flyingbrick Posted July 13, 2017 Share Posted July 13, 2017 Hi guys. I have a project at the moment which requires the purchase of TEN electric ATV style winches. The kicker is that they need to be SLOW. We have used ATV winches before and although perfect for the job I've ended up installing a triple pull pulley system to get speeds low enough. You'd think that this wouldn't be a problem however winch users usually want things as fast as possible - being SLOW isn't considered a good thing. I think I currently have two real options- a PWM style electric speed controller that could be set and forget (pwm should mean the DC motors maintain their tq i think?) or finding a slower winch (which could be $$$) Does anyone have any ideas or other input? I figured there's enough smart people here of varying backgrounds that ya never know what may pop up. Ps, the amount of total PULL required is around 2m- I will look at reducing drum layers to reduce diameter, this will help some. Anything much appreciated! Quote Link to comment Share on other sites More sharing options...
h4nd Posted July 13, 2017 Share Posted July 13, 2017 The speed is likely to be proportional 1/ the load? So if you PWM, it'll be slow 'till it takes up the slack, then crawl / stall? Quote Link to comment Share on other sites More sharing options...
KKtrips Posted July 14, 2017 Share Posted July 14, 2017 Why not run the winch through a series of pulleys/block and tackle. Pretty easy to figure out the ratio and how much slower it will be. 1 Quote Link to comment Share on other sites More sharing options...
Threeonthetree Posted July 14, 2017 Share Posted July 14, 2017 He ran it through a pulley system last time so I think he is after a winch that will be geared down low enough to not need the same treatment this time. Or something like that. Xoxoxo 3 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 14, 2017 Author Share Posted July 14, 2017 this is where i need help- I understood pwm was very good at keeping TQ high because voltage stayed the same but you simply pulsed the motor? I'm happy to be told otherwise but need to know. The other bonus is with a decent controller we can program in acceleration/deceleration ramps. Ideally i can find a suitable winch but after many emails around the place it doesn't seem that easy. line speed needs to be around 1m/minute or slower. preferably slower. max weight loading needs to be around 1T and we will use maybe half that. Neal is correct- I have had to retrofit a pulley system to previous systems to slow things down however it is a messy and difficult setup which we really need to avoid. the main drawback is that the two components we are pulling together end up very close to one another- there is extremely limited room left for cables to change direction between pulleys and with wire cable going around 3 pulleys you end up with a fair amount of resistance needed to stretch things back out again. I have found a great controller in the states from midwest motion products HOWEVER i cannot send them an e-mail as all their addresses bounce. Only other motor controllers suitable seem to be on ali express and banggood.... i wont put the customer through that! bahahaaha Quote Link to comment Share on other sites More sharing options...
Spencer Posted July 14, 2017 Share Posted July 14, 2017 Sounds like a winch with a expensive/decent stepper motor would be the go? I imagine this kind of control problem has been solved if you dive into the internet with the right words. 2 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 14, 2017 Author Share Posted July 14, 2017 I was going to say that custom stuff is outside the budget HOWEVER we may have to consider this idea. It would be a relatively simple job to laser cut an adapter plate and with the right winch (one that has a planetary gearbox on the opposite side to the motor driven by a driveshaft which runs through the center of the drum) it would be easy enough to couple the new shaft. Thanks spencer! food for thought. edit. Perhaps rather than a stepper I use a DC motor/worm drive gearbox adapted to the winch..hmmn. i am hoping at this stage that one of the suppliers comes back with the ability to stack their planetary sets to increase ratio hugely. 1 Quote Link to comment Share on other sites More sharing options...
Spencer Posted July 14, 2017 Share Posted July 14, 2017 Yes gearing for your application rather than motor control would be the way to go for sure. /have you considered a powerglide? 4 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 14, 2017 Author Share Posted July 14, 2017 they have already turned down my request for a propeller propelled container house rolling on turbos...dont wanna push my luck 1 Quote Link to comment Share on other sites More sharing options...
KKtrips Posted July 14, 2017 Share Posted July 14, 2017 What are you trying to do? There may be another solution. Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 14, 2017 Author Share Posted July 14, 2017 Unfortunately not. I can't discuss specifics however it is used to raise and lower a very long mast.. the mast has a very expensive and heavy flag on the tip. Hard to explain but a winch is the only viable option for many reasons. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted July 14, 2017 Share Posted July 14, 2017 Is the mast telescopic or does it extend in one piece? 1 Quote Link to comment Share on other sites More sharing options...
Bling Posted July 14, 2017 Share Posted July 14, 2017 How much budget is there? Two pulleys and two pillar bearings bolted to something too expensive? I just tried to draw it in paint, but failed terribly. Basically a small pulley fitted to the winch. Which drives a large pully, via a fan belt or some shit, which is mounted to a shaft which has the wire spool on it. Basically how I reduced the speed of my wheel polisher down. This idea may have been covered, but most seemed to rely on the wire going around pulleys which takes up more space, this idea could be kept quite compact. And it's easy enough to source the correct diameter pulley depending on the end speed you want. Polisher example, just spool the wire on the axle. Imagine the large pulley fitted to the turned down section with a fan belt attached. Can't find the pic right now. Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 14, 2017 Author Share Posted July 14, 2017 Thanks guys. Kk I'll flick you a message. @Bling your idea is pretty awesome but likely too complex and bulky. But thanks. Can any electrical gurus explain how I could reliably make a DC motor run at half speed? Would need to be approx 12v and 100a capable. @Ned I'll send you a pm Quote Link to comment Share on other sites More sharing options...
Ned Posted July 14, 2017 Share Posted July 14, 2017 So PWM keeps torque the same, will just change the speed... What's the deal with it wanting to unwind? Is there a sprag clutch/ratchet clicky thing? How does it unwind? Does the motor go in reverse and unwind? What slows that down when there's a 1ton load on it? Or is it a worm drive it something that can't be back driven? A 100A speed controllers isn't the hardest thing to make, but getting someone to design one for you won't be cheap... Some numbers I would expect from an electronics firm would be 30 hours research and design, $1000 in parts for first prototype, 15 hours writing code. Then put it in a box and fill with epoxy. Guestimates parts cost for the 10 units would be ~$150 each, so looking at $6500+ to build 10 units? You'd also be looking at a 4 or 5 week lead time on that at least I could do it much cheaper from home as a home job, but not sure how I feel about building a motor controller for something that lifts a big heavy thing, and having no liability insurance etc for home jobs. Also, those are numbers I pulled out of my thumb... But would be what I'd have used back when I worked at ProTech doing that sorta shit... But I am notorious for under quoting haha What's the thing you found that's perfect? 2 Quote Link to comment Share on other sites More sharing options...
Get it done Posted July 14, 2017 Share Posted July 14, 2017 Have you considered something like a planatery reduction drive, very compact and no need to keep adjusting etc Quote Link to comment Share on other sites More sharing options...
nickrock Posted July 14, 2017 Share Posted July 14, 2017 I have a 40 to 1 reduction box ,several single phase motors of that helps Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 14, 2017 Author Share Posted July 14, 2017 1 hour ago, Ned said: So PWM keeps torque the same, will just change the speed... What's the deal with it wanting to unwind? Is there a sprag clutch/ratchet clicky thing? How does it unwind? Does the motor go in reverse and unwind? What slows that down when there's a 1ton load on it? Or is it a worm drive it something that can't be back driven? A 100A speed controllers isn't the hardest thing to make, but getting someone to design one for you won't be cheap... Some numbers I would expect from an electronics firm would be 30 hours research and design, $1000 in parts for first prototype, 15 hours writing code. Then put it in a box and fill with epoxy. Guestimates parts cost for the 10 units would be ~$150 each, so looking at $6500+ to build 10 units? You'd also be looking at a 4 or 5 week lead time on that at least I could do it much cheaper from home as a home job, but not sure how I feel about building a motor controller for something that lifts a big heavy thing, and having no liability insurance etc for home jobs. Also, those are numbers I pulled out of my thumb... But would be what I'd have used back when I worked at ProTech doing that sorta shit... But I am notorious for under quoting haha What's the thing you found that's perfect? Thanks mate. http://www.midwestmotion.com/speedcontrols.htm , http://www.midwestmotion.com/products/speedcontrols/MMP 100A 20-62V Manual.pdf.. no idea on price though, will phone next week but i expect $$$ $650 for a unit that works reliably isn't bad, I'll take that number back to work with me on monday. I'm unsure what mechanism brakes the winch but its purely mechanical and there are no issues with it falling due to any electrical failure- motor reverses to lower it back down. In both horizontal and vertical positions it is kept securely locked with a big pin. Quote Link to comment Share on other sites More sharing options...
rusty360 Posted July 15, 2017 Share Posted July 15, 2017 We use a whole bunch of motovario gearboxs at work. you can get to 100:1 easy but can add a pc unit that will get you even lower if needed say 500:1 or even 900:1. then just bolt ya 12v to that make a small drum to hold the cable? 1 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 15, 2017 Author Share Posted July 15, 2017 Hi man. What's a PC unit? Quote Link to comment Share on other sites More sharing options...
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