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SmithingWitch

Working on a Champion 400 blower

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Ive recently picked up a champion 400 blower thats in all around great shape except for one glaring detail- the bronze gear has worn down to ragged, razor-sharp teeth. It will turn but the amount of play and the amount of metal remaining on the teeth is alarming and makes me think its on its last legs. Ive been able to disassemble everything else (despite the several pounds of hardened dust in the fan case) but the shaft for the bronze gear is eluding me. The cast iron gear's shaft came out easily with a couple taps but seeing as how the gearbox is thin cast iron and the shaft ends are HIGHLY hardened, im wary about both hitting it with too great a force and of heating it up too hot lest I ruin the shaft. Ive read one side of the shaft may have a shoulder and examining mine, there seems to be one on the side where the small transfer gear is. This gear lost its last leg a mile ago but ive got a lot peronally put into this blower (less financially and more sentimentally) and would really like to get it up and running again provided a local machinist can make a replacement OR I can 3d print and then cast one. Blacksmithing items at a decent price are in relatively short supply near me and finding a donor machine locally is pretty far fetched, though if anyone has a parts machine with a good bronze gear please let me know. 

So far the shaft has defied all attempts at removal and several days of gentle heating and flooding with penetrating oil. I dont want to damage anything further so the only idea I can think of is maybe stick the gearbox in a bucket of kerosene for a week or so and forget about it, unless anyone has any ideas? Ive been working on old machines since I was little with an old sewing machine but ive never had to remove a gear quite so finicky, and none of the other 400 threads ive read talk about removing the bronze gear. Any help or advice would be greatly appreciated. 

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Instead of kerosene, mix up a batch of automatic transmission fluid and acetone 50/50 and soak it in that. I guarantee it will cut through any rust and crust in a day. It works just as well as Kroil and is a lot less expensive. I think there are several You Tube videos on taking the 400 apart, I'll see if I can find them. This is the one I'm thinking of.

 

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I have a Champion 400 in what sounds like a very similar predicament. It's in excellent condition, except that the phosphor bronze gear's teeth are worn quite thin. I have tried removing the gear, but with no success. A gear-maker that I contacted about making a replacement gear said that it would cost about $600, which is ten times what I paid for the entire machine, so that's not really an option for me.

If you do find a solution, please let me know! And good luck.

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Welcome aboard, glad to have you. One of the things that makes ATF good for freeing up old machinery is all the anti corrosion chemicals in it. Automatic transmissions are darn susceptible to corrosion and electrolytics is always a factor. The fluid really heats up and auto trannies are designed to dissipate a lot of generated heat. The thermal cycling of the fluid means there's going to be condensation and there are a lot of dissimilar metals in the fluid. Long back story, sorry. 

Anyway the inside of automatic transmissions is always at battle with: electrolytic corrosion, oil gumming up due to thermal cycling and moisture. This makes ATF one of the best fluids for softening gummed up oil and grease and corrosion. Just by itself it's an excellent penetrant but add a strong very low viscosity solvent like acetone and it's unbeatable. . . Well, for reasonable $ that is. It doesn't even need to be a 50/50 mix a quart of ATF in a couple gallons of solvent works fine it's just slower. 

Kerosene is just thin oil, it's a good penetrant but no comparison and it has zero anti corrosives. If I still had my 59 Chevy Apache, 4x4 pickup I'd still be putting a quart of kerosene in the warm crank case and running it for a minute or so to flush the gum. WAY different situation than say breaking one loose that'd been seized from sitting for a few years. We used ATF and gasoline in the old days but acetone is a much better choice, it just works better, it's an old OLD trick.

My Champ 400 blower is suffering the grindy binds and seeing as it's finally warming up I'll be finding out if I'm in the same boat. Hopefully there'll be enough left to 3D print a pattern. A friend of mine is a caster and if it's close enough hand finishing is basic bench work. 

Frosty The Lucky.

 

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Irondragon, thanks for the link, I had watched that series over the past few days to see if I could glean any advice but unfortunately he doesnt pull the bronze gear. I cant blame him, but for me leaving it in just means im left with a blower shaped object. So It looks like if this last drenching of PB wont do the trick ill be getting some transmission fluid. Im assuming im going to want a metal or solvent proof plastic container and other than that, just leave it to soak? how bad of an issue is evaporation with a 50/50 mix? Im thinking if I find a way to plug up the holes where the worm drive would go, and place the bearing caps on where the bronze gear is I could just set the gearbox in a suitable container and flood it with the fluid. Either way its a trick im going to have to look into so I appreciate the tip. 

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Its been a few days, I rearranged the bearing caps to plug the worm drive holes as well as the bronze gear bearings, propped the gearbox up and flooded it over the shaft level with 50/50 acetone and ATF. Tonight I tried to try and drift the shaft out again, still to no avail. Does ANYONE have any ideas from here? Im at my wits end dealing with it, and im not sure im doing it right to begin with. I dont want to put too much force on the hardened shaft ends or the cast iron housing, and the best method ive got to actually apply force involve slipping a bit of pipe around the end of the shaft, lining up the shoulder of the shaft on the other side to the housing hole, and sticking a pice of concave brass rod over the tip of the shaft and tapping. This seems like a bad idea for several reasons and prevents me from really applying force. I feel like removing the key could really help but I dont know if its a strait key like the other gear shaft in this machine or if its a wedge, as the bronze gear side of things has the key flush with the bronze but seems to slope up as it goes in. The other side, near the small iron gear, the key emerges a couple mm as does the rest of the shaft in what appears to be a shoulder making the shaft one way. On this end however rather than a slope on the top side of the key, the edge of the key sits proud a bit. Imagine the overall shape of the toothpick of a swiss army knife. This is outside of my wheelhouse and id love to hear any advice or ideas from people here who probably know about a million ways better to do it than what ive tried

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On 5/4/2019 at 10:45 AM, Irondragon Forge & Clay said:

 I think there are several You Tube videos on taking the 400 apart, I'll see if I can find them. This is the one I'm thinking of.

 

He disassembles practically every part of the blower, but does not remove that gear. :( Very good video series though, as all of his videos are. 

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On 5/10/2019 at 1:50 AM, DHarris said:

He disassembles practically every part of the blower, but does not remove that gear. :( Very good video series though, as all of his videos are. 

Thats the general rule of all the videos ive watched, all food videos but none actually remove that gear. HandToolRescue doesnt even remove the caps that center the shaft and set screws and thats been the other best video ive found. I suppose I could in theory cut the shaft, remove the gears using a press to punch out the remnant inside them, and remake a new shaft but I doubt id be able to effectively cut it or to temper the new one as hard as this is 

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Same boat here. I'm trying to disassemble a 400 as well and it's fighting me every step. Mine was paint red and it must be some tough paint. Took ALOT of doing just to get all the caps off and it was pretty dry in there so I really would like to replace the bearings. I have it mostly done except the cone shaped screws that holds the ball bearing in place. Had it soaking in just about every type of oil/penetrating fluid for weeks. Nada. Made a tool to fit the holes but it bent. Nothing has worked so far. I've yet to apply heat but not that confident it would work. I didn't realize how soft that gear was and bent it just a tad. I've straightened it out by eye but would really want to remove it so I can index it on my lathe.

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Mutant, mine didnt give me issues on the bearing cones except the worm drive opposite the fan end, and that was grip. Id scrape any gunk from around the junctions of the shaft and cone, heat gently so as not to mess with the hardened surfaces, and blast with penetrating oil. The heat really made a big difference in mine, now if only it would work for my bronze gear. Ive let it soak in vinegar after degreasing just to see if it might dissolve anything in there and help the next heat/oil/tapping cycle get the job done

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I think your best bet is to just put it back together and use it till it fails. In the meantime look for a blower with a good gearbox and a busted fan housing. When you find one, just attach your good housing to the donor gear box. 

After that.....just heat and beat yours until you either break it loose or you just break it period. 

And since there seem to be no videos showing removal of that gear, you may want to make one. If you succeed, others will see how you did it. If you fail, others will see how to NOT do it. Either would be informative. 

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Unfortunately its on its last tip-toe and the edges of the gear are thin sharp and feathery, but i have a tiger blower in good shape to work until i either find a donor gear/gearbox or can figure how to fix this one. Fingers crossed i can find one of the fabled  “left handed” gearboxes while im at it, i realky like the look and performance of the 400 blowers

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I expect you would have better luck finding a Bigfoot answering the call. 

But I am curious about that. Can the blades be removed and reversed?

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ironically as soon as i mention a left handed model someone posts a thread about one, lol. The blades turn either way but the handle protrudes from the opposite side of the gearbox to be cranked with the right hand

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