Jan 25, 2011
Author: Logan Imlach
Eeeeeeeyo, Logan Imlach here. This week I’m going to give a little insight into my experiences building a high speed winch for urban shredding. There are three things you should be aware of before getting into these directions: 1) I set out on this project trying to create this winch with the lowest cost possible (because I am a cheap S.O.B.), so my directions will push you to cut corners wherever possible, and will probably eventually cost you more in the long run. 2) You need to be mechanically inclined to set out on a project like this. Not only should you have welded before, but you should have some basic grasp on engines, designing things, and access to proper machinery to actually go through with the construction (or have your dad do it). 3) There is most definitely not one way to do things. So if you use your brain and figure out a better way to do any of these processes, by all means, go for it! That being said, let’s see this schematic.
*Note, Logan Imlach shall not be held liable for any injury during the construction or use of any winch that branches from this guide. This is not meant to be professional instruction, and any user/users of this guide are doing so at their own risk.
1: Motor: I chose a 5hp Briggs and Stratton motor because, well; I had a buddy who happened to have it in his garage and gave it to me for $50. I would strongly recommend if you are buying an engine new to go with a 9.5hp motor, or look through craigslist to find one. It will provide more much needed torque than the 5hp, and save you with gearing issues later in the process (we’ll discuss that in step 7). The myth of building them out of lawn mower engines is just that, a myth. I looked into this first (upon receiving a free 5hp lawn mower engine) and because of the lawn mower’s vertical shaft, you will be force to buy bevel gears and that shit is not worth the time or the money.
2: Frame: How and what you build the frame out of is completely up to you. I used 2” angle iron because I had a friend with a stack of scraps that I got for free. Plus, angle iron was probably the best decision I made because the angle will dig into the snow and save you from having to anchor the winch in use. The biggest thing in nailing down the final dimensions of your frame is the width of your axle (more importantly your spool) so you should probably hold off on welding it up until you have a solid idea of how much space your axle is going to take up. After you get the dimensions dialed in, you also need some angle in place to mount your engine to, so keep that in mind.
3: Clutch: Most high end winches run a belt drive centrifugal clutch right off the engine because of the braking abilities that are inherent to the belt, but they are expensive. I used a 10-tooth chain drive centrifugal clutch (conveniently off of an Arctic Cat Kitty Cat) which just slides right on the horizontal drive that comes out of the engine, and is held in place using a bolt (your horizontal drive should have interior threads) and washers. If you can’t find these in your town, they are easily found at any online go-kart parts store, and I would recommend using a 12-tooth Comet.
4: Keyed Axle: If you are scrounging up parts I would strongly recommend using a 1” keyed axle, but if you are purchasing all of your other parts online, a ¾” would be better. 1” accessories are much easier to find locally, because they are more common, but with the low amount of torque you’re putting on the system, a ¾” shaft will be much lighter and provide plenty of stability, and accessories will be readily available online. DO NOT ORDER THIS ITEM. They are heavy as shit and will cost you an arm and a leg in shipping. Also, make sure that you get the same size keyway as all of your accessories, and get the key wherever you buy the axle.
5: Rear Sprocket: Keep in mind when purchasing your rear sprocket that it HAS to be for the same chain size as your clutch. If it isn’t, you might as well toss the whole thing in the dumpster. My clutch was for a #40 chain, therefore, when going to purchase my sprocket, I got a 6-inch diameter (I forget out many teeth) sprocket for a #40 chain. The trick with the gearing of your sprocket is to determine what kind of torque your engine/clutch can produce, and get the smallest sprocket to overcome that torque. That way you are maximizing the speed. The only problem with this is that the only way to find out is to test it, and by then it may be too late, but don’t fret, there are some adjustments you can make to your spool after the fact to help with your torque/speed tradeoff. Also, your sprocket will most likely come with a keyed pressure coupling, which is necessary for connecting it to the axle, so make sure it matches up with your axel size. It is also incredibly important that once your rear axle is assembled to make sure that the rear sprocket is directly lined up with the teeth on the clutch, so you don’t throw a chain.
6. Rear Hub: I stole this idea from a winch that I saw online, and in their case it was genius, but mine is a little overboard. They purchased a two piece wheel from an online go-kart store, which I do recommend (4” is probably your best bet), along with 2 hubs for attaching it to your axle. The holes for go kart wheel posts make it incredibly easy to attach your spool, and the keyed hubs are ideal for attaching it to your axel. In my case (cheap ass move again) I went to the local go-kart track and asked the dude if I could raid his spare/old parts. The hub that he had was oversized and heavy, and I had to fabricate a second plate hub for the other side of the wheel (pain in the ass). If you stick to a two piece wheel, and two keyed hubs, you will be golden.
7. Spool: The material you make your spool out of is probably the least important feature of the winch. I went to Home Depot and got them to give me an old wire spool straight off of the rack, which I then trimmed down to fit in my frame. The tricky Part of the spool is adjusting the diameter of the center, where the rope is wound. You don’t want it directly on the axel, because it will provide no speed, but you don’t want it too big, because your clutch won’t be able to hand the torque being put on it when it starts to pull you in. This isn’t an exact science, because its dependent upon your clutch, sprocket, rope size, rider weight, peak RPM, and the list goes on. This is going to be a learning process (which I still haven’t nailed down), so really the only way you can figure it out is by testing it. I would recommend using all thread between the two sides of the spool (not shown in the above photo), and changing the distance that the all thread is from the center of the spool until you reach a solid balance between torque and speed. Remember, the further the all thread is from the axle, the faster you will go, but the more torque you’ll put on the clutch. The closer it is, the opposite.
8. Axle Supports: This is where you’ll have a lot of freedom in your design, the taller and further away from your engine they are, the larger your spool will be. The one thing that I will recommend is not to configure your rear bearings on the support like I did. I got lucky as shit that my chain length lined up well, because mounting them vertically gives you no room to shift the axle and tighten the chain. I would recommend mounting them horizontally, or on the angled piece you see on the support, so that you can shift it closer and further away from the engine to tighten the chain.
9. Pillow Blocks: Pillow blocks (or journal bearings) are the bearings that allow your axle to spin freely. They have to be the same size as your axel, and make sure that you get ones with a set screw, to avoid your axel travelling side to side during operation. Also, if you can find bearings that are pre-packed with cold weather grease it will be really good, because typical bearing grease doesn’t hold up in cold weather. If you have a garage (or laundry room like me) to store your winch in, you shouldn’t have too big of an issue with normal bearing grease. MAKE SURE that you warm these bearings up a little before use by doing some half speed tow-ins because you don’t want to crack a bearing during use.
10. Chain: The chain can be one of the last items installed, and needs to be the correct size for both your clutch and rear sprocket. I would suggest drilling your pillow block holes dead center in the bearing mount (they are generally rectangular so you can adjust their position) then cutting your chain to the closest link, inserting your chain splice (that you purchased with the chain), then moving the axle assembly to tighten the chain. You want a little bit of play in it, but not too much and not too little, to avoid throwing the chain or stripping out gears (which is a royal mess and could cause injury).
11. Rope: The rope you see in the photo is entirely too large and was quickly written off. You want extremely thin rope on your setup (I went to 3/16” in the second iteration) for constant speed and the ability to not fill up your spool too quickly. I would recommend buying cheap nylon rope, because if anything is going to break, trust me you want it to be the rope. With this setup (not having a brake), DO NOT PUT A HANDLE ON THE SETUP. That shit will just break things and mess up god knows what else. You have to tie a couple very small knots in the rope to hold onto, so that when it’s released, it will just freely wind on the spool. You should also install a guide on the spool (I would suggest a fairlead, but I just used a steel eyelet), so that you know it’s going to wrap evenly on the spool.
12. Frame Connections: You need something to attach the frame to the ground so that the winch will stay in place as it pulls you in. I installed some U bolts near the base of the frame, which I pound stakes through to hold everything steady. You can also ratchet strap the winch to any nearby solid object if you aren’t on soft ground.
So there you go! I know it was real vague, but to be honest, if you aren’t mechanically inclined enough to figure some things out, then you probably shouldn’t try to build this anyways. Now go hit some urban! Here’s a video of my second test run with the winch.
Logan is sponsored by Moment Skis, Kombi, Level 1 Productions, Lethal Descent, Capix, Spy, Joystick, Marker Bindings, Full Tilt and Purplejumpsuit Apparel