found a motor
 

I was digging through my big ol` box of junk when I found a motor I hung on to.

It is a brushed motor (not from any RC stuff) it measures about 70mm long by about 55mm wide. With a tiny fan on it I could get it to pull about 20 amps (fan is a small load) at 14.4 volts, and about 18 amps at 7.2 volts.

Would it be worth my time to put this in my Nitro V with about a 100 amp ESC? Or should I just forget about it and go brushless?<br type="_moz" />

RE: found a motor
 

Wow, thats a big one................sounds like an 900 size........or bigger. Can you see any brand name or marking on it? Johnson....Mabuchi etc..................... Probably heavy. You might consider it if it has decent rpms at 14.4v.

RE: found a motor
 

The only mark I found on it is the "j" symbol. See pic. the shaft is about 3 or 4 mm as well.

here's a dumb question, what would I use to check the RPM?<br type="_moz" />

RE: found a motor
 

Its definitely a Johnson...........................sorta similar to this one: http://www.johnsonelectric.com/media...IdProduct=1273

It may be roughly the same specs too......................this one puts out over 1000 watts[X(] You could contact johnson to see if they have any specs on it.

RE: found a motor
 

this is interesting, it's got a huge diameter; so it'll have loads of torque; i'll need to investigate this tomorrow, maybe it's cheap too.

i used to rewind 540 size drill motors, and this one might be easy to rewind too, either to increase or decrease RPM, drill motors are very basic but they're dead strong and last for years, my 7v drill motors used to swing 70mm 4 blader props inside Kortz nozzles and these props are very bulky too, this large motor will swing a 90mm prop easily

but i doubt it'll be fast enough in standard form, but if it can be rewound then yes it will be, the only problem being :- removing the back plate.

the good news is the backplate is easy to remove, but the bad news is it's 12 pole, so it'll be a nightmare to rewind, never mind !

even so, there might be another similar motor that can be used, maybe even a Graupner version, as long as it's no more than 6 poles, i'll take a good look tomorrow.

RE: found a motor
 

Some hobby stores sell tachometers. You point the light beam on the prop to get a reading.

RE: found a motor
 

i can find plenty of motors but none are fast enough, there probably is no subsitute for a proper race motor..........Wattage yes but not RPM

one could try rewinding a Graupner speed 820 turbo race at 24 000 RPM stock speed, but costing 55 pounds; it's too expensive, just get a purple motor from HONG KONG instead at only 30 pounds.

RE: found a motor
 

with all the torque this thing will put out, could you not just gear it up? over drive it to get he desired RPM?  If it will not work, I will just not use it.  I had it laying around.  I probably got it for nothing at a garage sale when I was young or something.  So at this point it is free, so if I can use it, I will.<div>
</div><div>any links to a tach so I get an idea what I am looking for?</div>

RE: found a motor
 

not sure, but that motor would probably be best geared down and put into a tug boat, running at no more than 3000 rpm !

go brushless, because that motor wont be any good for high RPM

RE: found a motor
 

That would be one hell of a tug boat!<div></div><div>what unloaded RPM should I be going for? And does anyone even sell a 100amp 14.4volt ESC for a brushed motor? I can't find any.</div>

RE: found a motor
 

that was for a smaller tug boat, my largest one had twin Robbe Power 1000, she had 105 mm props, bollard pull 17 LBS, she had a 12 v car battery and weighed about 75 LBS

but all of this fast electric stuff is totally new to me, so i'm a bit stuck like you, but we need to know the size of the Nitro V boat that you have and this might help choose a suitable motor, plus do you want it to be rocket fast !!!

RE: found a motor
 

If its going to be direct drive and you are attempting to use this motor, you need to get it into the mid to high 20k rpm range. The KV rating is the key here. Can you get it to those rpm levels on 14-16 cells? Tug boat comparison is not helping you. Somehow find how to measure the rpms at a given voltage...........if its 14,400 on 7.2v then its a 2000kv motor etc........................ If you cant get the specs from Johnson electric then try to take it somewhere that can give you an rpm measurement or see about picking up a tachometer as 13BT recommended. Just starting out here............does it rev up fairly high on 14.4 just to your ear? Compare it to another motor on 14.4v...............is the pitch close? I do this quite often on similar motors to get a general idea of how fast it is spinning. A Traxxas evx should be able to run it also.

PS -the motor i linked to you by Johnson spins at around 21,000 at 24 volts..............yours may be around there or possibly higher.

RE: found a motor
 

hey nobodyfamous, i have a couple of johnson motors which i used when i was scratch building landingcrafts, if remember when i bought them, the advertisement said 6-12v but that was it

any info i have found on the interweb seems to point me towards motor vehicles so i am assuming that maybe they are for small electrical purposes

after more looking this is what i found out

- operates on 1.5v-12v
- high torque
- no load speed 28,310rpm's
- 1.0a current draw @ 1.5v
- 1.7a current draw @ 12v

its helped me find this info out about the 2 motors i have

RE: found a motor
 

I think I will try and get a tach reading off this motor, I will see how many volts it will take to get it to 26k rpm and then set it up that way!

RE: found a motor
 

Hey nick......................are they 550's? (36x57) or 540's (36x50)?. Is the nominal voltage 12v.........where they came up with no load speed of 28,000 rpms?

RE: found a motor
 

the ones i have (x2)are35mm wide, 65mm long (3565) same can diameter as my sp500's and my ansmann clash motors (2x 28 turn, 1x 15 turn)so i suppose they could be considered as 550 long, nominal voltage is 6v-12v, i have put a lipo on it and it span up quite loud but i'll try again and see what happens

2 of them pushed a scratch built landingcraft up onto plane at about 10mph, the boat was about 3kg plus a rc tank that wieghed just under1 kg and they were on straight shafts aswell with 45mm 3 blade props

RE: found a motor
 

Wow...................600's, that would not really help in his nitro vee as a single motor although it would go, but it could be an upgrade for his villain. He could run the two 600' and 10 cells in parallel...............and gear it acoordingly. Hmmm

RE: found a motor
 

well, im wondering what gear ratio to use if i was to put one in 20" cat or even a hydro on a straight shaft, certainly gives you something to think about

what would you do??

prop, battery etc

RE: found a motor
 

i think that's a mini-ev motor
http://www.robotcombat.com/products/0-MMEV.html
hope this helps

RE: found a motor
 

having looked at the link, its the wrong size motor but it looks like the motor is mentioned there, thanks for looking it up

RE: found a motor
 

ernest2, I'd say thats it.  I was just eyeballing the measurements against a measuring tape.  Looks like it would spin to slow.  Maybe I need to build a tank, or some kind of military vehicle. . .  and customize a paintball pistol to fit it! (I used to run Warheads Paintball Inc. so I have lots of that stuff around)<div>
</div><div>I guess I will go LiPo brushless crazy for the Nitro V.</div><div>
</div><div>I bought a <span style="font-family: Arial, Helvetica, Verdana, sans-serif; font-size: 13px; line-height: 19px; ">Digital Laser Photo Tachometer off ebay.  I hope it works, but for $0.90 and minimal shipping, not to bad if I can only use it on a real motor.</span></div>

RE: found a motor
 

Here is a link to a hobby tachometer: http://www.horizonhobby.com/Products...?ProdID=HAN156

RE: found a motor
 

Well, that tach showed up today.  So here's what happened.<div>
</div><div>I tested it with the prop in the picture It spun about 17,000 rpm @ 14.8V.  I was pretty disappointed because the prop is not a huge load, though it moves allot of air.  I decided to test it unloaded.</div><div>
</div><div>I put a small pice of electrical tape on the shaft, and stuck a piece of the reflective tape (for the tach) to that.</div><div>
</div><div>Unloaded the motor spun 23,800 rpm @ 14.8V, hell yeah!!!</div><div>
</div><div>I was using to old crapy 6 cell NiCad packs wired in series. So running 12 cell.</div><div>
</div><div>The 14.8v was about where the packs started to hold voltage, so thats the reading I took. </div><div>
</div><div>I think I am going to through this motor into the Nitro V with a simple mechanical speed control I pulled out of my Stampede.</div>

RE: found a motor
 

You should run it on 14 cells!!! That would be unloaded around 27,500, good rpm range for direct drive!

RE: found a motor
 

I decided I was going to buy 8 cell packs for the Villain, so I will run 16 cell in that bad boy! But for now, 12 will have to do.

I have been unable to find a good sized ESC to run on this brushed motor, everything seems to be for brushless. Any recommendations?<br type="_moz" />