DoAll DBW-1 Bandsaw-Blade Welder
|Remember to always; clean up and return the equipment to a fully functional, safe state before you leave. This includes returning any safety mechanisms to fully working order.|
DoAll DBW-1 Bandsaw-Blade Welder
This highly specialized welder is really only useful for one thing: repairing broken bandsaw blades. It is also called a buttwelder, because the technical name for the type of weld it makes in the blade is a butt weld.
- Ownership: TBD, best contacts are Dave Scholl, Dave Alvarez, or Steve Hermann
- Location: The welder is currently hanging on the red shelves between the chop saw and the table saw. Its long-term location is still TBD. The current location is convenient because the welder can be plugged into the 220V table saw cord for testing. (At times, the welder may be moved to a workbench in the wood shop to have open access to both sides.) These welders were usually installed inside the frame of a bandsaw, but this one was extracted from its bandsaw some time before it was brought to i3. The benchtop repair stand, box of old parts, and broken blades are on a plastic shelf at the north end of the user storage area.
- What it looks like:
The welder was originally made in the 1940's, and has been painted at least five times since then. Under the layers of paint, and an abundance of dirt, most of it appears to be original. The main contactor is labeled with the date "Sep 1941".
- Make/Model: DoAll DBW-1 Buttwelder
- Part Number: S/N (unknown)
- Don't try to repair bandsaw blades yet, and please don't plug in the power cord.
- One particular i3 member, who is a bit of a wag, has been claiming to anyone within earshot that if you have two butts on or about your person, this piece of equipment will weld them together into one butt. Don't worry, nothing could be further from the truth.
Things that Need to be Done
- Continue evaluation and repairs
- Disassembly and cleaning is finished, reassembly and rewiring is underway.
- Status of electrical testing/repairs
- New light socket and bulb are installed and work at 220V.
- Grinder motor runs quietly, appears OK, grinder switch works OK.
- An electrical schematic diagram has been drawn and most of the wiring has been replaced.
- New insulators have been cut from 0.016 DMD sheet (Dacron-Mylar-Dacron from a motor shop, to replace the original waxed cardboard)
- Transformer wiring completed. Weld switch, heat switch, anneal switch, all transformer taps, appear to function OK. With 243VAC on the primary, the open secondary voltages are as follows:
- Anneal: 0.93 VAC
- Etching: 1.65 VAC
- Less: 3.00 VAC
- LessLess: 3.27 VAC
- More: 3.52 VAC
- MoreMore: 3.80 VAC
- These open-secondary voltages are higher than the nominal values listed in the manual, apparently because the nominal primary is 220VAC and our primary is 243VAC. For this reason, it is likely that the Less and LessLess heat switch settings will make better welds in our shop.
- A new knob has been fitted to the force adjustment.
- Oiling tubes for the motor bearings have been reinstalled
- Replacement grinding wheel is installed. It needed more clearance inside the housing, and we were able to use the wheel to grind its own clearance.
- The moving jaw moves freely and has been aligned parallel to the fixed jaw.
- Steve H. has made new plastic tips for two of the adjustment screws, and both have been installed.
- Now that the mechanism has been completely installed, the movable jaw travel limits can be set, and the rough adjustment of the weld stop switch can be made. The final adjustment of the weld stop switch is made during welding trials.
- Box is needed to cover the parts behind the front panel
- Long-term location with 220V 1PH 30A power is needed
- Has anyone else ever repaired one of these old welders? Yes, someone rebuilt an entire 63-year-old DoAll Bandsaw, and rebuilt the welder as part of the project. Photos and written discussion are available on this thread in The Garage Journal. The URL is to page 5 of 26 pages, which is in the middle of the section that discusses the welder. The same author has made over a dozen videos of this project. They are available in the YouTube channel for APmachinist. Blade Welder Parts Repair is #14 in the Bandsaw Rebuild video series, and is one of several videos that discuss the welder. Note that the author's welder is model 1A, which is more recent than our model 1, and features different electrical adjustments, among other differences.
- Can bandsaw blades made with newer technologies (1950 or later) be repaired with this welder? Yes, if the annealing instructions from the manual for a newer model, e.g., the DBW-15, are followed.