Mashima 1015 motor - low torque problem

[Barry Ten]

Hello all. I took over a stalled chassis project from another forum member which involved a Comet gearbox and Mashima 1015 motor. The chassis had suffered some distortion which proved impossible to rectify, and by the time I built a replacement, I found that the motor seemed to have lost its power, in that the engine would stall under even a moderate load. Thinking I might have overloaded the motor during the testing of the old chassis, I ordered a new 1015 motor and yet found that it made no significant difference, with the engine still being gutless.

 

The chassis is free-running without the motor engaged, and I can't track down any stiffness in the chassis or gearbox which might be overloading the motor. In order to fit the motor into the engine, I had to trim the rear drive spindle but I've done this on previous motors without obvious difficulty. However I suppose it's possible I might have dwelt a little too long with the cutting disk. I'm wondering what the symptoms of a damaged or overloaded motor might be? It still runs silently, so I don't think the bearings are damaged, but might I have weakened the magnets? I find it odd that both motors seem similarly feeble.

 

Any suggestions gratefully appreciated.

 

 

[ngtrains.com]

I believe that motor is noted as being feeble. Can't remember where I saw it now but I have seen one of the custom built chassis websites advising against using it because of that

[34theletterbetweenB&D]

The much superior alternative - roughly 3x the power - is the Hanozono (also sold as Tenshodo) 'minimotor' (equates to 915 in Mashima dimensions, with a 1mm dia shaft) which is a complete beast. If the small motor size is critical for fit in the model, this is the one to use. Needs a large reduction though, has to spin at about 20,000 rpm for maximum power development.

[Barry Ten]

The 1015 is the recommended motor for the Comet Dean Goods chassis - space is tight! The gearbox has to be underslung. Others seem to have had success with it, so I wonder what I'm doing wrong.

[Thane of Fife]

I have two Mashima 1015's in docks tanks with High Level 108:1 gearboxes. They are ex-NER Y7 & Y8, from NuCast & Kay's kits.

They are both on scratchbuilt chassis. They run very well; extremely slowly, but that is how I wanted them to run.

The Y7, being heavier is the better hauler/pusher. It will shunt six coaches quite happily, The Y8 will shunt four coaches before spinning. 

If lead was added to the locos, I think they would haul more.

I have a J71 converted from a Mainline J72, fitted with a Mashima 1020 and 80:1 gears. It has quite a bit of lead added. That will handle 20 wagons easily. 

You haven't said which ratio Comet gearbox you are using. If it's 38:1, then I doubt whether the motor can get up to its best operating revs.

According to my calculations;  Mashima 1015 running 38:1 gears and 20mm drivers would have to run at a scale speed of over 50mph to reach it's maximum power.

However, with 108:1 gears and 14mm wheels (my Y7), it's only 10mph. 

 

Thane of fife

[34theletterbetweenB&D]

The EM Gauge society had a good summary of motor characteristics which allows simple appreciation of what gearing to apply for a desired speed range, and from what speed the maximum power output is developed. Is it online, don't have time to run a search now?

 

The short answer is 'small motor, big reduction required, expect it to have no great speed; larger motors, smaller reduction is feasible, makes it possible to have scale maximum speeds.

[Thane of Fife]

I have just checked the Y7 and it will shunt 20 wagons, but spins wildly if load increased.

If there was more adhesion (lead in boiler & sidetanks) it would move more, but who needs a dock shunter to move more than 20 wagons?

 

Thane of fife

[Tim V]

Heat could have weakened the brush springs.

 

I've used a number of these motors with complete success, but I make a point these days of never cutting off any shafts. Also as others have said what ratio is the gearbox? I use the 54:1 by High Level.

[Barry Ten]

Hi all - thanks for the comments. I think the gearbox must be the Comet 38:1 one. I didn't build it, though, only inherited it as part of the sale of the unfinished project.

 

I regret not doing a partial test with the spindle not cut off, but I needed to remove it to fit the body, which has most of the weight in it.

[Thane of Fife]

I have never used a disc to cut a motor spindle as I like fitting a flywheel.

However, everything gets hot when I use a cutting disc. 

You can get replacement springs and brushes.

The High Level Humpshunter gearbox is about the same size as the smallest Comet gearbox. It gives 60:1, 80:1, and 108:1 gearing. I have used it in my Y7, Y8, and J71 shunters.

You can download a gearbox planner from both Comet and High Level.

 

Thane of fife

[34theletterbetweenB&D]

For cutting a motor shaft, I still use a technique shown me years ago. Eye protection! Lightly clamp motor body, put mole grip or similar on waste part of shaft as heatsinking, put water (spit!) on tool jaws and shaft contact area for better effect, make cut fast with disc at maximum rated speed. The motor shaft will be a handholdable temperature by the time the cutting tool is turned off and put down, if done right.

[Barry Ten]

I agree about the eye protection - very sound advice.

[Andy Reichert]

I think motor torque is directly proportional to armature diameter if comparing otherwise identical motors. So never use a narrower motor than absolutely necessary.

 

Andy

[Barry Ten]

Just reporting in that I've tried a third 1015 in the Dean, this time without touching the motor spindle in any way, and it has much the same characteristics of the first two. Interestingly, after removing a small amount of ballast weight, I found that I could get the body on without cutting the spindle, so it may never have been necessary.

 

Over on this blog thread, Buffalo suggests that the motor/gearbox combination is not well matched for a Dean Goods. This seems to fit my experience as the loco runs well, if unrealistically fast, at top speed. It's only at the lower, more realistic speeds that the motor seems unable to supply enough power.

 

http://www.rmweb.co.uk/community/index.php?/blog/1569/entry-15188-the-locomotive-shop-dean-goods-2322-part-1/

 

I think I need to start looking at other gearboxes...

[Red Devil]

I've had a couple of not very good 1015s in the past. A poster further up relates to a website warning about them, I can't remember exactly where but somewhere it was mentioned on the Hollywood Foundry site that it was not a recommended motor for their various drive systems as they found that it could sometimes be classed as 'weak'.

[Barry Ten]

I've had a couple of not very good 1015s in the past. A poster further up relates to a website warning about them, I can't remember exactly where but somewhere it was mentioned on the Hollywood Foundry site that it was not a recommended motor for their various drive systems as they found that it could sometimes be classed as 'weak'.

 

Yes, I've also had some helpful advice along those lines from Hollywood Foundry.

[PGC]

As other posters have said, the 1015 can be a good motor, but needs to work at high revs to give of its best, so a high reduction gear box is necessary.

 

Like Thane of Fife, I have a Y7 (but mine's built from a Pocket Money Models kit and no longer available - great shame!) and it's powered by a 1015 with a Porterscap (from Backwoods Miniatures, also no longer available - another great shame!) 80:1 gearbox, the loco runs very sweetly, as this clip shows 

 

Being a GER modeller I know nothing about the Deans Goods to be of informative help, but I would suggest, as others have, that you download the High Level gear box planner and try another gear box with a higher ratio.

 

Phil

[Horsetan]

....a Porterscap (from Backwoods Miniatures, also no longer available - another great shame!) 80:1 gearbox,....

 

I sold one of these recently on eBay, but I think mine was the 54:1 variant.

 

The Backwoods Porterscap range seemed to be very much overwhelmed by High Level's range, which to me looked very similar in execution.

[Dr Al]

The 1015 is ideal for N gauge use, as it's the same dimensions as some Farish N gauge motors, and Union Mills, whilst is 5 pole and much superior slow speed performance.

 

For N the torque out is more than adequate to pull 50 wagon trains.

 

Cheers,
Alan

[Thane of Fife]

I think the 1015 would be too small for a Dean Goods. 

 

I would aim for a 1024 which is about three times more powerful than a 1015.

The 1024 is another high revving motor and needs a high ratio gearbox. 

I would look for 54:1 or 60:1 gears to provide good slow running.

 

Thane of fife

[Bulldog]

 Converting a Dean goods at the moment.

 The high level kits roadrunner +  gearbox, ratio 54:1 with a mashima 1220 fits.

 A little needs to be shaved off the bottom  edge of the cab back head.

 High levels speed calculator gives an estimated  scale top speed  of 58 MPH.

[Barry Ten]

Thanks for the advice, all. Looks as if I will be going down the High Level route in the New Year.

[halfwit]

on the subject of cutting motor shafts, after wrecking a motor using a cutting disc I now use a triangular needle file, see this topic.

[micklner]

High Level recommend the 1024 for their Dean Goods chassis with a 108.1 box

 

http://www.highlevelkits.co.uk

[Quarryscapes]

FYI I have an 80:1 High Level gearbox and 1015 in my Dean Goods, could have fitted higher gearing in there too but didn't know at the time how the different ratios were accommodated in the same box so played it safe at 80:1. 

 

Their own chassis only has 50:1 though.