Oberst

I have suspicions that the Great Planes Ballancer is giving me false readings, because when I get my 3 bladed prop ballanced, I'll turn the prop around to re-check it and it's unballanced again.

What is your opinion of this ballancer, and if my suspicions are correct, is there a more accurate ballancer on the market?

Pete

Gray Beard

My Feedback: (-1)

Du-Bro makes what I think is the best but I have been using my GP for years without a problem. Sometimes a three blade is a pain the the hinderpoo.

FlyingPilgrim

My Feedback: (26)

Not sure which balancer you have, but it's possible you might not have the tapered pieces that hold the prop getting a good center. Make sure you are getting a good hold on the prop with them, and the hole in the prop is not buggered up to the point it gives an inconsistant hold. I use the Top-Flite magnetic balancer for smaller props, but bigger props are too heavy for the magnets to hold, so I use a fingertip balancer for big ones. If you're using a fingertip balancer, use a gentle touch to hold it to allow it to spin easily.

Oberst

I WAS WRONG!

I ment TopFlite ballancer, not Great Planes. I'm sorry, I had a brain fart.


Oh boy, I agree with that statement about ballancing 3 blader's. But when we do get them ballanced right they are very nice and a pleasure to use.

I don't know if it's me or what. I'm trying to ballance a 3- blade 14x7 and a 15x7 Master Airscrew with the Topflite Prop ballancer, and when I think I have each section of the blades ballanced, I'll twist the tapered pieces that hold the prop a little and re-check. Then I notice the prop is off again in the ballance.

I get a little frustrated. I'm starting to say to myself "Close Enough!" But deep down it bothers me that close enough isn't good enough.

If any of you can tell me what I'm doing wrong please chime in. Is my props too big for this ballancer?

http://www3.towerhobbies.com/cgi-bin...?&I=LXHY61&P=7


Pete

scooterinvegas

My Feedback: (1)

Try it with the tapered cone in the front of the prop and the flat side on the back of the prop. Twist and push the cones together tightly.

Oberst

OK, I'll give it a shot.

Thanks,

Pete

JohnBuckner

My Feedback: (1)

Scooterinvegas is absolutly right. With the magnetic balancer the cones are quite sharp and will meet in the middle with many props which destroys centering.

With wood or Master props it does not make any difference which side of the hole you put the flat on. APC props are an exception. All APC props have two holes. The front side being smaller. It is this back side, which is larger, that is the accurate hole. When using the GP magnetic balancer the tapered cone should be inserted from the backside and the flat of the other cone should be on the front face of the prop.


John

Oberst

Yes I tried what scooter suggested, and it kept loosening up. I wound up taking the tapered cones and inserted them towards the prop in the hole like I did originally. I got one of the props ballanced, but I think what you said John is correct. My ballancer is over 9 years old and might not be true in the points anymore.

I figure I'll order the Dubro one in about a week because I noticed that my engines and planes have become larger over time. I think it's time to replace the ballancer and give the old one to a begginer to play with so he can use it for smaller regular props up to 14", not for the heavier 3-blade 14x7 or larger.

Thanks for your help,


Pete

scooterinvegas

My Feedback: (1)

The cones get hard over time on slip a lot easier mkaing it hard to keep them tight.

JohnBuckner

My Feedback: (1)

Those large multi blade props are really not very practical for the magnetic balancer. I find that that any of the wheel types are a lot faster and a bit easier to use but for the smaller two blades the magnetic even though it may take longer actually will get a finer balance and make it possible to balance side to side and not just end to end. I have a magnetic as well as a Sig and a no name all metal wheel types so use whatever works best.

Ya I agree with GB three bladers are a pain in the 'Hinderpoo'! I never really use them but I can remember in my foggy past carving or modifying a bunch of single bladers and they were often in the deep Poo also.

John

sscherin

My Feedback: (1)

If you suspect your balancer is off try setting up a known true opject like a spinner back plate..
Check it, mark the low point on the shaft and object.. rotate it 90 deg on the shaft and check again..
If the shaft always turn to the same point it's probably bent..

For large multi blade props I found it was easier to roll my own balancer..

This thing can pick up a slight bend in a section of 5/32 music wire.. I hope that is good enough..

JohnBuckner

My Feedback: (1)

Sscherin

That is an absolutely lovely piece of work.

John

sscherin

My Feedback: (1)

Thanks.. I find it to be Functional but Ugly (fugly)
Just scrap MDF, roller skate bearings and some scratched CDs..
I made some aluminum cones to center the prop on the lathe.

It gets the job done but I do need to replace the music wire shaft with some nice straight drill rod.
I straightened the rod so it's close but it's still a tiny bit tweaked.

huck1199

Sscherin

Where are the roller skate bearings? On the CDs? I like your tool and I will build one. Thanks for sharing.

JohnBuckner

My Feedback: (1)

Indeed said like a true modeler. Love the idea of using the CD's.

Just for giggles here is one I used all the time in the sixties. Just a block of balsa and a couple of single edge blades with a drill rod and some tape to fill out larger prop holes. Crude but sorta worked

John

sscherin

My Feedback: (1)

The bearings are mounted right in the CD's and held on with CA..
I used a 608 bearing ($1.25 each at fastenal) flushed the grease out with solvent and oiled them with some tri-flow..
The grease is thick and causes rolling resistance.

Now because the 608 has a 22mm OD and the CD has a 15mm opening I had to turn the centers out to 22mm on each CD.
I only cracked 3 of em getting it right You could also do it on a drill press using 15mm and 22mm forstner bits..
Align and clamp using the 15mm then swap in the 22mm bit to cut..

Since then I found the F696 bearing.. (I haven't bought any yet)
The F696 has a 15mm O, 6mm ID and a flange.. it should be a drop in self aligning fit in a CD.. a little CA to hold it in place and it should be good to go..
The F696 cost a little more than the 608 but I think the extra cost vs not having to turn CDs will be worth it.

The CD's are all glued on the same.. offset to one side of the bearing..
Then you mount one flipped vs the other and get a nice overlap on the wheels without using spacers.

I put 2 washers between the bearing and the wood to prevent the disks form rubbing on the frame.

When you make the end boards just screw the 2 pieces of wood together and do all your cutting and drilling on them as a set.. then when you separate them all the bolt holes and cuts are in perfect alignment.

huck1199

Sscherin

Thanks for the details. Very nice setup.  Do you know Greg Julian? I bought a 1/3 Spacewalker from him and am in the process of building it now. Greg is a real gentleman.

sscherin

My Feedback: (1)

I don't think I know him.. Is he from around here?

huck1199

Yes, Greg is from Kennewick, He recently emailed me that he just got back from seeing Bruce Tharp, an old friend of his. I forgot what club he belongs to.

Oberst

Now that's a ballancer if I ever saw one!


Pete

Gray Beard

My Feedback: (-1)

When I first got into RC I made one using a CD cut in half, I mounted the halves in balsa several inches apart then just used a finger balancer that would sit in the center hole of the cut CD. I found it worked as well as the GP balancer I have, even better on big props for gassers. I gave it a toss when I moved here but may make up another. Again, nothing original from my brain, I got it from a TAPS TIP in MAN.

sscherin

My Feedback: (1)

I'll ask around at the club meeting tomorrow but I don't see him on the roster..
He might be a member of MAA. The other club in town..