Logan 200 series
Logan Engineering reportedly made some 90,000 lathes between 1940 and 1971. The first sold under the Logan brand name was the 200, appearing in February of 1941. Its eventual replacement in the 10 inch market, the 800 series, appeared around September 1942. The big difference was that the 800 series lathes usually had quick change gearboxes and automatic aprons. However, the 200 series lathes, with conventional change gears and "plain" aprons, continued to be made and sold. Evidently, the reason was cost. The QC gearbox and auto apron increased the price of the lathe a hefty - perhaps even excessive - 44%. The 200s and 800s went out of production in 1953, replaced by the 1800 series, with V-belt drives replacing the flat leather belts of the earlier machines.
There were quite a few changes to the 200's design during the dozen years it was produced. Some of these changes were probably made to allow the various lathe models to use common parts, and some changes were technical improvements. However, I believe the improvements were marginal; generally, it is not worth the trouble to try to retrofit later "improved" parts to earlier lathes. (Well, maybe moving the power switch from inside the headstock casting to a real drum switch was worthwhile.) In any event, all the changes are important today because they can make it difficult to find parts to fit a particular lathe.
Keeping track of the changes is a bit of an annoyance. Logan has changed its part numbering system several times, so any particular part may appear with different numbers. The early drawings tend to be sections, which can be a bit mysterious; the later ones are generally isometric explosions. The printing on the drawings tends to be far too small, and too often the numbers are damn near impossible to read after the images have been xeroxed. The drawings are undated, and usually don't identify which lathes they are for by serial number range. This last is particularly vexing; when a part change affected the entire series, there's little excuse for failing to note at which serial number lathe the change took effect.
Here are the drawings which I have so far collected. Most started as fairly crummy Xeroxes, scanned and laboriously cleaned up by me. The Xeroxes came to me in a big pile when I acquired the lathe, and their earlier history is unknown, but they all look like they started out as factory publications.
Ideally, other owners will send me copies of drawings they have but I don't, which I can then add here, and eventually a picture of all the variants of the 200 may emerge.