COX engine throttles

What i do is... i copied the pic of the side piece's from the pdf. then opened it in paint, and saved it as a jpeg, then used the the page setup option when printing to minimize it, after getting it close, i cut the paper pattern and check to see if its a tight fit between, the top cooling fin and the lip on the cylinder, this can take a few attempts, i tried 25%,26%27% and settled on 28%, then print a bunch of copies at that size... sorry Jaspur a bit ... make it easier on the technologically challenged

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Ok Ok thats it, I must make plans to get some compter classes in the near future, you lost me by the time you" piant" ;sadly not joking but way funny isn`t it? @ me

1 word of caution though, copying a patented device could have problematic results.

My best results with throttles were similar to the throttles on the Norvel engines equipped on Lite Machines heli, an exhaust pressure plug basiclly but working that out goes into the engineering of porting on the engine,thats where the functionality hiccup lies.
Second best is using intake and exhaust throttles in tandem to keep the mixture even while throttling.

1/2a engines are always a treat to throttle,some work well and some are like the original norvel .061AME r/c engine = a funky bit of business.
Simply reducing rpm is manageably but an actual sweet idle can be tricky.
The COX medallion that has a exhaust and intake tandem throttle system is a good example as well as the norvel 074 which is said to be great(but I have yet to run any of mine to confirm)

A small number made from a patent is called research. It is when you mass produce for sale that the problems arise. Expired patents however are fair game by the nature of the system!

Phil

pkrankow wrote:A small number made from a patent is called research. It is when you mass produce for sale that the problems arise. Expired patents however are fair game by the nature of the system!

Phil

Ok,I`m not sure how all that legal mumbo jumbo works. Besides, a patent is just the oportunity for a legal monopoly right? lol

I made another attempt at a video, I uploaded it to my youtube channel but the sound goes all haywire. I`m assuming the webcam in my laptop got max`d out by the engines db because I was very disapointed to hear the sound all lousy like that.
I must find a way to move my laptop further from the engine and still be able to get a good view somehow

jared
place a piece of tape over the microphone on the webcam.
that will usually muffle the sound enough... without making it sound horrible

a.

Good stuff guys!

Ado, i really like your simple intake slide design.. nice and simple


Jaspur, im aware of the problems of copying a patent, however i will not be selling these, this is just for personal use, it will never be sold, if anything i will give it away for free.

Im anxious to see your video!

I looked at Dave Robelen's carb drawing or the 010, i believe the little gem carb offered in the early ninties was based on his design

However people who used them claim the idle was quite high, AndyW wrote in the rcu thread his MF throttle idled at 8k, which is pretty damn good.


I brought my engine with me on my trip... and most of the stuff for it...

I have a question for those that have experimented with throttle sleeves... do you find the needle settings become very erratic with the sleeve? mine will start on the first or second try without one, but with a sleeve, the needle settings are completely different, and the engine is extremely finicky and prone to flooding, again no problem without a sleeve.

My motor has a few hours on it, i bought it used, but its really clean with very good compression, the piston was reset last month.

Im thinking maybe trying grinding the shoulder of the needle valve as recommended by andyw on rcu...

Ordered another needle last night so will see if the problems improve.
I also bought a new piston on ebay just in case.

ado1974 wrote:arthur

here is a better copy of the pic in my profile.

i have just dug out the second version, and will attempt to fit it up tomorrow....
unfortunately the only 010 i have is currently mounted in my tether car... see thread in models section.

but it need to come out for a good clean before the car is finished anyway.



cheers
a

simpler than i thought it would be for the throttle, one question. What did you use to cut the slot for the strip of metal u used?

Ive been thinking of trying a simple 1 piece design... like a hose clamp... with U shaped ports, seen similar attempts here and on rcg.

mitchg95 wrote:

simpler than i thought it would be for the throttle, one question. What did you use to cut the slot for the strip of metal u used?

mitch

i have an old taig II lathe mill that i stole from my father... it is a bit rough, but with practice i can get ok accuracy.

the strip of metal is a piece of razor blade... the ones with the reinforcing along the back edge and slot in the middle.

will post more pics tomorrow if i get a chance
a.

Cox International wrote:A few years ago we sold him a quantity of 049 engines as he was planning to develop a throttle for them. After not hearing anything for a year, we had our own developped.

He seemed like a real nice guy on the phone and he had some good ideas.

I talked to Roger 2 or so years ago and made a deal with him as well in which he sold me a PET throttle with couple 010 cyclinders and 010 pistons and found him a very nice guy.

I tried the PET on a 010 this January and found it a beautifully engineered piece of throttle control tool. I doubt it can be replicated from materials different than the original brass plate as the operating principle of PET relies on the different thermal expansion of steel and brass.

I called Roger in his Tacoma home a few times but have not heard of him recently, though...Bought also his PET operating manual with many interesting 010 topics in it...a real COXbsessed guru of small engines..he refers in his book to many contemporary COX specialists as the "late and great XY"....www.micro-flite.com

I finished mine today

Specs.

005 brass for the two halves.
025 for the shoulder pieces.
1-72 brass hardware.

I spent alot of time studying the pics i found, and took measurements, im quite sure this is the way its supposed to be. looks the same as the pics, its very smooth yet appears to be tight. Im thinking the hardware might be 0-80... but when i tried it it did not look right, will build a second throttle with smaller hardware, i bought 100pcs of each.

Also i used a differently designed throttle arm on mine.

Cutting pieces out by hand took me two days, im quite sure Roger photo etched his. This would be the proper way, but i threw out all my etchant and mask after i did my last circuit board.

One of the shoulder pieces came out a little off, (as can be seen in the pics) i will make a new one tomorrow.

Overall im pleased with it, will see in the next few days when i get my 30% nitro fuel, how well this attempt works.

The last pic is of the old MF site.

Pic of Andyw's engine from RCU... http://images.rcuniverse.com/forum/upfiles/14555/Om32296.jpg





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balogh wrote:
He seemed like a real nice guy on the phone and he had some good ideas.


I talked to Roger 2 or so years ago and made a deal with him as well in which he sold me a PET throttle with couple 010 cyclinders and 010 pistons and found him a very nice guy.

I tried the PET on a 010 this January and found it a beautifully engineered piece of throttle control tool. I doubt it can be replicated from materials different than the original brass plate as the operating principle of PET relies on the different thermal expansion of steel and brass.

I called Roger in his Tacoma home a few times but have not heard of him recently, though...Bought also his PET operating manual with many interesting 010 topics in it...a real COXbsessed guru of small engines..he refers in his book to many contemporary COX specialists as the "late and great XY"....www.micro-flite.com

He never had any instock when i called, not even just the throttle itself, it was always... "we are waiting for parts, try again in a month"

I would have kept trying but then the site went ofline.. and i decided to google his name.. thats how i found out that he had passed, http://www.legacy.com/obituaries/tribnet/obituary.aspx?pid=159848969#fbLoggedOut

Quite unfortunate sure would have saved me alot of headache if i could have got one, i wasnt even involved with the rcu brouhaha, maybe he thought i was...?
R.I.P

mx



very nice work!

... now hurry up and test it


cheers
a

ado1974 wrote:jared
place a piece of tape over the microphone on the webcam.
that will usually muffle the sound enough... without making it sound horrible

a.

I will give that a shot, Thanks for the tip


I use the throttle sleeves in tandem with intake throttling any time I want to get a low reliable idle rpm,it should work great with the MF style design.
The hiscott/lite machines norvel heli exhaust plugging restriction is still the best I have found but is tough to make in the 010 size,I have only managed to achieve it at a "sweet" functioning level once so far but am currently giving it the stubborn old try until I get fully machined up to get it right every try,stay tuned viewers

ado1974 wrote:mx



very nice work!

... now hurry up and test it


cheers
a

Thanks, im awaiting for fuel, as the 20% stuff ive been using is suspect, im also waiting for a new NVA, i got a new needle but the engine doesnt like it (old needle is fine), so will switch the whole thing.

When the engine is restricted, it doesnt run too well, floods easy, wont achieve full rpm, and wont run without the glow driver attached, as i mentioned in a previous post it runs fine without restriction.

Who knows... im gonna replace the NVA and use 30% fuel.. and see how it goes..

I made a new shoulder piece today to replace the defective one, and spent most of the day tweaking the fit, been using castor oil for leak testing... and even though it appears airtight, its not, the fit has to be absolutely perfect, i must have assembled and disassembled it atleast 10 times today, what a chore

Ok good news!, i got my new NVA today and ran the engine on the old 20% nitro fuel, it throttles!, idle rpm is till too high.. but i know why! the shoulder pieces arent perfect and have to be remade there is slight leekage around the vents, and some flex that should not be there, will remake them.. four of the nuts will be ground down 0.25 to make a smaller opening...

It does work... im very pleased! best throttle attempt so far with room for improvement, was fun sitting there and revving it

My neighbours probably hate me... as im running it in my small apartment

I like it,now we want to see a video too , the guys always do this to me but seriously nice work

Jaspur_x wrote:I like it,now we want to see a video too , the guys always do this to me but seriously nice work

I really have to find a way to cut down the download timw, 2 minute video should not take "713 minutes remaining" after 2 hrs into downloading

YESSSS!!! IT WORKS!! It finally works! Video coming in the next few hours! stay tuned... hope nothing goes wrong

Anxiously awaiting the video..........

Uploading now, will take abit...

Ok... after two days of tweaking and adjusting, tweaking and adjusting, tweaking and adjusting, it finally works!!! The shoulders were remade, making sure everything is perfect, four of the nuts were ground down for a tighter exhaust gap, leak testing was done .. and more adjustments... And almost loosing my mind.

I had to drive to my parents house (they are out of town)... as it was simply too late to test it in my apartment, i already have 2 noise violations against me

Also a few pics of the parts, and the final version of the throttle.
In pic 2, its just tarnished on the bottom, its not bent. also i used my old throttle arm on this one, the final design will be quite different.

Idle rpm is quite low, but very touchy.. move it 1/2mm too far and it kill's the motor, will have to adjust for it on my dx7.
I wish i had a laser tach.. but i dont.

Now i have my eye's set on recreating Dave Robelen's 010 carb...

Here's the vid.. i will upload another.. running rich. http://vimeo.com/58516902


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mx862 wrote:Ok... after two days of tweaking and adjusting, tweaking and adjusting, tweaking and adjusting, it finally works!!! The shoulders were remade, making sure everything is perfect, four of the nuts were ground down for a tighter exhaust gap, leak testing was done .. and more adjustments... And almost loosing my mind.

I had to drive to my parents house (they are out of town)... as it was simply too late to test it in my apartment, i already have 2 noise violations against me

Also a few pics of the parts, and the final version of the throttle.
In pic 2, its just tarnished on the bottom, its not bent. also i used my old throttle arm on this one, the final design will be quite different.

Idle rpm is quite low, but very touchy.. move it 1/2mm too far and it kill's the motor, will have to adjust for it on my dx7.
I wish i had a laser tach.. but i dont.

Now i have my eye's set on recreating Dave Robelen's 010 carb...

Here's the vid.. i will upload another.. running rich. http://vimeo.com/58516902


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bravo! i love it

Here's the other vid.. https://vimeo.com/58519335 running rich, in this vid idle rpm is quite low! Have to adjust EPA and expo on the radio.. i will be using a 3.5gram servo for throttle in my plane, i have one with good resolution, nice and smooth, it will need fine tuning.. but once set, it should work very nicely, i can use the 3 point switch to change throttle curves and shut the engine off.