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RV A model nose gear idea

Clarification....

Earlier this evening a couple of posts which referenced this YouTube video were deleted by me. The reason was that the individual that posted them was not an advertiser on this site, and he was using the forums to promote his commercial product. Rule number five at http://www.vansairforce.net/rules.htm

I deleted those posts. Then I sent that individual a private message.

He replied positively and will become an advertiser most likely next week, which is why I am happy to keep this thread up.

Please understand that this website is how I feed my family, so it is very important to me that my posting rules be followed and not abused. I have everything riding on it, which I'm sure everyone can appreciate.

Kindest regards,
Doug Reeves (site owner)
 
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I saw the earlier post and then it disappeared. I thought it must have been a vision. Glad you have it worked out. Also, good job on this website.
 
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Thanks to you Doug for your diligence.
This looks to be a viable product with an ellegant solution to a potentially troubling problem. His explanation of how his bracket works
is easily understood by the non-engineers in all of us. At least it makes sense to me.
 
Looks good

to me - wonder if there will be several sizes, etc. We'll wait and see. Kind of like preventative medicine - you can never be sure if it works or has worked for you. Hope that this is THE answer to non-pilot induced tip overs. I'd install one if my kit was an airplane!:cool:
 
High pressure nose wheel?

This DOES look cool, esp. for the fearful low time pilot. As forgiving as a Cessna 172? Maybe not.

BUT the video seems to recommend a 50 lb pressure in the nose wheel. A bit high no? Won't this cause shimmy grief?

Dkb
 
I need to see more of the engineering behind this idea. It's obvious that he has taken the damaging forces away from the vulnerable part of the gear, but those forces are transfered somewhere else now. I want to see the result of the new forces on other parts of the gear leg and elsewhere.
 
This DOES look cool, esp. for the fearful low time pilot. As forgiving as a Cessna 172? Maybe not.

BUT the video seems to recommend a 50 lb pressure in the nose wheel. A bit high no? Won't this cause shimmy grief?

Dkb

I usually run 45 lbs in my nose wheel and have had no shimmy issues (it's important that the tire/balance/disc washers/break-out force are all in good conditon and set correctly).
 
I need to see more of the engineering behind this idea. It's obvious that he has taken the damaging forces away from the vulnerable part of the gear, but those forces are transfered somewhere else now. I want to see the result of the new forces on other parts of the gear leg and elsewhere.

It's free to flex the other direction, if you plop your airplane onto the runway. It will most likely save your prop and potential engine damage should the forces (from angles shown in the second demo) be enough to curl the leg back...........as has happened numerous times. At that point, I don't care too much about a possible leg or engine mount repair. Since I've just been through this scenario..........I think it's a wonderful idea!

L.Adamson --- RV6.....a
 
I looked at the video. In theory, it appears to be a good idea.

There is an old video of the nose gear being held to the surface until it begins to oscillate fore and aft like a wet noodle. I believe that video was created by deliberately holding the NG down during acceleration way beyond normal lift off speed and may not be a valid test of real world flying.

Whether or not this modification would dampen and prevent such an oscillation and what the consequences would be with the engine mount are unknown. It should work if the clamp will hold the bracket in position and the not allow it to go off one side or the other of the strut. It is a flat piece of material, perhaps a quarter inch thick, meeting a curved surface.

I looked at an old image of the NG strut on my airplane after an off field landing and flip in 2003 in soft river bottom sand. It definitely bent where the designer of this device says the weak spot is located. But it may not have prevented the flip as the airplane was nearly stopped when it happened. The NG had been launched from a previous gradual depression on the surface, a police officer measured the distance and there was something like 20-30 feet of no tire mark, and when it contacted the surface again the front of the NG dug in and over it went. The event felt like it was in slow motion and a stiff strut may have acted as pogo arm anyhow, I don't know.



Uploaded with ImageShack.us
 
Dave's picture not same

If I understood the video correctly, this picture shows a failure at two points other than and to either end from where the anti-splat developer predicted. The straight part is where the brace goes. Or is the picture of a test of the new device?

I looked at the video. In theory, it appears to be a good idea.

There is an old video of the nose gear being held to the surface until it begins to oscillate fore and aft like a wet noodle. I believe that video was created by deliberately holding the NG down during acceleration way beyond normal lift off speed and may not be a valid test of real world flying.

Whether or not this modification would dampen and prevent such an oscillation and what the consequences would be with the engine mount are unknown. It should work if the clamp will hold the bracket in position and the not allow it to go off one side or the other of the strut. It is a flat piece of material, perhaps a quarter inch thick, meeting a curved surface.

I looked at an old image of the NG strut on my airplane after an off field landing and flip in 2003 in soft river bottom sand. It definitely bent where the designer of this device says the weak spot is located. But it may not have prevented the flip as the airplane was nearly stopped when it happened. The NG had been launched from a previous gradual depression on the surface, a police officer measured the distance and there was something like 20-30 feet of no tire mark, and when it contacted the surface again the front of the NG dug in and over it went. The event felt like it was in slow motion and a stiff strut may have acted as pogo arm anyhow, I don't know.



Uploaded with ImageShack.us
 
Sheesh.....

I don't have an A model, but if I did, I wouldn't be looking this gift horse in the mouth. I would be ordering this bracket. This fellow is going to be very backlogged.
 
I need to see more of the engineering behind this idea. It's obvious that he has taken the damaging forces away from the vulnerable part of the gear, but those forces are transfered somewhere else now. I want to see the result of the new forces on other parts of the gear leg and elsewhere.

Thanks for the post. I was beginning to think I was the only skeptic out there. While the idea looks good and sounds plausible, there is no data to support the claims nor is there any evidence to suggest the added reinforcement won't create some other unexpected problem.
 
I need to see more of the engineering behind this idea. It's obvious that he has taken the damaging forces away from the vulnerable part of the gear, but those forces are transfered somewhere else now. I want to see the result of the new forces on other parts of the gear leg and elsewhere.

Exactly my thoughts, just could not figure out how to express my concerns as eloquently.

My non-engineer WAG is the upper end of the stiffener will transfer the force to the point of contact, and cause the failure to occur in that region. Or, where it sockets into the mount.

Once there is sufficient energy in the nose gear system to cause a failure, pretty sure it is going to fail. Question is now where???

All that said, I am pretty sure this will end up being an improvement.
 
I agree with Mike and Don. The test jig didn't seem to include a realistic engine mount for the nose gear. Perhaps someone with engineering skills could run some modeling as to just where the energy goes and what the results would be.
That said, I also agree that even if the transferred engery caused some engine mount damage (etc), the bracket might prove its worth in preventing a tip over.
 
Thanks for the post. I was beginning to think I was the only skeptic out there. While the idea looks good and sounds plausible, there is no data to support the claims nor is there any evidence to suggest the added reinforcement won't create some other unexpected problem.

I like the design approach. The added stiffener only comes into play somewhere near the point of permanent yield of the nose gear. In normal operation it should have zero effect on the nose gear characteristics.

The jig video showing the angle of the force from a small pothole explains a lot of what the -A models see just before a flip occurs.

When the device becomes operational, you are already into the realm of any "other unexpected problem" and something is about to break anyway.

The device might be better compared to a parachute or seat belt - it is only needed after the "unexpected" has happened...:eek:
 
The device might be better compared to a parachute or seat belt - it is only needed after the "unexpected" has happened...:eek:

I included this pic in the original thread last evening. And it does prove a point. The device seems to provide a better outcome than I see with my C/S prop..........which is easily seen in the shadow below.

spg7rr.jpg


L.Adamson
 
This approach is interesting. However, I wonder if this solution will cause a new problem, namely corrosion of the gear leg it'self.

The gear leg bends in all directions as it rolls over the ground and I wonder if the two "saddles" at the stiffener's ends will contact the gear leg in an undesireable way (occasionally) wearing off the powdercoat and possibly scratching the leg material, leading to corrosion over time.

Would it not be better to "attach" one end of the stiffener or the other permanently to the gear leg?

Furthe, should the saddle be made of the white plastic material we use elsewhere in the kit to prevent metal to metal contact?

Bevan
 
I Like It

I like it!

I don't think the corrosion issue will be much more than you get now with the fairing attachments and what not wearing on the gear powdercoat.

Anyone get a price yet?


Hans
 
Gear leg stiffener

I want one for my soon to be finished 8A. This has the most potential of any "fix" that i have seen so far.
 
I like it!

I don't think the corrosion issue will be much more than you get now with the fairing attachments and what not wearing on the gear powdercoat.

Anyone get a price yet?


Hans

Agree, I believe the price was around $379.
 
Agree, I believe the price was around $379.

I was quoted $379 in a PM, waiting for him to establish his advertisers status here and then I'll place an order for one.

This device won't do much for you during "normal operations" other than add another pound or two to the nosegear weight. The only time it would come into play (like an airbag or seatbelt) would be those few points in your flying career when the boring hours are being punctuated by panic moments. If you have the airplane in a situation where this brace is being used - things are already off the flight plan considerably, and while it might not stop you from going over or tagging the prop, it also might be just enough to allow you to terminate the landing at "bad" rather than "worse".

I would much rather be doing a hard landing structural inspection than a prop-strike teardown.
 
I wonder if Doug can work out a group buy arrangement.

I'd be in on a group buy if the price was right... haven't had any trouble all these years and don't "expect" to, but hey, I'm open to the idea of improving the chances if I happen to fall asleep at the wheel one of these days :rolleyes:
 
I like the design approach. The added stiffener only comes into play somewhere near the point of permanent yield of the nose gear. In normal operation it should have zero effect on the nose gear characteristics.

The jig video showing the angle of the force from a small pothole explains a lot of what the -A models see just before a flip occurs.

When the device becomes operational, you are already into the realm of any "other unexpected problem" and something is about to break anyway.

The device might be better compared to a parachute or seat belt - it is only needed after the "unexpected" has happened...:eek:

how much does the jig he made follow a real tire and gear set ups flex? It looks like his "tire" doesn't spin, or is it even rubber?
 
I like his approach... something to experiment with and even maybe expand on, extremely simple, well worth the price just to have the ability to perform more actual field testing. Way to go! :)
 
fairing?

On average, I bet this would be a significant improvement (by "on average" I mean it would likely prevent far more failures than it would cause).

One question (I emailed antisplat, waiting to hear back) - I hope this would fit under my existing gear leg fairing. Would be a pain to have to make and paint a replacement fairing to fit over this.
 
One question (I emailed antisplat, waiting to hear back) - I hope this would fit under my existing gear leg fairing. Would be a pain to have to make and paint a replacement fairing to fit over this.

On one of the video's, they show a new faring that comes with the kit. The standard Van's won't fit.
 
how much does the jig he made follow a real tire and gear set ups flex? It looks like his "tire" doesn't spin, or is it even rubber?

It wouldn't make much difference. He is only showing the angle of forces. A real tire would actually "squish" a bit more, increasing the contact area, and actually move the angle of the force in a more "bad" direction.

It's the best explanation I have seen for the pogo stick effect that many others have reported/experienced.

As I said earlier, we should regard it as more of a seat belt/parachute idea for when stuff has already gone wrong. Operationally, Vans design is unaltered.
 
New gear leg product

First I would like to apologize to all you guys for my lack of knowledge about posting info on our product in this forum. I didn't read the rules and seemed to jump the gun a little. After receiving the PM from Doug Reeves in regards to advertising here in this forum I realize I made a mistake and it all makes sense. He makes his living from this site and it is only fair to be reworded for the fabulous and tireless job he performs. That being said I will resolve this on Monday. Please let me thank all of you for the great responses, interest in and words of encouragement you have offered. It makes us feel like our efforts were not in vein.
The reason the web site is not operative is because it is new and under construction. It will be operational in a few days. Due to legal issues and liability concerns it is necessary to market this product through a new
LLC as our parent company doesn't wish to be exposed to the "Experimental Market". They are one of the largest aircraft parts manufacturers and suppliers on the planet and have a mind boggling engineering department (moves slowly I might add). Many of you I am sure have purchased turbine engines or parts from us in the past or are currently flying a commercial aircraft with our parts installed. This product was not conceived in somebody's garage over a six pack and a guess. It was a team effort of some of the finest engineering minds available with access to the best modeling computers, machine shops and metallurgy in existence. They are collectively convinced that this is the best that can be done with the available gear leg to lesson the failures. I have personally invested over $30K in the engineering and development of this product and will feel blessed if I were to recover it through sales. I am sure there will always be the "Nay Sayers" out there that try to find un-based fault with anything and everything. Would be interesting to see there efforts or offerings. Usually if you follow there posts you will see the negative jump out at you. Please bear with us a few days and we will be back here with our products and information, Regards all, Allan AntiSplatAero
 
Nice Product!

Intriguing product Allan. Thanks for developing it and bringing it to our attention.

I'm looking forward to seeing your site and to seeing the engineering analysis to back up the assertions made (and from what I can tell proven) in the video demo.

I like the idea of a margin of safety added to the original design. I don't consider myself immune from mishaps despite the fact that I am no longer a "low time" pilot, and I don't want to count on getting every landing 100% right to keep my plane and I intact.
 
Intriguing product Allan. Thanks for developing it and bringing it to our attention.

I'm looking forward to seeing your site and to seeing the engineering analysis to back up the assertions made (and from what I can tell proven) in the video demo.

I like the idea of a margin of safety added to the original design. I don't consider myself immune from mishaps despite the fact that I am no longer a "low time" pilot, and I don't want to count on getting every landing 100% right to keep my plane and I intact.

Hello Antony
I don't think you need to be at all concerned with the occasional bad landing or for that matter anything you do intentionally. To me the concern lies in the unexpected off field landing that is highly probable if you fly long enough. I have been flying for some thirty five years with several thousand hours in just about anything that will fly. In that time I have made several forced, off field landings. Any of which could have had disastrous consequences. I can think of a few that were I in my RV-A would have been ugly. That being said, anything that adds any margin of safety is well worth what ever it costs. Imagine yourself flying along in your A- model over the wide open spaces with plowed fields and bumpy dirt roads with unknown bump sizes below. Suddenly, silence, the prop stops! Do you want the stock unmodified gear leg or one with the kit installed. I hope you will not ever be in that situation but I want all I can get. Wow! I'm a pretty good salesman. Regards, Allan
 
Allan you mention adding something to the original gear leg to get the best improvement possible. Was it too difficult to machine a different gear leg to get the improvement or not possible or to expensive?
 
It wouldn't make much difference. He is only showing the angle of forces. A real tire would actually "squish" a bit more, increasing the contact area, and actually move the angle of the force in a more "bad" direction.

It's the best explanation I have seen for the pogo stick effect that many others have reported/experienced.

As I said earlier, we should regard it as more of a seat belt/parachute idea for when stuff has already gone wrong. Operationally, Vans design is unaltered.

Very well said! You've got it perfect. Thanks, Allan
 
Pretty sure I will be on board for one. Will be watching for the availability announcement.
 
Allan you mention adding something to the original gear leg to get the best improvement possible. Was it too difficult to machine a different gear leg to get the improvement or not possible or to expensive?

We looked at making a new gear leg that was stronger, but that also makes it more rigid, degrades the ride and it's ability to absorb bumps etc. We actually made a new more rigid titanium gear leg but it is prohibitively expensive for most people, far more involved installation and it seemed wasn't worth what you had to give up. It tried to shake the instruments out of the panel. I would like to emphasize the fact that the gear leg that vans has designed is a very nice, well engineered assembly that treated properly will never let you down. It's dynamics and performance as designed are flawless. That is why our product in no way alters is function as designed. Lets face it, nothing about this plane was designed for off roading and nothing you do will make it so, short of converting it to a tail drag er and installing 22" tall balloon tires. We just want to add a little safety to the great system that is already in place. Thank you for your question. Allan
 
Hey Allan - nice looking idea! I'm glad that you guys took an engineering approach to the problem and did a bunch of testing, gathering actual data. Of course that costs money - and like you said in the videos, you ruined a few gear legs along the way.

I am not nay-saying, just asking a question because that's what engineers do....A lot of the pictures of flipped "A" models and bent nose gear legs show a pretty distinct bend ABOVE the region that your brace is stiffening. Did you find anything in your testing to show that the upper bend is a result of the lower part of the strut bending first? I could picture how that would be the case, and if so, then if you prevent the mid-strut bend, you prevent the upper bend. Just curious if you ever had the strut bend above the reinforced area once you reinforced the middle, and if you have any thoughts about the bend up near the socket.
 
Braking Effects

Allan,

This looks like a great product and your videos show the best explanation I've seen yet of what can occur with the Van's A-model nosewheel. While I'm no engineer, it just seems reasonable to me.

Just curious... There never seems to be any mention of braking effects on the weight encountered on the nose wheel during landing. It seems to me that if brakes are aggressively applied - before or after the nosewheel touches - there would be additional weight applied to the nosewheel (regardless of elevator application). IN MY OPINION, this could be a contributing factor to some of the past nose wheel collapses, especially during short field grass strip landings, and I hope your brace design could alleviate this.

In your testing, did you calculate or test the effects of braking on the weight applied to the nose wheel?

As I'm building a taildragger RV-7, I have no skin in the game, but one of the major reasons I went with the RV-7 was the RV-7A nose wheel design.

Keep up the good work and I wish you success.
 
Actually, this is very close to a few set-ups many have been discussing. Not a gear leg stiffener as we need the gear leg to do it's job as to some motion. This is the best idea so far I've seen. I will purchase and test this unit.

[ed. One sentence here at the end that I felt was derogatory towards my moderation policies was deleted by me. dr]
 
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Hey Allan - nice looking idea! I'm glad that you guys took an engineering approach to the problem and did a bunch of testing, gathering actual data. Of course that costs money - and like you said in the videos, you ruined a few gear legs along the way.

I am not nay-saying, just asking a question because that's what engineers do....A lot of the pictures of flipped "A" models and bent nose gear legs show a pretty distinct bend ABOVE the region that your brace is stiffening. Did you find anything in your testing to show that the upper bend is a result of the lower part of the strut bending first? I could picture how that would be the case, and if so, then if you prevent the mid-strut bend, you prevent the upper bend. Just curious if you ever had the strut bend above the reinforced area once you reinforced the middle, and if you have any thoughts about the bend up near the socket.

Hello Paul;
Yes you are correct, the failure will occur over the entire gear leg but only after it fails in the weak area pointed out in the video. When this area fails it just snowballs and plants the friction nut in the ground.
at this point the outcome is pretty much inevitable. Look closely at the different photos and you will see substantial damage to the bottom of the aircraft where the nose wheel has impacted the plane. This happens during the failure and demonstrates the fact that the rolling up of the gear leg is actually worse than the post crash photographs show as they have a tendency to unwind like a spring. You need to attempt to stop the event before it can get underway. Thank you for the questions. Allan
 
Allan,

This looks like a great product and your videos show the best explanation I've seen yet of what can occur with the Van's A-model nosewheel. While I'm no engineer, it just seems reasonable to me.
In your testing, did you calculate or test the effects of braking on the weight applied to the nose wheel?
.

Yes we did take this into consideration and found that the gear leg is actually very strong in this direction and is more than adequate.What heavy breaking does is puts extra weight on the nose wheel. Not a problem as long as you don't hit something. The extra weight caused by heavy braking will make the contact patch longer and will make the gear leg more prone to failure should you over stress it. Thanks, Allan
 
His web site doesn't work. I ended up on Go Daddy. ?????
Looks like he's secured his domain name, but doesn't have an actual website yet.

I need to see more of the engineering behind this idea. It's obvious that he has taken the damaging forces away from the vulnerable part of the gear, but those forces are transfered somewhere else now. I want to see the result of the new forces on other parts of the gear leg and elsewhere.
The bending moment is supposed to be transferred to his brace so the NG doesn't bend in the area where the brace is. So in a significant NG incident, the NG is still going to suffer damage, but not so that it curls under the aircraft.

I mean it would likely prevent far more failures than it would cause.
Don't think so...I believe it's designed to prevent catastrophic failure (i.e. total NG collapse) leading to nose-over accidents...not designed to prevent NG failures generally.

Whether or not this modification would dampen and prevent such an oscillation
Unlikely. This brace is clearly designed not to prevent the NG oscillating or even to prevent the NG from failure. Rather, it seems designed to prevent the type of failure that leads to nose-over accidents. But even for that one purpose it is worth it, if it acts as intended.

I do have one question for the developer: would it be wise to have some rubber-like inserts between your brace and the Van's nose gear? Surely during normal runway/taxiway use the brace must contact (bang on) the NG? So the rubber-like inserts would prevent damage to either brace or NG.
 
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Modeling clay test

I do have one question for the developer: would it be wise to have some rubber-like inserts between your brace and the Van's nose gear? Surely during normal runway/taxiway use the brace must contact (bang on) the NG? So the rubber-like inserts would prevent damage to either brace or NG.

I was thinking it would be interesting to put modeling clay in that space and do some landings to see how much compression happens in normal landings.
 
I was thinking it would be interesting to put modeling clay in that space and do some landings to see how much compression happens in normal landings.

It would be hard to keep any dampener in place due to the action multiplier on the part... maybe a molded rubberized fixture that can be replaced at the condition inspection. :)
 
It would be hard to keep any dampener in place due to the action multiplier on the part... maybe a molded rubberized fixture that can be replaced at the condition inspection. :)

This would be completely unnecessary as there is no contact until the gear leg is over stressed. At that point you need to look closely at everything, including landing technique. Allan
 
This would be completely unnecessary as there is no contact until the gear leg is over stressed. At that point you need to look closely at everything, including landing technique. Allan

Cool... can't wait to see how it functions, again one of the best designs I've seen to date! :)
 
Am I wrong? For this product to perform it's function, would it not be in contact with some part of the gear leg? :)
 
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