Anyone ever check the balance of their spinners?

I maidened a little no-brand Chinese .40-size Ultimate ARF today (exact copy
of The World Models Ultimate). I used a new Super Tigre .40 ringed for
power. I was having a hell of a time getting it to run right... it was
unresponsive to the needle at times due to what seemed to be fuel foaming.
I was getting some nasty vibration with harmonics shaking various parts of
the airplane at various RPMS. =:-0
I took off the prop and checked the balance... fine. Then I took off the
cowl and checked the engine mounts, the engine mount bolts, etc... fine.
When I got home, I decided the put the spinner on my magnetic prop balancer.
It was way out of balance. Even after drilling six 1/8" holes near the rim
of the backplate on the heavy side, it still wouldn't come close to
balancing.
The spinner was one of the very nice-looking polished aluminum types that I
bought from either Maxx Products or Cermark. They are very inexpensive and
look great. I took it off and replaced it with a high-quality (and
high-priced) model and everything is running smoothly now.
I guess I'll be avoiding the budget spinners in the future....
Good flying,
desmobob
Reply to
desmobob
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Good to know. Might be important to know which brand it was. mk
Reply to
MK
I only use those "spinner nuts" from Dubro. Checked some of them wa
back and found that they were pretty well balanced. Haven't checke one since, but now, I think I will check again. There is som vibration in some of my set-ups, and it may be the spinner nut ....
Thanks for the "heads-up" !
-- indoruwe ----------------------------------------------------------------------- indoruwet's Profile:
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Reply to
indoruwet
I like the spinner nuts and use them whenever I'm able. But lot of models need a spinner, and I don't like the plastic ones. The aluminum ones are pricey, so I thought I'd save a few bucks with the cheap ones. False economy, I guess. I have a few more of these cheap spinners on other airplanes and I'll be checking them for balance before I fly again.
mk: I can't remember the brand, but I'm pretty sure I bought the spinner from either Maxx Products or Cermark. That would make it a "ProSpin" or "Spin Right" brand. I'll look later to see if there are any brand markings on it.
Good flying, desmobob
Reply to
desmobob
These are the ones with the plastic cone against a metal backing plate? In Australia, TY1 seems to be quite common, and decent quality as some Taiwanese products seem to be - or so I though since I haven't thought to check the balance on them - however there seems to be a number of Taiwanese/Chinese products appearing, including World Models. It'd be good to know the better/worse manufacturers.
Reply to
Poxy
You should be able to balance them by epoxying weights on the inside, or thinning the inside walls. It may be false economy, though, given the amount of time you'd have to spend.
Reply to
Tim Wescott
I just took a look but couldn't find any markings. I took a spinner of the same type off another model and checked it... same thing! So far off balance that I couldn't make it right by grinding with the Dremel or drilling the backplate. It seems more likely that the holes are drilled off-center. In the trash with that one, too!
Just to be sure I wasn't imagining things, I took a Dave Brown spinner off another model and checked it... VERY close. I was able to get it just about perfect by moving the backplate. When I got a good result, I indexed the cone and backplate so it will be installed correctly.
So... those two spinners that I "saved" about $5 apiece on ended up in the trash. :-(
Good flying, desmobob
Reply to
desmobob
TY-1 seems to be well built. I have one but yet to use it but all the members of our club who use them say they are great.
I currently have an all plastic spinner that came with my Seagull Boomerang 40 trainer. After 150hours of use on a 40LA plus some use on an underprop'd 46AX it's still in one piece.
I also have a Magnum alloy spinner. Very nice unit, just wish it came with adapters to suit it's use on smaller engines.....the plane requires a large spinner to suit the cowl but the engine is only a 46AX. Magnum make the larger spinners with prop shaft holes aimed at larger engines. Yes, there are spacers available but I would have preferred them to be included with the spinner.
The main failings in spinners I see relate more to how some people: abuse them (ramming the starter onto them!), modifying them badly to fit the prop, or fitting them loosely.
Reply to
The Raven
Did you forget the link, Ed? I'm wondering what spinners are absolutely perfect... seems they may be worth the expense.
Good flying, desmobob
Reply to
desmobob
You're right. I forgot the link :) Check out the True Turn Stuff here:
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I have three and they are works of art
Reply to
Ed Forsythe
OK Ed, I'll try one. I just put a standard 2 1/2" model and adapter in my Tower shopping cart.
Good flying, desmobob
Reply to
desmobob
I'll post my thoughts when I eventually fill up an order from Tower and get the Tru-Turn.
Right now, I have a couple of Dave Brown spinners which I like very much; a CBA Tatone spinner that's OK -- it needed additional cutting to fit a normal APC prop; and three of the cheap spinners, two of which I've found to be horrendously out of balance (I haven't checked the third one; it's too big to put on my prop balancer).
In a Tower order that's on the way, I have a Great Planes brand aluminum spinner, and in my shopping cart is a Tru-Turn. By the time I figure out which brand I like best, I won't need any more! :-)
Good flying, desmobob
Reply to
desmobob
I checked it out and it makes me wonder if my efforts to balance the cheap spinners was unfounded. Then, I remembered how the quality spinners balanced nearly perfectly on my magnetic balancer compared to the cheap ones. And, the cheap one was definitely causing some horrible vibration on my model.
To add a little more to the story, my new Great Planes 2 1/2" aluminum spinner came today. It had a big "Made in China" sticker on the backplate. It is a very nice-looking spinner; highly polished.
When I put it on the magnetic balancer, it swung HARD and showed itself to be way out of balance. I did some drilling of the backplate until I got it close (seven 1/8" holes!). Then I got more frustration when I mounted it. I was mounting it on a Super Tigre G51 and so I ordered the recommended Great Planes adapter kit for Super Tigre .34-.51 engines. Well, the backplate bushing that comes with it has a 1/4" hole. As you Super Tigre fans know, the 1/4" ST crankshafts have a small stepped up area next to the thrust washer that is 7mm. (Tru Turn's Super Tigre adapter kit specifically mentions having a 7mm bushing.)
I drilled the bushing out to 7mm.
I got everything all mounted up and was admiring the new spinner when I felt the spinner cone move. The Allen bolt supplied with the adapter kit was too long... just enough so you might not notice it! That could lead to a dangerous situation. I cut the bolt down a few mm and reinstalled it. The spinner cone was now snug.
So... scratch Great Planes off my list of spinner sources! Considering it was way out of balance, the recommended adapter kit had the wrong size bushing and a dangerously over-length cone attachment bolt, I'd say the Great Planes spinner is even worse than the spinner I was replacing.
I'll stick with Dave Brown spinners in the future, and will report on my luck with the Tru Turn spinner I'll be ordering soon. I have a feeling it will be a quality unit.
No more bargain spinners for me, desmobob (which my spell-checker suggests I change to "disrobe")
Reply to
desmobob
The bolt did not come with the adapter kit; it came with the spinner. Sorry for the error....
Good flying, desmobob
Reply to
desmobob
Whenever possible I forego the use of spinners altogether. Even the best will be slightly out of balance and will rob your engine of rpm.
Yes, there are times when you have no choice but to use a spinner, such as on a scale model that would look totally inappropriate with anything less.
However, when designing models for sport flying and other non critical apps, I design with an AMA safety nut in mind.
Ed Cregger
Reply to
Ed Cregger

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