Stinger on 4 place

[Bearhawk535]

I have my tundra tailwheel tacked in place on the fuselage. Seems to have appropriate kingpin angle with room for loading to gross weight

[Bdflies]

That's a great looking tailwheel! I have a Tundra Tailwheel on my Patrol and I am constantly amazed at the comments about how nice it looks. A word of note: Eric menions that the Tundra model is recommended for aircraft that will not be operated primarily from hard surfaces, because of shimmy tendancy. I can vouch for that! In my vast experience (20.4 hrs so far ), I've landed on asphalt only once. Shimmy it does!! In a couple of seconds, it shook off a steering chain. Considering how nice it works on grass, I was blown away by the intense shimmy on asphalt. I've since tightened the snubber, a bit. But haven't ventured back to the asphalt yet.
Anyone leaning towards the Tundra version should heed Eric's advice about hard surface ops.

Bill

[jaredyates]

Have you used a gopro to record any of your grass landings? That's how I found that mine would shimmy on grass too, I just didn't know about it.

[Bdflies]

No, no GoPro. It could well be shimmying on grass, but the affect on my butt is way different.
The camera is a great idea. Right now, the goal is to reach 40 hrs, between the weather, cutting grass and life in general.

Bill

[Battson]

That's a great looking tailwheel! I have a Tundra Tailwheel on my Patrol and I am constantly amazed at the comments about how nice it looks. A word of note: Eric menions that the Tundra model is recommended for aircraft that will not be operated primarily from hard surfaces, because of shimmy tendancy. I can vouch for that! In my vast experience (20.4 hrs so far ), I've landed on asphalt only once. Shimmy it does!! In a couple of seconds, it shook off a steering chain. Considering how nice it works on grass, I was blown away by the intense shimmy on asphalt. I've since tightened the snubber, a bit. But haven't ventured back to the asphalt yet.
Anyone leaning towards the Tundra version should heed Eric's advice about hard surface ops.

Bill

Avoiding landing on the hardtop also works! But the one time I did, it shimmied. We don't have a shimmy damper installed either, but I don't think we've landing on seal in the last hundred hours, and probably never will again.

It's only a problem at landing speeds, taxi over seal is no problem.

..... back on topic, that stinger looks good. I would be keen to hear how they perform.

[SimonNicholson]

A small issue we have discovered with the stinger on a QB 4 place kit.

The steering horn is coming into contact with the mounting flange well before the rudder is reaching the stops.

I have been talking to Mark about this and he has been great, so we hope to have a solution soon.

[whee]

I had the same issue with my factory rudder and scratch built fuselage. I ground material away just as you propose. I think there is plenty of material left but I didn't have to take off as much a you have outlined. If I'm wrong and the horn bends I'll probably cut it off and bolt on a new one.

[Tim213]

Simon I had the same issue on my 4 place kit. I relieved the lower stinger attach bracket as shown in the pic.

[Mark Goldberg]

I am waiting for Bob Barrows to get back to me on the best solution for this little conflict in the parts. MG

[SimonNicholson]

Thanks guys. My only concern is with the possible flexing in that area of the tail I want to have a good deal of clearance to avoid any possibility of jamming the rudder on full lock. I am thinking of a mix of grinding the bottom mount like Tim and relieving the steering horn like whee.

[Mark Goldberg]

I just confirmed with Bob that indeed the fix that Tim did relieving some material from that aft flange of the tailspring adapter is indeed the correct approach. Bob said he had designed much more material into that adapter than is really needed, and removing some material from that flange would not cause any problem.

It would seem that this is a situation effecting very few builders unless the adapter and round spring become popular with guys flying their existing planes want to swap out the tailsprings for the round one.. Mark

[Battson]

I had a similar problem on my 4-place too, just as a reference point.
Anyone wanting to use the increasingly popular T-3 tailwheel also has this problem.

Of course the interference was much less in my case, because the lower bracket is a different design.

It may be worth Bob changing the design of those tailwheel steering horns?

[SimonNicholson]

Very similar to Tim I have removed material from the bracket. I have also taken a small amount off the steerer horn

[Battson]

Very similar to Tim I have removed material from the bracket. I have also taken a small amount off the steerer horn

Naturally you'll be wanting to sand those cuts as round and smooth as possible, to avoid microscopic cracks initiating at the cutting and filing marks.

[fairchild]

Could the steering arms just be made (from the beginning) with some more "curve" in the offset area ? (assuming you know that problem would happen ahead of time....)
Tim

[Wmilbauer]

Why don't you just get rid of the steering horns and use a free castering tailwheel like the tundra lite

[whee]

Why don't you just get rid of the steering horns and use a free castering tailwheel like the tundra lite

Some people like having a steerable tailwheel. I wouldn't stay on the ground because I didn't have a steerable TW but I wouldn't purposefully build my airplane without one .