Experimental Shock Options and Reviews

[Bill Rusk]

Folks

Larry Vetterman asked me to share a few photos and ideas for your consideration.......



This is his second Javron Cub and he is getting close to completion.
After a long winter away I’m getting back in the groove. Fuselage is now at the airport. One wing is in the paint booth. Then the other wing will get cover and primer and paint. Then it all goes together.



Here is a $95.00 Tempress deluxe boat seat that Clint found and is using so I figured I would try it. Very comfortable, made in the USA. I installed one in my white cub and tested it before I committed to use them in my new one.




Bill, I have no idea how to post pictures etc on SC.org, so feel free to pass this information along, as well as the first pictures I sent.

Here is a simple set of form blocks I made to make the end ribs on the covers. They are made from 6061T6 by .035 thick. The big cover is .025 2024T3. The top rib is screwed onto the shock frame and the bottom one floats on the shaft via a 1/4 inch uhmw block. Simple to make and maintain. Larry v.












Larry says.....I hope this helps.....


Bill

[tempdoug]

looking at that seat makes me want to sit in it, looks good.

[CharlieN]

There are a few boat seats that are not bad weight wise while utilizing firm enough foam so one does not bottom out. I like that.

[thunderhead85]

I like the boat seat idea! Bill can you ask Larry if he used one for the pilot seat also? How did he mount it if he did? Thanks

[Super11XP]

I like the boat seat idea! Bill can you ask Larry if he used one for the pilot seat also? How did he mount it if he did? Thanks

We’re , working on perfecting the mount to the seat base.

Ill post some pics when I figure out how to do it on the piper base.
Below pics are from my 172 winged contraption.
Totally different base and slider rail, but perhaps they will give you ideas.
Clint

[Dave Calkins]

clint. link us to other photos of this project!!!

[Dave Calkins]

photos of the airplane and 172 wings!!

[Super11XP]

photos of the airplane and 172 wings!!

Here ya Go!
0360
early 172 wings with sportsman stol
31” ABW’s
garmin G3X avionics.
Guessing that it will be 1060 empty, under 1100 for sure.

[Super11XP]

Oh yes and per the original post, I have TK1’s.
Excellent service, performance, and lightweight

[1934A]

Clint, you really need to start a thread with some more pics and details!

[stewartb]

Didn't your last one use C-150 wings? Not much difference between 150 and 172 wings, is there?

[Super11XP]

My last 2 planes I used 150 wings. The 172 wings add about 13” per side so there’s 13” more flap per wing which will be really nice

[WWhunter]

Clint, As good as the last one's performed, this one otta be awesome!!

[Farmboy]

Clint, looking good. Can you tell me about the lift strut interaction point at the fuselage and how that ties in?


Sent from my iPhone using SuperCub.Org

[stewartb]

My last 2 planes I used 150 wings. The 172 wings add about 13” per side so there’s 13” more flap per wing which will be really nice

Hmm, 206 wings?

[Super11XP]

206 wings?!? I’ve heard that the ailerons are much improved over the 100 series cessnas.
Larry sent me a pic of his seat base and how he attached the slider rails.
I ordered a couple sets of the slider rails from javron and will see what I can come up with.
Clint

[skywagon8a]

206 wings?!? I’ve heard that the ailerons are much improved over the 100 series Cessnas.

Not only that but the flaps are a lot longer. Bigger is better!

[1934A]

Clint, what will the gross weight be for this plane?

[stewartb]

206 wings?!? I’ve heard that the ailerons are much improved over the 100 series cessnas.
Larry sent me a pic of his seat base and how he attached the slider rails.
I ordered a couple sets of the slider rails from javron and will see what I can come up with.
Clint

I'll be hone in a couple of days and can give you real numbers. Bro in law's 206 is in my hangar while my 180 is in the yard. FWIW my old Hawk XP wing covers fit my 180 perfectly so I assume the 172 and 180 wings are the same layout? Compared to my 180 the 206 wings are like a Mackey SQ-12 to my Rev 2. Flaps are longer and deeper chord, ailerons are shorter and deeper chord. I've dreamed about cuffed 206 wings on a Skywagon more than once!

[Super11XP]

Clint, what will the gross weight be for this plane?

I’m going to use 2200 like the early 172’s used.
I’m not sure how I’ll ever get to much more than 2000 though

[Rob]

I've dreamed about cuffed 206 wings on a Skywagon more than once!

You are not the only one

And come to think of it, IIRC wasn't Doug Keller (ksecub) working on a 180 with RSTOL 206 wings? Seems like that's been a few years ago, wonder how that went?

[skywagon8a]

You are not the only one

And come to think of it, IIRC wasn't Doug Keller (ksecub) working on a 180 with RSTOL 206 wings? Seems like that's been a few years ago, wonder how that went?

I've wondered the same thing. I've also wondered what would have to be changed at the tail to make this work? There may be trim issues in order to compensate for the large flaps.

[Dan Gervae]

Any update on Shock Covers for TK1's???

[mountainflier]

Go down to your local off road accessories store and buy 4 shock covers and cut them to fit your TK1 shocks and install them. Maybe you can see in the picture I posted here how my covers are cut to fit on my Cub and how they look.

[Cooley]

How come noone says anything about Beringer shocks? I saw them in Sun and Fun this year and quality and design looked impressive. It is kind of different animal compared to Acme/TK as they are compression shocks - Stork/Superstol kind of thing. I read good things about them on Cubcarfters forum.

[mike mcs repair]

How come noone says anything about Beringer shocks? I saw them in Sun and Fun this year and quality and design looked impressive. It is kind of different animal compared to Acme/TK as they are compression shocks - Stork/Superstol kind of thing. I read good things about them on Cubcarfters forum.

you ain't gonna win any takeoff/landing records with them as they extend as the weight comes off them.... if that's your thing...

valdez stol competition videos from 2018 starting at 7:30 minute mark shows them

[Oliver]

Looks like American Champ is seeking approval to install T3 on their certified aircraft.
theyre gunning for approval by OshKosh event in July.
Ought to pave the way for field approval on other cert aircraft.

[vj88]

For those that went from bungies to Acme or Tk1's have you noticed any issues or reduction in taxi performance/stability? When turning hard when taxiing do you get the outside shock to compress and feel "mushy", in turn dropping the outside wing tip towards the ground? Any ill affects on side hill landings?

[tedwaltman1]

I have Gen 3 Acme. No mush or any issue taxiing. No side hill issues. No crosswind issue. The Gen 3 is excellent in all situations. No bounce when intentionally dropping it in for a really short field. Highly recommended!

[Jonnyo]

I have Gen 3 Acme. No mush or any issue taxiing. No side hill issues. No crosswind issue. The Gen 3 is excellent in all situations. No bounce when intentionally dropping it in for a really short field. Highly recommended!

After hundreds of landings on rocks, larger than softballs, the Acme Black Ops shocks have proven themselves amazing. I can immediately get on the brakes, and turn to avoid an obstacle. Landing on sidehills, in a crosswind, is not negatively affected by the Acme shocks that are the right degree of "firm" at low speed. Shocks that are too soft can add to a loss of directional control. Black Ops shocks give you more directional control. On rough ground, take offs and especially landings are shorter.

Recently, I added an Acme Stinger tail shock. On rough ground, at full gross, especially at the aft CG limit, the leverage of the heavy tail tries to make the airplane swap ends. If your tail is also bouncing around that tendency is amplified. The Acme Tail Stinger shock brings the bounce down to nearly zero.

I made the mistake of calling Acme at 6 pm, their time, on a Saturday. The owner picked up the call, while he was on vacation in Mexico ! My order went out on the Monday morning Fed Ex truck, even after they had to cannibalize some parts off another unit to get my non standard order shipped complete.

Jonny o

[vj88]

Can someone explain to me the type of load when functioning for the tk1 and acme? I'm still trying to understand the differences in the two and how their differences in operation.

[Oliver]

Can someone explain to me the type of load when functioning for the tk1 and acme? I'm still trying to understand the differences in the two and how their differences in operation.

Acme shocks function in extension under load, when load is applied the piston extends.

TK shocks function in more conventional compression when load is applied,

[Cooley]

another video on Beringer shocks

https://www.youtube.com/watch?v=PcIhHuCqCAs

[pbhunt]

I'm the guy that had the double ACME Gen 1 shock failure.

See the "ditch" that caused the failure in the picture. I was rolling with the tail up when I went across the "ditch", perpendicular to it, right to left. You can see the bare dirt on left side from the 31" Bushwheels and tail far left in same picture. It was a very short and soft "landing". Didn't even pull the shoulder straps. Speed was rolling, not at flying speed but faster than normal taxi speed.

Attachment 49109Attachment 49110

My point to Acme was shocks had to be too weak because nothing else in the whole landing system was damaged. All bolts where straight as new. Reused all parts except cabane vee and lower wing strut forks even though all where straight my mechanic didn't want to risk it.

When I purchased the shocks it was advertised on Acme web site and verbally as able to fail in tensile or pull test at 19,000 lbs. When in fact it failed at close to 9,000 lbs in the DER report and a later actual test by Acme.

I paid for the DER report which concluded the below summary. Acme did the actual pull test after I had had the DER test done. They used the wrong type metal and not enough material in the design.
The failed shock caps are made out of aluminum, not steel.

From DER report;
In Summary,
The ACME end cap will fail at a calculated load of 17,068 Lbs.
The OEM end cap will fail at a calculated load of 48,899 Lbs.
According to this analysis, the OEM end cap is capable of supporting 2.86 X the load of
the ACME end cap. In addition the OEM upper end cap is manufactured out of a ductile
non-brittle material much more appropriate for the type of loading.

I'm fully aware I'm the test pilot when experimental. But in the pursuit of a better off-road ride I wanted to believe what I was told.
Also was told verbally by dealer that shock travel was close to 6"+ and safety cables wouldn't be long enough. So I didn't have cables on. I do now. Turns out travel was/is closer to stock 3". Dealer later said I misunderstood the 6", he meant 3"+3"=6" right, now I understand!

In the end the, dealer sent me a replacement prop and a hard time. The dealer is an attorney and the repair bill I was asking help with was $10K
No point in court to force the issue as $10k in attorney fees is about 4 days and 3 letters worth of fight.

I'm not willing to have Acme warranty the shocks for lack of trust. I have the stock bungees from Cubcrafters on our Carbon Cub, working just fine.

We had a great mechanic get us back in the air, made our trip with a week delay and got a very nice mountain caribou in spite of the setback.

At this point I just want everyone to be better off after my learning experience. That includes all parties.
I do feel good that my incident (that nobody got hurt in) caused Acme to make changes and "recall" all Gen 1 shocks.
This was Aug 2016, I'm past expecting anything to happen except the learning.

Fire away with thoughts.

Peter

[mike mcs repair]

thanks... that wasn't even much of a "ditch", compared to the (tundra hummocks) where most cubs up here work out of....

[Oliver]

Thanks Peter,
I have regretted sticking my nose into this awhile back without knowing the whole story.
Thanks for providing more info, sorry you had to be the “test pilot”
As Mike suggested, this could have (and would have!) occurred to someone out in the boonies at touchdown speed, coulda been a lot worse!
You’ve provided a pretty convincing case supporting your side of the story.
My beef with acme is, and has always been not with their product, rather how they handled the situation. We all f*** up, it’s how we deal with it afterwords that demonstrates depth of character and commitment.
I have a great deal of respect for your choosing your battles wisely and letting this go, life is too short.
Certainty not too late for acme to chime in and make good...

Congratulations on the Caribou!

Doug

[DJ]

The end caps on my newer ACMEs are steel I believe. Noticeably different material than the cylinders.

Sent from my SAMSUNG-SM-G900A using SuperCub.Org mobile app

[RoddyM]

Thanks Peter,
I have regretted sticking my nose into this awhile back without knowing the whole story.
Thanks for providing more info, sorry you had to be the “test pilot”
As Mike suggested, this could have (and would have!) occurred to someone out in the boonies at touchdown speed, coulda been a lot worse!
You’ve provided a pretty convincing case supporting your side of the story.
My beef with acme is, and has always been not with their product, rather how they handled the situation. We all f*** up, it’s how we deal with it afterwords that demonstrates depth of character and commitment.
I have a great deal of respect for your choosing your battles wisely and letting this go, life is too short.
Certainty not too late for acme to chime in and make good...

Congratulations on the Caribou!

Doug

We have been through this discussion once if I remember correctly. There are just two words that’ll save you’re plane - safety cables. Buy em’ make em’ whatever. We’re talking experimental parts on a bush plane. I remember clearly, in a phone call with Acme; “should safety cables be installed with these new shocks?” “Do you have safety cables?” “Yes.” “Install them.”

[WindOnHisNose]

Any update on ACME certification status for the PA18?

Also, I had a fellow tell me that he has heard of problems with the ACME shocks holding pressure. Any input?

Randy

[tedwaltman1]

I had one shock that wouldn't hold pressure. Bent schrader valve (tube) assembly. Talked to Matt who shipped me two new complete value assemblies 2nd day air. AWESOME customer service!