simonr Posted December 19, 2007 Share Posted December 19, 2007 Yesterday Charles messaged me with an interesting idea for a product. While I was writing a reply telling him how difficult it would be to do - an easy solution popped in to my head. What Charles asked was - would it be possible to make an electric brake to stop/limit the run-on that you get on winches (particularly the 8274) when spooling in or out? Spooling in, this is an obvious safety concern as it will pull in a further couple of feet after you have released the switch. Easily enough to mangle your fingers. (I can see the promo video already!) I have designed a very simple (no computers ) circuit which will bring the motor to a stop very quickly. I've not actually built or tested it - but the principle is sound. The question - and hence the dragon reference is - do you think there is a market for such a device? Getting PCB's made and the boards assembled requires a reasonable investment. I reckon they would probably retail for between £15 & £20 - do the Dragons reckon I should stick to the day job? Si Quote Link to comment Share on other sites More sharing options...
gruntus Posted December 19, 2007 Share Posted December 19, 2007 first off encrypt all communications as I am sure scrapiron have an agent on this site! second make sure you get a patent before you go into production for the same reason! Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 19, 2007 Share Posted December 19, 2007 I guess the first question, without revealing too much commercially sensitive detail, is how would it work, and would it work well enough? Quote Link to comment Share on other sites More sharing options...
BogMonster Posted December 19, 2007 Share Posted December 19, 2007 (edited) Sounds worth a go to me - I fondly remember my old 8274s tendency to give an involuntary manicure I assume you've got something that [snipped out to protect a cunning idea from Scrap Iron Spies] Edited December 19, 2007 by BogMonster Quote Link to comment Share on other sites More sharing options...
rtbarton Posted December 19, 2007 Share Posted December 19, 2007 Depends on the demand and profit margin. There is a limited market so profit would have to be high, and once everyone has one the market is saturated. If manufacturers cotton on they could incorporate it in their design, so you will have to build in the cost of patents into the price, assuming the device is patentable in the first place. Also as it is marketed as a safety device you will probably have to get approvals and insurance cover. Because of that I'm out. A beter idea maybe to offer it to a manufacturer under licence, or sell it outright, but you risk having the idea rejected and then copied. If you want to make some extra beer money, offer the design as "This is wht I did" rather than "This is what you should do" and just happen to keep in stock the components needed to build it. Quote Link to comment Share on other sites More sharing options...
Sean Posted December 19, 2007 Share Posted December 19, 2007 a quick injection of reverse voltage does the trick - an oft used method Quote Link to comment Share on other sites More sharing options...
simonr Posted December 19, 2007 Author Share Posted December 19, 2007 a quick injection of reverse voltage does the trick - an oft used method Also good for wrecking motors! Si Quote Link to comment Share on other sites More sharing options...
white90 Posted December 19, 2007 Share Posted December 19, 2007 I'd buy two willing to invest for fun Quote Link to comment Share on other sites More sharing options...
Defender Posted December 19, 2007 Share Posted December 19, 2007 I think Britpart already incorporate this dead stop when you release the switch so the technology is already there but they seem to be the only people using it as far as I know. I think as an aftermarket idea for all the winches that are out there it's well worth doing. I know I for one would like to be safe when using my winch & I'm sure there are other people who would. In fact if you do go ahead please PM me as I may be interested in reselling the product or becoming a dealer. Thanks, Pete Quote Link to comment Share on other sites More sharing options...
Sean Posted December 19, 2007 Share Posted December 19, 2007 Also good for wrecking motors!Si it's been used in industry for many many years for braking both DC and AC motors Quote Link to comment Share on other sites More sharing options...
white90 Posted December 19, 2007 Share Posted December 19, 2007 Quickest way to knacker the 8274 as the motor tries to climb the main gear. I would only do it if appendages were at risk, ropes/blankets etc are easily replaced Quote Link to comment Share on other sites More sharing options...
Gromit Posted December 19, 2007 Share Posted December 19, 2007 Also good for wrecking motors! Isn't this how electric motor braking works in the likes of RC car motors? Applying reverse until the motor is stationary. Quote Link to comment Share on other sites More sharing options...
rtbarton Posted December 19, 2007 Share Posted December 19, 2007 it's been used in industry for many many years for braking both DC and AC motors A less viscous way is to short the motor (once the power has been removed!) Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 19, 2007 Share Posted December 19, 2007 Without wanting to give other manufacturers ideas, a burst of full -ve voltage is not the same as controlled regenerative braking. Then again. if the gearset is badly designed so it f***s the internals up under braking there's not much you can do about that. Mind you, most winch manufacturers seem to have little or no grasp of electronics anyway Quote Link to comment Share on other sites More sharing options...
Mark Posted December 19, 2007 Share Posted December 19, 2007 Si, I would be interested in one... Cheers Mark Quote Link to comment Share on other sites More sharing options...
will_warne Posted December 19, 2007 Share Posted December 19, 2007 Si, I think its a good idea and I'd certainly have 3 to see how they work. If they seem to be any good you might find they become a requirement for many events in the same way a cut off switch is as its not expensive and will make winching safer. Quote Link to comment Share on other sites More sharing options...
white90 Posted December 19, 2007 Share Posted December 19, 2007 As long as the idea doesn't appear in the glossy mags that are so pro Scrapiron as the spies/blacklegs are every where these days Quote Link to comment Share on other sites More sharing options...
simonr Posted December 19, 2007 Author Share Posted December 19, 2007 it's been used in industry for many many years for braking both DC and AC motors That is true, but in the case of winches, as other people have said, it can damage the gears and the motor mounting. All mine does is a controlled EMF Brake (similar to regen braking, but without the regen). EMF Braking isn't simple on a series wound motor as there are no perm magnets to make it act as a generator to generate the EMF. Si Quote Link to comment Share on other sites More sharing options...
rtbarton Posted December 19, 2007 Share Posted December 19, 2007 That is true, but in the case of winches, as other people have said, it can damage the gears and the motor mounting.All mine does is a controlled EMF Brake (similar to regen braking, but without the regen). EMF Braking isn't simple on a series wound motor as there are no perm magnets to make it act as a generator to generate the EMF. Si Shorting the motor is self-regulating, there's a highish intial current which reduces as the motor slows. Also there is no risk of the motor reversing as there might be if a more sophisticated circuit fails. I would have thought there would be enough residual magnetism for this method to work. Quote Link to comment Share on other sites More sharing options...
D9OSV Posted December 19, 2007 Share Posted December 19, 2007 We played with this about 18months ago, but decided not to produce it as at the time it would have been cost prohibative, plus the twins do not suffer with the overrun troubles of the single motor winch. Thus it was decided that people would not want more electrics.........? It did work very well once it was sorted. Still got a motor kicking around here that was used for testing it..........Somewhere If you can do it cheap enough, go for it We would try them. Jim Quote Link to comment Share on other sites More sharing options...
Daan Posted December 19, 2007 Share Posted December 19, 2007 Shorting the motor is self-regulating, there's a highish intial current which reduces as the motor slows. Also there is no risk of the motor reversing as there might be if a more sophisticated circuit fails. I would have thought there would be enough residual magnetism for this method to work. Not particularly clued up on sparking in general, however shorting does happen for this reason on most windscreenwipermotors to make sure they park at the right position. Daan Quote Link to comment Share on other sites More sharing options...
Andy-T Posted December 19, 2007 Share Posted December 19, 2007 I like this idea a lot!! I suppose it will depend on how easy it is to fit as well as price. I have seen loads of damaged winches, lines & fingers due to just this sort of accident. Take your eye off the winch for just a moment and watch the loonies try and stop a winch spooling in by trying to hold with their hands, almost as much fun as trying to stop your pride & joy rolling down a hill by standing in front of it - seen that too!! Now if you have a device for this as well................................. I would support their use in competitions. Andy-T. Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted December 19, 2007 Share Posted December 19, 2007 Yup, go for it Si, I'll take one. Mo Quote Link to comment Share on other sites More sharing options...
JST Posted December 19, 2007 Share Posted December 19, 2007 cant you just get used to the overrun and as a driver/codriver build that into your planning? if it becomes a safety issue then as TC says rev pol it. Quote Link to comment Share on other sites More sharing options...
simonr Posted December 20, 2007 Author Share Posted December 20, 2007 I like this idea a lot!!I suppose it will depend on how easy it is to fit as well as price. Guess I'd better build a prototype! The design just has five connections. F1 F2 A Batt+ and Batt- and is connected in parallel with the solenoid connections to same - so should be easy to wire up. Price is harder to guess - but even the more complicated version of the design only has five components. I had always appreciated that it was going to over run and made an allowance for it - but this year had a close call with my fingers & hawse! I guess that's the point that when it happens it is an accident and no amount of prior appreciation of the risk can stop that one fluke set of circumstances! Si Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.