Introduction: Helping an Abused Trolling Motor
A few days ago I answered a FB ad for a 3-year-old trolling motor and deep-cycle battery. I was set to go pick it up for the advertised price (a good bargain) when the woman PMd me that her husband had charged the battery and the motor "didn't work" so he would sell the battery for $25 and give me the motor free! Since the battery is worth $22 as a core trade-in, I agreed
Once I got them home, I found that the battery was holding a good charge - so no worries there, but the motor shaft was horribly scarred and the tilt mechanism was bent and unworkable. Upon hooking up the motor to the battery, it worked very well - smooth and steady and powerful. I suspect he was ashamed of the mechanical condition of the shaft and tilt. On the other hand, I found a sentence in the manual that said, "Do not hook up motor while battery is being charged."
Since I want to use this motor, I started thinking about how to return it to full working status.There's not much that can go wrong with these motors and I own one that is almost 70 years old and still chugs along.
This I'ble is entered in the STICK IT! contest, if you like what you see in my creative use if epoxies and glue, please vote for me.
Step 1: Why Is the Shaft Scored So Badly?
On this brand of motor, there is a collar around the shaft and a screw to adjust the steering tension so that steering is not too hard and not too easy. There is supposed to be a plastic piece (a friction strip, according to the manual) inserted in the rectangular notch under the screw to bear against the shaft. It was missing! The screw had been bearing against the aluminum shaft and scoring it badly. The first time I put my hand on the shaft, it came away with little shards of aluminum stuck in the skin - took a while, some tweezers and magnifier to get them out.
The first thing I did was take some 120 grit sandpaper to the shaft. This smoothed out the shaft, and removed the bits of metal making it easier to handle. Then I measured the slot to figure how big to make a friction strip.
Then I measured the shaft and found it to be 1" diameter. AHA! Would a piece of 1" PVC pipe work?
Turns out it would....
Please check out the photos for notes.
Step 2: Making a Friction Strip
Using the measurements, I cut a piece of 1" PVC pipe and filed and sanded until it fit. The actual friction strip has a molded knob on the top side to prevent it slipping out of the slot when the screw is loosened for adjustments so I cut a small piece, mixed some two-part epoxy and stuck it on (ENTRY FOR THESTICK IT!CONTEST!)
I painted the friction strip fluorescent orange so I can always be sure it is there. Then I cut another small piece and made a knob for the lower end and glued it on with cyanoacrylate glue (Super Glue). The friction strip is not going anywhere!
Be sure and check the notes on the photos.
Step 3: Improving the Shaft
Even though I had sanded the shaft, I was worried about the grooves. So I mixed another batch of two-part epoxy - a different kind with better wear characteristics BUT another reason for you to vote for me in the STICK IT! Contest - and slathered it in the grooves. Then I took a piece of 1" PVC and ran it along the shaft, removing the excess epoxy. After it hardened, I sanded it down. It's still a little rough but it's an improvement.
Step 4: Fixing the Tilt Mechanism
The tilt mechanism is a spring loaded pin that engages and disengages the "foot" which fits in the cogs and determines the tilt of the motor to the transom of the boat. To be honest, it is poorly designed and weak.
In this case, the pin was badly bent, and the lower casting to guide the pin had broken away. I think a gorilla tried to change the tilt without pushing on the pin.
I used a vise and channel-lock pliers to get the pin decently straight but in the process of disassembly I lost the snap ring that retains the spring.
I found some .032" stainless steel wire and a washer to fit the pin so I set about drilling a .045" hole in the pin to hold the wire. That is one SMALL drill but it worked. I started the hole with a center drill and plenty of OIL. Then I went to the .045" drill and again used plenty of OIL to keep the drill cool and flush away the chips.
Please check the photos for more notes.
Step 5: Assembling the Tilt Mechanism
I inserted the wire in the hole and twisted it, assembled the washer and spring and screwed on the foot. Finally I mixed another batch of epoxy and stuck it (STICK IT!) on a piece of brass to retain the pin in the broken lower casting.
The final two photos show the tilt mechanism working correctly.
Step 6: It Works!
Thank you for reading this far. Even though the motor operated correctly, it was virtually unusable in its previous condition. With a little help and some clever fixes, it is now fully functional.