Here we go again!
02-26-2009, 08:18 AM
#1
Senior Member
Thread Starter
Join Date: Jan 2002
Location: Indianapolis, IN
Posts: 996
Likes: 0
Received 0 Likes
on
0 Posts
Here we go again!
Ok .... so I know I should use the search. I did ........ and wore my eyes out trying to find the answer to my problem. I have a 3 bladed prop, 70 mm, that came in my Sea Queen kit. I am like a dog, chasing his tail, in trying to balance this prop. ( I have balanced MANY ...2 blade aircraft props with very good results).
I would like to know the STEPS in sequence, to balance a 3 blade prop. I have the blades numbered 1-2-3 to keep track of progress but so far I have not MADE and worthwhile progress. Add to the mix, the shaft is long on this boat and the shaft hole does not go all the way through the prop. If.......... I rotate the prop, (say 180 degrees), on the shaft, and put it back on the balancer, a different blade ends up allegedly heavy at the bottom of it's arc. Hey! this tells me the shaft is out of balance. I tried filing off a little on the "so called" heavy portion with no luck or change in results. I decided to ask some experts here on the forum. Any ideas??
Thanks as always,
lownslo
Bob in Indy
I would like to know the STEPS in sequence, to balance a 3 blade prop. I have the blades numbered 1-2-3 to keep track of progress but so far I have not MADE and worthwhile progress. Add to the mix, the shaft is long on this boat and the shaft hole does not go all the way through the prop. If.......... I rotate the prop, (say 180 degrees), on the shaft, and put it back on the balancer, a different blade ends up allegedly heavy at the bottom of it's arc. Hey! this tells me the shaft is out of balance. I tried filing off a little on the "so called" heavy portion with no luck or change in results. I decided to ask some experts here on the forum. Any ideas??
Thanks as always,
lownslo
Bob in Indy
02-26-2009, 08:40 AM
#2
RE: Here we go again!
You have a slow-turning prop, right? Don't waste any more time on it.
Your SHAFT is a big part of the problem you're having. It's flexing, and IT'S not straight. NO WAY can you balance it with the shaft attached.
If you really need the prop balanced, remove the shaft, drill it through, and work it like a standard racing prop. I KNOW you can find those online, because a dozen sites host that chapter I wrote.
Andy
Your SHAFT is a big part of the problem you're having. It's flexing, and IT'S not straight. NO WAY can you balance it with the shaft attached.
If you really need the prop balanced, remove the shaft, drill it through, and work it like a standard racing prop. I KNOW you can find those online, because a dozen sites host that chapter I wrote.
Andy
02-26-2009, 08:45 AM
#3
Senior Member
Thread Starter
Join Date: Jan 2002
Location: Indianapolis, IN
Posts: 996
Likes: 0
Received 0 Likes
on
0 Posts
RE: Here we go again!
Andy,
I was afraid that was the problem. The shaft rolls true on a plate glass surface but it is just not good enough. I was afraid to drill through for fear of damaging the threads in the prop. Someone also suggested to cut off the "bullet end" with a Dremmel. I really want it balanced so I will have to do one or the other I guess. Thanks,
lownslo
I was afraid that was the problem. The shaft rolls true on a plate glass surface but it is just not good enough. I was afraid to drill through for fear of damaging the threads in the prop. Someone also suggested to cut off the "bullet end" with a Dremmel. I really want it balanced so I will have to do one or the other I guess. Thanks,
lownslo
02-26-2009, 08:54 AM
#4
Senior Member
Thread Starter
Join Date: Jan 2002
Location: Indianapolis, IN
Posts: 996
Likes: 0
Received 0 Likes
on
0 Posts
RE: Here we go again!
PS...... I will have to drill it through because I do want to balance prop. Cutting off the bullet end will do no good since I would still have to drill anyway since the cut would not reach the thread depth.
lownslo
lownslo
02-26-2009, 11:09 AM
#5
Senior Member
Thread Starter
Join Date: Jan 2002
Location: Indianapolis, IN
Posts: 996
Likes: 0
Received 0 Likes
on
0 Posts
RE: Here we go again!
Andy,
The deed is done. Without a machine shop, and just an old antique drillpress, the hole drilled all the way through the prop turned out fairly good. I least I did not damage the props threads and the Top Flite balancer in photo will now work for me.
Note: You may just barely notice the Top Flite balancer the way it is pictured. You airplane guys will know what I have done. I have given height to the balancing shaft to allow for my 16" props to swing all the way through. The "PENCIL Erasers" are there to balance the aircraft's CG. (Center of gravity, for you sailors)
The deed is done. Without a machine shop, and just an old antique drillpress, the hole drilled all the way through the prop turned out fairly good. I least I did not damage the props threads and the Top Flite balancer in photo will now work for me.
Note: You may just barely notice the Top Flite balancer the way it is pictured. You airplane guys will know what I have done. I have given height to the balancing shaft to allow for my 16" props to swing all the way through. The "PENCIL Erasers" are there to balance the aircraft's CG. (Center of gravity, for you sailors)
