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Late 1936 and the first of the V-bed AA metal-turning lathes appears as the simple, plain-turning, 6-inch by 28-inch "Companion" model (Catalog Number 99 P 2021) listed as: "metal working, model maker's lathe". The 1/2" x 24 tpi headstock spindle ran in plain bronze bushes - the front was adjustable - and carried a 3-step V belt pulley. Unfortunately, in its first form, the machine was not as heavily built nor as well specified as it might have been; the front of the headstock casting was open and the front bearing given the minimum of support; both the headstock and tailstock were provided with O Morse tapers (fine for miniature lathes, but inadequate for anything with a swing of greater than 4 inches) and there were no graduations on the micrometer feed dials. There was no quick-feed rack drive fitted to the carriage, instead it was hand driven along the length of the twin V bed by a leadscrew and "full" nut - but at least the slide rest was a proper compound unit. Most small lathes have been arranged for the carriage and tailstock to run on different ways, or parts of the same way, to ensure that the tailstock did not have to run over the bed worn away by the saddle and spoil its height alignment. Unfortunately, on all 109s, in the interests of economy, the ways were shared. Notice that the lathe has no apron on the carriage, the leadscrew nut is fastened to the underside of the saddle front, a simple design used by other makers as well such as Portass of Sheffield. However, despite these simple arrangements, it is as well to bear in mind that it sold at a very competitive price and (devoid of almost all equipment) was listed at just $10.95 when even a decent-quality 1/4 hp motor from the Craftsman catalog was US$11.70). For the money this represented a remarkable achievement of production economics. Throughout its production life (1936--1940) the lathe was offered with only a very limited range of accessories: a 4-jaw chuck at $3.10, 0 Morse centres at 45c, a jack-shaft drive pulley system for $2.45  (that gave a speed range more suitable for metal turning) and standard or  "improved" pairs of adjustable motor rails at 50c.
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By late 1937 the lathe had been given an enclosed front to the headstock casting that both protected the operator's hands from the drive and provided a much better supported spindle - though there was no back wall and the left and right-hand sides of  rather slender proportions.
For once a maker was refreshingly honest about the lathe's limitations, stating: "Well suited to the model maker or man who wants to do light metal work. Not quite the accuracy and precision of the larger machines, but plenty close enough for most work." To put the machine into perspective although the price had now risen to $14.50 the nearest competitor machine in the Craftsman range, the newly-introduced and very well specified 6-inch Atlas clone, was $42.50 - a price that included a built-on countershaft unit but not a motor or set of screwcutting changewheels.
In order to compensate for the lack of a power feed to the carriage it is possible that a company, the "Sherman Clark Mfg. Co. of Jackson Michigan (USA)" offered a power feed kit and, if your 109 is so equipped, the writer would be interested to hear from you. The 109 model survived in the catalogs until 1940 when it was replaced by a more highly developed and useful version..
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Above: badged as a Dunlap the new-for-1941-season 109 with screwcutting and backgear. It was also available (left) bereft of these fitting as the  "Standard Model" 109.2046. Because the lathe was offered as a modular system it was possible to buy the ordinary model and then add features as finances allowed.

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Marketed by Sears the new-for-1941-version of  the AA109 6" x 18" at first carried the name "Dunlap", a name always used for the company's less-expensive models. By now the lathe had begun to grow up and also been given the contemporary "streamline"  treatment and, for the fist time, was fitted with an apron that carried a leadscrew half-nut the operating lever for which snapped into position through the operation of a spring-loaded ball detent. Although this mechanism gave a positive action, there was no compensating pad on top of the leadscrew to absorb the upward thrust. The new lathe was a model of mechanical simplicity and economical production with the saddle, apron and the cross-feed screw end bracket cast as one piece - as illustrated lower down the page. The lathe was initially marketed as just a single model with a capacity between centres of 18 inches (identification numbers included 109.07801 and 109.0702 with a hand-cranked leadscrew to drive the carriage (but no screwcutting), the 109.0703 with both screwcutting and backgear and later, for just a single year post WW2, as a short-bed version with models that included the  109.2062 and 109.20630. However, regardless of specification, all versions were of very similar appearance and the simple models always available with a range of extras to turn them into more effective machines; these extras included a 5 : 1 ratio epicyclic backgear ($3.95) built into the 4-step headstock pulley and a complete screwcutting set ($9.65) consisting of changewheels and mounting bracket, inner and outer guards, a 0.5" by 16 t.p.i. Acme-form leadscrew and a tumble-reverse mechanism that allowed the spindle turn freely or engage the changewheels to produce left or right-handed threads to choice. An interesting detail concerns the beds of these lathes: those with shorter beds, whether badged as Dunlap or (later) Craftsman, had a gap between the top of the two bed Vs of 2.50 inches whilst two specific variants, the longer 109.0702 and 109.073 models had beds that were narrower, with a V-to-V spacing of 2.125". Interestingly, although the "manuals" for this series of lathes mentions the 109.07** types, they fail to give separate parts numbers for either the bed or any of the other important items associated with it - the saddle, headstock casting and tailstock, etc. Should you come across a dedicated "manual" for the 109.07** versions, the writer would be very interested to hear from you. Whilst the improvements to both rigidity and specification were welcome all versions of the new model were still of limited usefulness for serious work as they retained the No. 0 Morse centres, had ungraduated micrometer dials and were not supplied with a speed-reducing countershaft unit. In recent years the inherent weakness of the headstock assembly (and flexibility of the whole machine) has been displayed by a number of scrap machines appearing less their main spindle. These were probably broken when the owner, an impatient beginner, "bore down" on the cross-feed to "compensate" for a dull, off-centre tool bit. Those more experienced user would have recognised the "wiggly" feeling as the tool got under the work - the precursor, of course, to something snapping. However, when new, the machines remained good value with the better specified of the two priced at $31.95 - something of a bargain when the 6" Atlas was $67.50 and the 12" Deluxe $135.
When driven directly from an electric motor 8 speeds from 580 to 2040 RPM were available - and threads from 8 to 96 t.p.i could be cut. However, because the lathe's bottom speed was so high, success in this department would have meant either specifying the optional epicyclic backgear assembly, which was built into the headstock belt pulley and reduced the bottom speed to a more useful (but still not ideal) 116 rpm, or looking through the Sears catalog in the hope of being able to adapt one of the speed-reducing "Jack-shaft" (countershaft) units made for the wood-lathe range. That the lathe was not offered with one of these as even an option was a strange omission, for, in earlier years, just such a unit had been listed as an accessory along with other metal-turning accessories.
When the Sears, Roebuck catalog reappeared after WW2, in 1948, the 6" lathe was marketed under a new model number "99 TM 2063" and, labelled "Craftsman Model 80"; apart from a shorter bed it looked identical to its last appearance in 1943 when it was labelled a "Dunlap".
The 2063 version of the Model 80 lasted for just one year and in 1949 the Catalog number became 99 AM 2127 (Model 109.21270) and the familiar three-rib headstock cover was replaced by an "engine-turned" decorative plate with other numerous styling changes to give it a more "up-to-date" appearance. No mechanical improvements were made to the lathe which now had a deliberately styled "consumer look", and was offered, as before, in basic form without motor or chuck.
The headstock spindle carried a three-step V pulley - whilst supplied with the lathe was a four-step pulley to be used on the customer's own motor. Although fitted with a planetary-type backgear assembly built into the face of the headstock pulley, tumble reverse and screwcutting there was no countershaft arrangement and, if directly driven by the recommended 1750 rpm motor, the bottom speed of 120 rpm would have made screwcutting very difficult - though no doubt serious users might have found a slower or variable-speed motor and fitted  smaller pulleys on its shaft or built a speed-reducing countershaft to get round the problem.
The company must have been aware of the limitations imposed by this arrangement for later versions were offered with the option of a double-step pulley on the motor and a proper countershaft assembly, thus doubling the number of available speeds and giving, according to the handbook, a range from 55 to 465 rpm in backgear and from 380 to 3050 in direct drive - a very much more satisfactory arrangement. The headstock spindle ran in bronze bearings and carried a nose thread of 0.5" x 20 t.p.i. 
To the inexperienced eye this would have appeared a little lathe of attractive design but, in reality, it was a bottom-of-the-range model and intended only for light-duty work. Although with experience, care and the use of light cuts satisfactory work could be accomplished on these machines, new owners, once exposed to the practicalities of using the machine, must have been quickly irritated by a general lack of rigidity, the tiny 0-Morse taper centres, the absence of a proper handwheel handle on the leadscrew end, the penny-pinching failure to fit graduated dials on the feed screws and, on early or standard late versions, a bottom speed that was far too fast.
Besides lathes the Double A Company manufactured many items for Sears including bench grinders, wet grinders, sanders, bench saws and a builders' saw. Production of lathes appears to have stopped in about 1965 and, unfortunately, parts and drawings are no longer available.
Although the two models are very different, confusion has arisen in the past between the "Craftsman 80" with another lathe sold be Sears, the Craftsman 6" made by the Atlas Company; the Craftsman 80 was in quite a different league to the Atlas, costing, in the mid 1950s, as little as $48.50 in comparison to the $160 of its much better built and better specified bother..

Listed for just the 1948 selling season, the Double A Company's Model 109-2063 was identical, apart from a shorter bed, to its last appearance in wartime 1943.

Economical casting. The saddle on the 1941 109-series was cast complete with an apron and cross-feed screw end bracket.

1949 6" x 12" Craftsman Model 80 - usually catalogued as the 109-21270

Craftsman 80 (Model 109.21270) screwcutting  changewheels and tumble reverse mechanism.
Note how use was made of the inner-guard cover to provide an indent location for the tumble reverse selector lever - a method also used on the English Murad lathe of the 1940s.

The 3-inch centre height by 19.25" between centres Model 109.21280 was the last machine in the AA series and listed until the late 1960s. It had a distinctly "square" appearance to the headstock, looked rather different to the earlier variants and, because of the styling, is sometimes confused with the later Atlas Mk. 2 6-inch (also produced  in a Craftsman version).
The headstock spindle ran in plain bearing and carried a 5 : 1 ratio epicyclic slow-speed "backgear" arrangement inside the 3-step headstock pulley that gave a total of 6 speeds; the headstock pulley was driven directly from the motor, with no intermediate countershaft. In comparison with earlier versions the lathe featured numerous small improvements, including a No. 1 Morse taper tailstock and No. 2 Morse headstock spindle, and further details can be found here. If you own a 109.21280  the writer would be interested to hear from you.