bike. If you don't keep practicing, your body will forget how to do it.
Hi,
Thanks sapwood for the encouragement, that helps. I've just visited the school and found that the clinic on gas welding/cutting spans 4 nights for a total of 12 hours of instruction. I don't think I will ever proclaim to be a welder and I further hope I have not offended anyone implying that I will be a successful welder with only a couple of days time. I have tremendous respect for all those who have taken formal classes and have become proficient through experience. Again, my goal is to have fun and to learn something new in the process.
Yes, I agree that the questions I've posed probably should be on a welding forum or something like that, but my original intent of the post was to inquire about how to "gear down" my wood working bandsaw to allow me to cut steel. It seems like we have gone a little off topic. Regardless, the folks here have been very knowledgeable and have given me a lot to think about.
Regarding my choice of gas welding verse arc welding, from what I've read so far, it's purely based on function of the tool and what it will allow me to do. For the cost of a torch setup (~450), I will be able to weld, braze, and cut. With the Arc welder, I will need additional equipment for the cutting part, and then there is the 1/2" steel that an inexpensive arc welder won't be able to handle (based on depth penetration of the weld)? (I'm not looking to debate one verses the other - as sapwood pointed out, I just might learn from the class that my intended choice of tools is misguided).
Finally, RickL, thanks for your advice, and in the end I will probably come back and admit that you told me so. ;-) But here's an opportunity for me to try something different. If it falls apart, I can always "re-weld" it :-)
Regards,
-David
I'd still buy the $200 horizontal/vertical bandsaw no matter which method you use. Much better than an abrasive saw and you can do curves with it.
The MIG welder is preferred over a stick welder as just about anyone can stick stuff together with the least experience. Gas welding is the most versatile as you can weld, braze, cut AND bend. It's also the background you need to TIG weld.
David,
In my line of work I've been known as a cobbler, Jack of all trades and the best one is from me personally I think I'm a legend in my own mind (ha ha ) at any rate I've worked with metal as well as later in life I now work with wood. I've tried to cut metal with a woodcutting bandsaw and unless it's very light gauge it just isn't'nt worth the time and effort of putting a metal cutting blade on your saw. If your project needs to look professional take the pieces of steel to a fabricator and have the pieces that need to be cut,cut on a press or break. The job looks far more professional and its far easier to weld than if the metals been cut with a torch.
Good Luck,
Sincerely
Jim at Clark Customs
Fletch, do you have a drill press? If so, paint the steel blanks with wide felt marker ink. Cut and shape a paperboard template of the part you want to duplicate. Scribe the outline of the template onto the inked surface (To save unnesissary work,align any straight edges of your template to an existing straight edge on your blank.)
Centerpunch a series of equally spaced indentations and drill out all those holes with an 1/8' drill bit. If the 'web' remaining permits, enlarge the holes with the next larger size bit.
By rocking the drill bit on a few starter holes, you will provide room for a metal cutting saber sawblade (or, Sawzall) Soap or wax the blade and cut out all the webs A belt sander or, disc grinder will smooth out any rough edges. Steinmetz.
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