[HOsteam] Hello I'm new, Loco regear


Les Grenz <lesgrenz@...>
 

From: marshall <zephyr03@swbell.net>
Reply-To: HOsteam@egroups.com
To: HOsteam@egroups.com
Subject: Re: [HOsteam] Hello I'm new, Loco regear
Date: Fri, 02 Jun 2000 20:16:15 -0500

Les Grenz wrote:

Greetings - I am new to this list. I model Colorado loosely in HOn3.
I do some loco repair primarily for myself. I would like to know if
anyone can refer me to a source for determining motor RPMs, gear
ratios, mph, etc. when remotoring. I see a lot of information in the
NWSL catalog but not specific formulas. Help anyone.
Take the motor RPM. Any gear set you are considering will have a fixed
(and usually listed) ratio such as 1:31 or 1:17. Divide the motor RPM
by the ratio (i.e. 17000 divided by 31) to get driver RPM. Multiply
your selected driver diameter by pi (3.1415926etc) to get travel per RPM
in inches. Multiply the travel distance by 720 (12" x 60 min.) to get
miles per RPM. Multiply that by the peak motor RPM and you have the top
speed of the remotored/regeared locomotive in scale miles per hour.

Marshall
Marshall - Thanks for the info. Exactly what I needed.

Regards from Les Grenz & the
Queen City of the Rockies.

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marshall <zephyr03@...>
 

Les Grenz wrote:

Greetings - I am new to this list. I model Colorado loosely in HOn3.
I do some loco repair primarily for myself. I would like to know if
anyone can refer me to a source for determining motor RPMs, gear
ratios, mph, etc. when remotoring. I see a lot of information in the
NWSL catalog but not specific formulas. Help anyone.
Take the motor RPM. Any gear set you are considering will have a fixed
(and usually listed) ratio such as 1:31 or 1:17. Divide the motor RPM
by the ratio (i.e. 17000 divided by 31) to get driver RPM. Multiply
your selected driver diameter by pi (3.1415926etc) to get travel per RPM
in inches. Multiply the travel distance by 720 (12" x 60 min.) to get
miles per RPM. Multiply that by the peak motor RPM and you have the top
speed of the remotored/regeared locomotive in scale miles per hour.

Marshall


Les Grenz <lesgrenz@...>
 

From: marshall <zephyr03@swbell.net>
Reply-To: HOsteam@egroups.com
To: HOsteam@egroups.com
Subject: Re: [HOsteam] Hello I'm new, Loco regear
Date: Sat, 03 Jun 2000 07:26:57 -0500

Les Grenz wrote:
Sorry, Les - I must've been tired . . . . I didn't have the last part
right:

Got it! Thanks again Marshall.

Regards from Les Grenz & the
Queen City of the Rockies.

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Ken Clark
 

In a message dated 6/2/00 10:49:06 PM Pacific Daylight Time,
lesgrenz@hotmail.com writes:

<< determining motor RPMs >>
For HOn3, motor RPM may be the most limiting factor for engine speed. In
brass models almost all of the manufacturers seem to have used a gear ratio
of around 28:1m the NWSL gearboxes designed to fit HOn3 models typical axle
size of 2.4mm also use this gear ratio. Some older Japanese models have axle
gears virtually identical to the NWSL gearbox. Unlike standard gauge, the
wheel diameter for narrow gauge engines seems to be within a fairly limited
range of 36" (C-16) to 44" (K-36), for example. with the same gearboxes and
a driver size range of 20% + / -, the big variable in model operations tends
to be motor rpm.

AS an example, the sunset C-16s and the WSM k-36 used completely different
motors but both had 12 volt RPMs around 5,000. By comparison a Sagami 1420
had a 12 volt rpm of 28,000, and a Sagami 1630 (about the strongest, best
running Sagami motor for HOn3 use) has a 12 volt rpm of 15,000. Comparing
the sunset C-16 mashma motor to a similar sized Sagami 1420 you see that for
HOn3 models you can find motor rpms varying by almost 600%, far more than can
be oversome by the typical gearbox and driver diameter changes. Unfortunately
the coreless 1230 used in the WSM K-36 is pretty gutless and needs the
increased gear ratios typically found only in geared (logging) steam engine
models.

By the way counting teeth on the gears in a model shay, climax or heisler
can lead you to a big mistake. For instance the WSM Westside Lumber Co. #3
used two worm/worm gear reduction sets in the gearbox; each worm gear had 15
teeth, I calculated the total gearbox reduction as 225:1 (15x15=225), boy was
I wrong. These models used a double spiral worm (instead of the typical
single spiral worm), so the gear reduction was only 7.5:1 and the total
gearbox was only about 56:1, a big difference.

The big problem with small motors, is that some run slow normally and others
only because they are underpowered and overloaded by the mechanism. With
NWSL motors having published specs, this can be determined, but many of these
models have motors for which the importers/builders have not furnished data.
A lot of modelers use the trial and error method of motor selection, while
others stick to 'if it ain't broke, don't fix it...'


ken


marshall <zephyr03@...>
 

Les Grenz wrote:
Sorry, Les - I must've been tired . . . . I didn't have the last part
right:

*Multiply the travel distance by 720 (12" x 60 min.) to get
miles per RPM.*
WRONG! Mutlipy the travel distance by *FIVE* (60 sec divided by 12") to
get *FEET* per hour.

Multiply that by the peak motor RPM and
--> *DIVIDE BY 5280 FEET PER MILE* <--
you have the top speed of the remotored/regeared locomotive in scale
miles per hour.
I gotta learn to check my work before I hand in the paper <LOL>

Marshall


Les Grenz <lesgrenz@...>
 

From: kenrclark@aol.com
Reply-To: HOsteam@egroups.com
To: HOsteam@egroups.com
Subject: Re: [HOsteam] Hello I'm new, Loco regear
Date: Sat, 3 Jun 2000 11:57:05 EDT

In a message dated 6/2/00 10:49:06 PM Pacific Daylight Time,
lesgrenz@hotmail.com writes:

<< determining motor RPMs >>
For HOn3, motor RPM may be the most limiting factor for engine speed. In
brass models almost all of the manufacturers seem to have used a gear ratio
of around 28:1.
Hi Ken - "If it ain't broke, don't fix it." Good advice. I, however, have in my posession a Precision Scale K-28 sent to me for repair. The problem is this individual aquired it sans motor, gear box, motor mount, axel pillow block covers, draw bar, etc. I am requested to come up with a smooth running engine. Also missing are several little screws and rivets. I was supplied with a NWSL #146.6, 28:1 gear box and a minimotor gear head motor which I think has a 400 something RPM. One could perhaps senic a small railroad in the time this loco would make one trip around the layout. I think I will return the locomotive. The gear box will have to be replaced. It can be mounted with a little milling to clear chassis cross members. The motor is much too slow and large to fit. This is all in addition to making numerous small parts. I guess if it were my own I would make the effort. Thanks, however, for the advice and input.


Regards from Les Grenz & the
Queen City of the Rockies.

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