Drybread gear

[rpellicciotti]

I am looking to purchase Steve Drybread's retractable gear kits for the Long-EZ. Someone has a kit in their shop out there somewhere.

[Jon Matcho]

Rick, glad to hear that you may be having CG Products copy your drybread gear. I'm sure there are many that would want to buy their own once available.

 

Personally... I'm looking forward to receiving my fixed landing gear bow.

[Richard Riley]

I am looking to purchase Steve Drybread's retractable gear kits for the Long-EZ. Someone has a kit in their shop out there somewhere.

There's also at least one unauthorized copy of a Drybread gear out there somewhere. It came up for sale a few years ago, I asked Steve about it, he swore and said it had come about when someone had laid up some legs for him and laid up a few extra that they sold on the side.

[Lifessamsara]

Jon, are CG Products looking to produce this LG design?

If Im not mistaken, it is also the same design used in the Velocity (Steve's former partner with the gear?), so i wonder if they sell the LG as a kit or even individual items?

 

Bruce.

[Jon Matcho]

Jon, are CG Products looking to produce this LG design?

I read that the CGs are interested in reproducing the gear, which I gather would involve Rick taking it off his plane.

 

I understand there are some differences between the Drybread and Velocity gear, but I don't know what.

[rpellicciotti]

I read that the CGs are interested in reproducing the gear, which I gather would involve Rick taking it off his plane.

 

I understand there are some differences between the Drybread and Velocity gear, but I don't know what.

Yes, the hydraulic pump, actuating cylinder and basic design and operation of the gear is the same as the Velocity. As a matter of fact, I ordered a hydraulic cylinder overhaul kit from Velocity for my airplane.

 

I have conflicting information about the gear legs themselves. Some say they are identical to the Velocity SE/RG gear legs. Others say they knew that Steve was molding his own gear legs and they are not velocity legs.

 

There is a Velocity SE/RG at EZ Jet, Inc. right now and we measured the gear and they do appear to be the same in dimension. They may be different in the number of plies, wraps, etc.

 

The other part that is unique is the "over-center" device that actuates the gear legs and locks them in the down position. This device works the same as the velocity unit but it is sized to fit in the hell hole of the Long. It is a fairly simple device and will be easy to duplicate.

 

I am going to Florida in January. I will try to go by and visit with the Swings while I am down there. Perhaps we can solve the mystery then. In the meantime, I don't see why anyone could not order the gear legs, well wells, gear doors, pump and cylinder from Velocity and install it in a Long. The over-center device is the only custom part and I am sure if I sent one to the Girrrrls, they could make them.

 

I have located a Drybread kit that is installed in a Long that is unfinished. I am negotiating with the owner to "borrow" his over center device so that I don't have to dismantle my aircraft. This may work out as this unfinished long is about to get inverted for bottom fill and sand work. While it is upside down would be the time to do it.

[Jon Matcho]

Rick, I am sure that would be most appreciated by the community. Please do keep us posted, and thanks for your efforts!

[Lifessamsara]

Guys, this is most encouraging news! Im not sure where this is leading, it is the intention that the design of this LG be available in the public domain in a some-what re-engineered way?

Any indication (as Im over here in Australia) as to the cost of the currently available Velocity RG kit, and it's comparative weight to the FG on the LongEz?

Great work on the research and active persuit of this sub-system as I think many are interested in an alternative to the somewhat good but expensive Infinity RG.

 

Cheers,

 

Bruce.

[rpellicciotti]

Guys, this is most encouraging news! Im not sure where this is leading, it is the intention that the design of this LG be available in the public domain in a some-what re-engineered way?

Any indication (as Im over here in Australia) as to the cost of the currently available Velocity RG kit, and it's comparative weight to the FG on the LongEz?

Great work on the research and active persuit of this sub-system as I think many are interested in an alternative to the somewhat good but expensive Infinity RG.

 

Cheers,

 

Bruce.

I think the way to do this would be to document the source of parts, make some drawings and leave it up to the individual builder to source the parts, make the custom parts (or contract it out) and do the install. This is not a EZ mod to do but it is not as big a deal as installing the Infinity gear. Building it into a newly built airplane (such as an Open-EZ) would be a lot more simple to do.

 

The pros and cons of the various retract kits have been hashed over a dozen times. I like the Drybread method for several reasons:

• Mounts to the existing Long-EZ gear attach points (no design change)
• gear leg is simple, composite part. No scissors, springs, air/oil shocks.
• Is a copy of the Velocity design that has a proven track record (100's built and flying. 1000's of cycles)
• Mechanical connection between the gear means that one gear cannot extend without the other one also extending.
• Loss of pressure in the system results in the gear extending and mechanically locking down.

The one thing that I do not like about it (so far) is that the gear does not have a mechanical up lock. G loads on the gear while retracted are transmitted through the retract mechanism to the hydraulic cylinder and its attach points. The E-Racer/Berkut gear had the same problem. It was solved on the Berkut with a sequenced outer gear door that serves as a mechanical up lock. Something similar could be done with the Drybread gear.

 

As far as the weight difference is concerned, I have documentation with my airplane that shows the installation of the gear and its systems added 16 pounds to the airplane. I changed batteries and gained 10 pounds of that back so the net difference is 6 pounds.

 

Performance wise, it doesn't do much for the airplane's top speed as compared to a plane with well faired in gear legs and wheel pants. 5 or 6 knots maybe. Where it really makes a difference is in climb and roll handling. When the unfaired gear comes up, the climb rate doubles (at 100KIAS). The roll rate is about double of a lot of Long-EZs that I have flown.

 

I have not priced the components from Velocity. That's on the to-do list.

 

Bruce, if you ever run across my friend, George Markey (Ultrabat), down there, tell him I said, "Hello".

[Marc Zeitlin]

I applaud your promotion of this different type of gear retraction - it's long overdue. However:

 

As far as the weight difference is concerned, I have documentation with my airplane that shows the installation of the gear and its systems added 16 pounds to the airplane. I changed batteries and gained 10 pounds of that back so the net difference is 6 pounds.

Apples and oranges - one could change batteries with fixed gear and save the 10 lb as well - the weight difference is 16 lb.

 

Performance wise, it doesn't do much for the airplane's top speed as compared to a plane with well faired in gear legs and wheel pants. 5 or 6 knots maybe.

That's about what would be expected - glad to hear that your experience follows the theory.

 

Where it really makes a difference is in climb and roll handling. When the unfaired gear comes up, the climb rate doubles (at 100KIAS).

Well, yeah - raising the UNFAIRED retractable gear would make a large difference. However, with only a 5 kt. difference in top speed between retracts and well-faired gear, I'd expect to see very little climb difference at lower speeds between retracts and WELL-FAIRED gear - the drag delta would be very low.

 

The problem here, with all these comparisons, is that it's really hard to do side by side apples to apples comparisons.....

 

The roll rate is about double of a lot of Long-EZs that I have flown.

Interesting. Do you have any other mods that might affect roll rate? I wouldn't expect raising the gear to lower the moment of inertia by a factor of 2......

[rpellicciotti]

I applaud your promotion of this different type of gear retraction - it's long overdue. However:

 

Apples and oranges - one could change batteries with fixed gear and save the 10 lb as well - the weight difference is 16 lb.

Yes, all I meant by this comment was that the mod does not have to cost you 16 pounds over your original, un-modded weight. There was an EZ 10 pounds to be had by simply changing batteries which netted a weight increase of only 6 pounds on this particular airplane. In other words, you don't have to pay for all of that increase if you can find some other way to lose some weight out of the airplane. I took a 330CCA battery that weighed 23 pounds out and put in a 630CCA battery that weighed 13 pounds. The mod did add 16 pounds to the airplane.

 

Interesting. Do you have any other mods that might affect roll rate? I wouldn't expect raising the gear to lower the moment of inertia by a factor of 2......

Robert Harris and I both agreed after flying the airplane that the roll rate is better than most any other Long we have flown. I am not an expert on aerodynamics. We have carefully measured the airplane for conformance and the ailerons are stock long-ez sized and normal as near as we can tell.

 

I have a stricly amateur aerodynamic theory about it. I believe it has to do with not having to push the landing gear and wheel pants sideways through the air when rolling. The airplane also has a canard that is 20 inches shorter than stock. I suppose that the shorter span on the canard could contribute to the higher roll rate. I know that E-Racers are reported to have a higher roll rate as well. What do you think about it, Marc?

[Marc Zeitlin]

I believe it has to do with not having to push the landing gear and wheel pants sideways through the air when rolling. The airplane also has a canard that is 20 inches shorter than stock. I suppose that the shorter span on the canard could contribute to the higher roll rate. I know that E-Racers are reported to have a higher roll rate as well. What do you think about it, Marc?

There are at least three contributors to the roll rate issue.

 

First is the raising/lowering of moment of inertia by moving the landing gear closer to the roll axis. The Infinity Gear has the wheels/mechanism pretty far out - further than the stock gear, so it might actually INCREASE the moment of inertia and slow down rolls. The Drybread type gear probably doesn't change the inertia much at all, since the wheels are about the same distance from the roll axis when they're extended or retracted.

 

Next is the aerodynamic resistance (drag) of the leg/pants when moving sideways, as you posit. Remember that the aircraft is moving forward as it rolls, so even with a high roll rate, what you've got on the gear is a high angle of attack, but they're not, by any means, moving sideways - the rotational velocity is still small with respect to the forward velocity. I wouldn't expect this to be a large contributor, but I could be wrong about that.

 

Lastly, since you stated that the canard is smaller, there will be less moment of inertia and maybe slightly less drag, but again, I wouldn't think that would be a large contributor.

 

So, I guess I'm saying that I have no idea why this aircraft seems to have a higher roll rate than normal - there must be some other factor somewhere that we're missing :-). Or maybe my understanding of the inertia/drag issues associated with the Drybread style gear is faulty.

[rpellicciotti]

When I was listing mods, I forgot to mention that the airplane has no lower winglets. I do not know what effect that has on roll rate, if any. All of the other Longs that I have flown had lower winglets.

 

I am about to begin experimenting with the aileron fences but that is a discussion for another thread.

[Jon Matcho]

My theory is that your shortened canard (20" -- "wow!"), retracted gear, and lack of lower winglets all adds up to LESS air resistance in roll, allowing faster roll times. Aren't all of these things comparable to a perfectly inefficient propellor? Make this propellor's "blades" more narrow or shorter and it will spin faster.

 

How much faster, and why exactly, is up in the air. With 3 variables you can't know for certain which one gives you the most improvement.

 

How's that?

[Lifessamsara]

Guys,

has anyone done an all up weight comparison between the infinity and Drybread fit-out? Further and perhaps more importantly, the moment calc', and the effect on a LongEz W&B (once the hyd' pump and accessories are included)?

Rick, I do look forward to hearing how your Jan' trip to Florida goes, and any updates on whether the CozyGirls will produce components/complete systems. Do you have any idea how much fuel tank volume is lost with the Drybread fit-out?

One other possible downside of the Drybread LG design is that it does not place the wheels and further outboard in the extended position to avoid the FOD/prop' issue (unlike the Infinity I understand). Having said that, simplicity is always going to be an advantage of the Drybread system. (hope you like that one Marc, although I know it's not as simple as fixed gear )

Cheers guys, and hope your Thanksgiving was a wonderful one.

 

Bruce.

[rpellicciotti]

Bruce,

There is negligible change in the CG with the Drybread mod. The hydraulic pump is mounted in the hell hole behind the rear seat. The hydraulic cylinder that actuates the gear (only one, operating both gear legs) is installed longitudinally, in the area where the NACA scoop would be, under the rear seat area and nearly on the CG. Most EZ's that would get this mod will also have larger engines. Extending the nose and installing the battery up front (standard practice for larger engines) will also compensate for the CG change (if any) of the gear mod. The CG does not change with extension or retraction of the gear as it swings "in plane".

 

I don't have in any of my literature what the total system weighs. I only have references to 15 or 16 pounds increase over the fixed gear setup. I guess we could calculate it if someone knows that weight of a fixed gear bow, the fairings and the wheel pants.

 

The fuel decrease is 10 gallons total, 5 per side.

 

I believe that most of the FOD damage comes from the nose wheel and not the mains. In my opinion, having the landing gear in the exact same geometry, location and attach points as the original design is worth the small chance that FOD will be kicked up by the main wheels. If anyone has seen some of my landings, they will understand why I don't want my landing gear bolted to my main wing spar.

 

I have now, on my bench, the over-center device out of another aircraft. I am in the process of measuring it, doing some drawings and so forth. My trip to Florida in January is still on. I will keep you posted.

 

I am attaching a PDF of Steve's original web site. It shows pictures of the landing gear kit and has various information about it.

ezrg.pdf

[Lifessamsara]

G'Day Rick, and happy new year!

 

Just wondering whether there has been any further progress on this retractable LG project. I know you had the internal fittings for reverse engineering, but any word on a viable way to manufacture the LG legs, or their specific lay-up for construction? Perhaps easier to buy the Velocity legs (if they are the same dimension)?

Hope to hear from you soon.

 

Cheers,

 

Bruce.

[rpellicciotti]

Hi Bruce,

I do have the "overcenter device" disassembled and measured. I am going to start on the drawings as soon as I get my new instrument panel finished and installed.

 

Regarding the gear legs, I would plan on using Velocity legs. That would be the easiest at least as far as I am concerned. While my airplane is down or the instrument panel upgrade, I am going to take some careful measurements of the landing gear legs. I will post them and perhaps a Velocity owner will do the comparison for us.

 

Rick

[Richard Riley]

Steve made his own. I can't imagine he would do that if he didn't need to.

[Lifessamsara]

Hi Richard,

 

I seem to recall that Steve used to work/share the LG design with someone who now works at Velocity? If this is correct, the Velocity gear was perhaps born from Steve (and partners's) earlier work. As a result, and if the legs are essentially still the same original design, then they may well just simply fit straight in, just like Steve's originals.

Any RG Velocity owners to chime in here please?

 

Cheers,

 

Bruce.

[Richard Riley]

Hi Richard,

 

I seem to recall that Steve used to work/share the LG design with someone who now works at Velocity? If this is correct, the Velocity gear was perhaps born from Steve (and partners's) earlier work. As a result, and if the legs are essentially still the same original design, then they may well just simply fit straight in, just like Steve's originals.

Any RG Velocity owners to chime in here please?

 

Cheers,

 

Bruce.

I agree with the first part, Steve said he worked with the Swings developing the Velo gear and his LE gear was based on it. But he had his own molds and made his own legs.

 

That leads me to thing that they must have been slightly different. Maybe they're a little smaller overall, maybe some of the dimensions are a little longer or shorter. But if they were the same - or close enough to be adaptable - my guess is Steve would have used Velo legs and adapted.

 

We'll find out for sure soon enough.

[rpellicciotti]

Richard,

I believe that some weight savings could be had by building a gear leg for a lighter weight airplane. A long time ago, we had a Velocity RG and a Long-EZ with Steve's kit in the EZ Jets shop at the same time. At that time, we did some quick measurements of the the gear legs and found them to be about the same. None of us seem to have written notes from the event though so we are going to try and do it again. That same EZ is the one that I have borrowed the overcenter device from (it has never been finished). The gear legs are also available. I can measure them and weigh them. We just need access to some Velocity legs for comparison.

 

It would be easy enough to make a mold off of these gear legs that I have access to but I don't know enough about it to figure out a layup schedule.

[Lifessamsara]

This is sounding even more interesting Rick. If possible, Id encourage you to make the most of the opportunity of being able to measure/weight the Drybread gear that you mentioned is fitted to that LongEz project.

I'm sure someone on the forum here must know someone with a Velocity project that could do likewise for us.

Lay-ups for a landing gear set is nothing for guess work. Striking some moulds would also be making the most of the availability of the Drybreak gear, but I think we still have some way to go on determining the correct lay-up............. one foot in front of the other I say.........

I wonder if anyone has made their own MLG for a LongEZ or are aware of the lay-up for the standard LG bow? Anyone?

Im sure many people will be interested to know the weight in particular as this is a component of the eternal debate!

I can access the lay-up for the Berkut MLG, but I suspect that it is so significantly different that that information will be of little use to this research.

Keep up the great work mate, and hope to hear the data on the Drybread weight and dimensions soon (don't forget to take pic's as well!).

 

Cheers,

 

Bruce.

[Richard Riley]

The layup for the Berkut gear was COMPLETELY different, and shouldn't be included as part of this calculation. A totally different shape and material.

 

The lighter weight legs for a lighter airplane makes sense. That would also imply that standard Velo legs might be reasonable for a Cozy 4

[rpellicciotti]

Folks, I had some Real Life issues step in and I dropped off the grid for awhile. I just wanted to post and let you know that there has been some movement on the Drybread gear situation.

 

The original molds have been procured and are being rejuvenated. A set of wheel well liners have already been produced. Gear legs are next. An overcenter device has been reverse engineered, drawings made and a machine shop has been engaged to make a new prototype.

 

Stay tuned....