Cab forward wheels

[hotrainlover]

Dear Board,
I purchased a Cab Forward front to convert a loco.  The 4 wheel truck that came in the kit has (1) 33" wheel set, and (1) wheel set that has bigger wheels.  They are plastic, and I planned on replacing with metal ones.  The problem is that I cannot find the "Bigger" set on Walthers, and do not really know what size it is.  How do I measure the wheels?  Do I measure the actual wheel, including flanges; with a caliper?  Or the the wheel, NOT including the flange?

[richG]

Measure the wheel or sometimes called the tire, not the flange. Convert using 87.
Where did you get the cab front and four wheel truck?

http://home.att.net/~c.h.waters/conversion_factor.htm

Rich

[hotrainlover]

Rich,
It is a kit that is offered by a Store near here.  If you want more info contact me off list, and I will scrounge it up.  It also came with the pieces to convert the tender to an oil burner.

[richG]

That sound like what I bought to convert a Mantua 0-6-0T into a cab forward oil fired 2-6-0.



I bought the loco and parts from the below person.

http://www.yardbirdtrains.com/YBDetailParts.htm

Rich

[hotrainlover]

Rich,
YES that is also who I used.  His place is about 200 mi. from me...

[hotrainlover]

Rich,
By the way...  I love the "cow catcher" on your engine.  Is it scratch built?

[hotrainlover]

Rich,
IF I read this right...

.4535/.03937 x 3.5 = approx 40.31 scale inch wheels?  Which is 40 inch wheel sets?  Right?!!

[richG]

The pilot is Precision Scale 3328, Santa Fe pilot cage.

http://www.walthers.com/exec/productinfo/585-3238

http://www.walthers.com/exec/page/search

I Just happened to know the part number. Here is an example of how to search for the Precision Scale parts, Manufacturer 585. You can enter the keyword, say pilot. or stack, or cab, etc. Just remove the 3238. I have the HO/Hon3 catalog but they cost $10.00 which is a good investment if you do a lot of super detailing.

http://www.precisionscaleco.com/

Yes, it is a 40 inch wheel but where did you get .03937 x 3.5 ?

The two wheel lead truck I got measures .317 inch tire = 27.579 inch tire.

Rich

[Jim Banner]

.03837 is approximately the reciprocal of 2.54 which is the number of millimeter in an inch.

H0 is 3.5 mm scale i.e. 3.5 mm = 1 foot  (Just like we talk about 1/4" scale and 1/2" scale, when we mean 1/4" to the foot and 1/2" to the foot.)

Dividing the measurement by .03837 gives approximately the diameter in millimeters.

Multiplying the diameter in millimeters by 3.5 does not give you anything.  In this case, it just happens to be close to the correct answer.

A better conversion would be

.4535 in x 25.4 mm/in = 11.5189 mm

11.5189 mm / 3.5 mm/scale ft = 3.2911 scale ft

3.2911 scale ft x 12 in/ft = 39.493 scale inches

Note that multiplying by 25.4 gives an exact answer because the inch is defined as exactly 25.4 millimeters.

Dividing by 3.5 and multiplying by 12 do not require you to use irrational number either.  So if your measurement is exact, your answer is exact to the number of decimals your calculator can produce.

That's the long explanation.

The short explanation is that I think that 2-6-0 cab forward of yours is GREAT!

[richG]

Ok, I guess. All I do is measure with a caliper and multiply inches or mm by 87. I have to use the KISS principle. I was never good with math.
Good luck on your project.

Rich

[Jim Banner]

Rich, that is what I do too.  The long method is for when you want to impress yourself with 10 decimal places.

[richG]

I can do the HO conversion with a calculator. Fortunately with the advent of the Internet, I have found many online calculators. Here is the one I use for Metric. I could never remember the conversion.

http://www.worldwidemetric.com/metcal.htm

Rich

[hotrainlover]

I was able to get the info from the link above.

http://home.att.net/~c.h.waters/conversion_factor.htm

Thanks for the help.

[richG]

Great, glad to hear it. For many years I have had a plastic dial caliper. The dial is US measurements to .001" with a small graduated scale in MM on the plastic body. Some error when trying to read MM.
Eventually, I bought a digital caliper with inch/mm measurements. Now all I have to do is to remember to turn of the device as it does not have a power saving mode.

Rich

[hotrainlover]

Yes,
I have a digital one too.  The batteries are expensive though.  I have forgotten to turn mine off several times