Cox Engines Forum
You are not logged in! Please login or register.

Logged in members see NO ADVERTISEMENTS!


TD020 Venturi Vibrates Loose from New CNC Carb Body Cox_ba12




TD020 Venturi Vibrates Loose from New CNC Carb Body Pixel

Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» Anderson Baby Spitfire - looking for the aft tank and gasket
by Boats13 Today at 9:18 pm

» Fuel residue stain clening help
by akjgardner Today at 8:53 pm

» my attempt at making an exhaust throttle for Cox .049
by roddie Today at 8:00 pm

» Another of C.T. engines cleaned ---- Cox Tee Dee .09 --- Just today (3/26/2024) more Cox parts
by sosam117 Today at 6:55 pm

» Cox powered boat litle shrimp hidroplane
by davidll1984 Today at 3:52 pm

» Introducing the new - "QZ" RR-1
by roddie Today at 2:08 pm

» STUKA bomb dimentions needed
by latole Today at 10:36 am

» Indexing COX cylinders
by davidll1984 Today at 8:56 am

» Introducing our Cox .049 TD Engines
by Yabby Today at 7:33 am

» 1/2a Skyray plans?
by 944_Jim Yesterday at 11:14 pm

» Postage stamp backplates
by JPvelo Yesterday at 9:52 pm

» Cosmic Winds, - Big Guy, Little Guys, Silver Guy and Wounded Guy.
by rsv1cox Yesterday at 6:18 pm

Cox Engine of The Month
March-2024
balogh's

"COX Budapest" .049 engine



PAST WINNERS
CEF Traveling Engine

Win This Engine!
Gallery


TD020 Venturi Vibrates Loose from New CNC Carb Body Empty
Live on Patrol


TD020 Venturi Vibrates Loose from New CNC Carb Body

Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  halfpilot Tue Sep 13, 2011 8:12 am

Hi all,

I bought my Tee Dee 020 a CNC Aluminium Carb Body to replace the red plastic item which had cracked around the screw thread. My thinking was that this shouldn't break in the same way as the plastic one, and I don't use the pressure system that can be made to work with the plastic carb body anyway so no difference to me in performance.

All was good until I had it running through a full tank and toward the end of the run the carb venturi and needle valve assemble vibrated loose from the new carb body. Luckily this was a bench run or I'd be combing my flying field for years looking for the missing parts.

I used to tighten the venturi into the plastic carburetor body using my fingers and my guess is that the plastic was a tight fit but malleable enough that I could tighten the venturi into it without it coming loose from vibration. With the aluminium CNC item the thread feels good and tight and obviously works but from this latest experience I'm guessing it's not good enough alone.

Two solutions have come to mind, make or find a tool that I can use to tighten the venturi into the carb body, or put a dot of non-permanent thread lock on the threads before putting the assembly back together. I feel that using a tool alone it would only be a matter of time before this happens again so has anyone got any reasons why I should not put a small dot of threadlock onto the threads? Speak now or forever hold your peace. I think that the biggest risk is overdoing it on the threadlock and having some get onto the rotating parts of the engine.

Thanks
halfpilot
halfpilot
Formerly known as:
ThermalSniffer

Formerly known as:ThermalSniffer

Posts : 96
Join date : 2011-09-06
Location : England

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  microflitedude Tue Sep 13, 2011 8:31 am

I would use threadlocker. Just a small bit, and see how it does after several runs.
microflitedude
microflitedude
Top Poster
Top Poster

Posts : 3417
Join date : 2011-08-17
Age : 26
Location : Columbia, SC

https://www.facebook.com/MiniCub?fref=ts

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  GermanBeez Tue Sep 13, 2011 8:38 am

this might be a little unorthodox, but you could use Lock-Tite to secure the Venturi. but first, disassemble it again, so nothing gets into the crank shaft. it would be best to stick a piece of cloth through the carb body, to absorb any excess
fluid. then put just a tiny drop onto the venturi thread.
another way-and i like this one better- is to use teflon tape. it is used to secure screws, and seal pipe threads.
you can get it at your local hardware store. simply wrap a layer of the tape (its very thin) around the venturi thread,
and screw it in. it's not surprising that aluminum has a more loose fit than the plastic one. plastic, to some degree,
is flexible, so usually threads are made a tad on the tight side. that way, there is more friction between the threads, and the venturi can't come loose that easy. i would use teflon tape, just because you can get it loose again.
and if you get any lock-tite into the carb body or even on the crank shaft, your engine is pretty much screwed.
Hope i could help you out!
(btw, teflon tape is much cheaper that lock-tite anyway!)
GermanBeez
GermanBeez
Platinum Member
Platinum Member

Posts : 1167
Join date : 2011-06-15
Location : Bavaria, Germany

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  GermanBeez Tue Sep 13, 2011 8:42 am

oh, one more thing:
i donÄt think it's a good idea to force it in there any further.
you might damage the thread or scratch the crank shaft if you're not careful.
if a metal thread doesn't go any further, than it's telling you to stop.
GermanBeez
GermanBeez
Platinum Member
Platinum Member

Posts : 1167
Join date : 2011-06-15
Location : Bavaria, Germany

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  halfpilot Tue Sep 13, 2011 11:20 am

Thanks for the suggestions, think I'm leaning to the GermanBeez way of doing this now. With a bit of teflon tape. Being teflon it's probably nitro resistant too. Teflon / PTFE is well known for being very unreactive.
halfpilot
halfpilot
Formerly known as:
ThermalSniffer

Formerly known as:ThermalSniffer

Posts : 96
Join date : 2011-09-06
Location : England

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  Admin Tue Sep 13, 2011 12:12 pm

Teflon tape, thread locker. Those would both work, when I had a issue similer to that on my TD 051 I used some of that instant engine gasket stuff out of a tube. Im on my phone so dont have the gasket stuff by me. It wont let it shake loose, it will give it a good seal and if you ever want it off, you could get it off with no real force.
Admin
Admin
Administrator

Posts : 6392
Join date : 2010-07-27
Location : Roseville, Minnesota

http://sites.google.com/site/coxenginecollection/

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  nitroairplane Tue Sep 13, 2011 12:18 pm

yeah,
i reccomend some teflon plumbers tape for it or a bit of red thread lock.
nitroairplane
nitroairplane
Top Poster
Top Poster

Posts : 6956
Join date : 2011-04-11
Location : London

http://modeldieselengines.forumstopic.com/

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  GermanBeez Tue Sep 13, 2011 2:20 pm

ThermalSniffer wrote:Thanks for the suggestions, think I'm leaning to the GermanBeez way of doing this now. With a bit of teflon tape. Being teflon it's probably nitro resistant too. Teflon / PTFE is well known for being very unreactive.
Glad i could help you!
i use teflon tape for all kinds of things round the house. it's really versatile. be sure to wipe any fuel or oil
from the threads before putting it on.
GermanBeez
GermanBeez
Platinum Member
Platinum Member

Posts : 1167
Join date : 2011-06-15
Location : Bavaria, Germany

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  Kim Tue Sep 13, 2011 2:52 pm

GermanBeez wrote:
ThermalSniffer wrote:Thanks for the suggestions, think I'm leaning to the GermanBeez way of doing this now. With a bit of teflon tape. Being teflon it's probably nitro resistant too. Teflon / PTFE is well known for being very unreactive.
Glad i could help you!
i use teflon tape for all kinds of things round the house. it's really versatile. be sure to wipe any fuel or oil
from the threads before putting it on.

Yeah...whichever way you secure it...REALLY clean it up with alcohol and get it good and dry before reassembly.
Kim
Kim
Top Poster
Top Poster

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 8509
Join date : 2011-09-06
Location : South East Missouri

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  jetpack Tue Sep 13, 2011 7:20 pm

I think the right washer would do it.

At first I thought of maybe a thin plastic one with some cushion to it, but then I thought maybe something more handy would be a glow plug washer made of brass (?) copper (?) They are 1/4-28 size, same as the Cox venturi.

You can get venturi's pretty tight by hand without a wrench if you use the needle body as you tighten. DON"T use the needle as a lever though, take it all the way out if you can't restrain yourself to using just the body itself to crank with. I cracked a TD plastic body like that once.

Some type of sealant wouldn't be a bad idea even though it is machined, if not a perfect match...its going to leak. Squareness of the threaded hole is a big concern and also the machine finishes that might be out there. Rough enough it could channel an air leak on top of it's error of the hole not being perfect square. Air can travel through threads quite easy sometimes.

Plastic seals better than metal to metal threads, I think - or at least how this assembly compresses when tightened. But, he advertises zero loss on pressure testing these.
jetpack
jetpack
Gold Member
Gold Member

Posts : 173
Join date : 2011-08-15
Age : 61
Location : Hobart, Indiana

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  halfpilot Thu Sep 15, 2011 4:17 pm

Since jetpack mentions that 'he', whoever that may be, advertises no pressure loss on these CNC carb bodies I thought it would be relevant to mention that mine comes from Mike Parkin who sells as ridenfligh on ebay. He actually said he only had a couple of 020 carburetor bodies left and it didn't seem like he wanted to make anymore. He said demand has dropped off now that the plastic part is available again. Personally I see the plastic part as a bit of an annoyance since it will inevitably break at some point. At least having the CNC part I'm alright if the plastic ones ever dissapear from the market again. Same for the fuel tank, there is a small PDF article I found some place explaining how to mod the Pee Wee tank for use on a Tee Dee. Not a difficult mod. Anyway, not sure who Mike has found selling the plastic ones but I'd take a guess at Mecoa.
halfpilot
halfpilot
Formerly known as:
ThermalSniffer

Formerly known as:ThermalSniffer

Posts : 96
Join date : 2011-09-06
Location : England

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  nitroairplane Thu Sep 15, 2011 4:27 pm

Yup mecoa are making and selling them.
http://www.mecoa.com/cox/index.htm
nitroairplane
nitroairplane
Top Poster
Top Poster

Posts : 6956
Join date : 2011-04-11
Location : London

http://modeldieselengines.forumstopic.com/

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  AT1984 Thu Sep 15, 2011 4:43 pm

Not trying to hijack the thread, but...

I have exchanged messages with Mike (ridenfligh), and he told me that he had some CNC bodies ready for the TD .09. I guess he's not selling those on eBay. Anyway, the Mecoa website has said "in process" for the plastic TD .09 bodies for a good long while...meaning they don't have them, yet.

The Tee Dee .09 fans can't catch a break! Smile

Allen
AT1984
AT1984
Gold Member
Gold Member

Posts : 146
Join date : 2011-08-16
Location : Spanaway, WA

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  jetpack Wed Sep 28, 2011 4:17 am

ThermalSniffer wrote:Since jetpack mentions that 'he', whoever that may be, advertises no pressure loss on these CNC carb bodies I thought it would be relevant to mention that mine comes from Mike Parkin who sells as ridenfligh on ebay. He actually said he only had a couple of 020 carburetor bodies left and it didn't seem like he wanted to make anymore. He said demand has dropped off now that the plastic part is available again. Personally I see the plastic part as a bit of an annoyance since it will inevitably break at some point. At least having the CNC part I'm alright if the plastic ones ever dissapear from the market again. Same for the fuel tank, there is a small PDF article I found some place explaining how to mod the Pee Wee tank for use on a Tee Dee. Not a difficult mod. Anyway, not sure who Mike has found selling the plastic ones but I'd take a guess at Mecoa.

I mention "he" in no ill respect in fact I have helped measure up some TeeDee cases that I have to get a statistical average and range on sizes. I had emailed him regarding an early run of them when he first started to offer them. I think they are an outstanding effort and something I wish I could have pulled off before "he" did! Hand Shake Mike put a couple aside for me unanodized so they could be left natural at the time he was anodizing all.

I had just recently ordered a few colored bodies to add to my boat hardware box for that effort and Mike had mentioned in an email there were .09's going to be for sale but not anodized. I am hoping to pick up one myself for an 09 RC. I think they are one of the coolest aftermarket items.

TD020 Venturi Vibrates Loose from New CNC Carb Body Dscf2019
jetpack
jetpack
Gold Member
Gold Member

Posts : 173
Join date : 2011-08-15
Age : 61
Location : Hobart, Indiana

Back to top Go down

TD020 Venturi Vibrates Loose from New CNC Carb Body Empty Re: TD020 Venturi Vibrates Loose from New CNC Carb Body

Post  Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum