Hi.

I fly a Hobbico Hobbistar 60 MKIII Trainer with a 12x6 prop. The problem with the plane mainly occurs when I'm taxiing. The field I fly at is a little rough and if I hit a little hole the prop goes into the dirt and cuts off the engine in addition to potentially damaging the wood props. And I taxi quite slowly.

It came with 2.75 inch wheels. I'm thinking about buying some oversized wheels (perhaps 6 inch) to help raise the plane off the ground and hopefully make it a little more stable while taxiing. How will this effect the flying? Or is this even a good idea?

Thanks.

I fly from a rough grass field. The club members use large wheels, typically the 3.25 inch foam ones. I don't know about 6 inch wheels - seems a bit extreme. I guess it should be ok, just don't forget to check your CG after you install them. Maybe think about goin to an 11x7 prop.

I think 6" wheels is a little extreme

Try 3.5 and no, they really won't have any adverse affect

I'll second Minnflyer. I wouldn't go above 4". If the field is that ruff then you may want to consider an alternative place to fly at.

Hogflyer

Can I get away with just putting a larger wheel on the front or should I purchase all 3 wheels?

I'd lean towards all 3 - if you do just the nose you're raising the angle of attack of the wing while on the ground and that could possible cause you land on the oversize nose wheel if you don't get good flair (which will happen while your learning landings).

Hogflyer

I have the same plane with 3.50 in. wheels on it , DON"T go to 6 in. thats over kill. All the ARF's that i buy I always put larger wheels on, they come set up for use on a paved runway, very few clubs have this luxery.If you are learning to fly slow the plane down on your final approach, this plane will fly real slow IF your throttle is set right and not stall.Many new pilots use a 1/4 in. smaller wheel on the nose gear to help flair on a landing.When I first started landings were the hardest thing I had to learn. Happy Flying Dan

Keep them the same size. I used 3.5 or 4 inch wheels on a Great Planes PT-60 and it seemed to have good clearance with a 12x6 prop.

And get rid of that wood prop. They have no business on a trainer IMO. Put on a Master Air Screw of the same size and you'll be fine until you learn. Or buy a lot of lumber.

I have that same plane. I use 3.5 inch foam wheels and fly off of grass. Since I am the grass mowing guy I try to keep the grass mowed pretty close though. I have no complaints with that set up. I turn a 12/7 prop with a TT Pro .61 it does well on taxi and take off. I would keep all three the same size even though you'll proably have to buy four. Most I've seen only come in pairs

Our field is an all grass runway, actually, it is a full-scale grass runway. We keep it cut pretty well, but it is mainly crab grass and quite bumpy. We roll it out as often as we can, but it still is quite bumpy.

I solo'ed with the Hobbico NexSTAR. I changed the wheels to the 3.5 inch light-weight (foam tires) and it did not affect anything. It made it easier to taxi around and take off and land.

DS.

I don't know much about this but wouldn't it just be simpler to get a slightly smaller propellor?
I've got 3 inch wheels on my LT-40 and that appears to work fine don't go beyond that. Besides the looks being a bit rediculous with such large wheels the weight would be way too much for a trainer.

But I would still go with getting a smaller propellor and keeping the wheels you got.

Just my 2-cents

Tigerdude,
Reducing the propeller size isn't always good thing to consider here. Reducing the prop size reduces the thrust put out by the engine which reduces the power output of the engine. Plus, if you put a too small of a prop for the engine you can ruin the engine. Adding larger wheels doesn't add that much weight to a plane at all, maybe a few ounces which isn't nearly enough to affect the flight of a trainer.

Ken

Good thread...I fly at a grassy field too and I have been considering the same thing. I may go to 3.5" wheels myself.

3.5 in. tires are the ticket. That and a roller to roll the field every time it gets mowed. I had a lawn guy tell me that doing that would stunt the growth of the grass. So I happily do it nearly twice a week. You see the results very soon, and I have a much smoother field now, every year it gets better.

Thanks for all the good advice.

I purchased two 4 - inch wheels for the back and a 3 1/2 - inch wheel for the front (I would have bought all 4 inch, but the hobby shop didn't have three in stock - they seem to only sell wheels in pairs for some reason). I looked at the 6 - inch wheels that I originally planned to purchase and started laughing to myself. Those wheels are gigantic. I also used a 11 x 6 prop instead of the 12 x 6.

The wheels made a huge difference. Taxiing was much easier and I didn't fear the prop digging into the dirt. I also felt more confident on the landings knowing that if I came in a little fast and rolled into the really bumpy part of the runway my plane could handle it. I also enjoy the little extra room that the 1/2 inch of the front wheel gives to the back wheels to help insure I land with the rear wheels first.

I didn't like the 11 x 6 prop as much as the 12 x 6. The plane seemed sluggish.

Don't use the 11x6, not enough prop for a 60 engine.