Prop/thrust washer
02-20-2009 | 04:12 PM
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From: San Antonio,
TX
Prop/thrust washer
I somehow lost two prop washers to two different engines. (Mag.91RFS and Saito 1.80FS) Can they be purchased at a hardware store? Sizes???
02-20-2009 | 05:20 PM
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From: Burtchville,
MI
RE: Prop/thrust washer
I would try a stainless fender washer. Just take your engine with you. It doesn't have to be metric but find one that fits closely to your prop shaft. If you have a buffing wheel you can make it look like chrome.
Bill
Bill
02-20-2009 | 07:17 PM
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From: Burtchville,
MI
RE: Prop/thrust washer
ORIGINAL: jeffie8696
I would look to Fastenal and see if they have anything in a hardened washer.
I would look to Fastenal and see if they have anything in a hardened washer.
Better yet. It wouldn't be foolish to use a hardened washer. Especially if your engine is large. You might also check with a local hobby shop if you are lucky enough to have one.
Bill
02-20-2009 | 09:06 PM
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RE: Prop/thrust washer
Saito 180 prop washer
http://www.horizonhobby.com/Products...ID=SAI170R3135
Magnum 91 Four Stroke
http://www.hobbypeople.net/gallery/280208.asp
http://www.horizonhobby.com/Products...ID=SAI170R3135
Magnum 91 Four Stroke
http://www.hobbypeople.net/gallery/280208.asp
02-20-2009 | 10:17 PM
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From: Cincinnati,
OH
RE: Prop/thrust washer
By all means, buy an original replacement from the sources w8ye referenced above. You do NOT want anything that is a sloppy fit on the threaded end of the crankshaft! That would result in a lot of vibration, or worse.
02-20-2009 | 10:19 PM
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RE: Prop/thrust washer
ORIGINAL: Ken6PPC
By all means, buy an original replacement from the sources w8ye referenced above. You do NOT want anything that is a sloppy fit on the threaded end of the crankshaft! That would result in a lot of vibration, or worse.
By all means, buy an original replacement from the sources w8ye referenced above. You do NOT want anything that is a sloppy fit on the threaded end of the crankshaft! That would result in a lot of vibration, or worse.
02-21-2009 | 04:21 AM
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RE: Prop/thrust washer
ORIGINAL: Ken6PPC
By all means, buy an original replacement from the sources w8ye referenced above. You do NOT want anything that is a sloppy fit on the threaded end of the crankshaft! That would result in a lot of vibration, or worse.
By all means, buy an original replacement from the sources w8ye referenced above. You do NOT want anything that is a sloppy fit on the threaded end of the crankshaft! That would result in a lot of vibration, or worse.
Any washer that is the correct size will do the job
If we take an extreme case of an improvised steel washer, with a thickness of 2 mm and an O/d of 30 mm; even if this washer does have a very sloppy fit on the end of the shaft (with a hole 1 mm larger in diameter than the shaft thread), the imbalance calculates to ~23.5 cubic mm of steel (specific gravity 7.8), which are 0.18 grams 1.5 cm from the center, or 0.12 grams/cm.
This is equivalent to an imbalance of less than 0.006 gram at the blade-tip of a 16" prop...
I don't think you can really feel such a level of vibration, at ~9,000 RPM, even if it was an electric motor spinning this prop...
With any single-cylinder glow engine, which inherently suffers from a partial primary balance, this will really be imperceptible.
...So much for using expensive magnetic balancers, for props intended for such engines...
02-21-2009 | 04:43 AM
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RE: Prop/thrust washer
I use to balance all my props very thoroughly, but since I got into high performance electrics I`m not able to balance the tiny 4.1" to 5" props. They are so light-weight that they don`t move at all on my magnetic balancer, making balancing impossible. Maybe they all are perfectly balanced from the mold? I have began to just slap them on and fly, I have not experienced any problems or vibration to speak off so far. I turn these props from 28 000 rpm to 42 000 rpm static. Too little mass I think, to make a difference.
Edit: This is me flying my Zagi Typhoon 430 in the early days of development, it is faster now
One shold think that these props would need to be balanced, but maybe they aren`t so bad to begin with.
http://www.youtube.com/watch?v=N_1uW_Ix8cs
Yeah, I know this isn`t glow, but I feel it fits this balacing thread somehow
Bottom line is that I agree that a small imbalance of a small washer on the output shaft turning about 9-12K propably will not be noticed at all
Edit: This is me flying my Zagi Typhoon 430 in the early days of development, it is faster now
One shold think that these props would need to be balanced, but maybe they aren`t so bad to begin with.http://www.youtube.com/watch?v=N_1uW_Ix8cs
Yeah, I know this isn`t glow, but I feel it fits this balacing thread somehow
Bottom line is that I agree that a small imbalance of a small washer on the output shaft turning about 9-12K propably will not be noticed at all
02-21-2009 | 05:18 AM
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From: Burtchville,
MI
RE: Prop/thrust washer
ORIGINAL: asmund
I use to balance all my props very thoroughly, but since I got into high performance electrics I`m not able to balance the tiny 4.1" to 5" props. They are so light-weight that they don`t move at all on my magnetic balancer, making balancing impossible. Maybe they all are perfectly balanced from the mold? I have began to just slap them on and fly, I have not experienced any problems or vibration to speak off so far. I turn these props from 28 000 rpm to 42 000 rpm static. Too little mass I think, to make a difference.
Edit: This is me flying my Zagi Typhoon 430 in the early days of development, it is faster now One shold think that these props would need to be balanced, but maybe they aren`t so bad to begin with.
http://www.youtube.com/watch?v=N_1uW_Ix8cs
Yeah, I know this isn`t glow, but I feel it fits this balacing thread somehow
Bottom line is that I agree that a small imbalance of a small washer on the output shaft turning about 9-12K propably will not be noticed at all
I use to balance all my props very thoroughly, but since I got into high performance electrics I`m not able to balance the tiny 4.1" to 5" props. They are so light-weight that they don`t move at all on my magnetic balancer, making balancing impossible. Maybe they all are perfectly balanced from the mold? I have began to just slap them on and fly, I have not experienced any problems or vibration to speak off so far. I turn these props from 28 000 rpm to 42 000 rpm static. Too little mass I think, to make a difference.
Edit: This is me flying my Zagi Typhoon 430 in the early days of development, it is faster now
One shold think that these props would need to be balanced, but maybe they aren`t so bad to begin with.http://www.youtube.com/watch?v=N_1uW_Ix8cs
Yeah, I know this isn`t glow, but I feel it fits this balacing thread somehow
Bottom line is that I agree that a small imbalance of a small washer on the output shaft turning about 9-12K propably will not be noticed at all
FASTER NOW? Gawd. Jack Northrup would be proud.
Bill
02-21-2009 | 07:14 AM
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From: Brisbane, AUSTRALIA
RE: Prop/thrust washer
ORIGINAL: asmund
I use to balance all my props very thoroughly, but since I got into high performance electrics I`m not able to balance the tiny 4.1" to 5" props. They are so light-weight that they don`t move at all on my magnetic balancer, making balancing impossible.
I use to balance all my props very thoroughly, but since I got into high performance electrics I`m not able to balance the tiny 4.1" to 5" props. They are so light-weight that they don`t move at all on my magnetic balancer, making balancing impossible.
Nice flying on the Typhoon, love sound of that screaming lecky.
02-21-2009 | 04:55 PM
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From: Cincinnati,
OH
RE: Prop/thrust washer
Dar, you are probably correct about the washer. It isn't that big or heavy.
I was actually thinking about a situation where a friend of mine lost the crankshaft adapter for his spinner. The hole in the spinner was a little too large for the crankshaft, and it vibrated so badly he thought his engine was JUNK! When I found that the spinner was missing it's adapter, I made a new one to fit. The engine ran fine after that. However, the spinner is quite a bit heavier than a washer, and the outside edges are a lot farther away from the prop.
I was actually thinking about a situation where a friend of mine lost the crankshaft adapter for his spinner. The hole in the spinner was a little too large for the crankshaft, and it vibrated so badly he thought his engine was JUNK! When I found that the spinner was missing it's adapter, I made a new one to fit. The engine ran fine after that. However, the spinner is quite a bit heavier than a washer, and the outside edges are a lot farther away from the prop.
02-21-2009 | 05:29 PM
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From: San Antonio,
TX
RE: Prop/thrust washer
If I purchase the washers online it will be $21.20 without shipping. That's a heck of a lot of money for a couple of washers. Just wasn't sure if I could get away with using some that were not quite OEM. I'll go see if they have something like them at the hardware store.
Thanks guys.
Thanks guys.
02-21-2009 | 06:51 PM
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From: Burtchville,
MI
RE: Prop/thrust washer
ORIGINAL: cruzomatic
If I purchase the washers online it will be $21.20 without shipping. That's a heck of a lot of money for a couple of washers. Just wasn't sure if I could get away with using some that were not quite OEM. I'll go see if they have something like them at the hardware store.
Thanks guys.
If I purchase the washers online it will be $21.20 without shipping. That's a heck of a lot of money for a couple of washers. Just wasn't sure if I could get away with using some that were not quite OEM. I'll go see if they have something like them at the hardware store.
Thanks guys.
$21.20 does seem a-bit over the top though.
Bill
02-21-2009 | 08:32 PM
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From: Cincinnati,
OH
RE: Prop/thrust washer
Well, the $21.20 DOES include not only the washer, but also a prop nut and locking nut for both engines.
Personally, I would pay it, and try to not lose them again...
Personally, I would pay it, and try to not lose them again...
02-21-2009 | 08:41 PM
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From: Burtchville,
MI
RE: Prop/thrust washer
ORIGINAL: Ken6PPC
Well, the $21.20 DOES include not only the washer, but also a prop nut and locking nut for both engines.
Personally, I would pay it, and try to not lose them again...
Well, the $21.20 DOES include not only the washer, but also a prop nut and locking nut for both engines.
Personally, I would pay it, and try to not lose them again...
That's more like it.
Bill
