Scale

[First Timer]

Hi guys,  I just want to find out something about MTH's and Lionel's SD70ACe.  MTH's measurement is 18 1/2 and Lionel is 17 1/2.  I was told that all MTH premier lines are scale size.  Will that make the Lionel version not scale since it is 1 inch shorter?  Or is the measurement of MTH from coupler to coupler and Lionel isn't.  I have a chance to get a Lionel version but having double thoughts because of the size.  Before I started on this hobby, i have decided to use only scale size locos.  Any advise or input will help.

Thanks

Glen 

[rtraincollector]

This may be a little confusing but I believe ( may be wrong) the difference here is that they both are scale just one uses a different scale than the other as in O gauge we actually have three scales 1:43, 1:48 and 1:50 now if the Lionel was 1:50 and the MTH was 1:48 it would be a little longer not sure exactly how much but there would be a difference.

basicly if 48  of and item = 100' and then some one else diid it where 50 of them = 100' you would see that of coarse the one that 48 was acually longer.

This is how I understand it any way so what you need to figure what scale you want to go with 1:50 or 1:48 then you will know which company you want to deal with or be happy knowing that there both scale just a diferent scale.

[lionelsoni]

I don't know who considers 1/50 to be O scale; but it is a popular scale for model airplanes and the like.

The three O scales that I am familiar with are 1/48, 1/45, and 1/43.5.  American O is 1/48, both for toy trains and scale models.  The scale modelers alter the gauge downward from 1 1/4 inches to match the scale.  Europeans use 1/45, keeping the gauge approximately the same as ours.  Since 1 1/4 inches is 31.75 millimeters, they consider the gauge to be 32 millimeters.  The British like to express scales quaintly as the number of millimeters per foot.  For them, O becomes "7 millimeter scale" or 7 millimeters per foot, which works out to about 1/43.5, often truncated to 1/43.  This scale is the scale that HO ("half O", 1/87) is half of.

[jmkk]

I would have to guess thy are both 1/48 scale. I think the difference is in one measuring the coupler and one not. Comparing some scale MTH cars to some scale Lionel the are as close to identical in length as can be measured.