I'm going to make the motor mount that is shown on the Piedmont site to use on my next project. Is anyone using it on their plane? Any word's of wisdom on it? It's for a 120 2 stroke application.

I've been using on 2 strokes and a Saito 100, use jam nuts on the back side of the well nuts, don't know if I would use on larger YS but works good on all others I have done including the Mintor 170.
Steve Maxwell

I've used it too with good results on an OS160.

thanks, I want to use it once on this plane to see if that's what I want to use on my 2 meter?

It works. I made a modified concept version for my Arresti. Check out my website, on the Arresti page, there are tons of photos of how I did the whole thing. Been holding up very well, but it doesn't do much for vibration damping...not bad, but not real good, either.

The nylon lock nuts on the BACK of the firewall is essential; don't even TRY to do one of these without those....you will have an UGLY surprise!

If it doesn't do much for vibration damping then what is the point?

Hard mount it...its lighter cheaper and you get the same results.

My Father-in-law has this mount on a Focus built by Dave Guerin. My advice to him was to hard mount the Webra 145 and just live with the vibration. This setup has a funny resonant frequency thing going on in his model.

If your question is will hold the motor in the model then I guess its a success as a motor mount. My personal opinion is that just because it flew the model and the motor didn't depart the airframe doesn't make it a good motor mount. I expect better from my equipment that that.
If you question is does it do anything for vibration then I have to say NO my experience is it makes it worse.

Just some quick numbers...I have one of those Hangar 9 current meters...Plugs in-line with the battery pack and will tell the current being drawn from the battery for the entire RC system. This then assumes that current draw is a good way to measure vibration levels. I won't argue that fact but I feel it is part of the indication of how hard the servo are working to hold center.

All the setups draw about 150-170ma when the radio is on and no engine running.

YS 160DZ on a Hyde AR type mount (5digital servos) 500ma draw at full power

Webra 145 MC carb on the well nut mount shown (same 5 digital servos)...1150ma draw at full throttle. Also a funny harmonic will draw almost 2000ma at about 1/3 power....considering the model only has a 1400ma nicad pack in it I don't like the idea of this harmonic.

By the way the same Webra 145 on a Hyde AR mount reads in the 500-600ma range at full power on a similar model and setup as the above Focus with the well nut mount.

Not to mention the constant vibration repair work that must be done to maintain the model...Belly cover screws, cowl and its screws, as well as eating servo pots and gears like candy. Clevis links...I actually saw Rocket city linkages wear out in short order.

As many know I'm a big supporter of Merle's......The REASON is his mounts work! It is as simple as that. I have been buying Merle's mounts since about 95' and there is nothing better in my opinion. I have never seen someone have a problem with his mounts...And when somebody at a contest has a motor mount problem it is always on another type....whether its a beam style mount like the DB, or MK or its a Gator Soft and safe, and a home made version of Merle's mounts....I have tried the others and keep coming back to what works.

I hate to see people getting a wrong steer. I don't mean to argue with the guys that like it.....but I have experience with it and I would not tell anyone its worth their time.



Troy

Were all the servos at full deflection when this large servo milliamp draw occured or at rest? I guess I don't understand why the big differential in draw when the motor is running. Is ther that much vibration transmitted through the balsa?
thanks

All Servos were at neutral just the same as when the motor was not running. No stick movement on the TX.

And yes those are the effects of vibration on the system. This is why I believe in the use a good vibration damping motor mount on my models.

And I feel that today the only mount to really use is the Hyde. It costs more but in reality you have to ask yourself a question.

IS MY MODEL WORTH IT?

5 Digital Servos --$400
5 High performance Analog servos $300
PCM RX --$150
Airframe --$800-$3000 depending on the model
Header $20-50
Pipe $80-200

How many hours to build-trim-and repair the model, not to mention lost practice time for repairs??????

How much is it all worth to you?

I may get blasted for my opinion on this issue...but I have been there and done that too many times. I have seen other wriggle and fight with the issues, and I know for a fact what that is worth to me!

TN

Troy, It sounds like you've done your homework on this subject. Let me play devil's advocate for a second. Up until 15(ish) years ago most people had never heard of rubber isolation mounts for their engines. Was there that much more crashing due to servos draining the batteries (that weren't as good as todays) than there is today? I used to fly a lot and have never had, to my knowledge, a crash caused by vibration related issues. I'm not argueing, just trying to get this straight in my own head. I certainly want to take precautions so as to not unduely risk my planes but is a $200 mount really necessary?
thanks again,
Tom

A $200 mount is NOT necessary. Neither is a $650 motor. Neither is a $1500 airframe.
The investment depends on the compromises one is willing to choose, the innovation and creativity that someone WANTS TO DO!!!!, and one's ability to enjoy many aspects of many elements of this game.

There is a "right" answer (read PREFERENCE) for EVERYONE, guys.

I run a $60 tuned pipe, pass the noise standard, and make huge amounts of power on my OS 1.60 with it's Perry pump....and I'm holding my own in my class.....

Well this may sound a little negative about the issue....So let me start out by saying it is possible to build a better mouse trap. I also admire the work people put into things and the innovation that is shown. On the other side of the coin I have struggled in my pattern career and found that when I used the right equipment, and paid attention to details like this my flying time increased and my repair or building time decreased. I'm trying to share my experiences with this group and not contradict someone else's ideas'

The YS or OS 140 AR is NOT $200 it is $120

This having been said I make my equipment choices based on the model lasting 3000 flights or more. If the setup needs to be replaced every 20-30-100 flights I choose not to use that product unless it gives me an advantage in another area. If there is no advantage to the performance of the model or longevity then I scrap the idea.

BB clevis links are an example---Yes they cost 2-3-4 times that of a Dubro clevis....But to get 3000 flights you 3-4-5 sets of the equipment over the life of the model. Plus if a failure occurs before you catch it and repair it you can loose the model. Not to mention the BB clevis has needed replaced in that 3000 flights so my time was not used to replace it....And it works in a more friction free, and tighter setup. The clevis into a plastic hole will wear also...SO this requires replacement and more bench time to reset the control throws and precision of the system.

Now to answer your question in a very straight forward NO BS way:

Up until 15(ish) years ago we were not running motors bigger than 60's with 11-12inch props. With 15-16-17 and now 18" props vibration is magnified. Not to mention that bigger motors make more power and the airframes really don't weigh that much more that they did with the 60's....We were flying 7-8lb models on 60's and now we are flying 10-11lb models on 140's 160's and the 170's. The models grew in mass by 20-30% and the power of the engines Went from 1.5hp to 3.5hp.... more than doubled.

Vibration problems usually doesn't cause the model to crash at least not in the short term.

What does it do? wear out servos! Wear out linkages, and so on..When the pots wear the servos don't center properly or well. And yet we pay premium money to get servos that do center well and hold their position. Also gear slop makes things like pot wear even worse. You may be paying anywhere from $50 to $100 for a precision servo....and after 200 flights it performs the same as a $9 Generic servo when the engine in the model is not properly mounted. Proper mounting in my vocabulary is more than just a mount that keeps the motor attached to the model.

If you are trying to fly precisely the last thing you need is worn servo pots and gears. It makes it impossible to fly in a straight line. It makes it impossible to keep your wings level, and it makes it impossible to pull a straight corner. Same with sloppy linkages. These points are all points of failure and if they don't fail then they become loose and defeat the purpose you are trying to achieve. PRECISION AEROBATICS

Are you willing to buy new or rebuild servos every 50 flights. That is what is required to keep the servos in working proper order on the above model with this mount. Now your standards may be lower than mine for precision on the servos, and the amount of pot wear you will accept...But I can tell you the servos will last 2-3-4times longer than a hard or (poor Soft mount) mounted system

There is a difference between, the servo moving the control surface, and the servo holding its position properly and centering properly.

Until you get really in-tune with your model and your flying, you may not ever realize the benefits of the equipment the successful pattern pilots choose. Those that are a success choose their equipment very carefully. Sponsorships really play very little role....Companies don't hand product to pilots except the top few 3-4 in the world. And these pilots can run whatever product they choose. Their choices are to make life easy on them, or for the performance advantage given by a specific product. If the product gives an advantage then the pilot can go get it from that company....Performance is just too important at that level of success. Not to mention when is something going to fail? When it counts in a round at the F3A NATS Finals. Or even at a local event when you are scrambling to get that extra point in Sportsman because there is bragging rights to be gained at the local contest. How many times have you guys witnessed a pilot that traveled to an event got there and could not fly in the contest? His model broke, something failed, motor went south, or even his motor mount broke and he needs to take it home and rebuild the darn thing. Well in all my years running Merle's mounts I never had this type of problem....It just plain works and is the best system we have right now. IS there a better one out there waiting to be invented...I'm sure there is.....But the Well Nut mount we are discussing is not one of those!

This is a game, and we keep score for a reason.

The unfortunate part of the internet is that just because someone says it or posts a picture that they did it doesn't make it is a good way to do things.

No offense to AeroBob as he told you the mount doesn't do much for vibration...My question is then why use it?

A Dave Brown Fiberglass $5 mount will keep the motor attached to the airframe.

This may sound harsh, but I make the choices on my models and I'm telling you why I choose the stuff I choose. I give this info free and its worth what you paid for it. The real question is what is you model worth to you and how much is your time worth to you.

Happy flying
Troy

First off, thanks Troy for the time it took to explain this in detail. I hope that my playing the other side of the issue didn't get something started. It was only meant to get deeper into the whys of it and not to make anyone mad or hurt any feelings. Being at the world level of competition you certainly know what types of equipment work for you and are in a position to see what works for others and I appreciate your insight on this. I have learned what I sought out of this thread and more.
thanks again, Tom

Seeing as how I created the well nut mount in question I suppose I might as well jump in here.

I devised it to solve a problem - did it on my own time and have no financial interest. Hard mounting creates severe resonances with the airframe, beam dampener mounts break, commercial rear dampener mounts are heavy and Hyde mounts are pricey for some people, especially pilots trying to get started in Pattern or with cost concerns for other reasons.

The well nut mount will not help much with low frequency vibration. This is typically what you see when the engine is idling at the flight line and you can literally see the plane shaking. A Hyde mount is somewhat better in this regard because it has no limit for radial movement. However, in order to be stiff enough hold the engine in place the Hyde still transmits low frequency vibration to the airframe, though to a somewhat lesser amount than other engine mounts.

All soft mounts help with high frequency vibration to varying degrees. We did quite a few tests with many brands of engine mounts and all worked. We hard mounted several planes and EVERY SINGLE ONE had resonances in the airframe that you could actually hear. In some cases it was a little scary. The issue went away with any soft mount we tested including the well nut mount.

4 stroke engines backfire every once in a while and for these engines I would never use anything but a Hyde mount. As I mentioned, the Hyde allows radical radial movement and without that feature you can take the nose off a plane if the engine has a severe backfire. I've seen beam type dampeners break with a backfire - in fact, you can almost count on it.

The well nut mount reduces vibration to the airframe, costs next to nothing, is simple enough for anyone to make and IMO is the best solution other than a Hyde mount. But, Hyde makes the best engine mount there is. No one has devised a better mount. If you're a serious pattern flyer I recommending getting one. They last "forever" so though the initial cost is high you're amortizing it over several years. I'm particularly fond of the "A" type mount that doesn't need a nose ring. Nose rings are hard mounted to the plane so somewhat defeat the purpose of having a soft mount.

Lee Davis
[link=http://www.piedmontmodels.com]Piedmont Models[/link]

I've done all three methods, hard mount, Lee's mount and Hyde mount. And now that I think about it, All three have been successfull from a noise standpoint. My Jupiter with an OS1.40 on a bolly muffler, with a 4 blade and Lee's mount was almost inaudible in the air and I've been asked more than once if it was an electric. My $140 Hyde mount was ruined in a crash last summer (wind shear, and I'm sticking to that story). So this year, all my stuff has Lee's mount to keep the price under control. I get in three-four flights on a single charge (1100 ma battery pack) and I'm lucky to get 100 flights a year. What I'm trying to say is Troy is right in the respect that if you need a plane to last 3,000 flights, better spend the money to do it right. But it would take me ten years to get that number of flights so I am perfectly happy with Lee's mounts, Hayes clevises and rustoleum paint.

Not trying to start anything but today I checked my Smaragd with the peidmont mount, OS rx 17X12 apc with 1 8411 digital and the rest of the servos 8101's 1650 4 cell nimh battery, using the Hanger 9 Digital Servo & Receiver Current Meter my reading at full throttle was . 280 amp yes that's between the switch and receiver, if I'm not mistaken thats 280 ma, really I was surprised at this because of everything I have always been told, there was a slight jump at about 1/3 throttle seeing .41, idle was at .31, I have a Focus that I have been running on and off for 4 years with the same mount never had to change servo pots and linkages, I only run about 40 to 50 gallons of fuel a year thats between 350 and 450 flights a year all double or triples according to which pattern I'm flying. Like I said I'm not trying to start something and this setup might not be good enough for the top flyer's but does good for me I'm probably not good enough to tell the difference, I think that one of the problems with pattern drawing more people is the fact that they think they need the the top setup to be competive, it's just not true, yes when you get to the point that Troy and other top flyers are you do need everything you can get, but not for the average joe burning fuel is still your best way to get better.
Steve Maxwell

Steve,

Hmm, that sounds a little low to me, and you might want to double check the connections. I hooked up the current meter wrong once, and instead of measuring the total current, I was really measuring across just one servo.

My numbers for my DZ 140 and aluminum beam Hyde mount (ARA), JR digitals all around - 9411s in the wings, 9411s on each stab, 8411 rudder, 3421 throttle, is 1 amp draw at full throttle. This is in my Partner which I think is nearly an apple to apple comparison to Troy's Supreme because he uses the same mount. Troy if I am not mistaken, the major difference between our setup is that you use a DZ 160. The other difference is that you use just one servo on the elevator, whereas I use two.

David

Had it pluged into the switch and receiver, is that wrong?
Steve

No, that would be right. What I did was pull the aileron wire when I thought I pulled the switch wire. The measurement across one servo was right around what you are reporting, so that is why I mentioned it.

David

Like I said I was shocked as well, now the real test would be in the air with the data recorder because I beleive the setting on the wheels would even make a difference.
Steve