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Century Helicopter . MTA Hobbies . MRC/Altech Marketing USA

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Bergen R/C Helicopters > G10 lower and upper side frames
 
 
syon
Heliman
Location: tualatin,OR

Just wanted to ask the forum if anyone has made the side frames (upper and lower) out of different, more stiffer material such as Stainless steel, or Aluminum.
Also if the main gear/crown gear is offered in different material as well?
I suppose i could take the side frames down and have a set hydrojetted, same for the gear.

Just wanted to know what everyones thought on this is.
Has it been tried? what are the ramifications? and on what basis?.


Syon

a heli is like a marriage, most of the time it works, the rest it don't.
07-23-2007 06:18 PM
 
 
CT.Chopper
Senior Heliman
Location: Meriden, CT

Why would you want to make them stiffer?

I think G-10 is the best choice for a gas helicopter because it helps dampen some of the vibrations that the motor produces,

a harder material will only amplify the vibes.

as far as the crown gear goes bergen has a driven tail set-up that is machined out of black delrin and is super smooth.

Rob Landry.
07-23-2007 08:19 PM
 
 
syon
Heliman
Location: tualatin,OR

Vibration from stiffer material

The vibration, i can isolate or at least minimize it, the trick is mainly in the engine itself, granted the G10 has vibration absorptive properties, but it (over time) deteriorates with high frequency vibes as well as some "not so perfect" landings.
Also, as for the delrin gear, the issue on that is, everything is so reliant on the tranny alignment, as well as the mesh, albeit, you have limited amount of adjustments can make to "mesh" it correctly, but once the bird is in the air, vibration will, in effect, loosen the nylock nuts, and the risk of damage to the rest of the assembly is, at that point in time,increased, unless you want to change out lock nuts on a daily basis just to make sure its tight and secure.
my experience in this related to the mesh having to be so critical, that once it moves 1/16th, teeths are being chewed, and another order for a main gear is in place.
Maybe the tranny could be one piece with the main bearing block, and the only adjustment is on the maingear (vertical movement by adding shims or such) to ensure no lash is present.

just wondering out loud here. not here bashing, as i love the bergen heli, i just want more life out of the parts rather than 10 minute MTBF that i am experiencing.

a heli is like a marriage, most of the time it works, the rest it don't.
07-23-2007 08:34 PM
 
 
CT.Chopper
Senior Heliman
Location: Meriden, CT

Dude,
if you are loosening nylocks all the time
and vibrating your frames to dust then i would
start working on getting the vibes out of your motor.

or do as i did call Al @ B.H Hanson and get your self the 3-D Max

Rob Landry.
07-23-2007 08:57 PM
 
 
syon
Heliman
Location: tualatin,OR

3-d max referral

Engine is fine-

Looking for a more intelligent response, rather than a "referral" to another website that offers something that can already be done locally.

just looking for others experience and recommendation without referral to another website.
so, DUDE,-
Unless you know something that can be useful, please refrain from referring to other totally useless website.

regards...

a heli is like a marriage, most of the time it works, the rest it don't.
07-23-2007 09:06 PM
 
 
CT.Chopper
Senior Heliman
Location: Meriden, CT

oh. so sorry toughguy.

if your looking for an intelligent response ....

ask a intelligent question.,

and have a good time with your stainless sideframes

I was trying to give you a clue of what would be the best motor
for you.... thats all

they do the best job of modifying motors,
and if you are so good and you can have your motor "done" locally do it
blasting guys trying to help you is not going to help.

Rob Landry.
07-24-2007 12:39 AM
 
 
Autoeject
Key Veteran
Location: Ashtabula, OH, USA

Other heli's have used aluminum in their frames. Rather that the deterioration you mention, the aluminum will work-harden and fracture. Also, in one of those "not so nice" landings, the more rigid material will be better at transmitting the shock load to the rest of the heli.

Regarding the main gear, I'm not aware of Bergen offering any other material. Excepting for my improper setting during the occasional reassembly, I've not had a bit of trouble from my tranny assy. I've also not run into issues with the nylock nuts.

Perhaps there is a bit more tuning vibe than normal? With my G26, when I've got it tuned right I don't have the issues with loosening hardware. My indicator of vibes has always been in the landing gear mount screws.

Of course, just my thoughts

Mark Webber
webberaerialimaging.com
Spartan RC Distributor
AIR-NRGi Batteries
07-24-2007 01:07 AM
HOMEPAGE  
 
 
Chris Bergen
Key Veteran
Location: location

If you have locknuts coming loose and allowing things to move, you DO have high freq vibes.

All of the problems you described are related to vibrations. And related to high freq vibes that can emanate from the engine due to not being tuned properly (which includes gas/oil mix), dial indicating the fan onto the engine, bent shafts, tail blaeds out of balance, etc, etc....

The materials chosen in our helicopter were chosen for a reason, and NOT so they would have 10 minutes of MTBF.....

As stated, aluminum fractures due to vibes, bends in a "not so perfect" landing, necessitating new frames. Aluminum also being a conductor, can lead to difficulties with rf interference, as does carbon frames. G10, being fibreglass, does NOT lend itself to rf interference.

Stainless, well, tough to work with, and has the same difficulties as aluminum.....

HTH,

Chris Bergen
07-24-2007 02:46 AM
 
 
syon
Heliman
Location: tualatin,OR

Thanks for the input

Chris-

I have to say i respect your experience and opinion, and offer my thanks for the experience you have given.
I have ordered the canfield balancer, as well as went with new nylocks.

Is there anything i should be looking at?

the engine is solid, the landing gear is solid, the tail does not "talk" to me when spooling up, its only when it gets up in the air of 40' to 50' before anything manifests itself, its at that time, i bring it down, and see the crown gear is chewed, which is why i posed the question on here about other material, it was just a wondering out loud kind of thing.
But this is not something that is happening all the time with my bird, it just recently popped up out of nowhere.
I have to say, when it flies, it flies magnificently, especially during AP work that i do.

Being an engineer myself, i was wondering why there would be a slot on the tranny, and not on the lower main block as well, the 4 bolts tend to lock it in square once the cap screws are tightened down, and the main block, the same.
What was the idea behind this design? wouldn't a solid one piece design been more apt for the application? it would have eliminated the
"set the lash" factor that most have been experiencing, i think.

Just wondering here... it may be stupid redundant questions, but i have been known to ask worst kinds. Please don't take this as an inflammatory remark about the existing design, i love how it is set up,built, designed. just wondering is all...

Thanks for the input from you guys...

regards

a heli is like a marriage, most of the time it works, the rest it don't.
07-24-2007 03:13 PM
 
 
Gary Travis
Veteran
Location: Utah

Vibes

I have worked on numerous Bergens to date and in my opinion you are most likely dealing with engine tunning issues. Or you could have a mixture issue. The Zenoah engines have a sweet spot that you must get to with mixture and oil choice. I have seen aprox three eb's in the past wich had severe high freq. vibes such as you are describing, all turned out well after some engine tunning and set up.
Gary

Bergen R/C Helicopters Duralite Batteries V-blades Magnum Fuels Wren Turbinesl
07-24-2007 05:04 PM
HOMEPAGE  
 
 
syon
Heliman
Location: tualatin,OR

Suuuuhhh weeet !!

hehe... canfield balancer and the driven tail assembly arrived today.

Sans directions or any reference to look at, it was still an easy piece to put together, as far as the "lash" goes, lets say it was right on the money.

An hour later, in the air she went, against the 15 to 20 mph gust, steady as a rock.

there were no noticeable high freq. vibes, i did change out all the lock nuts, just to be on the safe side, 3 tanks later, they were all still on
Starting to see some end results of bug control.

I guess now i can start modding it, eh?
ya'll want some pics of this beaut?....

also- Gary / Chris- thanks for the info you've given on here.

regards

a heli is like a marriage, most of the time it works, the rest it don't.
07-25-2007 01:33 AM
 
 
rtrickyjr
Veteran
Location: Drumore, PA (SW of Quarryville)

I'd love to see some photos of it.

Thanks,


-Rick-
09-05-2007 01:04 AM
 
 
syon
Heliman
Location: tualatin,OR

hmm....contrary

Just so everyone knows...

I went all metal on the side frames, and currently working with a local
hi tech machine shop to make a 1 piece tail transmission gear setup, rather than a 2 piece, (which i see is a huge issue with setting the back lash), this machine shop is looking to make upgrades for me at a reduced cost, but with the hopes of being able to sell it online eventually.

While G10 fiber is a good material, i have to say, metal is more suitable for the application that this helicopter is made for, it gives more latitude to isolate the vibration, and also handle the torgue that is prevalent up on handling a load (camera gear, transmitter, batteries, etc), if and when the tail tranny is done , i will post a photo of it, and also start the paper work trail required by FAA in order to get a COA, this is the only way its going to be legal, someone has to start somewhere.
I just think all that work that goes into setting the lash is really unnecessary, and should be user friendly than it is.
(also having a box full of used/chewed main gear is enough for me to just look for solutions.)

So, as it stands, the heli is all metal, weighing in at 15 lbs dry, with all the necessary gear, battery, etc, the camera gear adds another 7 lbs, and gives me a total of 22 lbs, with plenty of power to spare when lifting, hovering and recovering (auto's).

I just fail to see why someone has not yet went all metal, other than myself, and also point fingers at the tail tranny setup issues.


Peace out,
Sy

a heli is like a marriage, most of the time it works, the rest it don't.
09-05-2007 05:59 PM
 
 
Chris Bergen
Key Veteran
Location: location

Aluminum HAS been used in the past, just as full size have used aluminum in their construction for years.

However, current composites has taken us beyond the "old technology", but hey if you believe that aluminum is better for YOUR application, man go for it.

The reasons for NOT using have been explained, maybe you will have better luck.

Even if the tranny itself is "fixed" in place, you may STILL have to set the backlash with the main gear. That may prove more difficult now that you have fixed the pinion gear in one place.

Your next main gear may or may not have the exact same rise, so you may need to add or (cough, cough) subtract shims, which is difficult to do if there are NO shims!!

We do have to allow for small variances or tolerances. If you want to buy 500 main gears with an exact tolerance of +- .000, ask your machinists friend how much that would cost.....

Chris Bergen
09-05-2007 08:30 PM
 
 
syon
Heliman
Location: tualatin,OR

different material for different application.

Not here to bash, but just giving insight to what is becoming a proven method on material use.

G10 and other composite, when they take a hit, or are stressed, may not manifest itself as " visible damage", such as stressed, fractures, and the likes.
where as metal has a life to it, depending on how its cut, tooled, etc
obvious damage is from anything that produces warpage, such as heat.
(laser cutting, band saw cutting, or even machined from stock).

If one performs regular "scheduled maintenance" on a helicopter, then the life span is increased, but this requires close observation to critical components.

critical components should not fail under normal usage, and definitely should not fail from workmanship, which really covers alot of ground.
then theres the material selection.
Material selection plays a huge part in helicopters, in all aspect of aviation, however, if the part looks good, it doesn't mean its going to perform, after all there is no specs on the part or assembly, something that is required by FAA on normal aircraft.
If manufacturers were to spend the time using quality, best practice designs for any given material, they would see their profits soar, not only because of good customer service, but because their parts, workmanship, and material are guaranteed.

My biggest stab in all this is (and everyone elses), the helicopter can not be a quality machine unless quality engineering, and quality materials are used.
Best practice in this day and age dictates that aspect.
If a customer is spending money on the same replacement part time and time again, then something is obviously wrong with the design.
If the problem is rare, then i would place the issue with the operator of that particular helicopter.
Seeing that there is a majority of issues with various helicopters on the RC market, my biggest concern is, how come no one is spending $$ on R&D, to ensure that their production model is going to perform for the average joe cameraman? The warranty is voided the minute you add something on such as a generator or any other accessory.
How can a warranty be guaranteed if the helicopter is not guaranteed to perform under different tasks?

the answer lies here:
Material

Engineering

Documentation

Part life span

Best Practice for maintenance

Classification of helicopter (capability of the product, and not the theoretical " this is what it can do, but you need this and this and this..."

This isn't isolated to just bergen helicopters, i see the problem across the board.
and my thinking is, if the owners buy these things, there should be an statement in the warranty stating that this is an unproven helicopter or airplane, routine part failures, design elements are theoretical at best, even tho it flies, but not for a very long time, unless you, the owner of the helicopter, make the needed re-design of various parts on the helicopter itself to improve the life span, and to attain the actual ability for the helicopter to fly without wondering if this or that is going to fail, and cause bodily and/or property damage, nevermind the damage to the helicopter due to a part failure.

I do think several re-design of various components are in dire need to improve the reliability and safety of this helicopter.

Now i am going to sit back, and watch all the hate emails fly at me over this flak...

a heli is like a marriage, most of the time it works, the rest it don't.
09-05-2007 08:56 PM
 
 
Chris Bergen
Key Veteran
Location: location

Ahhhhh. No hate e-mails!! If you get some, let me know immediately.

There is nothing wrong with trying things, all I'm trying to get across to you is the fact that Aluminum HAS been tried before and found deficient.

But don't take my word for it, make your own and go fly for a month, 6 months, a year, if they last that long. But Please let us know what pitfalls you run across during that time, don't keep it a secret.

PS. edit, If you want the perfect helicopter, I CAN build it for you, just give me your CC number.

Chris Bergen
09-05-2007 10:33 PM
 
 
HFr
Senior Heliman
Location: Lagrange ,in USA

I might add to the list a little that my son who is an aircraft engineer is always preaching to me and my attempts to better stuff that I build ... "airplanes and helicopters are not built to crash ,,,, they are built to fly and only on a +3% margin of material saftey area."

Good luck on the perfect metal side frame test ,,, no need to let us know about how it turns out as I have flown and crashed many alum. side frame birds and don't want any more
09-05-2007 10:52 PM
 
 
syon
Heliman
Location: tualatin,OR

hmm how much would a perfect one cost?
is it attainable?

currently, i am with 304 stainless steel upper and lower side frames, so far, its been holding up for over a month, aside from changing out the bearings on a routine basis, (every 30 hours of flight on the swash plate, 30 hours on the main triple bearing block, and the torque tube as well).

Just an interesting note to mention, i use a DX-7 radio setup, and have not had any lockouts, or signal loss, nor signal degradation beyond 2500', only thing is, the camera downlink barely is viewable from that distance.

i'll post the pics on here soon as i get the time to take the shots.

till then, fly high,

a heli is like a marriage, most of the time it works, the rest it don't.
09-05-2007 11:26 PM
 
 
Chris Bergen
Key Veteran
Location: location

I cannot speak for everyone in the Industry, but my experience tells me that most of the answers to your questions on "Why?" has to do with $$$.

How much would the Perfect Heli cost? A better question, given the recent bashing here, how much would a complete run of heli's, say 250 or 500 kits, cost?

EVERY single part perfect, 0 tolerance, in 500 kits, a full years worth of R&D, maybe Augusto knows.

I sincerely hope that after all this time he does it up right, otherwise the vultures out here will have a field day.....

Your stainless frames, how much were they? How much for 500, uhhh, make that 1000 pcs for 500 kits? Also, hope that an engineering change doesn't require you to make them all over again.......Now you also need spares, people do crash when they don't set up their Gyros correctly and overheat the servo, How many spares do you need to manufacture? What happens when you run out of spares, but still have kits? Do you make another 1000 pcs to keep the cost per pc down, or do you only make a few that cost more per pc??

When you guys get all of that figured out for ONE PART, multiply it by however many pieces are in a kit, then let the rest of us in on your genius. I don't have it all figured out yet, But I'm a relative newby to this business, Might ask Bob Gorham, or Kam Wyatt!

Chris Bergen
09-06-2007 02:47 AM
 
 
syon
Heliman
Location: tualatin,OR

upper and lower frame set = 40.00 waterjetted to .002" (these are done on 316, .090" sheets of 12"X 24", and in a stack of 4, in order to maintain the tolerance, and takes about 15 minutes to make the cuts, which gave me more than i needed, and the frames are scanned in digitally, then transferred to the waterjet cutter on the computer, so if one set is needed to be replaced, its already in a file format for G coding the waterjet cutter. one phone call, and 30 minutes later, the set is ready)

currently, we're investigating the cost on the tail tranny, should be somewhere in the neighborhood of 45 to 55.00, mind you this is only the housing, and does not include the shaft, bevel gear, brass spacer, etc.

so far, that is what we are narrowing it down to as far as parts failure, and weaknesses seen for the application that its used for, i wouldn't recommend it for 3D flight, as i am not all that proficient in thinking in 3D as far as flying (except on the simulator, if that counts).

a heli is like a marriage, most of the time it works, the rest it don't.
09-06-2007 02:58 AM
 
 
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Bergen R/C Helicopters > G10 lower and upper side frames
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