Tarno 1/2 AR details

I do believe that is the same carb as the teedee carb, it looks to be from what I can see. they were said to be a good carb, I never managed to get my hands on one yet.

It appears they merely crafted a backplate carb/motor mount for the bee crankcase. look close at the pic taken from the rear, there is an adjustment screw that may be dificult to reach when mounted on the plane.
I also assume they provided for a reed retainer of some sort within the crankcase.

I was working on a similar design, thats on the workbench here somewhere lol

Sweet set-up you have there, can I ask where you got it?

http://www.mh-aerotools.de/airfoils/cox_3rdparty.htm

Scroll down. Maybe Martin would like a picture of the whole assembly, while your at it tell him to join the forum!

The carb is the same as the TD version. There is a reed adapter turned to fit the back of the crankcase. Here is an exploded view.

Is there a way to upload PDF documents here? I have created a PDF of the assembly drawing but am unable to upload it.

Jason

I have that feature disabled since it takes up a huge amount of space. I tell users to use this site: http://www.filesavr.com/ Upload it there and then post the link here!

@Jaspur_x wrote:

Sweet set-up you have there, can I ask where you got it?

I got it on RCG engine classifides last spring.

That's a nifty setup, never seen that before.

Doesn't look tooooooo hard to make. Maybe one could make one up using a tee tee carb?

I guess those backplates I have stashed in that box of projects to do, and that carb that just arrived today will be of handy use huh? lol

Engine looks cool. Somebody had some extra time to do this. Nice work to say the least.
Dan

@dankar04 wrote:Engine looks cool. Somebody had some extra time to do this. Nice work to say the least.
Dan

I day thats great work and wish i had the time and skill to get really good at stuff like this!

Nitroairplane, I agree, AND while I am at I want to do a peewee version just for giggles, even though I already have (throttled) teedee020`s lol

@Admin wrote:http://www.mh-aerotools.de/airfoils/cox_3rdparty.htm

Scroll down. Maybe Martin would like a picture of the whole assembly, while your at it tell him to join the forum!

I sent Matrin pictures, a PDF drawing and a link to this thread last week and havent heard anything yet. He probably gets hundreds of emails a week to sift through.

Jason

@Jason_WI wrote:

@Admin wrote:http://www.mh-aerotools.de/airfoils/cox_3rdparty.htm

Scroll down. Maybe Martin would like a picture of the whole assembly, while your at it tell him to join the forum!

I sent Matrin pictures, a PDF drawing and a link to this thread last week and havent heard anything yet. He probably gets hundreds of emails a week to sift through.

Jason

I contacted him a couple 2-3 times in the past year or so, never any answers back.

I have instructions for the AR. They carry enough dimensions to make a fold-out pattern I think

bump

The pictures of the carb in my first post are actually the incorrect carburetor for this version. The throttle stop screw is actually on the side of the carb for the AR version so it can be accessed through the small hole in the metal mount. The carb shown above is the regular TD version of the carb. What I bought on RC Groups many moons ago wasn't correct.

here's a TeeDee Tarno carb that just popped up.
https://www.ebay.com/itm/VINTAGE-TARNO-1-2A-COX-TEE-DEE-049-051-R-C-CARBURETOR-MODEL-AIRPLANE-ENGINE-NEW/352950577485?hash=item522d7e694d:g:8n4AAOSwoCFeL5nQ
Bob

@Jason_WI wrote:The pictures of the carb in my first post are actually the incorrect carburetor for this version. The throttle stop screw is actually on the side of the carb for the AR version so it can be accessed through the small hole in the metal mount. The carb shown above is the regular TD version of the carb. What I bought on RC Groups many moons ago wasn't correct.

Well, I bought two 1/2AR Tarno carbs new in the bag from Tower Hobbies back in the late 70's. Never ran them. Just purchased them for one day. Now looking at mine, it's the same as yours.



Why did they give a TD carb (throttle stop next to venturi) and then supply the reed adapter for the 1/2AR package? Was the hole in the mounting plate absolutely necessary for barrel adjustment with the TD carb on the 1/2AR package? Maybe not?

What is available on the auction site is a true 1/2AR carb with the barrel stop adjustment on the side of the carburetor.



Somewhat confusing yet more understandable with a picture.

Decided to look further in my engine box of forgotten memories.  Now I am beginning to wonder what type of quality control Tarno had with package assembly. Both were originally order as 1/2AR carburetors and received in the same shipment. Not ordered as a separate Tarno TD and a AR carb. Both carbs are exactly as I received them new. The AR carb has a pre-filed notch on the needle valve whereas the TD needle valve is missing the needle valve notch.  

I have a few and use them. The aluminum body is harder than that of the COX RC carb therefore it wont lose the throttle adjustment screw if the engine vibrates. I have lost a few screws from COX RC carbs where the softer aluminum thread in the carb body loosens and even a prestressed spring will not retain the screw from unscrewing.

The throttle arm is mounted on the barrel with just tightening the nut and is held down with a soft plastic washer. So  the servo can overrun the wide open or fully closed barrel positions without mechanical damage to the servo because the throttle arm turns on the shaft freely with some excess torque that you set by the extent of tightening the nut.
The bronze fuel nipple is a blessing versus the black plastic nipple on the COX, see my respective thread and the beautiful bronze replacement nipples made by Dave and Mauricio for the COX carb.(I will DIY one from a TeeDee 020 NV body when hit home later today).
Works well although the airbleed is fixed whereas you can play with that with a 2nd screw on the COX RC carb. I wish I had one for my TD09 that I saw on Brad's engine I guess. My 09 size is COX RC carb.

back in motorcycle days I got real tired of not being able to remove JIS steel screws from aluminum housings.....and carb screws that vibrated loose.....dissimilar metal corrosion

old fart mechanic at a NAPA parts counter.....
remember when we could sit, smoke and BS..
anyway old guy listening to my carping gets up and finds the package and hands me anti seize compound tube
45 years later I still have that tube........very very little is needed
tight fasteners will release when commanded by correct tool
loose fit low torque stuff will mostly stay put

there is a point in here I tink