Shock Monster landing gear...

[Russellmn]

accidentally posted this in Patrol scratch build forum, apologies for the crosspost.

I was talking with TonyK (the man behind TK1)the other day, and mentioned that I was starting to build a Patrol. He expressed interest in measuring one up to develop a landing gear option. This would be like the 4 place shock monster, a cabane setup. I'm too far away from him to help (since Oshkosh is cancelled) but he asked if I knew of anyone out west that would be willing to let him measure their plane.

Anyone willing to do so? I know many here don't care for the cabane v style gear, and I know the arguments. I'm not really sure which way I'll go when it comes time for mine, but that's not the purpose to this thread anyway... If you're willing, would you either contact Tony yourself or you can send contact info through me? I've known Tony since he was one of THE innovators in competetive rock crawling, he's a good guy that strives to put out the best product possible.

[Cguy]

When push really comes to shove (ha ha) added drag aside, there is nothing out there better then cabane "cub style" gear, assuming one is flying off airport, and I don't mean grass airstrips. The original gear on my RANS S-7S was a tapered spring rod going into a fuselage socket, like RV's. It was nicely faired and low drag. 1300 hours on my first 7, and the gear remained adequate.

Then I built my current 7, and when they became available, 29" Airstreaks, which lead me down the slippery slope of doing more and rougher off airport ops, and this showed me the original gears limitations. It somewhat "point loaded" the fuselage, all the stress going into a smallish area, and though that area was properly engineered and braced, it still proved inadequate for the arrivals I was subjecting it to, and I started developing some tubing cracks and other signs that something needed to change.

When John Roberts here in Idaho https://backcountrypilot.org/forum/r...y-avweld-11744 came up with his bush mod gear for the 7 I jumped on it, (pun?) and since then, with several times more total hours (2600 TT) and continued many hard arrivals, my air frame remains as it should (well, except for the tail section, but that's another story, one that the recently installed T-3 tailspring should help). Now that it is faired, A-frames fabric covered and the aft leg faired, plus airfoil fairings over the airshocks and bungees (I have both) and even the cabane faired, the drag hit is still more then before, but hugely better then when it was all unfaired. IF I was building a BH of any stripe, and was for sure planning on going off airport with it into who knows where....I'd for sure put cub style gear on it, but also plan from the get go to fully fair it as much as possible, and just accept a few MPH speed loss. Just going into the occasional grass airstrip, I would keep the stock gear as it is more then adequate for normal ops. I SCOUT 022.jpg 've opined on this subject before here I believe, but it's raining heavily and I have nothing better to do!

[AKKen07]

I love the discussion and any like these. Even though I’m keeping my gear original (for version one anyway) it is great to think about. Have you flown with Bearhawk style gear? Ive never heard anything but great reviews - even from some cynical types.

[Cguy]

My T-Craft had Bearhawk style gear I guess, no cabane anyway. I was low drag and worked well, but I never took it off airport.

[Gerd Mannsperger]

So does the Maule and it works any bit as good as Cub gear. If anything working on fine tuning dampening on a Bearhawk/Maule gear would probably be the most reasonable approach.

[Russellmn]

I think, if we're going to discuss the merits and drawbacks of cabane gear, we need to distinguish between stock Cub gear with bungees vs. the aftermarket gear with real shocks. I've seen video of the two types landing side by side and there is basically zero comparison. Do a little valving work on the aftermarket stuff and you can really get it to stick to the ground. Bungees like to toss you back into the air like spring gear does. If that was what I was talking about, I would likely argue that the stock Bearhawk gear is better.

[Russellmn]

Well, someone was kind enough to contact Tony and invite him out to visit and measure their Patrol. I won't mention any names, they can do that if they want to themselves, but THANK YOU! I love seeing new options become available for the Bearhawk aircraft, even if I don't use it myself, more options are never a bad thing.

[Lee]

Well, that would be me. My Patrol project landed in my hanger last week. Tony will be here next week. Nice guy.
Lee

[Russellmn]

Thanks Lee! Tony's an awesome guy, you'll probably have a pretty good time just hangar flying with him!

[Cguy]

The Cub style gear I have uses both bungees AND and a Fox Airshock (adjustable, via it's Schraeder valve), the bungees take the impact and the air shock controls the rebound. I hit and stick, I totally agree, having just bungees is ancient history! My gear is 10 years old, doing it now, I'd go with everything the same, but just shocks to do both impact absorption and rebound control.

I personally know of two Maules that have replaced the stock Maule gear with cabane style gear, one is the past owner of the ABW tire company, can't think of his name right now. His Maule is HEAVILY modded, may even be in the experimental category at this point. I have seen pictures on the internet of a couple others.

[Russellmn]

Just a question... why an airshock if you're using bungees anyway? The air or nitrogen is supposed to replace the springs, which is what your bungees are doing. It obviously works, you definitely seem to like it, just curious why you don't use a normal shock instead?

[500AGL]

Russellmn, as he mentioned, the air shock just controls the rebound (return rate once extended). On a light frame like the S7, this is a light, simple and very effective setup. When you move into TK1 or Acme shocks, you are moving into much more advanced system, controlling both directions, often sized/dialed in for weight, and quite a bit more expensive. Worth it off airport with a heavier airframe for sure, but much is not without some bit of compromise. In the case of Cabane Gear, drag is the culprit.

[Russellmn]

Didn't think about it running "backwards", so shock compression is suspension rebound. That makes more sense...

[Gerd Mannsperger]

If it was me I would check with acme aero to build a shock that fits right into the Bearhawk Gear with no other mods.

To go to a cabane allows the use of the shock monster set up but requires much more modification to the original and ads a lot of drag.

Lets not forget that although simple the Bearhawk gear is a dampened set up -- maybe a more advanced dampening system would be just what the doctor ordered.

[jetdriver]

Gerd Mannsperger I agree, I’ll be looking into that very option with Acme. I met the guys at OSH last summer and saw their suspensions up close. Very impressive.

[Russellmn]

Please keep us updated on this, if Acme can add valving shims to the standard gear that could help a ton.

[whee]

I’m glad someone stepped up! Thanks for doing that Lee. It’s always better to have options.

Personally I think the BH shock is sufficient for normal operations. I’ve had some fairly horrific landings but the BH gear does a great job soaking them up and damping the rebound. If you want to plow onto the ground at 500fpm in a STOL competition then maybe something other than stock would be worth looking at...but I think bushwheels the stock gear would be ok.

[Lee]

You are welcome Whee. I'm really looking forward to meeting Tony. I'm probably a year from flying my Patrol and doubt I will be a customer of his, at least at first, but it will still be fun. Lee

[kestrel]

Personally I think the BH shock is sufficient for normal operations. I’ve had some fairly horrific landings but the BH gear does a great job soaking them up and damping the rebound. If you want to plow onto the ground at 500fpm in a STOL competition then maybe something other than stock would be worth looking at...but I think bushwheels the stock gear would be ok.

It is! Even 8.50's at 18 psi are very good with the stock gear. On Bushwheels, it is fantastic for anything less than flying it right into the ground.

[svyolo]

Flaring to land is way over-rated and not recommended. At least that is what they taught me.

[kestrel]

Ha! :-)

[zkelley2]

It is! Even 8.50's at 18 psi are very good with the stock gear. On Bushwheels, it is fantastic for anything less than flying it right into the ground.

Ya, the stock gear is pretty good. I'm on 8.00s at the moment and I'm taking mine into all kinds of places. I'm only limited by flotation of the smaller wheels, certainly not the damping.

Like Whee said, if your goal is to crash into the ground in a STOL comp, then you should probably look into TK1s. For normal back country flying, I haven't found the damping of the struts to be limiting. Absolutely fantastic vs spring steel or bungees.

The only thing I'm running into right now is landing tail first if I'm doing an approach in the low 40s instead of 50. I do need more elevation in the front to get that 2 point attitude at slower speeds. Bushwheels soon, so I'll see how that changes things.

[kestrel]

The only thing I'm running into right now is landing tail first if I'm doing an approach in the low 40s instead of 50. I do need more elevation in the front to get that 2 point attitude at slower speeds. Bushwheels soon, so I'll see how that changes things.

On 8.50's, you can flare and then lower the nose to set it on the fronts without hitting the tail. Requires careful timing and reasonable precision. On 31" ABW's you almost don't need to lower the nose to set it on the mains. ...just about perfect, and one of the reasons I like using the ABW's even when not backcountry flying.

[Lee]

Tony flew his Cub in Tuesday morning and took measurements from my Patrol. I talked to him earlier today on the phone. The Shock Monster gear design is complete. For those who are interested the gear should be available in 30 or 40 days.