Neil Blythin Posted June 3, 2014 Share Posted June 3, 2014 Hello All, I have a small Canadian Forge & Blower Co. hand cranked blower, which decided to start giving me a hard time this past weekend. It started 'chattering', and grinding to a halt within a half-turn of letting go of the crank (was previously coasting about 2 turns when stopping). Anyways, I opened it up and found a couple of obvious problems... Firstly, the one large gear was being held on by the handle, as opposed to the spring clip which was missing. This allowed that gear to float in and out a 1/4" or so. The middle large gear also had quite a bit of play in it. Not sure if its due to worn thrust bearings, or missing washers, or whatever. I don't have a schematic of what its supposed to look like. Similarly, the smaller gear that the fan attaches to had a lot of this lateral play as well. So what was happening in use, was (refer to below photo): The two gear assemblies that are to the left in this photo would shift in the direction of what is the top of the photo, the one on the right would stay towards what is the bottom of the photo. This gives just enough play to allow them to disengage - causing the fan to spin freely. Again, I'm not really a machinery guy. I know it's not right, but I don't know the best fix. Can I just add washers to eliminate that play? The brass or bronze thrust bearings / bushings don't appear to be easily replaceable, and I'm not sure where I'd find replacements even if they were. I was thinking that brass washers might help... The second issue I've found, is that the large gear (that the crank handle attaches to), has worn teeth. Can I carefully file the side of the gear to remove the material that's been mushroomed over? And what about the top surface of each tooth, can I carefully file away those burrs as well? Will this help or hurt the operation of the mechanism? Sorry if these photos aren't great. It was the best I could get with my iPhone shooting through a magnifying glass. Any advice is greatly appreciated. I'd rather not mess this thing up any more than it already is. Cheers, Neil Quote Link to comment Share on other sites More sharing options...
VaughnT Posted June 4, 2014 Share Posted June 4, 2014 The teeth on those gears don't look bad, and I wouldn't bother with them until seeing how the whole thing operates once you get the slop taken care of. As you said, it was running smoothly until "all of a sudden" it let go and started stalling after you let off the handle. Whenever something just quits working that means something inside broke free. If the two gears now have enough slop that they can slide sideways and disengage from one another, I'd look down in the muck at the bottom of the crank case to find the part that just let go. You can buy what's called a locking collar (or clamping collar) that you can attach to the shaft to fill the void. Bronze washers are always a good idea if you can get the shaft and gears free of the assembly to install the washers. If not, go with the locking collar and a good lubricant to keep the gear teeth from rubbing too hard against each other. Quote Link to comment Share on other sites More sharing options...
Neil Blythin Posted June 4, 2014 Author Share Posted June 4, 2014 Thanks Vaughn. I've never heard of these collars before - will check them out. The inside of the gearbox was surprisingly gunk-free, and I've not found anything broken off and floating around inside. My working theory is that, since I've been using it a lot more (and oiling it more) than it's otherwise seen in years, the fresh oil & use has worked free some previously stuck part. I.e. It had missing parts (washers, spring clip, etc) but because the shafts were stuck in place, no slop. A bit of extra oil and use, and suddenly those shafts were moving in and out freely. I'll take up that excessive play with the collars you suggest, put it back together and see how it goes. Thanks again for the suggestion! Quote Link to comment Share on other sites More sharing options...
VaughnT Posted June 4, 2014 Share Posted June 4, 2014 Your theory sounds spot on, especially if there isn't something sitting down at the bottom. On the locking collar, word of caution. Two choices, either use Loctite on the bolts to make sure they stay put..... or get ready to cuss up a storm when they let loose and start rattling around where they're not supposed to be. Ask me how I learned this lesson. ;) Quote Link to comment Share on other sites More sharing options...
swedefiddle Posted June 5, 2014 Share Posted June 5, 2014 Good Morning, Neil You can make thrust bushings with brass, bronze, aluminum, fibre circuit board, even leather (leather absorbs the oil and acts as a seal as well. Leather from old boots works fine). I would shim it to take the thrust out of the shafts, make new bushings for the shafts if they are worn and use it with some gear oil (80W90). Most of the time I run engine oil in the blowers but if you want to give it a favour, use 80W90. Keep your eyes open for another blower, they pop up when you aren't expecting. I'm sure one of the guys in OABA can get you another blower, it you can't find one. Neil Gustafson Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 5, 2014 Share Posted June 5, 2014 80W90 means no cranking once the temps goes down in the fall! Quote Link to comment Share on other sites More sharing options...
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