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Zenoah engines !!!

14K views 23 replies 3 participants last post by  Peterv 
#1 ·
Does anyone know where I can buy a 231 or 260 PUH engine?
I'm at a point with my helicopter build, that without the engine I cannot proceed further as its required for the modified installation process.
I have spent the entire week looking on the internet. I go to sites which advertise the product, only to find that they are unavailable:confused:

Modelflight and 436 Model shop are just two examples out of many looked up that respond with "don't know" when or if they are placing another order, or worse, due to low sales of the PUH version they won't even stock them anymore:bang:

So, anyone out there that can suggest a place to purchase the PUH?
Obviously it appears that Horrizon hobbies are the sole trader in the US at least, but what about locally? I have seen prices vary between AU$400 all the way up to AU$630.................:mad:

Perhaps a slightly used one could be another option.
Very frustrating.

Thanks.

Peter
 
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#2 · (Edited)
#3 ·
Advantage have 26's in stock .. http://www.advantagehobby.com/?cat=388&manufacturerid=303


But I'd email DDM , here's their 231/260 puh parts page ; they are great to deal with .... http://www.davesmotors.com/s.nl;jse...34Pa38Ta38Pa3z0?c=885035&sc=12&category=27903

And theres always Hansons .. http://www.bhhanson.com/Helicopter Engine Product Line.htm

And TRM ..... http://www.toxicmarine.com/html/helicopter_motors.html

Its really a waste of time trying to source Zenoah PUH's in AUS.....

Appreciate the links, and I agree with your comments re sourcing Zenoah [but not limited to!] items in AUS. Not surprising, as to some extent its a typical hobby shop culture that has remained essentially unchanged here for over 25 years.

ERGO, why after lots of frustration we go overseas for most of our requirements.....pitty.

Thanks and cheers.
 
#5 ·
That's great !! now we just hope he doesn't have to rely on the SA agents to get stock to him ;);)
 
#6 ·
He indicated to me he is ordering direct from Zenoa, as they list him as their distributor. I thought I mentioned this in my email.......never the less, the SA people you are refering appear not to be interested in getting Zenoah's.:confused:

Anyway, time will tell if this was the right decision. Hopefully I will have some positive updates in the next couple of weeks.:eek:
 
#7 ·
Zenoah PUH finally arrived

Hi people,

Received the engine about a week ago. Took a little longer than anticipated, but mostly due to a customs/declaration missunderstanding by the importer. These things happen I guess, and BTW the engine cost me $385.

So while waiting for the engine to arrive, I had lots of time to search the forums for as much information as possible. I can tell you there are some very bodgy installations and pictures that frankly horrified me, and best avoided.

I have settled on a configuration using using as much of the original nitro version engine parts in the kit as possible. Some parts had to be made using a lathe and mill. As the installation progresses, I will take pictures in the hope that this may assist others contemplating the same activity.

Still need to buy servo's to get in a flying state.....:mad:

That's it for now.
 
#8 ·
Back again

Only started to work on the machine about a month or so ago due to work committments etc. I have managed to make my own bottom plate and used the existing two engine mounts included in the kit for additional suport of the Zenoa.

I had to buy a new pinion and main gear from Gasser to match the Zenoa lower RPM. The parts arrived promptly but I was slightly dissapointed that he did not mention on his website that I would have to re-position the pinion bearing assembly on the mainframes. The bearing block needed to be moved forward about 4mm, which is not much but involved re-drilling and elongation the existing holes in the mainframes.

I will take some pictures and attach, but all the comments by people who have seen the new installation swear it looks factory.

Performed the first test last week to verify possible interference. With the Tx antenna all the way down, and about 30m from the machine with the engine operating [no blades attached] there was no apparent intereference or servo miss-behaviour even at various engine RPM.

I was very happy with the results, because the possibility of spark induced interference has been on the back of my mind since starting this project.

Next step is the innevitable one.....attach the main blades and go for it.

This weekend I will be in Moree at the Monster truck show and will be running our Daihatsu Jet car to entertain the crowds, so the following week will be lift off.....perhaps!

Cheers
 
#9 ·
sounds good..

I had a few generated noise probs initially , on 36Mhz; sorted them out , was mostly too wide a plug gap; but I've been on 2.4Ghz for a couple of years now with no hassles at all ...

you doing a rappy conversion ???
 
#10 ·
Are you using carbon main frames and a belt tail drive?

Make sure you ground/earth the motor correctly, even 2.4Ghz radios wont save you if they are getting sparked :)

good luck with teh liftoff....it can be scary but a very rewarding experience, especially when you have scratch built the heli!
 
#11 ·
Hi Steve & Peter,

Steve, Carbon main frames and torque tube tail drive, as per standard kit.

Peter, rappy conversion? do you mean did I purchase the full gasserman kit?

No, I fabricated everything myself, the bottom support plate, spacers and using a lathe modified the standard clutch assembly so as to fit the tapered zenoa shaft. The only thing I purchased from Gasserman was the pinion and main gear.

Some additional info:

Running a JR PCM9XII Tx synthesided on 36mHz, using Align digital servo's and power is thru a 7.4V 4000mAh lithium feeding a linear voltage regulator down to 5.1v @ 8A max. All servo leads and power leads into the receiver have small baluns attached with 2 or 3 turns on each one.

Perhaps the above setup has saved me from interference....who know's, but I'm not going to conduct a process of elimination trying to identify which component supressed interference noise the most although it would be nice to know!! BTW, I would put my money on the baluns :thumb:

The biggest issue I had was the alignment of the engine to the clutch bell assembly, getting it right took a while so time will tell if I did a good job or if the frames eventually cracks to pieces. :mad:

cheers.
 
#12 ·
I wish i had a workshop to do things like that !!!

Expereince indicates that the plug gap needs to be 20thou, any more just makes the ignition work too hard and will generate noise..

I've never "earthed" booms etc, never has the need ......


progress reports needed !!
 
#13 ·
Back after almost one year !

Yes I was ever surprised when I looked at the date I purchased the 700, followed by the Zenoa engine. Unfortunatelly, even though I completed the machine around December 2009, I was reluctant to fly it for a number of obscure reasons which I won't go into here:(

Also being involved in building and operating Jet cars + a full time job elswhere does make it rather difficult to get motivated flying RC helicopters.

Anyway, yesterday was the Trex 700 gasser inorgural flight. Mind you I did run her up strapped to the table and checked out for possible interference etc.

So did she fly :confused: Well to my surprise she did fly with basically only needing a notch of forward cyclic trim and same on the rudder. After building and flying these contraptions for over 20 years I couldn't believe that the Zenoa idled and ran without requiring any adjustments.

Now for the slightly down part.:( I noticed the fuel in the tank foaming quite a lot, but this seemed to have no effect whilst the tank was almost full. After about 3 mins, as the level dropped to 3/4, I observed the foaming getting worse and entering the the intake line.

It was rather interesting to note that regardless of the fuel intake position, the bubbles in the fuel tank somehow mannaged to get sucked into the intake with the result the heli would no longer want to even hover as it was running very lean.

Filling the tank up to full once again allowed for another great 3 min flight and the problem repeated itself.

In the afternoon, I got some air cleaner foam which is not affected by gasolene, and rolled it up and forced it into the fule tank. When inside it opened up and positioned itself nicely inside the tank. I made sure the pickup was under the foam thinking that the foaming would be retarded by the foam and not get to the intake.

Wrong! again it found its way to the intake.

BTW, she is perfectly balanced as this occurs even without the main blades attached.

How have you guys solved this fuel foaming issue, assuming you have one.:thumb:
 
#14 · (Edited)
fuel foaming is usually a engine/fan/clutch related vibe; given you've got a new motor and it's hopefully running a tad on the rich side , I'd say the vibes are from the motor.

What petrol/oil ratio are you using?

Is the carb butterfly approx 1/3 open at hover throttle position ??

What clunk are you using ? The zenoah felt one seems to be the best .

Don't know if you got a 231 or a 26 , but the 26 does vibe lots more than the 231...
 
#15 ·
fuel foaming is usually a engine/fan/clutch related vibe; given you've got a new motor and it's hopefully running a tad on the rich side , I'd say the vibes are from the motor.

What petrol/oil ratio are you using?

Is the carb butterfly approx 1/3 open at hover throttle position ??

What clunk are you using ? The zenoah felt one seems to be the best .

Don't know if you got a 231 or a 26 , but the 26 does vibe lots more than the 231...

Hi Peter, and thanks for responding.

To answer your questions:

1. Petrol is standard unleaded mixed with 25% synthetic.

2. Butterfly is open......:confused: All I know is that I have a linear throttle curve on my Tx, ie 0% idle and 100% fully open. At hover my throttle stick was 1/2 way so I presume the butterfly was also open about 50%. I can check this tonight as perhaps mechanically this may not be the case.

3. The clunk and intergrated filter is from a lawnmower shop.

4. Engine is the Zenoa G231.

I did check the clutch runnout at the time while the engine was out and measured about 1 thou, so I wouldn't think its the problem.

Head speed was varied between 1500 to 1650 rpm but same foaming issue.

Obviously from your comments you don't have this fuel foaming issue.......l:thumb:

Cheers.
 
#16 · (Edited)
No , no foaming in mine , the occasional "washing machine" swirling effect as the motor runs in is all ..

Hope you mean oil at 25:1 ( petrol;oil) ratio , NOT 25% oil !!! I run 32:1 ....
And mineral oil is lots better for the first few litres, synthetic won't allow the " bed in " to occur anywhere near as quickly...

633 carb ? needles around 1.25 - 1.5 turns out? slightly smokey exhaust ?


Butterfly at approx 1/3 open at hover stick position is important; gets the transition from slow to main jets happening properly ..
 
#17 ·
No , no foaming in mine , the occasional "washing machine" swirling effect as the motor runs in is all ..

Hope you mean oil at 25:1 ( petrol;oil) ratio , NOT 25% oil !!! I run 32:1 ....
And mineral oil is lots better for the first few litres, synthetic won't allow the " bed in " to occur anywhere near as quickly...

633 carb ? needles around 1.25 - 1.5 turns out? slightly smokey exhaust ?


Butterfly at approx 1/3 open at hover stick position is important; gets the transition from slow to main jets happening properly ..
Good pickup, with 25% oil I would not have any fuel foaming because the engine would not work .....LOL

I didn't think about the 'bedding in' process.
What brand mineral oil do you suggest?

I was looking at the heli this morning with my mind focused on the foaming issue and clearly forgot to check the butterfly position at hover, but will do.

BTW, the return fuel line from the carby bowl, I have mine simply going back into the top of the tank, and a second breather line again from the top of the tank just dangling about pointing down towards the ground.
I remember my Nitro setup days which usually ran muffler pressure so I assume the above setup is fine?

Seriously I cannot wait to fix this foaming issue and get back into flying again. Not having to carry a starter motor/battery, glow plug battery, cleaning oil & gunk everywhere etc makes the whole exercise so much more enjoyable.

Cheers
 
#18 ·
I've got Castrol TT mineral oil , and Valvoline 2 stroke racing oil that I use , seems to do the trick! Tried a few , more expensive oils , in times past , for no apparant improvement ...


Have you checked the fan assy for balance? checked the fan/clutch for runout ?


Fuel line setup is correct too !
 
#19 ·
I've got Castrol TT mineral oil , and Valvoline 2 stroke racing oil that I use , seems to do the trick! Tried a few , more expensive oils , in times past , for no apparant improvement ...


Have you checked the fan assy for balance? checked the fan/clutch for runout ?


Fuel line setup is correct too !

Well at least I got the fuel line setup right!

I'll get some castrol TT or Valvoline 2 oil today,and mix to 32:1 as you suggested.

Clutch runout? Well as I mentioned previously this was checked during engine install and looked about 1 or 2 thou out so should be OK.

I am a little reluctant to pull the engine out again but who knows, if nothing else fixes the problem I may well have to do so. I guess if I pull the engine out, may as well have it checked and internally balanced while at it.

Cheers.
 
#20 ·
Pretty sure you'll find it'll be lots better when you get the carb butterfly setup right , it'll need a retune; start with both needles at a tad under 1.5 turns open ..

my throttle "curves " are like 10 , 15, 25, 35 , 100 , in " normal ; 100 , 45 , 100 in idle up... that's for 3/4 stick hover position ..

don't use a governor until the motor is run in , usually about 5 litres!!


I like to get the runout at no more than 1 thou , 2 thou is too much !! ( I reckon anyway!!)
 
#21 ·
Pretty sure you'll find it'll be lots better when you get the carb butterfly setup right , it'll need a retune; start with both needles at a tad under 1.5 turns open ..

my throttle "curves " are like 10 , 15, 25, 35 , 100 , in " normal ; 100 , 45 , 100 in idle up... that's for 3/4 stick hover position ..

don't use a governor until the motor is run in , usually about 5 litres!!


I like to get the runout at no more than 1 thou , 2 thou is too much !! ( I reckon anyway!!)
Thanks for the info Peter.

I checked the butterfly and it appeared to be about 40% to 45% at hover, but more of an issue was that the throttle servo was not moving linearly and this was due to the end points incorrectly set, with one at 105% and the other at 65% !

I reset them both to 100% and now at least there is linear movement so got stuck into getting the 30% at hover opening with throttle linkage length and little if any end point changes.

Finally, the only way I could do this is by changing the throttle curve accordingly so now at mid stick the butterfly is about 30% open.

Haven't run the heli yet so don't know if this will fix the problem.

Slowly slowly I guess !!
 
#22 ·
Finally in the air after almost 1 year !

As suggested by Peter, I got the butterfly open at around 30% hover, re tuned her a bit and the foaming was not as bad and managed a 20 min flight.

Flew ok, with reasonable power, not like a nitro but I knew that already and for scale flying is perfect. Did notice a slight porpoising of the nose, ie nose /tail going up down at the odd moment. Not too sure what could be causing it but then........................:eek:

Lucky the sun was getting in my eyes which prevented any high altitude flights because as she came past me at about 6ft off the ground and while pulling slight back cyclic to slow her down, suddenly engine died. To make matters worst on the way down she turned clockwise around facing me but somehow managed to land square on the skids:thumb:


Waited for the rotor to slow down, and then the post mortem.

No servo throttle movement and no tail servo movement a double wammy.

The throttle problem was easily identified as the servo plug had come out of the receiver about 3 mm. Not obvious until I pushed it back into the receiver and presto, throttle control. What amazed me is that the throttle spring on the butterfly had enough pull to shut it completely even with the 'dead' servo attached. I guess this would be preferable than the throttle staying open right!

Now the tail problem. It ended up being the servo, a Align DS620 which just simply stopped working at the same time the engine quit.....how weird. I opened the servo and instantly the burnt smell was obvious. I assumed the motor has burned out as the components looked fine after inspecting using a powerfull eyeglass.

I must admitt I did notice when the helicopter was on the ground idling/running up that the tail servo was vibrating about 4 mm left/right and I think this was caused my mounting the gyro on soft rubber foam. The foam most probably amplifying the engine vibrations causing the tail servo motor to be working overtime and burning out.

I guess in the end the heli did not crash which is a good thing:). I will remove the foam and mount the gyro a little more rigidly, followed by getting another servo real soon. As I don't have the need for super 3D fast tail response, perhaps a simpler non digital servo may be a better choice.


Cheers.
 
#23 ·
Hate it when servos die; had a couple of throttle servos do that .. Now running el cheapo hitec 422's on throttle, last much better than digitals there ..

But I'd stick with a decent digi servo on the tail, I really hate a lazy tail these days . Back in " the good old days " , 30+ yrs ago when I first decided that R/C helis were a good way to keep the bank balance low, there weren't even gyros , let alone good servos! I'm spoilt now...

Had a funny with one of my Zenoahs yesterday .. It's had a bit of a rattle for a while , but power was still good, so I kept flying it .. it wouldn't start after its first flight yesterday , spark was good , plug was wet , had a couple of us thinking hard !! Found today after removing it from the Spectra G , and removing the fan etc , that the top bearing is loose in the case . There's two bearings at that end of the crankshaft , the lower one is open , top one is sealed to maintain c/case pressure; and thats what it wasn't doing ,... Seems the rattle was the bearing bouncing against the metal fan !! I'm tempted to leave the bearing out and fit a full seal in its place ; think the marine motors have that ...

Theres always something more to learm with these things !!
 
#24 ·
Ye helicopters are real fun arn't the? Sometimes I ask myself how much actual flying time I have had the past 20 years versus repair time!

Don't do the comparison, it sucks.

Anyway, and BTW, it was only the rudder servo that burnt out. The throttle servo was fine, it was the servo plug falling out of the receiver that stopped it from working.

As far as the new slightly lazy [analog] tail servo I have fitted, for my part I'm not that concerned. Flew fine with much slower servos on the tail going back 25 years ago, and given the scale like flying I do they are just fine.

Reliability is my main concern, as is with all the other flyers out there. If I could buy 100% guaranteed ultra reliable servo's, [no such luck] frankly even if they only moved at a snails pace they would be preferable to the ultra/fast units with unknown service life :thumb:...............

Haven't had a chance to run the heli after replacing the tail servo as we have been very busy doing some jet car shows up in Brisbane lately.

Hopefully soon.

cheers
 
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