RESTORATION OF A Wade One Man Drag Saw

| August/September 1997

  • Wade one man drag saw

  • Pitman rod bearing
    Figure 8b. Pitman rod bearing with babbitt poured. Egg shape of bearing shell indicates use of saw with worn bearing.
  • Pitman rod bearing halves
    Figure 8c. Pitman rod bearing halves after boring.
  • Cross head saw holder
    Figure 9. Cross head saw holder mounted on glide rods. Note old welds on this part.
  • Left view of dragsaw
    Figure 10. Left view of drag saw showing fuel tank, engine and jack shaft sprocket.
  • Timer case, points and cam'
    Figure 2. Timer case, points and cam.
  • Crankshaft and babbitt main bearings
    Figure 1. Crankshaft and babbitt main bearings centered in lathe to cut pivot for timer case onto the left main bearing.
  • Fuel tank
    Figure 5. Fuel tank with rusted parts cut out before new bottom was soldered on.
  • Fuel tank and radiator tank
    Figure 5. Fuel tank and radiator tank after repairs.
  • Male taper, nut and key'

  • Left side of engine
    Figure 4: Left side of engine showing timing lever, timer case, points and cam.
  • Pitman rod bearing
    Figure 8a. Pitman rod bearing prior to pouring babbitt. Note shim stock separating bearing shell halves.
  • Jack shaft sprocket and crank
    Figure 7. Jack shaft sprocket and crank. Note that they are welded together.

  • Wade one man drag saw
  • Pitman rod bearing
  • Pitman rod bearing halves
  • Cross head saw holder
  • Left view of dragsaw
  • Timer case, points and cam'
  • Crankshaft and babbitt main bearings
  • Fuel tank
  • Fuel tank and radiator tank
  • Male taper, nut and key'
  • Left side of engine
  • Pitman rod bearing
  • Jack shaft sprocket and crank

3666 Millbrook Terrace, Salt Lake City, Utah 84106

Sometime in the early 1980s while visiting my sister Jane and her husband Jon in northern California, I asked Jon if he knew of any one-cylinder engines in the community. To my surprise he indicated he had one, or parts of one, in his 'bone yard.' When we looked at his machine I saw a small single flywheel engine powering, via a chain drive, a bull wheel and a pitman arm which in turn drove a reciprocating saw holder. All of this was mounted on a badly rotted wooden frame. Jon and I discussed how the machine might have operated and left it as we found it. On another trip in 1990 I asked Jon if I could borrow the outfit for restoration purposes, and he consented. I transferred the saw outfit from his bone yard to mine, suffering only a few detached rotted wooden parts in transit to Utah. In early 1991 Jon sent me a photo copy of an advertisement in a September 30, 1920, edition of the Plumas National Bulletin clearly identifying his machine as a Wade one man drag saw.

Engine Disassembly

In 1992, between other projects, I began minor limbering up of the chain drive and pre-disassembly oiling of engine. The engine was stuck.

In 1993 I began disassembly in earnest. All accessible points were bathed with penetrating oil, and oil was injected past the piston and exhaust port with compressed air. The Wade Company's use of standard pipe threads at the spark plug, intake and exhaust ports greatly facilitate this process.

Although the compressed air system soon had oil moving past the piston, it remained stuck. I heated the piston and cylinder. Overheating resulted in melting of the babbitt main and connecting rod bearings, but some piston movement was gained. I removed the crankshaft and flywheel from the connecting rod and made an attempt to pull the piston from the cylinder by mounting a slide hammer on the connecting rod. The slide hammer distorted the badly rusted big end of the connecting rod. In retrospect the connecting rod was probably rusted beyond salvage.

I finally tapped the piston out of the cylinder by inserting a brass rod through the spark plug hole (this is a headless engine). This tapping produced a minor chip on the upper end of the piston, but I now had a pile of freed parts rather than a frozen hulk!

As found, rust and rusty dirt filled the lower end of the crankcase. This engine had operated a foot or so off the forest floor, and the downward vented exhaust undoubtedly blew up chips and dirt from the ground for aspiration into the crankcase on the intake cycle (this is a two stroke engine).

Figure 3. Chain drive mechanism (right side of engine) showing male taper that fits female taper on sprocket wheel, a brass shim between male and female tapers, the compressing spring with nut and key. The assembled mechanism is attached to the crankshaft via a left-hand thread and forces a tapered flywheel hub onto a taper on the crank.

Portions of the cylinder, crank and connecting rod were scaled and pitted. A hairline crack on one wrist-pin boss may have been an old war wound, or may have developed as a consequence of the piston removal. The wrist-pin was rusted outside the piston bosses, but was clean where the pin ends were contained by brass bushings in the piston bosses. Overall condition of piston and rings (cracked boss aside) was clean and sound.

The chain drive sprocket is mounted on the crankshaft via a tapered socket, and friction is assured on the taper by tightening a large nut, thereby compressing a spring against the sprocket. This spring and taper system allows for slippage in the event that the saw binds while cutting. Subsequent models of Wade drag saws had automotive type clutches, but this saw has a piece of brass shim stock fitted onto the taper to prevent wear on the tapers when slippage occurred. Alternately, this shim may be a field-fix compensating for wear on the tapers, as I've seen no reference to this part in my Wade parts manual.

In trying to remove the flywheel from the crankshaft I erroneously assumed that the flywheel was pressed onto a second taper on the crankshaft. Attempts to press the flywheel off the crank badly bent the threaded portion of the drive mechanism. I then discovered that the drive mechanism is connected to the crank by a left hand thread, and that the threaded drive mechanism forces the flywheel onto a taper fit with the crank. Once I understood all this, I could appreciate the wisdom of this design. In assembling the engine, after the drive mechanism left hand threads are tightened, and the flywheel is forced tightly onto the crank, the flywheel is pinned to the drive mechanism by a 5/16 ' bolt. This pin indexing arrangement assures that the pre-balanced flywheel is always in the same relative position with respect to the crankshaft, thereby helping to maintain engine balance.

In September 1993, I attended the Utah Antique Machinery Association annual show, and saw an operating Wade drag saw and two or three other drag .saws in various states of repair. A participant displayed a copy of a Wade operation manual that I subsequently acquired. Inspiration!

Engine Rebuilding

I discussed a connecting rod fabricating strategy with my father-in-law, Rollin Van Zandt. The lower end of the connecting rod was turned from steel round stock, split longitudinally and halves were faced off on my 6' Atlas lathe. I drilled and tapped the split halves to allow use of split-bushing connecting rod bearings. The split halves were bolted together, centered in the lathe and bored to 1/8 of the rod bearing dimensions of original connecting rod.

I fabricated the piston pin end of the rod from mild steel round stock, and welded the clamping tabs on. These tabs allow clamping of the upper end of the connecting rod to the wrist pin, with the wrist pin moving in bronze bushings pressed into the piston bosses. These clamping tabs control end play on the wrist-pin.

Center distances between the piston pin and crank pin were established from the original connecting rod, and transferred to a jig in the form of a heavy piece of angle iron. I then drilled holes in the jig on these centers. The piston pin (upper end) and split lower ends (mounted on a mandrel) were secured on this jig with ' diameter bolts. The connecting rod center section was cut to length from steel bar stock and fitted snugly between the upper and lower ends of the con-rod as established on the jig, and I arc-welded the three components together.

I established the 'I-beam' cross section of the center portion of the rod by welding 3/16' steel strap to the bar stock center section while all parts were held in the jig.

The connecting rod was mounted on an angle plate and upper and lower ends were line-bored on Rollin's small horizontal mill. The lower connecting rod bearing split bushings were turned from lead-bronze stock on Rollin's 12' Craftsman lathe and fitted to the crank pin.

The crack in the cast iron piston boss was arc welded by a commercial firm in Bisbee, Arizona, while I was visiting Rollin.

The bronze wrist pin bushings were pressed back into the piston, and a smooth running fit was reestablished between the wrist pin and bushings by mounting the wrist pin on a bolt, chucking the bolt and pin in the lathe and lapping the piston bushings to the pin. Fit between the wrist pin and connecting rod was not critical, since the pin is clamped on the rod by a bolt through the above-mentioned tabs.

The crankshaft main bearing surfaces and the throw had been worn out of round, and these surfaces were ground true by a commercial automotive crankshaft grinding firm. This grinding preceded final boring of the split connecting rod bushings.

I had salvaged the babbitt from the original main and connecting rod bearings for reuse.

The crankcase cover and the engine block have the main bearing journals cast into them. Upon inspection I determined that the main bearing journals that receive the babbitt bearing had been line bored, and were circular. Before pouring new main bearings, the crankshaft was centralized in the castings by turning three ' thick aluminum washers to the ID of the bored bearing journals. I then bored a centered hole that permitted a tight slip fit over the crankshaft bearing surface into each washer. With the crank held in the washers, one on the inside of the flywheel end, and two (inside and outer end) on the opposite end, the crankshaft was aligned perpendicular to the cylinder bore, the casting was warmed, and the babbitt mains were poured onto the flywheel end of the crank. I slid the bearing off the crankshaft, removed the aluminum washer, and returned the bearing to the crank. Proper realignment with the crankshaft bore was assured by factory drilled holes in the casting that filled with babbitt when the bearings were poured.

The timing case pivots on an extension of the main bearing on the left side of the engine. To cast this extension integral with the bearing, a mold with a diameter greater than that required for the timer to pivot on was bored from ' steel strap, bolted to the bearing casting, and centered by eye on the crankshaft. Crank and cylinder alignment was assured by installing the bearing already poured on the crank, and placing one aluminum washer on the inside end of the bearing to be poured. I then formed the bearing and timing pivot extension in a single pour.

I again removed the left bearing from the crank, the centralizing washer from the left side, and then remounted both bearings on the crank. The crankshaft with bearings in place was mounted between centers on the lathe, and the babbitt lapped by running the lathe while holding the babbitt on a wooden clamp.

I established the fit between the babbitt bearing and the timer by clamping the bearing to the crank while mounted in the lathe, and turning the outer extension of the bearing to fit the timing case (figure 1).

The cylinder bore was honed, coated with STP, and the piston with connecting rod attached was installed.

The brass timing case was broken when acquired, and I shaped a piece of brass round stock to fit over the broken end of the timer and soldered it into place (figure 2). This repair reestablished contact between the timer and the timing adjusting lever via a rod.

The chain sprocket drive mechanism was centered in the lathe and the portion that was bent in attempting to press the flywheel off was turned straight. I bored a 1' diameter mild steel sleeve to a light press fit over the turned down portion of the drive mechanism and arc welded it into place. The welds were turned flush, the diameter reduced, and a 7/8 ' x 14' thread was cut onto the reconstructed drive mechanism. A 7/8 ' x 14' tpi nut was fabricated to fit the drive mechanism. Figure 3 is an exploded view of the drive mechanism parts separated from the crankshaft.

The oiler for the connecting rod bearing required new glass (purchased from Lee W. Pedersen). The brass oiler base had been bent so the glass would not fit. This was quickly remedied by turning an aluminum disc a few thousands larger than the OD of the glass. The disc was pressed into the oiler base which quickly assumed the shape of the aluminum disc. Upon removal of the aluminum disc, the glass fit the oiler quite well.

I purchased a new Champion 25 spark plug and wire from John Brillman, and a used model 'T coil from Robert L. Whitaker. Figure 4 shows the left side of the engine, the timing advance lever, rod, and the timing case and cam in place.

Engine Specifications

Manufacturer: R. M. Wade Company, Portland, Oregon.

Horsepower: 4.

Operating Range: 550-600 rpm (back calculated from sprocket sizes using manufacturer's recommended rate of 125 saw strokes per minute).

Cooling: Water cooled with detached water tank/radiator.

Engine: 2 cycle with crank-case compression. Fuel mix 1 pint oil/per 5 gal. gasoline.

Bore: 3' nominal.

Stroke: 33/8 ' nominal. Piston rings: Two compression with overlapping end joints, and ring alignment assured by detente cast into pistons and machined into rings. Lower ring is a scraper/stabilizer.

Flywheel: 16', weight 35 lbs. Carburetor: Lunkenheimer side draft with check valve.

Fuel tank: Detached, gravity supply to carburetor.

Ignition: Spark coil and battery regulated by breaker points from cam on left side (opposite to flywheel).

Timing: Pivoting breaker point housing around extension of babbitt main bearing. Timing changed by moving lever mounted on frame.

Lubrication: Oil in fuel; single oil dripper for connecting rod and wrist pin; grease cups on main bearings.

Other Repairs

The drive chain was rusted into its mounted configuration, but after soaking in oil and a little limbering up, was found intact except for broken link pin that required fabrication.

Before I found the engine, a considerate soul had removed the coolant drain plug from the lower side of the engine, something that undoubtedly contributed to free draining of rain water and melting snow from the radiator tank. During the abandonment period, both the engine block and the radiator survived the several decades of freeze-thaw and rust cycles in good form.

Such good fortune, however, did not bless the fuel tank and fuel line. The cap to the fuel tank was a ' pipe plug with a vacuum relief hole drilled through it. Moisture had entered the tank and fuel line. The copper fuel line had frozen and burst in one spot, but the resulting knot was easily peened closed and soldered. The rusted-in filler cap was drilled out a challenge given the overall condition of the lower third of the tank.

Against my better judgement, I opted to restore the rusted out sheet metal fuel tank. All rusted metal was snipped away (figure 5), and the interior scraped clean. I soldered new galvanized metal into place, and resealed the tank with a product ordered from Lee W. Pedersen. The wooden mount for the fuel tank and radiator was rebuilt, and the original mounting straps salvaged for reuse. I fabricated a new fuel tank cap by brazing a steel disc to a shortened ' pipe nipple, and departing from tradition, painted die radiator and tank (figure 6).

The jack shaft sprocket (chain sprocket on the saw stroke arm crank) was originally fixed to this crank by a key retained by a bolt. On my machine this design had been unsatisfactory to the original owners, who arc-welded the cast iron jack shaft sprocket to the steel crank (figure 7). An acquaintance of my sister and brother-in-law, long-time resident of northern California, and son of original owner A. E. Hunt, believes this weld to be one of the earlier electric welds made in Plumas County, California. The weld provided a solution to one problem, but one rendering complete disassembly of the jack shaft sprocket from the crank impossible. The stroke arm crank and jack shaft had relatively new (based on wear) brass bearings that required no attention beyond cleaning.

The jack shaft frame bolt plates are slotted to allow tension adjustment on drive chain. Previous loggers had evidently operated the saw with the bolts loose on the plates, resulting in breakage of the bolt plates. This did not preclude operation of the saw, as the broken plates were found bolted to the wood frame, but must have rendered maintenance of chain tension difficult. I fabricated some holding devices out of  ' strap that allow chain adjustment while rigidly holding the jack shaft bearings on the saw frame.

The pitman rod that drove the saw cross-head on its guide rods had babbitt bearings at each end, and one bearing required rebabbitting (figure 8 a, b, c). The cross head saw holder moves on the guide rods on babbitt bearings (figure 9). This assembly was badly stuck, and required repeated warming, applications of Liquid Wrench, and tapping (even pounding!) before it came free. Once free, a light sanding of the guide rods and oiling of the babbitt glide was all that was required to assure smooth function.

While rotted beyond salvage, enough remained of the wood saw frame to serve as a pattern for refabrication. The original green paint of the frame had badly faded; I decided on a forest green paint that I had from another job.

I made decals for the frame and water/fuel tanks by enlarging the R. M. Wade logo from the owner's manual to an appropriate size in a photocopier then reproducing them on overhead transparency mylar. Once reproduced in mylar, the logos were attached to the machine with varethane (figure 10).

I displayed the saw at the 1996 Utah Antique Machinery Association Show. I still haven't hooked up the spark coil and tried to run the engine. This was a fun project that taught me many things. I admire the beauty of a simple design that remained competitive for greater than 40 years. I found the welds, and other field improvisations that kept this machine operative, fascinating. Those who operate chain saws may turn up their noses at the Wade's heavy, reciprocating design, but those of us who have done time on one end of a two man 'misery whip' can fully appreciate what a great leap forward the Wade drag saws represented.

3/12/2016 12:58:02 AM

Operating one of these saws can be a terrifying experience. There are a lot of moving parts with no guards. That being said, it's a real kick in the butt. Cut up a 4 ft dia Fir log and had the whole neighbor hood there watching and helping.

9/6/2015 12:55:02 PM

Turns out that I owe the author an apology. Wade made different versions over the years and some did have a left hand thread. I strongly suggest each owner confirm the thread direction before working on the saw. Sorry for creating additional confusion over this. Bob

9/3/2015 3:41:59 AM

The author says the crankshaft is threaded with left hand threads on both the flywheel and sprocket ends. The crankshaft is threaded with conventional right hand threads. The crankshaft or flywheel could be damaged if someone tries to remove the flywheel by following the information here and forcing it the wrong direction. I know this article is 15 years old but the text should be changed to reflect the correct thread direction.


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