bertiedog Posted June 21, 2016 Share Posted June 21, 2016 I suspect that the main users are the electric drones, where 12 volts to 15 volts is applied to get the motors to max revolutions without worrying about the life of the motors. Some Chinese sellers are very optimistic about power output, revs, and voltages in general. Years ago they began in the Hi-Fi world to use peak power descriptions, and the Chinese still do, making a 2.5 watt stereo amp have a total "music power" of about 150 watts..... They are wildly optimistic about the light output in Lumens of LED lamps, quoting output as watts, which bear no relation to the power in watts in from the power supply. Also, as they sell optical tachometers to measure rotation, they miss use them to overestimate the speed, as they fail just like many users to read the shaft speed. Motors that claim 60,000 RPM are total BS, they would disintegrate at those revs. So always read the claims with caution, reading between the lines helps. Link to post Share on other sites More sharing options...
Richard Hall Posted June 21, 2016 Author Share Posted June 21, 2016 (edited) Years ago they began in the Hi-Fi world to use peak power descriptions, and the Chinese still do, making a 2.5 watt stereo amp have a total "music power" of about 150 watts..... Instant flashback to my younger days messing about with high-end audio systems. The cheapo manufacturers quoted something called "PMPO" (Peak Music Power Output) which sounded impressive on paper but meant nothing at all. Meanwhile I was running valve amps which claimed 20W output but would cause structural damage if you cranked the volume up. Happy days. Edited June 21, 2016 by Richard Hall Link to post Share on other sites More sharing options...
Petri Sallinen Posted June 22, 2016 Share Posted June 22, 2016 (edited) This small motor is very popular in Japanese H0 narrow gauge locomotives and in small normal gauge H0 bogies. I have used the motor in some small H0 16,5 mm gauge rail tractors etc. The voltage of motor is 9V but you are also able to give it 12V without any problems. I think this motor might also work in 2MM scale models. The price of motor is about 10 euros. In pictures you can see bogies (16,5 mm gauge in H0) made by Japanese ARU Model using this motor. The motor with double shaft is also available as you can see in the last picture. Motor bogies (in several WBs) made by ARU Model are in kit format — very nice design and easy to build. Both motors and bogie kits are available via Toma Model Works (Mr. Kenji Toma) using email in English. http://tomamw.c.ooco.jp/index-e.html Here is some information of motors. http://arumo.a.la9.jp/rp0001.htm Edited June 22, 2016 by Petri Sallinen 3 Link to post Share on other sites More sharing options...
garygfletcher Posted June 22, 2016 Share Posted June 22, 2016 Talking about frames and mechanics I've been creating a pint rest board for some time others may find useful https://uk.pinterest.com/garygfletcher/2mm-frames-and-mechanics/ Link to post Share on other sites More sharing options...
bertiedog Posted June 29, 2016 Share Posted June 29, 2016 (edited) The tiny twin shafted motors have arrived and they work, which is amazing as the motor is 3x4mm! totally useless for larger locos, they would do fine in small 2mm locos, and even Z gauge locos. They seem powerful for the size, but long term wear and tear is unknown. A pin punch will remove the weights from the shaft, grip the weight in a vice, and gently tap the shaft. They are very good vibrators though, and would act as a point vibrator, fitted under the track, activated by a magnet on the loco, the theory is as the loco passes over the point the track is vibrated at high speed and it minimises the chance of stalling. A sustain circuit with a 555 timer chip is needed to allow the reed switch to close and trip the timer to give a burst of say up to 10 seconds of the vibrator. Set to normal voltage of 3volts the vibrator makes little noise, but would vibrate the point. Stephen Edited July 3, 2016 by bertiedog Link to post Share on other sites More sharing options...
Richard Hall Posted June 29, 2016 Author Share Posted June 29, 2016 The tiny twin shafted motors have arrived and they work, which is amazing as the motor is 3x4mm! totally useless for larger locos, they would do fine in small 2mm locos, and even Z gauge locos. micro vib.jpg They seem powerful for the size, but long term wear and tear is unknown. A pin punch will remove the weights from the shaft, grip the weight in a vice, and gently tap the shaft. They are very good vibrators though, and would act as a point vibrator, fitted under the track, activated by a magnet on the loco, the theory is as the loco passes over the point the track is vibrated at high speed and it minimises the chance of stalling. A sustain circuit with a 55 time is needed to allow the reed switch to close and trip the timer to give a burst of say up to 10 seconds of the vibrator. Set to normal voltage of 3volts the vibrator makes little noise, but would vibrate the point. Stephen Now let's see someone build a Wickham PW trolley in 2mm. Link to post Share on other sites More sharing options...
bertiedog Posted June 30, 2016 Share Posted June 30, 2016 These motors would do a Z gauge Wickham Trolley, and amazingly would work across the frames in a 9mm track locomotive, they are only 4mm long! Stephen Link to post Share on other sites More sharing options...
Titan Posted June 30, 2016 Share Posted June 30, 2016 Now let's see someone build a Wickham PW trolley in 2mm. Already been done: https://www.youtube.com/watch?v=uOyKHXJxTyQ&feature=youtu.be I think these are also the motors used in T-gauge, my T-gauge HST runs remarkably well with them. Link to post Share on other sites More sharing options...
Richard Hall Posted June 30, 2016 Author Share Posted June 30, 2016 I now have the skew wound 5 pole open frame motors (see post from 15th June). I'll see if I can stuff one in my long-suffering J39 tender drive, or possibly the 4F, and report back. Link to post Share on other sites More sharing options...
RMweb Gold 2mmMark Posted July 2, 2016 RMweb Gold Share Posted July 2, 2016 (edited) Here's an addendum on the Citizen coreless motors described earlier in the thread. (eBay item 191907647343) The gear they come fitted with is steel, has 12 teeth and meshes with a 100DP gear. The gear is easy to remove with a 0.95mm dia. punch, provided you can grip it strongly. It's a press fit but I wouldn't describe it as an interference fit. Behind the gear are 2 washers and it appears the gear or something like it is absolutely necessary to control the motor shaft end float. Looking at the motor, it's definitely not suitable for mounting a worm on. The shaft only projects about 1mm beyond the motor body and it's 0.97mm diameter. However, the front bearing looks pretty strong so anything involving a side-thrust or avoiding end thrust would be fine, i.e. gear, pulley or u/j connection. I can't see any easy way to press on a replacement gear or pulley so a sliding fit with Loctite or similar will be needed. The motor body has a 5.5mm mounting thread so the 2mm Scale Association's Maxon and Faulhaber motor mounting bush part number 3-261 would suit this motor. Can dimensions are 24.6mm long, 9.95mm diameter. The M5.5 mounting thread projects 2mm beyond the main body. Taking the prefitted connecting wires into account, the motor needs about 30mm in length to accomodate it, so that points towards a larger tender. Weight is 11 grams which is useful and points towards a substantial build quality. As suggested earlier, a "top-hat" type of adapter which accurately cups the gear is an alternative way to get a drive connection. The 12 tooth gear is 3mm overall diameter. For the price being charged, I think they are definitely worth considering. Mark. Edited July 2, 2016 by 2mmMark Link to post Share on other sites More sharing options...
Squirrel Posted July 3, 2016 Share Posted July 3, 2016 The ebay link in post 11 (page 1) now shows nil stock, but http://pages.ebay.com/link/?nav=item.view&alt=web&id=311577682012&globalID=EBAY-GB is near the same price and has a double ended shaft, so could take a flywheel if needed. Link to post Share on other sites More sharing options...
Valentin Posted October 21, 2016 Share Posted October 21, 2016 The fears about problems with end thrust on these small coreless motors is overstated in 2mm. I have over a dozen locos running with Nigel Lawton or similar motors, John Greenwood also uses them as standard. All the tank locos have the worm mounted directly on the motor and all have run many hundreds of hours. I've never had a problem or a failure yet. I've bought a load of the little 7mm coreless motors, they are all but identical to the latest Farish motor and may well be the same. I've attached some pictures, the Farish on has the F on it so I could tell them apart! image.jpg image.jpg Edit to apologise for poor pictures - will snap some better ones later Jerry Does anyone know what's the "no load" speed for these motors? Link to post Share on other sites More sharing options...
bertiedog Posted October 21, 2016 Share Posted October 21, 2016 Does anyone know what's the "no load" speed for these motors? Very high indeed for coreless types, this is why the drones favour the types as motors, in railway use the load is higher and the max voltage should be safe, but always consider you do not use the max in normal operation. Some coreless can run at over 40000 revs.,, but not for long!! It is the brushless AC motors that can run even faster. Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted October 21, 2016 RMweb Premium Share Posted October 21, 2016 Does anyone know what's the "no load" speed for these motors? Afraid I don't, but the Farish ones seem quite happy driving my 3FT and 4F at all speeds using the 40-1 ratio the locos have whether running light or under load. Not sure if the ones obtained via ebay have exactly the same specs, hard to tell just test runnng them out of a chassis but comments I have read suggest they perform just the same when used as replacements for failed Farish ones. Izzy Link to post Share on other sites More sharing options...
bertiedog Posted October 22, 2016 Share Posted October 22, 2016 I checked one of the type shown in posting and at about 8 volts the revs were 21,000 with no load at all (optical rev counter on disk target), and any load drops the RPM dramatically. Most coreless have a steeper graph of power output than cored motors, the usable power is lower to mid range. The eddy currents and back EMF stops the revs increasing on cored motors, the graph slope tops out. You would have to make a small dynomometer load for tests and measure voltage against current to test each motor. It only needs a wood clamp around the shaft, leaving a small groove for the shaft to rest in, with gravity providing the pull on the weight, made in box wood if possible, to get consistency in readings. A hinged pair of box wood rulers would make a clamp, one screwed to a base, the other able to take weights hanging from notches on the edge. Useless to take really scientific readings, but great to compare motors, and get performance graphs. Stephen Link to post Share on other sites More sharing options...
bertiedog Posted October 22, 2016 Share Posted October 22, 2016 On a web page, in Japanese, translation by Google, whilst looking up small motor bogies mentioned above......... http://arumo.a.la9.jp/ A shot of a 9mm track adaptor that works at 25mm track centres, therefore the radius of the turn is about 1/2 inch! Now that would make an interesting small layout, it would need the gauge widening needed testing out. The locos would have to be good slow runners on PWM controllers as well to get the best out of it. They also appear to do one at 37mm track centres. Stephen 2 Link to post Share on other sites More sharing options...
Chris Higgs Posted October 22, 2016 Share Posted October 22, 2016 On a web page, in Japanese, translation by Google, whilst looking up small motor bogies mentioned above......... http://arumo.a.la9.jp/ 13003.jpg A shot of a 9mm track adaptor that works at 25mm track centres, therefore the radius of the turn is about 1/2 inch! Now that would make an interesting small layout, it would need the gauge widening needed testing out. The locos would have to be good slow runners on PWM controllers as well to get the best out of it. They also appear to do one at 37mm track centres. Stephen And there we are tlelling people to not use less than 18" radius! Link to post Share on other sites More sharing options...
Valentin Posted October 22, 2016 Share Posted October 22, 2016 Thank you for your feedback. My intention is to use the Chinese 716 in a small tank loco with a 47:1 total gear ratio. If I won't be happy, I will probably choose to model another prototype as there is no way to fit larger gears in that small engine. (6.75' + 7' wheelbase ant 4' wheels). Link to post Share on other sites More sharing options...
RMweb Gold queensquare Posted October 22, 2016 RMweb Gold Share Posted October 22, 2016 Thank you for your feedback. My intention is to use the Chinese 716 in a small tank loco with a 47:1 total gear ratio. If I won't be happy, I will probably choose to model another prototype as there is no way to fit larger gears in that small engine. (6.75' + 7' wheelbase ant 4' wheels). I think you should be fine Valentine. One of the T9s we had running on Wadebridge when you saw it last weekend has one of the cheap Farish 'look a like' motors recently fitted in it. It's perfectly controllable down to a crawl with 38:1 gearing, 13mm drivers and a. CT chip. Jerry Link to post Share on other sites More sharing options...
Yorkshire Square Posted October 22, 2016 Share Posted October 22, 2016 On a web page, in Japanese, translation by Google, whilst looking up small motor bogies mentioned above......... http://arumo.a.la9.jp/ 13003.jpg A shot of a 9mm track adaptor that works at 25mm track centres, therefore the radius of the turn is about 1/2 inch! Now that would make an interesting small layout, it would need the gauge widening needed testing out. The locos would have to be good slow runners on PWM controllers as well to get the best out of it. They also appear to do one at 37mm track centres. Stephen Can you get a Mk 1 coach round it? Link to post Share on other sites More sharing options...
Richard Hall Posted January 28, 2018 Author Share Posted January 28, 2018 Another little Chinese motor to play with. It is claimed to be 6-pole but I would guess 5 is more likely, 9 volt rated and relatively slow-running by the standards of these things. 10mm square by 15 long, 1mm shaft and £6.95 for five, post free. I'm in. https://www.ebay.co.uk/itm/Mini-Minebea-Square-Motor-DC6V-9V-7-2V-1700RPM-10-10mm-6-pole-Rotor-Large-Torque-/282607882699 Richard Link to post Share on other sites More sharing options...
Caley Jim Posted January 28, 2018 Share Posted January 28, 2018 Another little Chinese motor to play with. It is claimed to be 6-pole but I would guess 5 is more likely,.... One of the photos of it dismantled definitely shows 6 poles. I wonder what effect that will have on the running? I always understood that there needed to be an odd number of poles to avoid it stopping in what would be the equivalent of 'dead centre'? Jim Link to post Share on other sites More sharing options...
Richard Hall Posted January 28, 2018 Author Share Posted January 28, 2018 One of the photos of it dismantled definitely shows 6 poles. I wonder what effect that will have on the running? I always understood that there needed to be an odd number of poles to avoid it stopping in what would be the equivalent of 'dead centre'? Jim That's why I thought it was more likely 5 pole but you're right, it's 6. I suppose it depends how it is wound - if it is in effect two 3 pole motors 180 degrees apart on the same armature it could be rather nice. I've never heard of such a thing, but I am sure someone more knowledgable will be along shortly to explain. Richard Link to post Share on other sites More sharing options...
D869 Posted January 29, 2018 Share Posted January 29, 2018 The odd number of poles results in doubling the number of 'cogging' positions, so a 3 pole motor with a 'conventional' magnet arrangement will have 6 but a 2 pole motor would have just two. It should also reduce their severity because only one pole is aligned with a magnet at the 'cogging' position' but with an even number of poles you have two poles aligned. But a conventional magnet arrangemeng on a cored motor usually results in a rectangular casing when viewed end-on rather than square. Makes me wonder how the magnets are arranged in this square motor casing - maybe 4 magnets, one in each corner? It's not clear from the eBay pics. That could certainly be unconventional so interesting to see how these perform. Regards, Andy Link to post Share on other sites More sharing options...
decauville1126 Posted January 29, 2018 Share Posted January 29, 2018 Many thanks for the ebay info. 10x for £1.20 each now winging their way to UK. Link to post Share on other sites More sharing options...
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