Thread: Metabo drill doubling as a router

Hi all,

last week i purchased a very well preserved Metabo Sb800/6S drill from an Ebay seller in Bielefeld, Germany. He was surprised to learn that i would not use it but rather restore it and keep it in a collection. He didn't know that stuff like electric tools were considered intersting enough to be collected and preserved. To prove to him that his machine had found a good new home and that my hobby was not a joke, i sent him a pic of his machine after a bit of cleaning and laid one of its predecessor-models beside it for comparison. Since i had this pic anyway, i thought it might be fun to show it in this forum as well, and tell a bit about this fairly unique Metabo drill model.

Sb800/6S means an 800 Watts percussion drill with 6 speeds and an automatic disc type safety clutch ("Sb" = Schlagbohrmaschine and "S" = Sicherheitskupplung).

This model type was designed in 1967, when DIY was an upcoming trend. Home tool users could be persuaded into buying better-than-budget drills if these could also double as a versatile power source for attachments. These drill-and-accessories-systems were offered by most serious power tool brands, sometimes with their own coupling systems, like the Skil bajonet. Kress even used a bare motor unit to drive several attachments with their own gear system, meaning that the drill gear box with or without a percussion unit, was also sold as an attachment. In Germany, standardisation between several brands (Metabo, Bosch, Fein) was agreed upon with the 38 mm. collar, later changing to 43 mm. diameter as a European standard.

Metabo's first electric drill from 1933 was called "Model 750". It had single reduction gears in a cast iron gearbox. The spindle's bearing was also made of cast iron, in fact it was the hole drilled in the gear case itself, without an intermediate bronze bushing. This solution reminded very much of the hand driven geared drill that Metabo started with in 1923 ("Model 18" hand drill), since these drills also used cast iron frames and bearings. Even the chuck on the Model 750 electric drill was of the same design as used on the hand drills. The 750 had a nickel plated deep drawn motor housing with a spot welded rear grip arrangement, a conventional toggle switch at the rear, bakelite grip segments, straight (not yet spiral-shaped) cut gear teeth, a sleeve bearing at the motor's front and a ball bearing at the rear. The rear bearing array had an adjustment screw to adjust armature axle play (because the front bearing was a sleeve and the rear ball bearing was not laterally fixed inside its bush), the AC/DC motor was rated at 1,1 Amps (approx. 230 Watts) and load speed was 1200 rpm (no load speed 2100). The cast iron gear case was painted red or dark blue.
Its successor, model 755, was fitted with an alloy gear casing and its chuck was either a hex key or toothed key operated (crown array) type. The 755 also had a nickel plated and later a grey painted motor housing.

Metabo drills kept the "75xx" type number scheme until the early 80's and this scheme mostly designated pro models. The B7532-4 is the only Metabo drill model still carrying it today. Other dedicated pro machines with their own motor (angle grinders, circular saws, sanders) were numbered in the 6000-range and Metabo introduced an alternative number range in the 4300-series in the early 70's. Examples are the famous 4320 orbital sander, the 4350 belt sander, the 4360 and 4381 planer, the 4380 router motor and the 4341,4345 and 4346 circular saws. There are also drills in the 4300-range. I never fully understood the logic behind it, because this number range contained semi-pro solutions but also several machines with seriously professional features.

But in the latter 60's, all Metabo drills were still in the 75xx- or 75xxx-range, and so was the predecessor of the Sb800/6S. This type started its career as the 7512/3. It was a T-grip type drill with a 450 Watts motor and a two-speed alloy gear box. As a bonus, the motor housing's rear end consisted of two hinged halves, secured with a screw. With the halves opened, the motor's armature was disposable as an additional direct drive option with 20.000 rpm, to be used with a flexible shaft for grinding, or as a router in combination with an accessory router base. The gear case's chuck side had a standard collar, but the motor axle side also had one.The armature axle was fitted with a 6 mm spanner, to take router bits, little ceramic grinding tools or the flexible shaft, all with standard 6 mm coupler shafts. To avoid the seizing of the user's hairs while concentrating on the workpiece, the gear case had an additional-zero-setting between speed I and II, to fully decouple the drill chuck while routing with the motor's direct drive spanner. This feature has been standard on all successive models of this type.

Thus the 7512 offered three speeds (two through the gear case, that originally had no safety clutch yet, and one directly from the motor). The 7512 was improved in 1969, with a larger 500 Watts motor that called for a redesigned motor housing. The gear case remained the same, but was now fitted with the familiar Metabo safety clutch that was soon to become popular (changing 7512/3 into 7512/3S). Around 1974 the model was further cranked up to 600 Watts. The livery was changed from pale green hammerite and red to Ascot green and black with a hint of dark blue. The gear case was also fitted with a percussion mechanism and was sprayed in hammerite silver. This finish suggested a metal gear case, as was customary for Metabo drills, but it was in fact made from fibre reinforced resin. The version from Bielefeld, a bought through Ebay, was made in 1978. By this time the model was souped up to 800 Watts, and was also fitted with an electric switch for two motor speeds. This switch doubled the mechanical speeds (changing 3S into 6S) and in the mean time Metabo had also changed over to a different type name scheme, including motor wattage, working capacity and machine type abbreviations (Sb, Ba, Sr, Ks, Ws, etc.). Examples: SbE1000/2S or Ks1785S (1700 Watts circ.saw with 85 mm capacity). Metabo had also returned to its well known red ring between motor housing and gear case, from now on using only the black for semi-pro machines.

Thus this type came to be a Sb800/6S and it survived in the catalogues until 1983. Its last livery was the now familiar dark green with red and silvergrey hammerite. It never had electronic speed control.

Pictures:
Model 750 with dark blue gear case and its type plate(Ebay pics), 755 in grey (notice the gear case's grease replenishment screwcap!), typical latter 50's 75-range drill, type plate and packaging, typical early 60's Metabo box and latter 70's model 75016 drill, 7512/3 unrestored (all Ebay pics), 7512/3S with hedge clipper accessory (Ebay pic), speed indicator decal on Sb600/6S, homemade pic with 500 Watts 7512/3S together with Sb800/6S and Sb800/6S with lid halves opened (orange and blue arrows were added by Ebay seller to explain the two regular mechanical speeds and the additional motor direct drive).

All machines shown are part of my collection.

greetings

gerhard