ddennison

My Feedback: (15)

MY Goshawk is about ready to go. I noticed last night that my right main wheel (tire) is not holding air. I dont hear a leak or feel a leak. It seems like a very slow leak.

This is my first SM landing gear/wheel model. I am wondering if I am to disassemble the wheel and try to reseat it in the hub or if I have a problem I cant fix without a new wheel/tire?

Thanks for any help,

(I wonder how quickly I can find and replace a main wheel for the plane....
Dave

f106jax

My Feedback: (16)

Dave,

When you take the wheel apart you'll notice a thin O ring in a groove that is machined into one of the wheel halves. On occasion, this O ring is not seated when they assemble the wheel and that causes the slow leak. I would suggest that you take the wheel apart, place a fine coat of O ring lube onto the O ring so it will remain seated in the groove. Reassemble the wheel and see if it leaks. Hopefully this will take care of your problem.

ddennison

My Feedback: (15)

Thank you Mike.
I got it apart and sealed for now. I hope it stays inflated...
Thanks for the instructions.

Dave

ddennison

My Feedback: (15)

Flat again...but after a day or so, but the other wheels remian as inflated as they were a month ago, clearly still a leak.

Before I pull the oring out again, I am wodnering if I can find a replacement in case it breaks or doesnt seal this time.

Does anyone know where I could find that exact Oring? I have not seen one quite like it at the local hardware stores.. I would like to have a few backups if possible.

Thanks
Dave

ddennison

My Feedback: (15)

Flat again...but after a day or so, but the other wheels remian as inflated as they were a month ago, clearly still a leak.

Before I pull the oring out again, I am wodnering if I can find a replacement in case it breaks or doesnt seal this time.

Does anyone know where I could find that exact Oring? I have not seen one quite like it at the local hardware stores.. I would like to have a few backups if possible.

Thanks
Dave

blackcat

i have had this problem a few times with my f16 (which is now 7 years old) i discard the o ring. thoughroughly clean the hub, particularly the groove where the o ring sits.from hardwood or ply make a tool that is nice and flat, with a small groove that aproximatly mirrors the o ring groove, perhaps a little larger.insert silicon into the hub groove, and make sure you work it in. follow the groove with your ply tool, then remove all excess silicon (turps). assemble th other hub half, insert and screw in the hub attatchment bolts while the silicon is still wet to flatten the silicon but don't tighten, just make sure there is about 1 to 1.5 turns of the bolts left, let it dry for 24 to 48 hrs then tighten and fill with air. mine have lasted a year and i cant remember the last time i put air in them. and just you wait until the next test!

blackcat

omg i thought you were a pommy! disregard the test comment!

f106jax

My Feedback: (16)

Dave,

I bought replacements at a local company called Bearings, Belts, and Chains. You probably have a similar company locally. You won't find these O rings at a hardware type of store.

ddennison

My Feedback: (15)

Thanks.
So far I only had time to look at ACE. I will try to measure it the Oring when I get the tire apart again.
Dave

joeflyer

My Feedback: (48)

If the ARF is a recent purchase I would contact Skymaster for some o-rings or a replacement wheel.

The wheels are made by Airpower. You can get replacement o-rings from them.
http://www.airpowernet.com/twe3/index.php?cPath=38

In a pinch I expect that a very thin bead of RTV would work.

Joe

ddennison

My Feedback: (15)

Thanks everyone. Great to know where to get things for these wheels.

DD

ddennison

My Feedback: (15)

Hi everyone.

Well I flew the Goshawk maiden. Unfortunately my wheel wont hold air. I resealed the hub assembly a few times and I think the central Oring is likely sealing but it might be leaking at the tire edge...

It holds air for a few hours, I think. But also was flat after flight; wondering if laeking at tire/side of hub interface. I cleaned all the edges of the tire etc for a better seal...still flat.

I wish I could just have a working system or solid tire.

Any other ideas?

I am trying to contact SM for a trial of a replacement O ring/tire.

I also am not sure where and how quickly I can get the tire from another source?

Thanks for any help.

Dave

AndyAndrews

Take the wheel apart and pack it with dense foam and then reassemble. The wheels should stay firm enough to use.

noahb

My Feedback: (67)

You can also order the solid tires from Todd at Dreamworks.

joeflyer

My Feedback: (48)

Dave,

I had the same issue with one of the mains on my X-treme F-4. The problem was one of the aluminum hub halves was warped. I have the same wheel on my F-16 and found that out by swapping parts until it held air. Skymaster sent me a replacement half hub after I explained the problem to them and sent them a picture of the part that needed replacement. It took about two weeks to get it from China.

If you don't have another wheel, or can't borrow one that probably doesn't help much. You might want to contact your dealer (I went through BVM) or Skymaster directly and ask for a replacement wheel.

Good luck,
Joe

rc4flying

My Feedback: (21)

Other than the wheel issue, how did the maiden go ?

ddennison

My Feedback: (15)

Thanks all for your advice, I have sent a note to both BVM and to SM....will see.

Not to get off topic but the maiden went fine. 180 rx dialed down a bit. I had the balance at about 220 and added a 4 oz "just to be safe" nose weight. IT took quite a bit of up trim and felt a little mushy in the turns. I was also trying to keep the speed down on purpose - i might have been a little slow. Once trimmed with a bit more power it seemed fine. Landed fine even one go around since I was a little fast on the first approach. Just went from landing to TO falp and hit the gas a bit wen around and setup again. Wind was 10-15 45 degrees off center, no issues. Plane pulled to "flat tire" on landing though....was holding air at TO.

WOuld like to get the wheel fixed...

Thanks guys,
Dave

rctech2k7

My Feedback: (1)

Hi Dave, How's your wheels now? If it's not yet fix try to submerge it into the water to find where leak is coming from. If it's coming from tire, use CA glue and tape to seal it, but better to replace it. I just bought set of tires from Dreamworks and tested one to replace my leaking tire and it works better for the cost of $12. I have to maintain 55-psi of air pressure so it doen't look flat when loaded with fuel on takeoff. Higher than that it goes expand and becomes bigger than original one.

ddennison

My Feedback: (15)

Still no air on my tire and no word back from BVM or SM...granted I emailed and have not called yet...

Is the dreamwork tire you are using solid?

I may have to call and order one. I just wish I could get this one to work, the other two are fine...

Dave

rctech2k7

My Feedback: (1)

I still have the solid tires but it won’t work with rim for inflatable, when using old rim it won’t fit into the new landing gear axle. I’ve got this new landing gear set because my old one was offset. One gear or maybe both mains are suspected to be few quarter inch behind the original distance. This would give me a hard time on taking off on the grass field as my preparation for Florida Jets on that time. The gear is better than old one because it has bearing rather than bushing. There’s no more play on the wheels and nuts are tight very well. I have only one issue and it’s the same as yours on one gear. I didn’t noticed earlier that it contributing problems on takeoff with side wind and worse on landing. Found out that one tire has lower pressure. Fill it up to 80-psi to compensate and few minutes later one wing is lower than other and that tire has no more air. I vulcanize it while awaiting for parts and it work with the use of CA glue and tape. If it’s on the o-ring those above suggestion should be working. That's why I suggest to put under water to find out the cause of leak. Silicon is also works very well while you’re awaiting for replacement o-ring. On the bigger o-ring on the center of the rim where it seals the air inlet valve use o-ring lube. If it's one the side of the rim or tire edge you may use gasket sealant. Tar is the last resort.

Now I replaced it with the new one. Forgot, it was the $16 one (AP-ITR7683).

Here’s my new gear in action:
http://www.youtube.com/watch?v=KWIsZruIWFE

AndyAndrews

I'm telling you the foam works...

ddennison

My Feedback: (15)

Thanks Andy.

Just trying to see if I can get it to work like the other two wheels. Will certainly do the foam fill if I cant get it resolved.

joeflyer

My Feedback: (48)

This is a typical example of something that on the surface sounds like a technological advancement, but due to poor application is a lot more trouble than it's worth. They may absorb some shock on landing if properly inflated, but I see no other potential advantage. Due to typical Chinese quality control and/or poor design they are not reliable. In addition to the kind of problem Dave is having, one tire may hold air while the other has a slow leak. Consequently l have to check and inflate my tires every time I go flying.

I wish Skymaster would go back to solid tires, they're a lot less hassle. Are you listening, Anton?

Joe

P.S. I feel the same way about their hydraulically damped/pressurized struts.

grbaker

My Feedback: (29)

I have no experience with the Skymaster tires but helped a friend of mine solve his air leak problems on a FEJ 1/6 scale F-18 with the following:
Buy some cheap foam tires about the same diameter as the air filled tires.
Remove the foam tire from the rim and then trim it to fit inside the air filled tire. We used a band saw and a belt sander to get it to fit.
Install the Skymaster tire (with the insert installed) onto the wheel.
No more air leak and had the added benefit of making the F-18 handle on the ground much better

dbsonic

My Feedback: (3)

Great idea guys on the foarm. I am hoping the foam makes them last longer too? I have a kind of Flintstone flat spot thing going on mine and need to change to new tires.