I received the ten Mabuchi SF-266SA motors I ordered on Oct 2 Saturday the 26th. I first checked out the two motors I intended to install in an Athearn SD40-2 frame that will receive a Hobbytown Cast metal E7 body.
I built up a crude dynamometer using a pair of SF-266SA motors each with it’s own 0-.999 amp digital ammeter connected to the motor terminals. With the ammeter directly across the motor connections when they are turned by the test motors they become generators, equal RPM in the generators equal milliamps on the digital meters.
I connected the two motors under test with metal universal joints to the generators. I parallel the two motors under test from my bench 0-20 volt power supply, same voltage to both motors.
In this test I used one new Mabuchi SF-266SA and a Canon EN22-R11N1B.
I was both surprised and very happy to see that the two motors track very close to each other. The Canon produced slightly less current at the low end and just a tad more at max RPM.
As far as I’m concerned they are an exact replacement motor for the Canon EN22 at a fraction of the cost as well as readily ava
I modified three of these Athearn U33Cs with dual motors and extra weight…
The motors are from Mashima, and are mechanically independent of one another - my thought, at the time, being that if one truck slipped due to track condition, the other might not…
Each of them weighed 33oz., although if I had kept them, I’m positive that I could have got them to at least 40oz. each.
Other than running them with various heavy trains, I had no scientific way to determine their drawbar pull (I later acquired the test meter from MicroMark, but by that time, the diesels had gone to a friend in Wisconsin).
I did, however, manage to arrange for a nearby club to test (and quantify) their pulling ability, and they determined it to be 8.3oz. per unit…about what I would have suspected, relative to some info I’ve read on power relative to adhesion (weight), which works out to roughly 1/4 of the loco’s weight.
My own tests with heavy trains (not so precise, I’d guess) was to use one of those U-boats on a train of loaded hoppers on the curving 2.8% grade between Elfrida and South Cayuga on my layout. It’s an elongated S-curve just under 18’ long, with a straight stretch of track about 3’ long separating the two curves.
I don’t recall the test train’s length, but it was 44 loaded hoppers with a total trailing weight of 22lbs.
The single loco moved the train easily until it (the locomotive) left the curve at the top of the grade and entered straight track, where its wheels began to slip.
I would have liked to have been able to perform the test on the much longer grade to the second level (45’ with two curves, lef
The most weight I’ve added to a locomotive is 16 oz. That brought the Model Power E7A & B up to 28oz each. Both have Canon EN22 dual shaft motors, haven’t checked the drawbar. I would guess in the vicinity of 8oz for both.
It takes at least 5oz drawbar to pull 11 Athearn 72’ passenger cars up my 3½% grade. My Cab Forwards have 5.8oz and the wheels slip occasionally pulling 11 Athearn Heavy Weights up my 3½% helix. I normally operate my layout twice around counter clockwise which makes the helix the down grade.
Nothing has been a problem for a pair of my 2¼ pound E7s. They will pull the paint off the walls.
I have continued my testing of the Athearn SD40 frame with the dual Mabuchi motors and they look better with every test.
I increased the total locomotive weight to 3.119 pounds and the wheels do not stop. With the wheels slipping I measured the drawbar at 9.4oz and the total current at 6.24 volts was 630ma or 315ma per motor with very little increase in motor heat after 10 minutes. The room temperature is 69° and after 10 minutes I could tell a slight warming to the touch.
The motors measured 2250 RPM at 6.24 volts ÷ Athearn gear ratio 12:1 = 187 wheel RPM 42 " scale wheels = 40 MPH scale speed of the locomotive.
Bottom line is the Mabuchi SF-266SA is a extremely good motor.
I’m really interested in these. I’m curious to know how consistent these are and if there are any problems to be had if one spins at a slightly different speed than the other.
I do have some oldies that could use an upgrade and this seems like a way to do so without investing alot in cheap locos.
I have purchased a total of 12 so far everyone are the same max RPM ± about 100 at 6700 RPM (seems to be max at 12 volts). I think that’s the best I can measure them with my meter and power supply. Tenths of volts makes a large difference at the high end.
Pretty darn good quality for the money.
EDIT:
I thought I would post a picture of my RPM Meter
It measures the RPM by counting the reflected Laser beam off the white stripe I painted on the universal. The meter is quite accurate for a cheapie.
As always you can click twice on the picture to enlarge.
Nice find on those motors! I’ll have to keep those in mind. Mabuchi’s motors have done very well for me in my projects. Two of the somewhat small FK-130SH motors were powerful enough to drive a DD40!
By the way, here’s a slight correction to the scale speed calculation based off motor RPM for you. I hope this helps!
2,250RPM ÷ 12 gear reduction = 187.5 wheel RPM
42" x Pi = 131.9469" ÷ 12 = 10.9956’ wheel circumference
circ x 187.5 = 2,061.67 feet per minute
x 60 = 123,700.2107 feet per hour
÷ 5,280 = 23.43 scale MPH
To reach 40 scale MPH, the motor needs to run at about 3,840RPM. At the motor’s maximum 6,700RPM, the maximum speed will be about 70 scale MPH.
You are correct I missed that one. I went back over my calcs and it came out correct, I’ll chalk that one up to a brain fart.[D)] I have no idea where that 40 MPH came from. The older I get the more often it happens.[sigh]
I ordered four of these on Oct 29th and they arrived today. Quick shipping from China. Not sure what I’m going to use them in, but the newest rule of Model Railroading is - If you see it, better get it, it may never be available again.
How many pole motor are they? 3 or 5? I have seem some skew wound 3 pole that would give a 5 pole a run for its money. For now, I stick with Canon or a high quality coreless when I repower a brass model. Should be interesting to see how these motors hold up in some long term use such as on a club layout that puts the locomotive thru its paces for several hours at a time.
The Mabuchi SF-266SA is a 6 pole non skewed Rare Earth Magnet (Neodymium) motor. I believe that the 6 pole armature makes it equal to the 5 pole skewed Canon EN-22 in performance.
Very good low RPM torque and smooth running from almost 0 to 6900 RPM (no Load). If anything I think the SF-0266 has more low end torque than the EN-22, again probably due to the 6 pole armature.
It is slightly smaller than a Canon EN-22 and my tests have shown to me that it is so close to the EN-22 that it makes a great replacement for the hard to find EN-22.
I now have Mabuchi SF-266 motors in four locomotives. One Athearn SD40-2 frame with a cast metal E7 body and three Rivarossi articulated, all run equal to the Canon EN-22 in similar equipped locomotives, all four of the locomotives have added weight.
As far as I’m concerned the SF-266 is a great replacement for the EN-22.
Sounds like a good replacment motor if it holds up in long term use. I use mostly the CN series from Canon and not the EN, wonder what the differance is in them? The motor in my PFM 2 truck Shay is a CN22. Mike
I think the EN22 has higher torque than the CN22. I have a Hallmark/Samhongsa E1A/B set that came with CN22 motors, and compared to the 3-pole DN22 in my Stewart/Ajin switcher, it’s easier to stall under load. It’s by no means a weak motor since I used one of them in my DJH 2-8-0+0-8-2 Garratt with great results, but it doesn’t seem quite as strong to me.
Mel has done a great job in his testing and review of this motor. A big thanks. It is way more than I found in the Remotor/Regear “Groupsio” where I first read about this motor while looking for an EN22 alternate. That group included lots of success stories in DC and DCC loco uses. If anyone is still somewhat skeptical about using this never heard of motor, they should again consider the fact that their current cost, just over $2 each, makes them a great gamble AND they are easy to find. I bought 8 but have used only 2 so far on which I removed the plastic end cap and shortened the drive shaft on each to fit space available. Mabuchi makes this motor for automobile rear-view mirrors. So, they maybe could be a future model railroad go-to motor. Thanks Mel.
I opened up one of my Canon EN22-R11N1B several years ago and it is a 5 pole skewed 12VDC - 6900 RPM (No load). I checked the RPM with my cheapie meter.
They apparently made a 3 pole CN/EN22??? motor at one time or another according to the picture below.
I’m pretty confident on the reliability of the Mabuchi 266 motors, there primary use is motorized rearview mirrors on vehicles. The mirrors on our Ford Freestar are still working OK after 12 years of Bakersfield heat. Before I ordered the motors off eBay I popped one of the mirrors out of the housi
Thanks Mel,
This is the main issue I was considering as far as using these. Two of these are still vastly cheaper than a motor and flywheels and I have a few old Athearn (some with and some without flywheels) that could use an upgrade.
I have some very nice condition (probalby 80’s or 90’s) Athearn BB open motor and flywheel sets (though not enough for all my old BB locos) and now I have some of these on the way. I may try both methods on similar locos and do a head to head.
Thanks again for all your work on this. Very helpful, especially for us budget railroad guys.
I got some of these motors from China through feebay and the price was right. Only took 3 weeks to get them here.
QUESTION: I also ordered one of those tachometers. I’m having a hard time getting a battery for it though. It seems there are no 6F22 9v batteries in NW Arkansas. Would a regular 9v battery work? I don’t want to damage the thing.
6F22 is just a plain old carbon-zinc 9V battery. The ones called “Heavy Duty” are usually just carbon-zinc batteries as opposed to the more common alkaline. An alkaline 9V is still 9V, so there should be no issue using whatever you have.
