Introduction: Sawmill From 12" Bandsaw and a Mower
This will be my first Instructable, seems I never take a picture until the project is done ;-(
PLEASE comment and ask questions of you have them!!!
I have a camp property 29 miles from the edge of civilization, and therefore need to use my resources instead of driving back and forth trying to get just about anything. You plan ahead before going. Not enough beer? 58 miles. No propane? 58 miles...you get the idea. It gets worse when you have to hook up the trailer or take the big truck because you need more lumber to make some small project or build a barn. So, having access to plenty of logs, I need to make my own lumber. I have seen a zillion ways to make a band saw mill, but why not use something that has almost everything I need instead of building from scratch? The saw I am going to hack is a Craftsman 12" band saw. That means the wheels holding the belt are 12". It already has all of the rollers, alignment adjustments, pulleys, etc. we'll need. I'll also be tweaking them a little for strength and longevity. I will be converting to a gas engine, so we'll remove the electrical equipment and save for another project.
The truth? I'm cheap. Well, maybe frugal. Wife says nuts (and brilliant depending on when you ask her). Still need a mill though. My best friends? Junk shops, junkyards, yard sales. The whole premise of our property is to do almost everything ourselves; learning about and understanding every phase of a project and the equipment, for as little money as possible to create a nice working farm. We are proof that you can do it while still staying out of debt. I found an almost free double wide home that needed work for a temporary camp while I build my barn and living quarters at one end of it, a backhoe and grade tractor, as well as a dump truck all for very little money. I could purchase a new mill for a few thousand, use someone else's design for a couple thousand, or design and build my own for a few hundred bucks. So:
Lets see: a workshop band saw is already.....a band saw, so???
I'll have to make a rail system
An adjustable carriage to hold the saw; able to raise and lower to cut different size boards.
Somehow attach the gasoline engine to run it.
A handle system for control and safety.
Step 1: Gather a Bunch of Stuff
I purchased a used 12" band saw from a yard sale for $100.00...but remember, we aren't using the electrical so if it doesn't work you can find cheaper ones... just make sure the wheels and stuff are good, otherwise you'll spend money fixing before you ever use it!
I found 2 used end braces for commercial shelving 16' for free (if it's free it's for me) Scavenging skills are definitely handy!
I have a 13hp Honda 2 cylinder water cooled engine from a lawn mower I will tear apart...it's a 2 cylinder, electric start, and amazingly quiet. The mower is going to supply a bunch of parts, an engagement system for the band, throttle and electrical controls, a ready made engine cowl (way cool for a saw!) and maybe even a drive system for the carriage. I bought it for 50 bucks because it needed a starter that from Honda is EXPENSIVE! (I found a used one on e-bay for 40 bucks)
About a bazillion feet of good stout angle iron, and some lighter duty for bracing, etc.
Box tubing for saw cradle
4 jacks to raise and lower the saw
Various pulleys, nuts, bolts, etc. which I will describe as I go; remember your build will be unique so be ready to "junkyard dog it" a little
A good friend with talents and a strong back ;-) (Mine was my buddy Scotty and I can't thank him enough for his help).
Step 2: Tools and Equipment
I'm not going to list all of the tools I use, this thing would be 40 pages! You can never have enough tools, but here's a start
Hand tools...ALL OF THEM! Oh, and you're probably going to borrow a few also.
Welder. I use my MIller 200 wire feed, but a good stick welder is fine.
Various grinders, cutting tools, etc.
Good straight edges, levels, squares
Full first aid kit
Gloves, safety glasses etc so you don't have to use said first aid kit...safety first (or second if you like trips to the E.R. band aids, loss of sight, etc.)
Step 3: Overview of Build
Here I go. A wood working band saw is a vertical saw and although I could move the log to make it work, I need to turn it on its side.
I'll get rid of all of the table and stand stuff.
The actual working space is only about 7", so I'll have to widen that to fit a fairly good sized log, say 16-18", the depth of cut is fine at 12" so I could in theory cut a 12X12. Here in Florida I don't get logs or poles larger than that, so why go bigger.
Once lengthened, I'll go to a larger blade designed for lumber cutting, not finish work.
I'm going to have to figure out how to mount the gas engine. The reason I cannot use the electric motor is twofold. One, I am off the grid and why run a gas engine on a generator to power it. Two, my blade is much "badder" than the finer one, the teeth will be almost an inch apart and huge! the original 3/4 horsepower motor would just give up.
I have to build a solid rail system.
Build a log mount/roll set up for leveling, holding steady, as well as assisting in turning the log.
Build a cradle for the saw which will roll on the rails and be designed to raise and lower the saw.
Mount it on something or add an axle so we can move it around if I so decide.
Step 4: Scrounging Tips and Build Tricks
1. Your local lawn mower shop is a great place to look for small engines. Although you can buy Chinese clones from places like Harbor Freight, once you get above 6-7 hp they get expensive. Many riding mowers are scrapped because the deck rots, but still have a perfect 10-20 hp engine. They are electric start, and can be bought for next to nothing. Even if they are horizontal shaft instead of vertical, you can make one work. Most shops have a lot more than they can stand; be nice, smile, wear your oldest clothes and look needy! While you're there, ask if you can look through their old mowers, you may see a pulley, lever, or who knows what. Remember to write down makes, model numbers and any other information you can from your donors though; it will help down the road if you need a replacement part!!!!!
2. Yard sales, local Craigslist ads, even Facebook pages have great deals. You won't think your wasting your time when you find the deal of the week!
3. When trying to keep a box tubing rail straight when extending, cut only opposite corners first, then clamp angle iron and weld to each of those corners on one side only! Then, wiggle your blade through the slot and finish cutting the other sides. This acts like a jig when you cut through. When you finish weld, remember warpage. Weld opposite corners a little at a time to reduce it.
4. A great source of 1" angle iron is old bed frames. The old ones were made of angle iron. Newer ones are just stamped tin.
5. Remember everywhere you look during your build you may see a solution for a problem you've been fighting. While writing this, I came up with the wheel idea for the rail system.
6. I've seen a bunch of Instructables and youtube videos that are filmed after the build, and they have had to cut, modify, re-design to finish. Mock up, tack, lay it all out BEFORE you weld it all up. Think ahead, it will save you headaches later.
7. I am cutting lumber here. If you find pieces of junk laying around that will work, remember they may wear out, break or destroy something else. I want all of this to be easily and rapidly repairable. All of the parts I acquire are readily available and easy to repair. Don't get some old junk, work your butt off building it, abuse it and then have to redesign the whole contraption later to fix it. If you start with a shoddy set-up, you can't expect it to live!
Step 5: The Saw and Mower Hack
My first step is to hack up a perfectly good saw, which in my opinion is much better than jumping from a perfectly good airplane for fun or getting slapped in the face with a dead fish.
I'll remove the electric motor, blade and the wiring as we are going gas.
I'll then remove the table.
I'll leave it on the base because it is heavy, and to make it easier to plan cut for extension parts.
As you can see, using an existing saw comes with many advantages. The wheels are perfectly sized and carry sealed bearings, it has the alignment adjusters already designed and even has a blade tension adjuster with a gauge. Plus, it has an adjustable blade guide, so when cutting smaller boards you can close up the blade exposed length making your cut more accurate.
When you plan this part, plan your overall cutting area, as well as how your guide will move, how much "meat" you have to attach your extension to, and then sit and rethink it all 10 times before you chop it up!!! As you can see from the picture, I didn't use my own tip #3 from the previous page. That was because I have a metal cutting band saw. I cut it after making sure the tube was straight and chopped away! This particular saw has a box tube as its "backbone". The size of the tubing is an odd one, not available so I just used a slightly smaller piece I had and then added angle iron on the outside for added strength.
Because I used an existing saw with a spec tag on it, once I extended it 12" it was easy to go on line and order blades. I just added the 12" we extended (times 2) and ordered blades from Spectrum Supply:
Length - Feet: 9 - Inch: 5- 1/2"Width x Thickness x TPI: 1" x 0.035 x 1.3T
These blades are reasonably priced (about 15 bucks each) and can be made in any length you need, and with a variety of configurations.
I also have to cut up a mower; be sure to have a drink and think this over for a while first, you don't want to cut it up wrong and then try to figure out how to fix your screw up. As yours will probably be different, I won't go into a lot of detail on the mower. You will see in the next steps how I cut and used a lot of it.
Step 6: The Rail System
My rail setup will consist of a 16' section of shelving support. These are the type the large box stores use. The ends are reinforced, and very strong. They are also already square, so no worry about tracking to start. I'm primarily going to be cutting wall studs, 2x4's, 2x6's, 2x8's, some 4x4's for fencing, and just maybe 6x6's for barn posts.. All of them will usually be less than 12'. My one section will allow a cut that long, but I want the ability to cut to 16' so I'll make an attachable extension for longer boards.
As I made no modifications, I failed to take a good picture of the actual rail. It is; as you will see a standard end for commercial shelving. The reason I chose it was because it was free and luck had it that it had a channel that was facing out, thus allowing me to place a wheel on top and a guide wheel in the slot for straighter tracking.
Well, sometimes even the best plans change. A local boat dealer was modifying their building and I scored I-beams that will be much stronger and also longer. So, hundreds of dollars worth of I-beam that was going to the scrap yard is just better. Because the logs I will be cutting are so heavy, I was planning on reinforcing my rails, but now I can use these I-beams and not have to. Also, they are longer, so I won't have to make extensions.
Step 7: The Cradle
Here is where you have to play around with your design a little. Or a lot. Many beers were found empty before the final ideas started to gel. Here we go:
Your cradle is going to carry everything, the engine, fuel and water tanks, battery and of course the actual saw. That adds up to a bunch of weight. I have seen a bunch of home built saws using two lifts, or a cable and pulleys, but remember the weight you have to move? Well four is better than two. I chose to use trailer jacks, with a 17" lift, so if the saw weighs 300 pounds each jack is only lifting 75...less wear and much easier to turn the handle. I purchased these new for about 70 bucks each, because I wanted them identical so that they moved the same amount with each revolution of the handle. Plus as they are going to be welded on I didn't want used ones that would wear out too soon. These are from Tractor Supply, and have a 17" vertical travel. I am going to have one handle control all four jacks, attached together with chains. This way all will move at the same rate and maintain level. For wheels to ride on the cradle, I searched for strong wheels that could take a beating, but most of the wheels I saw with brackets and bearings were ridiculously priced for the job. Here is where a little shopping is important. I found solid hard wheels at my local lawnmower shop for 8 bucks a piece; just deck wheels for a riding mower! I then chucked them up in my lathe and cut a flat surface to true them so they glide on the rail smoothly just in case they weren't perfectly round. I then took a piece of 3" angle iron and welded two nuts on it, then slid the bolt through the wheel and ta da! Not only did that work for the vertical wheel, but it also worked for the guide wheel and pad for the jacks! Be sure to keep the shaft greased and no problem! Another beer! The guide wheels are just inexpensive 4" wheels with brackets from Tractor supply, remember they carry no weight so they don't have to be crazy expensive ones.
The actual cradle has to be strong, but also reasonably narrow so as not to use up too much of the rail. I decided to mock the saw on blocks on top of the rail and see where it sat. As you can see in the picture, the cradle in its first mock up is on the rails, with one set of jacks in place. We also installed a temporary brace at the front of 2x2 box just to keep square.
Step 8: Fitting Everything on the Cradle
OK, I have a cradle that rolls, a saw laid on its side...now I have to mate them and start to figure travel height, fitment of everything...I started with milk cartons and boards to get the saw level, then I tacked the engine in place to plan drive belt and jack clearances.
******* You must make sure your saw is level at all times during your build BOTH WAYS (side to side and fore and aft), or you will have to adjust it later somehow. If it is not, your blade will either climb out on your cut (up) or down, thus you will never have a true board. Easier now than trying out how to change it later. Yes, you can level with the jacks, but then down or all the way up they will not match, so travel length will be affected.
I used thick wall pipe to attach front and rear jacks making sure there was room for chain and gear clearance.
Now that the jacks are in place, I need to attach the chain drive between them to raise and lower the assembly. I'm doing my best to over build the entire machine for longevity...so I purchased #40 chain at Tractor Supply and gears, gear hubs all too heavy duty, but should last a long time. I purchased the chain in bulk, two 10' rolls, and bought a chain breaker also to make it easier to size them. I used master links to connect the ends once cut to length for each section.I removed the handles from the jacks, which is where the hubs will fit. I slid the gear on for the drive jack, and on the other three slid two on spaced for chains to clear. I then welded the gears to the hubs and slid on the jacks. They are held on by set screws. After they were all in place, I welded the handle assembly on top of the drive jack. After the first turn, I realized the crank was either too short or just too hard, so I cut the mower steering shaft, and removed the handle, replacing it with the steering wheel. What a difference and once again used another part from the mower! I also used the old bag attachment bracket from the mower for our push handle.
Note!!!!!It is easier to make the chains up prior to mounting jacks, as if you are 1/4" off the chain can be too loose or so tight you cannot turn the handle. OOOps! Thankfully, I was able to cut the tacks and adjust the jack a little to tighten chain. Because there is very little stress on the chains, stretch should not be a problem, if so I can adjust by taking out a half link is needed.
Notice one picture with dash, one with tank...mocking it over and over...or is it mocking me?
I still have controls and more to add... The engine sits with the exhaust facing rearward, in the middle of the saw, so I will put the fuel tank as far outboard as I can. I will put the battery next to that, with the control panel in the middle area so I can use the existing wiring harnesses and control cables for throttle and clutch. I am even going to use the mower cowl for sound deadening and it will look cool too. I made a mount for the fuel tank from scrap bed frame angle iron and used the mower battery tray by just adding a scrap of box tube to weld it to saw frame. For both comfort for the operator and safety, I added a 3/4" piece of conduit for an exhaust extension, diverting down and away from the control area.
Step 9: Engine Controls, Pulleys Turning
My mock up allows me to adjust distances, etc. so I can hopefully use the original engine and clutch controls. The clutch and throttle are controlled by a cable, so I really don't want to search for aftermarket ones. I moved the engine cradle close enough that I can use both factory cables, once again making replacement easy. Because the engine is facing the opposite way from its original configuration with the controls, I did have to extend the wiring harness. Don't be afraid if you have to do this. There were 7 wires, all color coded, so after I removed the electrical tape, I cut them and just spliced in a couple feet so everything would reach. You can do this one wire at a time if you are afraid you'll get the connections wrong. Because this was a riding mower, if you were not seated, the blades would not engage. So, I easily converted the electrical seat switch to a kill switch. I used a boat kill switch connected to a tether so you can attach to yourself. In the event you trip, or need to walk around the saw, if you go too far away from the controls or close to the blade the entire saw will shut off. SAFETY FIRST!!!
OK, so I'm going to have to make a system of belts, pulleys and bearings to convert engine motion to move the blade. I removed the original pulley from the electric motor. I then took measurements from the motor to figure out depth through the hole in saw housing.
I wanted this part to be strong so I opted for 3/4" pillow blocks. I machined the end of the bar stock down to fit the original drive pulley off the motor. We then tacked a piece of angle iron to the housing once we had the approximate alignment of the belt inside.Once we had that in place, I purchased a pulley that would allow my blade to move at the right speed with plenty of throttle adjustment. I want my blade to run at about 4000 feet per minute (yup, 45 mph!) As the electric motor ran 1740 rpm and my mower engine can run 3600, I reduced my rpm to around 2000 and went with a pulley that will turn the pulley inside at 1740 easily which is 3000 fpm and I can adjust throttle up to find my sweet spot for different wood densities. Mower engines are throttle adjustable governed, so whatever rpm I choose the governor can keep it there unless load becomes to much to compensate for. The old belt from the mower was cut to length so I could go to the mower shop and buy the perfect length belt. A simple tensioner from the mower deck set the tension.
As you can see, I tried different placement for controls and failed at first...mock up is invaluable!
Step 10: Bringing It All Together
This could go on for ten more steps, but your design will be different so I'll jump forward some.
It's amazing that I could use so much of the mower and the saw, and although it looks complicated, it actually keeps it quite simple. The mower supplied the tank for the coolant/ lubricant, the controls and electrical, the engine, and cowl. The saw had all of the bits I would have to otherwise engineer from scratch and both are well known brands with replacement parts readily available from the manufacturers. This means almost everything on this saw can be bought simply as replacements, instead of having to make a new whatever it is if something fails.
I added a small air compressor I had from a set of air horns to blow off the sawdust and with that included the coolant connected with a "Y" so air forces coolant, under pressure to cool and clean blade at the same time sort of like a mini pressure washer. The coolant flow is adjusted with a simple valve in the line from the tank.
I set up a temporary log cradle under the saw, and threw a 10" power pole 6' long on it.
My first test cut tried to climb out of the log, which was caused by interference when I aligned the blade. I found out how sensitive the blades are to metal parts...in ten seconds the kerf was gone. Thankfully I bought more than one blade, so lesson learned. Ya need some clearance, Clarence! The interference took the kerf out of my blade in less than ten seconds. After changing the blade and re-adjusting the tracking, I had success, my first cut perfect flat, and my second EVER 9/64" thick (that's thinner than the diameter of a pencil) 6' long. Less than a quarter inch thick from a bandsaw and a mower. The accuracy is amazing, performance flawless...and for less than a good sized TV costs!
My final rail system will be in another instructable.
My total cost is less than $750.00, not bad for a strong, easily repaired sawmill.
Please note; I could not have done this without the help of a great friend Scotty, whose help mocking up as well as heavy lifting made the project fun.
Hope you liked my first instructable! Please be kind, and vote for me! I don't know if I am able to fix typos, or anything else after I post...I'll let you know in the comments!