I am considering purchasing a Modelcompositi composite engine mount.
Normally my preferred choice of mount is the Hyde, which I have used with good results on my previous model with both a YS120AC and a YS140FZ. However, I did break one of the plastic arms, (due to a landing in the rough catching the engine) which is why I am considering the Modelcompositi.

The engine I will be using is the YS140DZ Dingo fitted in a ZN Evolis.
My question is has anyone experience of operating these mounts and if so: -
1) How durable are they over long-term use are they fit and forget?
2) How do they compare to the Hyde mount for vibration damping qualities in the airframe.

They are said to be lighter but, they are just out. I would try wait for as long as possible to get the first wave of reports. I have a friend who has one, and he likes it. I saw some in England, and they were looking the business. You would nearly need sunglasses on a sunny day to look at all that composite stuff. The Hyde is tried and tested, and I think that it would be worth sticking to it for now, as what could go wrong?

Hy Martyn,

This is my answer to your questions:

It has reported that several mounts have gone more of 500 flights without any problem so far.
This is also because:
Carbon fiber cannot be affected by nitro fuels (unlike cheap wood) and is also fatigue free (unlike cheap plastic).
The rubber edges are protected by a wrapping of carbon fiber (no chanche for the rubber to go apart)

Sometimes it happens that someone send me an Hyde mount to be fixed, but that's another story...

His behavior in general is similar to the Hyde, but my mount has a shift that provides the following:
-doesn't allow the engine to move ahead when at full throttle (more precise and constant carburetor control)
-doesn't allow the engine to move up and down under high G manouvers (thrust line constant)
-doesn't allow the engine to wobble (better and constant mixture adjusting)
It has been reported that some cases of mixture problems on the DZ has been solved replacing the previous engine mount with a Modelcompositi mount.

Plus, my mount has a wider and stiffer rear mounting plate that allow for a lighter firewall (for the versions without the front nose ring supporting arm). The firewall itself can be ulteriorly lightened by making a large hole (70mm.) in the center.

All of this, plus being much more pleasant to look at (...) at the same price (or lower) of the other mounts made with cheap materials.

I will not deal about the ratio -cost to the manufacturer/cost to the customer- because there are no arguments to deal with....

I'm here to answer any questions.

Roberto Bracchi

Modelcompositi

Modelcompositi

Roberto,

thankyou for your comments, I have just taken delivery of a Modelcompositi Mount purchased from Probuild in the UK. I must say, I am very impressed with the quality and the weight.

Sounds to me like you don't really prduce soft mounts Mr. Bracchi. I thought that you wanted that play to reduce damage to your radio equipment, and you use a nosering to keep the thrustline. Please correct me if I'm wrong.

Your products look good though, keep up the good work!

hi Ryan,

My mount is actually a soft mount: it works on the same principle of the Hyde one. A rubber tube that is allowed to withstand the primary forces that shake an engine (the ones that make the cylinder head go left-right, and that are the ones that make our airplanes shake and rattle and make damages to the radio).
The retaining axle is located on the crankshaft axe, so not to hurt the primary job done by the rubber.
His use comes to play whenever there are other forces acting on the engine: the engine is free to rotate (dampened by the rubber) but not to wobble erratically in any direction (just pure rotation along the thrust line)
In this manner, the rubber is allowed to work at his best (on pure torsion)
Since there are no pulsed forces acting along the nose-tail axe, the retaining pin doesn't contribute to propagate secondary vibrations to the airframes.
Hundreds of customers can witness this easily.
I have no one customer that I know to be replacing my mount with another one. Until now, of course..

Let's keep in touch

Roberto Bracchi - Modelcompositi

The biggest problem I see with the retaining axle is it would reduce the mount's ability to absorb the vertical motion created by the piston's travel, transmitting that vibration to the airframe. The advantages you list over the Hyde mount are really not an issue anyway. The engines don't move forward, nor do they wobble during high G maneuvers due to the nose ring on the engines. It's no different than your mount actually in that respect. With the Hyde mount, you either have the nose ring on the airplane, like with the AR variety, or the nose ring is incorporated into the mount, exactly like your mount, with the ARI version.

Chip has some mounts with over 3000 flights on them without failure. The Hyde mount is certainly the standard to compare against, and with so many people using them for so many years, I think it's pretty hard to say there is anything 'wrong' with their design. Merle charges the prices he does for his mounts because they're all hand made, by Merle himself. It's his labor going into the mounts. IMO, they're the best pattern mount there is, with solid evidence to prove that over the last 15 years.

That being said.. Roberto showed me his mount when he was here in the USA at the TOC, and it's very nice work. I don't doubt it will work very well.

Doug Cronkhite

Hi Doug, thank for the nice words,

The reason why I got in production with my mount was not because I wanted to copy another product already well established into the world market.
It was because Sebastiano Silvestri made some testing on the Hyde mounts he was using, discovering the problems I issued in the past posts.
He suggested me to try to make a mount that could solve such problems, being lighter and more reliable (There are Hyde mounts that last 3000 flights and mounts that fail after 20 flights -proved-).
After having made some prototypes, we agreed that the retaining pin was an improvement over the ones without it.
If I wouldn't put that on my mounts, they would cost less so that I could sell more of them.
On request, I can produce mount without it easily. No problem.

My mounts too are made by hand (my hands). To make a carbon mount is simple: cut 7 to 10 layers of carbon fabric for each part the mount is made (6 parts), lay them down imprgnated with epoxy resin into each mould. Let them cure at 90°C. for three ours. Take them out from the moulds, trim them to measure with diamond tools, and assembly them togheter with 90°C. cured aircraft grade adhesive in a 3 separate oven steps procedure.
It takes 3 to 4 times the time to make an Hyde one (I tryed to make some mounts the Hyde way for comparison)

A full sq yard of carbon fabric is needed to make ONE mount, we all know his cost.

If I just wanted to make business, I would have made exact Hyde clones selling them at 1/3 of their actual price.

For a product, to have been using it for 15 years, it doesn't mean it is impossible to discover that a better product can be made. (Otherwise we would go with old Wolkswagen Beetles until now...)

Anyway, I don't want to make a soft mount war.
The USA resident people are not allowed to buy my mount because there is an US patent on that. Right.
All the rest is free to decide what to do with their money by themselves.

Roberto Bracchi - Modelcompositi

Roberto
I am building my first pattern plane in which I am installing a Webra 145 Aero X. Is you mount suitable for use with the two strokes or is it best used with the YS four strokes?

Mike

Hi Mike,

There are several mount I make for different engines:
1)-OS140 - 3M140/170
2)YS140DZ
3)Webra 145
4)OS160

These mounts are different because of the different sizes/requirements of such engines, and are available with the integrated nose ring supporting arm and without.
For pattern use, I suggest to use the mount for the Webra without the arm (the aluminum nose ring is anyway included with the purchase).

You can order it at www.Probuild-uk.com.

Bye

Roberto Bracchi - Modelcompositi

Roberto, I found this comment a bit interesting...while not really on topic, do I understand you correctly that you are willingly infringing on a US patent? Or this is the agreement you and the US patent holder made (to not sell yours in the US)? Just curious...

Yes, there is an US patent regarding the use of a rubber tube used as dampener between two objects.
This patent is valid in USA only. To get an international coverage of a patent, someone has to patent it in each country of the world.
Anyone can produce/sell items regarding US patents elswhere.
That's what the international laws state.
I could sell my mounts in USA only if I would have an agreement with the patent's holder, but I suppose that Mr Hyde wouldn't agree, remembering how much he was upset when looking at my mount during last TOC. :boxing:

Fair enough if thats what the laws state, but surely you can understand why Mr Hyde would be so upset?
Those mounts are his job, and were originally his idea.

To see such a blatant rip of of your own product that you have spent many years developing must be very disheartening.
Also for the fact that his share of the market will be reduced, and hence profit will be hurt.

(alright you improved the mount some, but the basic idea is very much the same)

Roberto, I hope you consulted with a lawyer before you took your current position. I should preface my comments with the fact that I'm not a lawyer but I am generally familiar with intellectual property. I believe that if the mount is sold in the U.S., either directly or indirectly, you could be subject to triple damages for willful infringement. You also need to be aware of countries that have patent treaties with the US (Canada, for example).

You might consider patenting your improvements to the original mount and then you might be able to arrange some cross-licensing of patent rights if Mr. Hyde is interested and then you could lawfully sell it anywhere.

I consulted one of the examiners of the European Patent Office (www.epo.org).
He took care of my case in detail, and the results are these I told previously.
I can't patent my mount anyway because it's already on the market. Once something can be seen by someone that is not deeply into the project, it can't be patented anymore.

If Mr. Hyde would have prevented all of this mess, he should have patented it worlwide, and not in USA only.

I am sure that either company will still do very well regardless.