"Mapping gettysburg" Topic

I am doing the first day of Gettysburg and have plenty of maps, but was wondering how to scale them to 10mm. Any tips would be welcome.

Thanks,

you need to know the scale of the map so say 1:5000
this means 1in on the map is equivalent to 5000in in real life

so divide the 5000 by 161 (161 is 10mm scale) to give 31.05in at 10mm scale if you then multiply the 31.05 by 100 it gives you the percentage to enlarge the map by so 3105% in this case

so (map_scale/figure_scale)x100 = enlargement factor%

I'm not quite sure what you're asking.

Are you using a specific set of rules? If so, scale the maps to whatever the ground scale the rules use.

you can also use the above formula slightly modified to see what size one scaled object would be in another scale so if we have a scaled drawing of a model at 1/72 scale but we want to build it at 1/32 scale how big would it be

(model_length x Scale)/Desired_Scale = model_length_new scale

so say the model we wish to rescale a 1/72 model that measures 3in in the drawing and we wish to know how big the model would be at 1/32

(3x72)/32 gives us a model size of 6.75in if we multiply the model size by 100 then divide by the original model size this gives the percentage size to enlarge the plans by

this gives us (6.75 x 100)/3 = 225% enlargement

You need to use the ground scale not the figure scale.

Thanks for the info.

As MajorB says, you want the ground scale, not the putative scale represented by the size of your figures-unless you will be using a one-to-one ratio of one 10mm figure representing one soldier and even then the putative figure scale likely wouldn't accurately reflect the scale area occupied by your figures if you put them on bases so they don't fall over.

After all, the 10mm (or a bit more) height of a 10mm figure will be the same, and therefore sufficiently accurate for vertical scale, whether the 10mm figure represents one soldier, 20 soldiers or 50 soldiers. But the scale frontage or area occupied by the 10mm figure-and therefore the ground scale-will change depending on how many soldiers are represented by one 10mm figure under the rules you will use.

You could calculate the ground scale occupied by your figures as based and in formation. So, for example, if you will be basing your 10mm figures in two lines of 5 figures each on a 40mm by 20mm base, then your frontage for each figure would be 8mm. You could then compare this frontage to that occupied by however many soldiers would be represented by one 10mm figure under the rules you will be using and that will give you a ground scale. But a calculation based only on the scale frontage occupied by the number of solders represented by one 10mm figure would overlook other factors such as spacing between subunits and the like.

So a better way to determine the ground scale for your 10mm army (and therefore for the maps you wish to convert) would be to determine the frontage of a typical unit in line and compare that to the frontage occupied by the same unit in real life (you use frontage rather than area because the frontage is more important in linear warfare and, more importantly, because, at any playable ratio of 10mm figures to soldiers for the ACW, the depth of your units will be too big with no way to avoid it). So you could compare the frontage of a regiment of your figures in line to the frontage of a regiment of the same size in the ACW and that will give you the game to real life ratio you need to apply to the map's scale to get for your tabletop.

You could make the same calculations if your rules use brigades or divisions as the typical maneuver element, but then you would have to make assumptions about exactly what real life formations are represented by your tabletop equivalents in order to determine what frontage your figures will be representing. I've seen some discussion of this issue in some brigade level and larger rules-perhaps Napoleon's Battles or Volley and Bayonet.

The virtue of this method of calculating ground scale is that it will allow you to have the same number of regiments in line occupy the frontage on the map occupied by their real life equivalents. On the other hand, the rules you use may well have musket and artillery ranges that don't match the ground scale you derive from your unit frontages.