Hello all. I'd like to put a bigger foam wheel on my Superstar 40 trainer. The 10 x 5 on my OS 40 LA is about 2.5 inches off the ground, which means I mow a lot of grass with my prop unless the grass is freshly cut.

My question is, can I just put a bigger nose wheel on? Or must I change all three? My concern was that with a larger nose wheel only, the angle of the fuselage will change (i.e. the angle of attack will be more like a tail dragger).

Does this matter? NOTE: current wheel dia. is 2.5"
How about a 3.5"?

Thanks,

Paul

3.5 might be overkill.....3" should work good. If it were me, I would change all 3 wheels.....you might be able to adjust the height of your nose gear to compensate for the change in angle, but it would probably be easier and look better to change all three....don't forget to throw the plane back on the balancer after changing the wheels!

Mike

about airplane attitude on ground

an airplane that sit nose down, will want to stick on the runway on take off because of the wing negative angle off attack. As the speed increase, the plane is push down harder on the runway. A lot of elevator will be requird for rotation . but once the rotation is acomplish, the plane will pop quiclkly off the ground and jump into the air at hig angle.
On the other hand, if the model sit nose Hig on the ground, take off will be smoother , but landing will be more bouncy if the nose wheel touch first...

the best alternative for a beginer in my opinion, is to have the plane level or at a slightly nose down attitude....


hope this help

Okay, I'll start with 3" wheels. I don't want the monster truck look!

What Salmonbug said above...

Except: for a beginner on a grass field that is mowing grass with a 2.5" clearance, that tells me you have long grass. We've had a really wet spring out here this year, and the grass on the field is longer than anyone remembers, it's scary.

When the grass is long, a nose high attitude is best. You won't have the problems with bouncing in to the air on landings because the grass will cause so much drag on touchdown that you will "stick" quite well. And on takeoff, you need that nosewheel out of the grass as soon as you can, so ever bit of nose-up helps.

If you are flying from pavement, what Salmonbug said is right on.

I just went to a 2.75" wheel on my nosewheel on my extra trainer to make the plane sit nose-up for easier take offs in the high stuff. 3.5 is a bit big, but maybe not too big, depending on your field. I used to fly off of some really un-prepared fields, and we used 3" mains and 3.25 nose wheels on .40 size trainers, and frequently made our own heavier wire nose struts that were longer than stock to get more ground clearance and not bend so much when we hit the potholes. Had to really reinforce the gear mounts and firewalls too. Ahh, memories At least we didn't have to walk 15miles in the snow, barefoot, uphill both ways.

I totaly agree with montague about a nose hig attitude on grass field.
the fact you are flying on grass was out of my mind when I wrotte my previous post

Gotta echo Kirks words. I flight at his field and it is like carrier landings there! You land and stop like hitting the third wire.

Lee

I don't pay the landscaping bills where I fly, so I do have to put up with real long grass at times. I'm going to try the "nose up" attitude with a bigger wheel up front.

First off, remember that the size of the wheel is the diameter. ie going from a 2.5" to a 3" maybe 1/2" up in diameter but it will only give you 1/4" extra clearance.

Another option which may give you more height is to simply bend the landing gear. The main gear on the Superstar is probably quite wide and could be bent in a little for more height. bend both ends to keep the wheels perpendicular. Then you should also be able to adjust the height of the nose leg also.

I don't recommend putting the plane in a nose high attitude. When I put my LT-40 together I had to use a nose leg from elsewhere as the original wouldn't fit. The replacement is a bit longer resulting in a slight nose high attitude. I'm finding that when landing, I have to keep the nose up to for a proper 3 pointer. This makes it tricky to keep the plane down when you're still carrying some airspeed.

BTW I've also got about 2.5" clearance. The length of the grass isn't the problem, its that the runway is a bit bumpy it could either be the unevenness of the ground or the spring in the nose gear causing the prop to hit.

Alos, if you're going to change wheels, don't use foam wheels, go for the ruber type, they last longer, look better and don't loose their "round" form when left onthe floor for the winter

in my opinion you shoumd go with foam weels, they are lighter and because you plan to oversize your wheels, this could be an interesting particularity

My experience with foam wheels has been with ARF's.

A couple of years ago I got a Superstar 60. It came with the kind of wheel you might put on a park flyer. No ay would these stand up to the weight of a 60 size airplane.

Recently I bought a Hobbistar 60 and a LT-40. On both these aircraft the wheels are much more dense and IMO are good enough to use.

The wheels I got with a Ripmax Zephyr were pretty spongey too, but then the plane only weighs just over 2lb.

Having said all that I can't tell mch weight difference between a 3" Dubro wheel and a 3" foam wheel anyway. You won't notice it on a .40 size plywood box...

I had some very bad foam wheels that came on an ARF...can't recall which one.....on an asphalt runway they would barely turn....the nose wheel tire looked like it wanted to come off of the rim....they were not dense at all......there are some nice, dense foam wheels out there though.

tiggerinva,
Yes, going from a 2.5" to a 3" wheel only raises the axel by 1/4", but it makes a huge difference in rolling though tall grass.

Also, as I said before, nose high is only good for tall grass, on nicely cut grass or pavement, I agree with you. Beleive me, bouncing is not something you're going to do on my field right now. Touch and goes are an iffy thing unless you cary enough speed to risk pulling the gear off the plane, or manage to do more of a bounce and go at just the right point on the field.

When I say tall, I mean grass that is deep enough that the stock wheels on LT-40 arf kits are not visible when the plane is sitting still. It looks like the plane is sitting on wire legs on the taxi way. The shortest part of the runway is only marginally shorter. This is not normal for around here, we have had a spring that is just making the grass grow like crazy.

To go from a 2.5 wheel to a 3" wheel will give you 1/4" more height (3 - 2.5 = .5 /2 = .25). Instead of buying new wheels, see if you can extend your nose wheel by 1/4" and add a 1/4" block between your main gear and the fuse.

Good advise MInnFlyer!!! sometimes the simple things are overlooked.. I still believa (and has been my experience that foam wheels do not last as long and become ugly when older this is specially true on paved areas

How would I do this? If you mean I should loosen the little allen bolts and pull the nose gear wire down 1/4", then I don't have wire to spare (after just looking). And wouldn't a block just move the wheel forward? I'm not getting it, Minn.

Sounds to me like you need to dump some more airspeed before touchdown. I've become quite an expert at coming in too hot, and have a collection of busted props to prove it.
A "proper 3-pointer" as you put it applies to taildraggers landing nose-up on the mains and the tailwheel -- trikes should come in on the mains with the nose gear slightly higher, and then settle to the nose gear as more airspeed bleeds off.

BTW, I fly off rough (and sometimes long) grass. I just put 3 1/2" "tundra tires" for mains on my newest plane with a 1 1/4" tail wheel. It's not the height as much as the rolling resistance and ability to cruise over turf without bouncing all over the place and/or getting hung up behind a clod or tuft. I'm beginning to understand why bush pilots are such special people!

Convert your plane to a tail dragger, problem solved.

tail draggers solve the prop clearance problem, but you really need bigger diameter wheels on them on rough fields, since they really don't like too much rolling friction. You wind up on the nose a lot.

However, I do find tail draggers with lots of power easier to get off of high grass, you don't need much roll at all . Not good for a beginner though.

btw, if you have a nose-high trike, and you still bounce no matter how slow you get it, you can try releaseing the elevator out of the flare as soon as the wheels touch down, or even feeding in a little down elevator. You gotta get the timing right, since you don't want to deckdive and really bounce up. Generally, if you have a problem bouncing, and you are landing slowly, lower the nose a tad, you don't need the "up" you have. In the deep grass, bounces aren't a problem.

As the grass gets shorter during summer, I expect to be re-adjusting trainers around here to sit level again.

Luckily, there aren't many guys currently learning to land, but I do worry about them developing bad habits while landing on the field as it is now, and they'll be bouncing all over by mid-summer.

If you don't have any extra wire at dimension "A" below, there's not much you can do I guess, As far as the block goes, this is what I was referring to:

Taildraggers will solve your clearance problem, as Montague said, but remember you may need to increase the diameter of your tail wheel as well if the field is rough. A small wheel will bounce around on small rocks and such causing your plane to point where it wants...

Ed

Thanks Minn. I said to myself, "Nah, he can't have a diagram of this." Ok, now I'll never doubt you! And regarding the wood block, that's not the setup that I have.

I say convert it to a tail dragger... gotta practice for that cub of yours....

btw how is it comming. is it ready to go yet? have you got it in the air?

Chris, I'm okay with tail draggers. No problems with the ultra stick 120 (rip). The cub is ready to go. It even shed some weight after moving things around. All we need is one good weekend from Mother Nature... See, you've got toys that are good in mud, I don't. Maybe that's the solution.