Dubro spinner backplate slipping
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Dubro spinner backplate slipping
I don't know if I'm clueless or what, but I've bought a few Dubro spinners over the years and they always seem to be a pain to get on. For instance, I go to put on my spinner backplate, then the prop, then the washer and prop nut. I align the backplate with the prop so the spinner fits through the prop cut-outs. This is where the problem starts. When I go to tighten the prop nut the backplate moves just enough so the alignment of the backplate and spinner are off just a hair. At this point the spinner won't click on , so I loosen the nut and start over[:@] The only way I can get it right is if I jam an allen wrench through one of the backplate holes then against the prop and start tightening with the other hand. Sometimes this works, sometimes not. I thought those little plastic nubs on the backplate were supposed to prevent the backplate from spinning. Have I been doing something wrong all these years?
#2
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RE: Dubro spinner backplate slipping
Welcome to the club.
That's a common situation with the nylon backplate. It's just slippery.
I've found wood props work better with gripping the backplate, better than the APC or MA composites.
That's a common situation with the nylon backplate. It's just slippery.
I've found wood props work better with gripping the backplate, better than the APC or MA composites.
#3
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RE: Dubro spinner backplate slipping
Cut a couple of pieces of sandpaper (any grit) about 1 inch square or so and glue them together paper side to paper side. Cut a hole in this big enough for your engine's crankshaft. Place this sandpaper piece between the spinner backplate and the prop. This helps hold them in place while you tighten the nut. Fought that battle many times...
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RE: Dubro spinner backplate slipping
Hi John,
The suggestions of sandpaper and scoring the plastic may help, but I think I've developed a technique that doesn't rely on those things.
First, assemble the parts as you said, "Put on my spinner backplate, then the prop, then the washer and prop nut." Leave the nut finger tight. Turn the motor crank CCW (running direction) until it just comes onto the compression stroke. Orient the prop so it's horizontal, turning CCW to stay on the compression of the engine. Facing the front of the plane, hold the left prop blade in the fingers of your left hand (curled under the blade), then turn the backplate CCW with your right hand until the pins come up to the back of the prop blades. Then hold it in place with downward pressure with your left thumb, and tighten the nut with a wrench in your right.
It works for me.
Good luck,
Phil
The suggestions of sandpaper and scoring the plastic may help, but I think I've developed a technique that doesn't rely on those things.
First, assemble the parts as you said, "Put on my spinner backplate, then the prop, then the washer and prop nut." Leave the nut finger tight. Turn the motor crank CCW (running direction) until it just comes onto the compression stroke. Orient the prop so it's horizontal, turning CCW to stay on the compression of the engine. Facing the front of the plane, hold the left prop blade in the fingers of your left hand (curled under the blade), then turn the backplate CCW with your right hand until the pins come up to the back of the prop blades. Then hold it in place with downward pressure with your left thumb, and tighten the nut with a wrench in your right.
It works for me.
Good luck,
Phil
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RE: Dubro spinner backplate slipping
Gee, wow this sounds farmiliar, I fought this battle for about 20 minutes at the field yesterday trying to get the spinner on my chipmunk. I like the sandpaper idea. We were going to try it but didn't have any at the field. I have no magic solution, only sympathy.
Tim
Tim
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RE: Dubro spinner backplate slipping
Hi!
Well... sandpaper might work ...I have always used 0,4mm plywood discs behind the back plate..but I use only Tru Turn alu spinners. Nylonspinners could be a little more slippery though.
Regards!
Jan K
Sweden
Well... sandpaper might work ...I have always used 0,4mm plywood discs behind the back plate..but I use only Tru Turn alu spinners. Nylonspinners could be a little more slippery though.
Regards!
Jan K
Sweden
#11
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RE: Dubro spinner backplate slipping
ORIGINAL: jzinckgra
I don't know if I'm clueless or what, but I've bought a few Dubro spinners over the years and they always seem to be a pain to get on. For instance, I go to put on my spinner backplate, then the prop, then the washer and prop nut. I align the backplate with the prop so the spinner fits through the prop cut-outs. This is where the problem starts. When I go to tighten the prop nut the backplate moves just enough so the alignment of the backplate and spinner are off just a hair. At this point the spinner won't click on , so I loosen the nut and start over[:@] The only way I can get it right is if I jam an allen wrench through one of the backplate holes then against the prop and start tightening with the other hand. Sometimes this works, sometimes not. I thought those little plastic nubs on the backplate were supposed to prevent the backplate from spinning. Have I been doing something wrong all these years?
I don't know if I'm clueless or what, but I've bought a few Dubro spinners over the years and they always seem to be a pain to get on. For instance, I go to put on my spinner backplate, then the prop, then the washer and prop nut. I align the backplate with the prop so the spinner fits through the prop cut-outs. This is where the problem starts. When I go to tighten the prop nut the backplate moves just enough so the alignment of the backplate and spinner are off just a hair. At this point the spinner won't click on , so I loosen the nut and start over[:@] The only way I can get it right is if I jam an allen wrench through one of the backplate holes then against the prop and start tightening with the other hand. Sometimes this works, sometimes not. I thought those little plastic nubs on the backplate were supposed to prevent the backplate from spinning. Have I been doing something wrong all these years?
The problem is that the threads of the propnut are binding with the threads on the crankshaft.
The solution to your problem is simple.
Lube the threads on the crankshaft.
Dan
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RE: Dubro spinner backplate slipping
Dan, my OS91fs backfired and loosened up the prop nut so had a chance to try your "oil the threads" idea. Guess what, it worked. Thanks for the tip, much easier than sandpaper or any other voodoo magic. It's so darn simple I feel stupid for not thinking of it. This is a prime example of over thinking and over complicating something.
Thanks
Tim
Thanks
Tim
#15
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The best solution I've ever found for plastic spinners is to buy a roll of open mesh plumbers sandcloth. Open mesh drywall sanding sheets work too. It's rough on both sides and really tough. You cut a piece a little bigger than your prop hub with a hole for the crankshaft. Even with the prop nut just hand tight, you'll find that the sandcloth locks the prop into place really well. I've never had a backplate slip since I figured this out, even with a flooded engine.
To address the issue of the backplate slipping, I hand tighten the prop nut and recheck the backplate position. You'll still be able to move it if you need to, then it won't move on its own when you finish tightening it.
To address the issue of the backplate slipping, I hand tighten the prop nut and recheck the backplate position. You'll still be able to move it if you need to, then it won't move on its own when you finish tightening it.