# NER EE-1 Nightmare with 936 teeth -part 2



## ralphbrades (Jan 3, 2008)

Well a slight re-cap.

This is experimental gearbox number 1 -which I though was far too fast with a ratio of 1:37.5 *20:40 10:30 16:100*











This is production prototype gearbox number 1 -which is far too slow with a ratio of 1:750. *1:30 10:40 16:100* 

However this concoction of 60 thou ABS sheet and balsa *did* actually propel the loco.











This is production gearbox number 1 which I now think is "about right" with a ratio of * 20:30 10:40 16:100* 

Yes the gears are the same as in experimental gearbox number 1 -but they are arranged differently. This is to produce a smoother increase in torque. The gearbox is made from 0.6cm thick polycarbonate and the 0.4cm thick shafts sit in ball races. The gearbox has been coupled to my milling machine and the gears broken in at stepped speeds -the final was 2,000 RPM and there was no apparent distress. The polycarbonate is quite easy to work with -just VILE!!!












The next shot shows the spine with the quill drives installed into the loco chassis. The two transverse bars transfer power from the spine to the chassis. The two end gearboxes will also mount onto the stubs via a simple L bracket. The 1cm steel axle shafts can be seen in their ball races fitted to the horn blocks, (the horn guides are not yet fitted).











The next shot shows the two gearboxes in their position, (just placed there for the shot), and a motor in the position that it will occupy in relation to the gearbox -simply Blu-Tacked there(!) The motor will drive the gearbox via a 1:1 cog and chain system. The MM534M motor has a stall torque of 1,800 Gramme Centimetres, after the sequence I have found that only one of this type of motor would move the loco, (and it will have three)...












When I have finished mucking about with the gearboxes I promise that I will "P" clip the wiring loom back into position !!!


regards

ralph


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## david bunn (Jan 4, 2008)

Very inspiring Ralph.I admire your dedication to this project and the results, they are superb.It will be great to see the finished beast.What next I wonder? 
Regards 
David


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## Les (Feb 11, 2008)

Ralph,

That's awesome looking. The workmanship is superior, too. Makes me want to get going on something.

Les


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## dltrains (Jan 2, 2008)

Ralph I'm still here following the build. I've been to your site also. So what is the final gear ratio with that configuration? And math formula if you don't mind enlightening me.? 

Dave


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## ralphbrades (Jan 3, 2008)

Les, 

Thankyou for the compliment -I personally think it is a *hideous mess* that is best hidden under the bodywork! 


David,

This: http://www.cabbagepatchrailway.co.uk/metrovick.html

Dave,

The final ratio of the production one is the same as the experimental one .*1:37.5*


This is worked out as follows:

{(20 / 30) x (10 / 40) x (16 / 100)} = (1 / R) 


{0.666 x 0.250 x 0.160} = (1 / R)


0.02664 = (1 / R) 


1 / 0.02664 = R


* R= 37.54 * 

The next problem is that the Bull Gear is smaller than the Drive Wheel so that the output ratio from the gearbox RAISES. 


This factor is *70:95 * -so the final effective drive ratio from motor to drive wheel is* 1:27.37 *


Henry Greenly recommended a ratio of between *6.5:1* and *8.5:1* for Gauge 3 models. However his 1920's motors were series wound and had armatures circa 5-7cm across. The modern permanent magnet motor has smaller armatures but can operate at far higher speeds. And to be honest I think that Henry Greenly ever contemplated an electric locomotive weighing in at 20Kg. The motor is capable of 16,500 RPM which gives a *physical speed* of 3.03 Metres per second equates to a *scale* *speed* of 151 MPH. Which I think is fast enough as the original was only supposed to do 86MPH with 16 teaks behind it.


regards

ralph


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## david bunn (Jan 4, 2008)

Ralph,excellent choice for next project,more nightmares I reckon. 
David


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## dltrains (Jan 2, 2008)

Ralph thanks for the quick indepth reply Dave


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## Les (Feb 11, 2008)

Posted By ralphbrades on 29 Aug 2009 01:20 AM 
Les, 

Thankyou for the compliment -I personally think it is a *hideous mess* that is best hidden under the bodywork! 


David,

This: http://www.cabbagepatchrailway.co.uk/metrovick.html

Dave,

The final ratio of the production one is the same as the experimental one .*1:37.5*


This is worked out as follows:

{(20 / 30) x (10 / 40) x (16 / 100)} = (1 / R) 


{0.666 x 0.250 x 0.160} = (1 / R)


0.02664 = (1 / R) 


1 / 0.02664 = R


* R= 37.54 * 

The next problem is that the Bull Gear is smaller than the Drive Wheel so that the output ratio from the gearbox RAISES. 


This factor is *70:95 * -so the final effective drive ratio from motor to drive wheel is* 1:27.37 *


Henry Greenly recommended a ratio of between *6.5:1* and *8.5:1* for Gauge 3 models. However his 1920's motors were series wound and had armatures circa 5-7cm across. The modern permanent magnet motor has smaller armatures but can operate at far higher speeds. And to be honest I think that Henry Greenly ever contemplated an electric locomotive weighing in at 20Kg. The motor is capable of 16,500 RPM which gives a *physical speed* of 3.03 Metres per second equates to a *scale* *speed* of 151 MPH. Which I think is fast enough as the original was only supposed to do 86MPH with 16 teaks behind it.


regards

ralph 



Ralph,

No, that's good workmanship, particularly for a handbuilt one-off, so to speak. (I know two more are in the pipeline--assuming one with each motor and I don't see how you could do it otherwise).

Uhh ... I've been somewhat ill the past days, so when you posted earlier on figuring gear ratios, was it thus: {starting from motor shaft gear, the number of teeth divided by the number of teeth of the next driven gear} x {3rd gear up the line (driven by first set) divided by # of teeth of 4th gear} x etc?

All I want to do is design a 'generic' (!) gearbox so that I can take a motor of unknown RPM's with a spur gear of unknown tooth count and come out with about 40:1 at the wheels. I have a wide range of motors & gears, some from R/C cars, some from other toys, but no way of checking the rpms unloaded, and with only vague plans to compare current draw unloaded vs current draw loaded to some resistance that seems reasonable. My present plan is to select a suitable-looking motor, do the above electrical measurements, and start going through my drawers of gears until I come up with the output shaft going much slower than the motor shaft, then time it along a known distance, say 10 feet, and 'tune for effect' as the oldtime radio amateurs used to say.

After all that excitement is passed, I'll do some drawbar measurements with a pulley and known weight. I only intend to pull 3-4 car strings of short 2 axle cars. After that, I'll have all the technical information my little RR deserves.

Les


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## ralphbrades (Jan 3, 2008)

Les,

To be honest with you *I would cheat!!!* Although there are a multiplicity of motors available they do fall into certain recognisable configurations. This is one of the largest suppliers of small DC motors in the UK. 


http://www.mfacomodrills.com/motors/motors.html

Now if you work your way through the list you will find that 90% of the motors that you have will find a "match" with one of the spec sheets there.


Right, one of my alternate personae is, The Secretary of the Gauge '3' Society, and in this persona I have written a large document called "The Technical Manual" -it runs to 148 pages of A4... If you like I can forward you by e-mail the relevent parts on Gears and Motors?


regards

ralph


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## Les (Feb 11, 2008)

Ralph posted: "Now if you work your way through the list you will find that 90% of the motors that you have will find a "match" with one of the spec sheets there."


Uh-huh. After taking a number of these dead vehicles, robots etc apart, I had an idle moment and began visually inspecting them. Many _look_ identical, and I'll hazard that a number of them even carry the same part #. When you figure that all these things were made in China, the chances of coming up with duplicate parts is quite large.

I did err: I said I wanted a ratio of 1:40, but what I want is much larger, I want all my engines will be 'creepers', in that I don't want a great deal of speed, something in the range of the Shays. Power at the drawbar is not important, save that it's got to pull a few cars.

Part of the reason I'm doing this is to see if I can. I delight in making something from nothing, or re-mixing second-time-around parts to create something I want.

What I have been putting off is looking into the Machinist's Handbook on the subject of gears. It made my head hurt the last time I did that. 

I'm going to flag your post so I can save it, and if I can't make any progress, I'll ask you to email it across.

A little frustration: every time I get ready to build a bench and lay track, someone in my household get sick, or something expensive breaks, or a long-delayed repair has to be done, and I'm out of $ and energy for weeks to months, depending.

Thanks for your generous offer.

Les


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## Torby (Jan 2, 2008)

If you want to build stuff that *works*, weird or otherwise, get to know our Mr. Brades.


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## Les (Feb 11, 2008)

Posted By Torby on 30 Aug 2009 12:11 PM 
If you want to build stuff that *works*, weird or otherwise, get to know our Mr. Brades. 



I rather feel I do, within the restrictions of the medium and his off-board occasional communication with me. It's rare that a man of his educational status will help lesser folk so willingly.

I find your other comment, re '*works' *vaguely insulting, given the oddball problems I used to solve in the XP shop at MAC, let alone running a down-at-the heels Ozark farm to the Tri-county's 3rd largest feeder pig operation in slightly over a year. I like to think else. And I've proven myself to the only person who really matters: me.

Les


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