3Phase – Not To Be Confused With PhaseOne

The Brother DB2-B791-015 would not get the proper power because it is/was a 3-phase motor system. This is why it would in fact turn on, but would quickly short out in the power switches fuse. Everything (although the mystery of the 2-pole – 4-wire socket outlet relationship remains) was in proper order, except the number of phases the building used and the number of phases the motor required. This would have never been known had a certain Jim Snook who is now a retired mechanic/electrical technician of sorts had not brought it to attention that without 3-phase power none of the machines electrical parts would work. This of course was good and bad, it was good for the fact that all the mysteries had been explained, it was not so good because it meant that a new motor would have to be purchased, if it was important to make the Brother DB2-B791-015 head work. Because the Brother had such nice table and legs, and needle feed head, it seemed like buying a new motor was the best bet, despite all the lost costs for the 220 volt outlet and other unsuccessful purchased goods for alleviating the machine of it’s ailments. So far there was about $400.00 into it without any return and the costs did not seem to be going down anytime soon. Of course a new industrial sewing machine will probably cost about double this – however the intent was to save money by purchasing a used machine – not spend more money and lose time trying to fix it. This just goes to show that when you buy used stuff you are usually buying someone else’s problems.

Originally the thought was to get another servo motor, but a simpler & cheaper one that uses a regular treadle, instead of an electric pedal system like that of the Mitsubishi motor. Fortunately there is a Singer sewing shop near by, which has a fairly good selection of odds and ends, and also caters to the industrial sewing crowd. Since the frustration of the motor had pretty much come to it’s peak, a quick purchase was made. The choice was a “Family” brand servo motor, which quite honestly was a piece of junk. But it was available, a servo, and not too expensive ($50.00). After getting it home and taking a closer look at it – it was fairly obvious that it simply would not stand up. Figuring that the diameter of it was about that of a compact disc, it seemed as if there would never be enough high end torque to really sew through much of anything. After bringing that back to the Singer shop and trading it in for a good ol’ fashioned clutch motor it was time for the install. The new motor was an Eagle brand 1/2 hp – 110 or 220 volt motor. It had your usual belt drive and needed a regular treadle system to activate it. The first task was figuring out how to lift the beastly motor up and bolt it into place without any help. Of course any sane person would just wait for an extra set of hands. After about 30 minute of fumbling with it, the thing was hanging and could have it’s bolt anchors tightened up. Unfortunately with the motor positioned to as far left of the Brother head – the belt wanted to drag on the right side of it’s slot in the table top. If you do not know exactly what this is, look to the diagram and you will see where the belt comes up to the table, also note the 3-hole mounting pattern.

The only way to remedy this was to pull out the rubber bumper which were not quite the exact size as their housing units (the rubber bumpers are the “U” shaped pieces in the diagram – they look to have legs on them. Either way, because the rubber bumpers were too big the motor could not slide to the left of the machine head enough. After using a box cutter to retro-fit the bumper it was time to re-install the motor again. This was acheived by turning the entire table upside down, this way the motor could simply rest on the table while it was positioned. Of course the Brother’s head was off, and the oil pan was dry (no need to spill oil everywhere). With the bolts in place (and loose) and the motor close to it’s eventual position – a hammer was used to essentially push (pound) the motor as far to the left as possible. Once it was in place, the bolts were tightened up and the table was lifted back up. With the Brother DB2-B791-015 in place and the belt routed it was time for a test run. Although it was not completely free of the belt’s slot – because when the clutch is engaged it moves the pulley (and thus the belt) to the left, which allows the belt to run freely. In other words when the belt is resting it is just barely touching the righ side of the slot, but when the motor is running the pulley, the clutch mechanism pulls it (the pulley) in slightly which takes the belt to almost center of it’s designated slot. It worked – finally.

The only thing left now, was the treadle system. That would be another task of customizing and light-engineering to get it working. In the next entry there will be pictures of this to show why.

3 Comments so far

  1. vs.vs.vs November 11th, 2007 5:46 pm

    Alright!!!
    and nice diagram.

  2. […] is no advocate of hierarchies. A little re-cap of some of the things we have seen this year are: 3-phase 220volt motors, treadle modifications, thread tension issues & re-issues, double tap feed mechanisms at Delta, […]

  3. BROTHER DB2-B791-015 » Shop November 20th, 2008 12:45 pm

    […] possibility of running the old Mitsubishi Limi-StopZ motor was very exciting, but once againg the 3-phase system escapes, which is necessary for such a beastly motor. However, because of some of the […]