Impact Wrench

[pfhoeycfi]

I'm assembling the aerovee and have the crank in the half case with the flywheel on, the gland nut hand snug. It looks like I need to buy another tool that I will use once...an impact wrench, so that I can tighten the nut so as to check the endplay in the crankshaft. I've never used one. I cant see using a torque wrench with the shaft just laying in an open half case. I will use the torque wrench to the 227 ft-# when the nut goes in for good. Anyway I am looking for recommendations for an impact wrench, make model etc. I don't want to overdo it in this step so is there a maximum suggested torque rating for the impact wrench? Can a std 36 mm socket be used with an impact wrench? Any other suggestions and/or advice always welcome...

peter
snb0021

[tx_swordguy]

Hi peter if all you are doing is snugging it up tight a cheap 1/2 “ impact will work. It may or may not reach 227 ft lbs. if it gets it to 150 that should still be very snug in my opinion and torque it the rest of the way. 1/2 drive 36 mm socket will work in an impact. It is possible although i have never done it or seen it, ( just stories) that you can potentially break a non impact rated socket in an impact gun. I would highly suspect those were super high torque impacts being used on something way out of line for a basic socket. I believe you will be fine.

[johnnn]

I would not recommend an impact wrench. I stripped my glad nut doing that. I would go out of my way to get torque wrench that goes to 250 ft lbs. You have more control and then you know what you've got. I bolted a 2 x 4 x 4 foot board to the propeller hub and had a helper hold that down. I expected it to take more force than it did to get the 250 ft lbs. Just be careful and not force it. I know of one other builder who also stripped the gland nut. It's easy to do.

[Bryan Cotton]

I somehow locked the crank to the case, like with a piece of scrap bolted to the flywheel and case. I forget the exact detail. I put a pipe over my breaker bar, weighed myself, and calculated where to stand to get the right torque. I had Adam counterbalance me. This seemed to work fine.

[Rynoth]

re: the replies so far... the OP is just trying to set his shims (i.e. the case halves aren't mated yet) and the plans do indeed call for an impact wrench to be used. That said, I believe I just snugged it up with a breaker bar, but I don't recall how I secured the crankshaft. It is a bit of a tricky maneuver since the crank is still loose in half of the case, and an impact wrench may help reduce motion of the loose crank.

Since the purpose is just to set the shims, I don't think full torque is necessary or even desirable... the main thing is just to be sure the flywheel is flush/tight against the crankshaft to get an accurate shim measurement.

Edit: I actually just found some video when I did the end-play shim measurement and I did indeed use a battery-powered impact wrench on the gland nut. No special securing of the crankshaft was needed.

[pfhoeycfi]

re: the replies so far... the OP is just trying to set his shims (i.e. the case halves aren't mated yet) and the plans do indeed call for an impact wrench to be used. That said, I believe I just snugged it up with a breaker bar, but I don't recall how I secured the crankshaft. It is a bit of a tricky maneuver since the crank is still loose in half of the case, and an impact wrench may help reduce motion of the loose crank.

Yes thats what I meant. I found a WEN electric 230 ft # impact wrench online... it worked perfect for this and I didn't have to worry about overdoing it since it tops out at the specified torque plus 3. It was dirt cheap. Its now collecting dust on the one use tool shelf.
Thanks,
Peter