Propeller keyway fit

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I went to put the DQ 486 back on the shaft and noticed some play in the keyway to shaft fit. The prop is lapped to the shaft taper and to me fits well. I was checking to see that the key wasn't sitting too high or riding up on the end of it's cutout and I saw that there was about 1/16" play back and forth just before I sent the prop home on it's taper. Of course once the prop seats there is no play but that's the taper not the keyway holding it. Key is a little worn showing a line along it's length but I turned it 90 degrees and no difference. I ordered new keystock in both stainless and brass but I don't think this will make much difference.
DQ 486 on 1 1/2" shaft, 3/8" by 3 1/2" key
 

captjohn

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I went to put the DQ 486 back on the shaft and noticed some play in the keyway to shaft fit. The prop is lapped to the shaft taper and to me fits well. I was checking to see that the key wasn't sitting too high or riding up on the end of it's cutout and I saw that there was about 1/16" play back and forth just before I sent the prop home on it's taper. Of course once the prop seats there is no play but that's the taper not the keyway holding it. Key is a little worn showing a line along it's length but I turned it 90 degrees and no difference. I ordered new keystock in both stainless and brass but I don't think this will make much difference.
DQ 486 on 1 1/2" shaft, 3/8" by 3 1/2" key
I think it makes a difference!!!
 

ARC

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The good news is , if lapped properly the key will do almost nothing but index the prop. If you torque down properly [ that means torque and retorque 24 hours later ] next season you would be able to slide the key out by hand.
 

leaky

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First time I ever delt with this is a month or two ago, but the collective info is fresh in my mind from all the help.

The 1/16th is fore and aft? As in you are saying that the key wasn't jammed in place until you fully seated the prop on its taper?

There shouldn't be 1/16 sideways, that's wierd. I don't think that's what you mean.

The key ideally both doesn’t have any play on the shaft but also doesn’t hang up the prop or take more than a light tap (ie plastic handle of a screwdriver once) to seat in the shaft. In the process you want to make sure the prop keyway doesn't have any snags as those can cause wierd results, file off if they exist and make sure the key fits the prop OK too before trying to seat the prop.

Took me 3 tries when I did this as first 2 I over filed the key.
 
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Side to side play was my worry. Just before the prop seated on the taper you could rock it side to side more than what i thought was OK. The old key slides back and forth in the both the shaft and prop keyway, but doesn't seem that loose. That's why I was surprised when the prop twisted so much side to side just before seating on the taper. It seats ok, I had to use a puller to get it off the shaft but i was surprised how loose the prop was on the key. If you push the prop up to stick on the shaft you can push the key easily back and forth. That wouldn't worry me if the prop didn't move side to side so much just before dinging on the shaft.
 

ARC

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Keep lapping. You do not have it yet. When lapped properly , if you slide the prop up the shaft it will stick like glue . You will need a puller to remove it. You need 100% contact . It takes time and lots of grinding compound. 90Deg turns only.
 

leaky

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Side to side play was my worry. Just before the prop seated on the taper you could rock it side to side more than what i thought was OK. The old key slides back and forth in the both the shaft and prop keyway, but doesn't seem that loose. That's why I was surprised when the prop twisted so much side to side just before seating on the taper. It seats ok, I had to use a puller to get it off the shaft but i was surprised how loose the prop was on the key. If you push the prop up to stick on the shaft you can push the key easily back and forth. That wouldn't worry me if the prop didn't move side to side so much just before dinging on the shaft.

When I felt my key was right, it slid into the prop but kinda snapped in place on the shaft with the full force of my grip or a tap or two.

To me sounds like the prop isn't quite lapped or your test expectations aren't quite right - they really stick themselves in place once lapped. If not seated fully I think the play is normal - once lapped right, without a key or with a well fit one, when you slide the prop on it has a certain sound, has zero play, if tapped off a touch so you can spin it they tend to seat themselves again and require tapping back off.
 

leaky

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Just to give you an idea of what I found - took me a good 20+ hours of reading, asking questions, lapping, cleaning, checking, file this or that, repeat, so many gallons of water and alcohol, multiple tubes of compound, stepping back and securing my shaft just right so the process was easier, 3 keys, before I finally felt it was good to go - and at that point I felt I knew for sure. Takes patience.
 
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