zim Posted October 7, 2011 Share Posted October 7, 2011 Afternoon, I'm curious.... I have 2 winch motors - one is 12v the other is 24. Both from tds' and both physically look the same on the outside. The brushes look the same. But what makes the one 12v and the other 24v ? Are the armatures different ? Are the magnets the same ? You know what i'm going to ask next..... Can i put the 12v armature into the 24v housing ? I'm trying to troubleshoot a problem on the 12v motor. Basically it spins in one direction at a normal speed, but if you go the other way it starts off a bit sluggish and then slows down. It's not the solenoids. It's not brushes. Cheers Gordon Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted October 7, 2011 Share Posted October 7, 2011 What does it spin like by hand in each direction? I'd have thought the difference between a 12v motor and a 24v motor would be the resistance of the armature, higher resistance for 24v. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 7, 2011 Share Posted October 7, 2011 Should just be the impedance of the windings, swapping the armature over shouldn't cause a problem for test purposes, though if using the 24V one on 12V it will run slower in BOTH directions.... obviously, I hope Quote Link to comment Share on other sites More sharing options...
simonr Posted October 7, 2011 Share Posted October 7, 2011 It will run with less torque either way - 12v armature in 24v housing or vice versa. The rotor and field windings are connected in series (why it's called a series wound motor) so if either of them has a higher impedance, the overall impedance will increase, current will be reduced and the motor will produce less torque. Si Quote Link to comment Share on other sites More sharing options...
zardos Posted October 7, 2011 Share Posted October 7, 2011 I believe that some motors like Warn's xp motor is asynchronous and is 6.5hp winch in and 4hp winch out which makes sense as you don't need as much power to winch out. Quote Link to comment Share on other sites More sharing options...
SORNagain Posted October 8, 2011 Share Posted October 8, 2011 More turns of thinner wire on the 24v motor, both on the field windings and the armature. I guess you could swap them just to diagnose the problem but you need to keep them matched up for actual use as Si says. Are the brushes free from dirt or grease? I have had brushes where the gunge prevented the springs from pushing them in contact properly, and oddly this seemed to manifest itself more in one direction than the other. Are gaps between the segments on the comutator clean? Quote Link to comment Share on other sites More sharing options...
zim Posted October 8, 2011 Author Share Posted October 8, 2011 Morning, Well the 24 motor housing magnets are "shorter" than the 12v version, so i didn't try swapping them over. Trying to work out which motor will be best for my application - This is the centre winch, which we actually use quite a lot. I want fast spool in / out speed with no load. Yes i know about freespool, but to be honest being used on the centre it's difficult to get them free enough - hence the spool out. I am 12v and have no intention of fitting a second battery or turbo pack as my main winches are hydraulic. Bow 1, Bow 2 or XP ? We did fit a 5.6hp motor to a little t-max yesterday and that is now pretty quick ! G Quote Link to comment Share on other sites More sharing options...
Boothy Posted October 8, 2011 Share Posted October 8, 2011 Zardos, is what you say correct, I thought an XP is the same in either direction and because they are series wound, it's just a case of reversing the polarity on the field windings (i.e. F1 & F2) and it's off the opposite way, if that's correct then how can it be less power one way when it's the same winding but reversed? I'm NOT saying you're wrong just questioning how that theory's made, I not spoiling for a fight just trying to figure it out. Mainly because I've just re-brushed both my front XP's and got them both running the wrong way round so have simply just reversed the wires on my switches for now to save pulling them both to bits again to reverse the field coil brushes, I didn't notice any loss in performance on last weeks LRS (it was me suffering from lack of performance) so that sort of told me that they were the same either way. C'mon Si what do you think????? Boothy Quote Link to comment Share on other sites More sharing options...
zim Posted October 8, 2011 Author Share Posted October 8, 2011 (it was me suffering from lack of performance) no...it was you trying to take a shortcut and breaking something in the process :hysterical: Quote Link to comment Share on other sites More sharing options...
SORNagain Posted October 8, 2011 Share Posted October 8, 2011 Boothy, I know that on some high speed motors they alter the timing angle on the brushes to optimise speed in one direction - I think it helps compensate for for the inductance of the armature or something. Dunno whether they do it on winch motors though. That's the only way I can see you might get different performance in either direction. Quote Link to comment Share on other sites More sharing options...
simonr Posted October 9, 2011 Share Posted October 9, 2011 Chris, SORNAgain is spot on. If you advance the timing, i.e rotate the brushes with respect to the field magnets / windings, you get more speed but less torque. If you retard it, you get more torque & less speed. Most motors are set in the middle to give the best of both - and to be honest that's how I'd set a winch motor in the middle as you need both! Having done a bit of comparative motor testing - the best two are definitely XP and Bowmotor2's. I can't remember which way round they were, but one won on torque and the other on speed - but both were give or take the same power. Bow2's have the advantage that replacement parts, brushes in particular are much cheaper. I get the impression that Bow2's last a little longer before needing service / replacement but that's subjective. Different people swear by each - so there's probably not much to call it! Si Quote Link to comment Share on other sites More sharing options...
zardos Posted October 9, 2011 Share Posted October 9, 2011 Zardos, is what you say correct, I thought an XP is the same in either direction and because they are series wound, it's just a case of reversing the polarity on the field windings (i.e. F1 & F2) and it's off the opposite way, if that's correct then how can it be less power one way when it's the same winding but reversed? I'm NOT saying you're wrong just questioning how that theory's made, I not spoiling for a fight just trying to figure it out. Mainly because I've just re-brushed both my front XP's and got them both running the wrong way round so have simply just reversed the wires on my switches for now to save pulling them both to bits again to reverse the field coil brushes, I didn't notice any loss in performance on last weeks LRS (it was me suffering from lack of performance) so that sort of told me that they were the same either way. C'mon Si what do you think????? Boothy So first off, the difference in the hp of each direction is just something I was told, google search turns up a few other people who have been told the same (somebody said they were told the same thing by devon 4x4). So it might not be true, I have no hard evidence. Just to point out that unlike other Warn motors, Warn call the xp motor a parallel series wound, the other motor are just series wound, so I don't know if this makes a difference. But having more speed for winch out when all the power you really need is to just overcome the brake. And more power for winching in sound a sensible idea. Quote Link to comment Share on other sites More sharing options...
Boothy Posted October 9, 2011 Share Posted October 9, 2011 Si With a Gigglepin 50% geared twin top housing I definately prefer the XP's over the Bow2 but I'm only running 12v on 75mm copper multistrand (top quality) using a pair of Albrights and everything is paralled up just in case and then onto a pair of big yellow top Optima's, I do however use an extended Deltatek which as you know is a bit less diameter than standard. However after recently having both XP's fail due to brushes worn out i went back to Bow 2's, following pricing the XP brush packs I had a root under the bench and found that some old standard motors with what appeared new brushes including holders and plate assembly were the same, so now it's back to XP's until my old mate John Sales has one, a sale that is. XP's do seem superior in performance especially on a hard pull. Cheers Chris Quote Link to comment Share on other sites More sharing options...
simonr Posted October 9, 2011 Share Posted October 9, 2011 With 50% you are going to need torque more than speed - so I guess it was the XP's that won on torque out of the two. With standard gearing, or a regular winch the torque/pull generally isn't too much of an issue - so a bit of extra speed with a Bow2 is probably welcome. Si Quote Link to comment Share on other sites More sharing options...
HoSS Posted October 10, 2011 Share Posted October 10, 2011 What Zardos is saying could be correct, if they are using a coumpound DC motor. Brief summary: There are 3 types of DC brushed motor 1. Series wound - high starting torque, but speed reduces with load. 2. Parallel (shunt) wound - medium torque but constant speed 3. Compound - has both sets of windings and has some of the advantages of both types. If they are using a compound motor and switch the windings over depending on 'in' or 'out' you could get your high-torque, low speed 'in' and your high-speed medium torque 'out' Hoss an interesting side note (from the days when i was doing my apprenticeship for a motor/generator manufacturer - parallel wound motors will 'run away' if the field winding goes open circuit. in effect this means that they quite quickly run up to a speed where the bearings/armature disintegrates rather spectacularly. Ask me how i know... I was standing next to a large (125 kVA) submarine motor when it happened Quote Link to comment Share on other sites More sharing options...
Team Idris Posted October 10, 2011 Share Posted October 10, 2011 I was wondering the same thing last year. If the field winding was 'shorted' with a restistor load, what would happen. 1. Motor goes slower as current in the field is reduced, so less turning force? 2. Motor goes faster, as the reduced field strength reduces back EMF allowing the motor to run faster? Don't know, and havn't tested it..........yet Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted October 10, 2011 Share Posted October 10, 2011 Yes, it's a common technique to use field weakening with DC drives. Back off the field to reduce the flux and allow the motor to spin faster than rated. This gives a good compromise of constant torque Vs constant power. Quote Link to comment Share on other sites More sharing options...
Team Idris Posted October 11, 2011 Share Posted October 11, 2011 Are we saying my tds goldfish will be quicker if I put a big resistor accros the field windings then? Because thats a lot more feasable than 24volt, and the motor should last better. Or are we saying, "you go test it steve" and you can tell us about the attending fire engine afterwards ? Quote Link to comment Share on other sites More sharing options...
Boothy Posted October 11, 2011 Share Posted October 11, 2011 I wished I'd spent more time in the classroom than the pub when I did my HNC in electrical engineering a few years ago..... Saying that all this palava makes hydraulics look a lot more favourable.................... Field weakening a common thing eh !!!! another pint of Pedigree please landlord...hic...hic...hic.... Quote Link to comment Share on other sites More sharing options...
Team Idris Posted October 12, 2011 Share Posted October 12, 2011 Ah but, necessity is the mother of invention. I can't get a second hydraulic winch through the house keeping as a 'necessity'. Hence the need for invention Quote Link to comment Share on other sites More sharing options...
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