Balancing a wheel? balancing a windmill prop?

[Ribenapigeon]

I'm fettling a windmill to generate power (I know nuts) but I'm wondering how to go about balancing it as I'm going to fettle the prop myself. I'm thinking someone here by knowing about balancing wheels might have some advice on how to proceed.

Cheers.

[G]

I'd suggest you should be looking at people who balance propellers, not wheels.

With a wheel you just add weight at the exact point needed to counterweight how much it's out by.

If you have an external disc around the tips of your blades this may well work, otherwise it's getting each blade set up right.

[Ribenapigeon]

I lknow I need to add weight but the problem is how to find the right spot and how much weight to add.

[stinkwheel]

With balancing anything, you generally allow it to spin freely and mark the lowest point when it comes to a halt then repeat. If the same point lands up lowest you either remove weight from that point or add weight to the highest point.

Then repeat. If it stops at the same point, you need to add/remove more weight. If it stops opposite, you need less. It's balanced when it comes to rest at a different point each time.

With a vehicle wheel, you'd stick/cinch small lead weights to the rim or (the old fashioned way) wrap bits of solder round a spoke.

With a crank, you'd either drill holes in the flywheel or grind the outside of the flywheel to lighten it.

With a windmill prop. Not sure how they'd do that. Maybe add weights to the hub?

True before you balance.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[G]

[james1988]

I did some work experience years back in stage 2 compressors (I think that's the right term) for the GE90. To balance the turbine it was a case of swapping the blades for a heavier or lighter blade. No idea if that's of any use.

James

[Ribenapigeon]

I did wonder if it involves a certain amount of dead reckoning then trial and error with weight placement. So thanks for confirming it.

The kind of prop I'm going to make will be more of a barral with vanes on somewhat like a centrifugal type, if that makes sense, so it spins whatever the wind direction.

[G]

That type you should be able to balance with weights like a wheel as they generally do have a couple of rings to keep everything held together.

[Ribenapigeon]

[yen_powell]

[DrDonnyBrago]

I balance wheels using a shaft running on a set of bearings, two bearings on each side with the shaft resting between them, pop out the seals and replace the thick grease with light oil and they become very free running.

Basically a DIY version of these:

https://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_12675.jpg

https://www.motorcyclenews.com/upload/Knowhow/sep28%2005%20balance%20wheels/4-01.jpg

Heavy bit falls to the bottom, place weights directly opposite.


Can't see why it wouldn't work for you.

[Ribenapigeon]

I'm going to balance it after i've mounted it in a frame. i've found some skateboard bearings on amazon that are a good source of cheap bearings.

I can see the logice of just turning the wheel then seeing where it comes to rest and will probably use that method. But what are they doing in tyre fitters when they spin the wheel up to high speed on that machine they have.

[stinkwheel]

[james1988]

Just a thought, haven't you got to get the pitch of the prop / fan blades the correct angle too?

James

[Pete.]

[stinkwheel]

[Ribenapigeon]

[Ribenapigeon]

Pete, I will probably do some sort of assembly ballance tests as well but nice to start with a balanced prop to start with.

[Pete.]

Yes having the blade pitches all the same is important. It's easy to make a cardboard template for doing that. You have to make sure that's right before doing any balancing otherwise you'll be adjusting weight balance to correct wobble from varying effort.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[mudcow007]

is this of any help?