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

Logged in members see NO ADVERTISEMENTS!


Fine Thread Needle Conversion Cox_ba12




Fine Thread Needle Conversion Pixel

Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» Vintage Vornado fan project
by Admin Today at 3:51 am

» Cox PT-19 Wing
by getback Yesterday at 11:57 am

» So to the rescue of an EZ BEE .049 r/c
by MauricioB Yesterday at 10:12 am

» My Cox .049 Marine inboard engine
by F4D Phantom II Wed Jul 17, 2024 7:03 pm

» Sturdi Built?
by rdw777 Wed Jul 17, 2024 12:22 pm

» Jim Walker "Firebrand"...It Flys !!!!!
by 944_Jim Tue Jul 16, 2024 8:45 pm

» The "Funky Bee"
by rsv1cox Tue Jul 16, 2024 9:39 am

» 1975 BMW R90S
by Yabby Tue Jul 16, 2024 6:40 am

» Roddie-Rigger.. a 2005 original design
by roddie Tue Jul 16, 2024 12:28 am

» Cox Super Cub 150 firewall/engine mount
by crankbndr Mon Jul 15, 2024 9:42 am

» TIEBREAKER-POLL **COX-ENGINE-OF-THE-MONTH** (July 2024)
by getback Mon Jul 15, 2024 4:14 am

» Jim Walker Bonanza etc.
by rsv1cox Sun Jul 14, 2024 7:43 pm

Cox Engine of The Month
July-2024
robot797's

"ULTIMITE COX 010: it has a clutch, E starter, throttle, exhaust, aluminum tank, aluminum venturi, gearbox with forward and reverse, and now its on a custom drawn and printed stand"



PAST WINNERS
CEF Traveling Engine

Win This Engine!
Gallery


Fine Thread Needle Conversion Empty
Live on Patrol


Fine Thread Needle Conversion

Page 1 of 2 1, 2  Next

Go down

Fine Thread Needle Conversion Empty Fine Thread Needle Conversion

Post  coxaddict Mon Mar 15, 2021 10:27 pm

Decided to try my hand at converting TD needle valve bodies to fine thread assemblies using postage stamp parts.  
Fine Thread Needle Conversion P3140111
Used a No. 25 (.149") drill bit to enlarge hole.
Fine Thread Needle Conversion P3140112Fine Thread Needle Conversion P3140110


Last edited by coxaddict on Tue Mar 16, 2021 3:40 pm; edited 1 time in total
coxaddict
coxaddict
Gold Member
Gold Member

Posts : 429
Join date : 2013-01-27
Location : north shore oahu, Hawaii

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  coxaddict Mon Mar 15, 2021 10:38 pm

Fine Thread Needle Conversion P3150113
Turned down a piece of K&S 3/16" thick walled aluminum tubing to fit
Fine Thread Needle Conversion P3150118
Pressed into body using a small vice
Fine Thread Needle Conversion P3150117
Drilled hole through new piece using a No. 60 (.040") bit


Last edited by coxaddict on Tue Mar 16, 2021 3:49 pm; edited 1 time in total
coxaddict
coxaddict
Gold Member
Gold Member

Posts : 429
Join date : 2013-01-27
Location : north shore oahu, Hawaii

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  coxaddict Mon Mar 15, 2021 10:40 pm

Fine Thread Needle Conversion P3150119
coxaddict
coxaddict
Gold Member
Gold Member

Posts : 429
Join date : 2013-01-27
Location : north shore oahu, Hawaii

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  OVERLORD Tue Mar 16, 2021 2:33 am

Well done, that looks like the method discribed in RCM in 1977?

https://www.coxengineforum.com/t11875-fine-thread-nv-assembly-for-a-td?highlight=fine+thread
OVERLORD
OVERLORD
Diamond Member
Diamond Member

Posts : 1799
Join date : 2013-03-19
Age : 58
Location : Normandy, France

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  davidll1984 Tue Mar 16, 2021 4:00 am

I have plastiques neadle body no insert for the neadle ??never use this piece I wonder what model of neadle can be used with it look smaler than .049 nva do y nead insert ? Just the neadle? Y wil try To Find it and get picturs
davidll1984
davidll1984
Diamond Member
Diamond Member

Posts : 2302
Join date : 2020-02-12
Age : 39
Location : shawinigan

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  coxaddict Tue Mar 16, 2021 4:37 am

Thanks for the comments. I actually machined an aluminum tube and press fit the spray bar into it, aligning the fuel hole in the valve body. The fine thread spray bar has a shoulder on the nipple end that would prevent the holes from aligning, so I took some material off the valve body. You could also file the shoulder off the spray bar. No epoxy was used as all parts are held by a press fit.
coxaddict
coxaddict
Gold Member
Gold Member

Posts : 429
Join date : 2013-01-27
Location : north shore oahu, Hawaii

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  getback Tue Mar 16, 2021 6:02 am

Good job on the conversion , was hoping you would tell us a little more about how you did it with great pictures . St.Pats Beers
getback
getback
Top Poster
Top Poster

2022 Supporter

2023 Supporter

Posts : 10267
Join date : 2013-01-18
Age : 66
Location : julian , NC

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  davidll1984 Tue Mar 16, 2021 7:10 am

I like the way you use to change the part once the insert is removed It is possible to anodize it to color it by the following look like Good upgrade i was tinking how To color wit that métal insert in To place i  think I can do it, but where can I find the part? Other than on the postal back plate ? I have a plastic one i want To complète i nead the nva inserts wit the plastiques seal ? Fine Thread Needle Conversion 16158910
The way i thought i should complete i didn't think i should change the neadle as wel Now that I know a little more I'm looking for the right pieces To complète the parts for the plastiques one Is it possible to use the same part on both?
davidll1984
davidll1984
Diamond Member
Diamond Member

Posts : 2302
Join date : 2020-02-12
Age : 39
Location : shawinigan

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  coxaddict Tue Mar 16, 2021 3:01 pm

The hardest part of the conversion is finding the fine thread (128 tpi)  needle and spray bar. The pictures show the different types that I  found off of engines from early RTF models.  Some postage back plates had 80 tpi needles.  I can usually tell the difference by the step machined on the needle tip  With the needle screwed into the spray bar press the parts out towards the fuel nipple side as it has a tiny shoulder on that end.
 
Fine Thread Needle Conversion P3150125
Fine Thread Needle Conversion Dscf1011
coxaddict
coxaddict
Gold Member
Gold Member

Posts : 429
Join date : 2013-01-27
Location : north shore oahu, Hawaii

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  coxaddict Tue Mar 16, 2021 3:11 pm

I made a puller of sorts from some tubing, washers and bent broken needle valves.  I cut off the needle portion and ground a groove and a slight taper on one to clean the threads of the insert. It makes pulling the insert out easier.
Fine Thread Needle Conversion P3150131
Fine Thread Needle Conversion P3150129
Fine Thread Needle Conversion P3150130
coxaddict
coxaddict
Gold Member
Gold Member

Posts : 429
Join date : 2013-01-27
Location : north shore oahu, Hawaii

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  dckrsn Tue Mar 16, 2021 3:42 pm

OVERLORD wrote:Well done, that looks like the method discribed in RCM in 1977?

https://www.coxengineforum.com/t11875-fine-thread-nv-assembly-for-a-td?highlight=fine+thread
I converted one using the RCM method., using
K&S 5/32" od tubing. Surprisingly easy.
Bob
dckrsn
dckrsn
Diamond Member
Diamond Member

Posts : 2750
Join date : 2010-10-21
Age : 71
Location : Long Island, New York

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  coxaddict Tue Mar 16, 2021 4:06 pm

Yes the RCM method works.
coxaddict
coxaddict
Gold Member
Gold Member

Posts : 429
Join date : 2013-01-27
Location : north shore oahu, Hawaii

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  NEW222 Tue Mar 16, 2021 4:32 pm

A great job done and some fine workmanship. Thanks for sharing your adventures of a needle valve!
NEW222
NEW222
Top Poster
Top Poster

Posts : 3895
Join date : 2011-08-13
Age : 45
Location : oakbank, mb

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  davidll1984 Tue Mar 16, 2021 4:33 pm

Huh... tink i wil save my old nva and i will take an aluminum bar to form a half circle over its entire length then cut the pieces to make my new parts for anodisation wit new color I think I'll save some time maybe mony To like the post This is very inspiring Thumbs Up
davidll1984
davidll1984
Diamond Member
Diamond Member

Posts : 2302
Join date : 2020-02-12
Age : 39
Location : shawinigan

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  coxaddict Tue Mar 16, 2021 5:01 pm

I have been experimenting with improving the fuel metering 80 tpi needle. I will be testing my mods soon. If anyone has any experience with any mods that work or not please comment.
coxaddict
coxaddict
Gold Member
Gold Member

Posts : 429
Join date : 2013-01-27
Location : north shore oahu, Hawaii

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  dckrsn Tue Mar 16, 2021 7:20 pm

dckrsn wrote:
OVERLORD wrote:Well done, that looks like the method discribed in RCM in 1977?

https://www.coxengineforum.com/t11875-fine-thread-nv-assembly-for-a-td?highlight=fine+thread
I converted one using the RCM method., using
K&S 5/32" od tubing. Surprisingly easy.
Bob
PS, CoxAddict, I didn't mean to poo-poo your technique. I was
commenting as one with minimum tools. You way is much more
refined. The RCM way is just functional. i like your technique better. Thumbs Up
Bob
dckrsn
dckrsn
Diamond Member
Diamond Member

Posts : 2750
Join date : 2010-10-21
Age : 71
Location : Long Island, New York

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  coxaddict Tue Mar 16, 2021 8:02 pm

I appreciate everyone's input.  We can learn by sharing. I Love This Forum!   What's wonderful about Cox engines is that you don't have to spend a lot of money on them to have fun. Very Happy   Nowadays most of my fixed income goes to paying medical bills.  Old Bugger    I try to find ways to get the most from my hobby dollars Flying
coxaddict
coxaddict
Gold Member
Gold Member

Posts : 429
Join date : 2013-01-27
Location : north shore oahu, Hawaii

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  bakergw Wed Mar 17, 2021 4:09 am

Hi All,

I have tried and tested a very rough method of setting up a needle valve on a TD 049 given the difficulty getting NVB for them. i basically drilled the venturi through the side right through. Press fitted a standard 049 spray bar. Blocked off the 3 holes in the venturi, screwed it into the venturi body and used a normal surestart needle. My TD still screems and its a really easy and cheap way to keep a TD(d) running with the shortage of NVBs for them. The same would work with any spray bar you have. the position of the spray bar in the venturi is something I still sorting out, but it definately works really well. Just need to do more testing of moving the spraybar within the venturi and probably grinding down the OD of the spray bar to get more air flow. Or of course I can use my dremel to open up the venturi. Works really nicely and is simple. Would work with any spraybar and needle.

Cheers,
Gary
avatar
bakergw
Account Deactivated by Owner

Posts : 76
Join date : 2020-09-20

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  OVERLORD Wed Mar 17, 2021 10:03 am

bakergw wrote:Hi All,

I have tried and tested a very rough method of setting up a needle valve on a TD 049 given the difficulty getting NVB for them. i basically drilled the venturi through the side right through. Press fitted a standard 049 spray bar. Blocked off the 3 holes in the venturi, screwed it into the venturi body and used a normal surestart needle. My TD still screems and its a really easy and cheap way to keep a TD(d) running with the shortage of NVBs for them. The same would work with any spray bar you have. the position of the spray bar in the venturi is something I still sorting out, but it definately works really well. Just need to do more testing of moving the spraybar within the venturi and probably grinding down the OD of the spray bar to get more air flow. Or of course I can use my dremel to open up the venturi. Works really nicely and is simple. Would work with any spraybar and needle.

Cheers,
Gary

That becomes a medallion lookalike then. If your TD still screams indicates that the venturi setup doesn't matter and that the crankshaft makes the difference between the TD and the Medallion, not?
OVERLORD
OVERLORD
Diamond Member
Diamond Member

Posts : 1799
Join date : 2013-03-19
Age : 58
Location : Normandy, France

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  bakergw Wed Mar 17, 2021 2:30 pm

Hi Overlord,

yes it does have a medallion sort of look. Does that mean the only difference between the TD with my carby setup and the medallion is the crank. Possibly. I have about eight 049 TDs and I like trying out different things to see what happens. I dont have great equipment, just me and my dremel so I try things out within my constraints. I would expect the medallion crank and the TD cranks to make a difference with their different timing. The spray bar as I have done will change the Venturi intake capability, air velocity, even the misting of the fuel etc. It well may be a really bad idea, but for me, it works, and has solved my problem, nicely, easily, simply and cheaply and I still have the performance that I seek. i definitely would like to use a finer NV in it though as they helping tuning quite a bit in my view.

Cheers,
Gary
avatar
bakergw
Account Deactivated by Owner

Posts : 76
Join date : 2020-09-20

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  batjac Wed Mar 17, 2021 10:12 pm

A few months ago I decided to do  my own fine thread needle conversion, seen (here)

The Backwards Mark
batjac
batjac
Diamond Member
Diamond Member

2022 Supporter

2023 Supporter

Posts : 2356
Join date : 2013-05-22
Age : 61
Location : Broken Arrow, OK, USA

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  aspeed Fri Mar 19, 2021 9:39 am

I suppose those postage stamp 128 TPI needles are unobtanium now like the Kirnkraft ones. I don't see why the 80 TPI needles can't work. The old Supertiger/Rossi needles with the split lock would work well as there was no slop. One 20th of a turn was exactly that. Anyway, just thought I would add another old picture of an even older remote needle sleeve I used on a speed plane about 45 years ago. It worked well in a tight cowl with the KK remote needle. It might save butchering an old hard to get needle assembly although I suppose it is a good improvement. I have also soldered up the steel hole for the needle to use a remote needle. That was more of a butcher job. Fine Thread Needle Conversion Td_rem10
aspeed
aspeed
Platinum Member
Platinum Member

Posts : 790
Join date : 2013-01-18
Location : Leamington Ont. Can.

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  coxaddict Fri Mar 19, 2021 8:22 pm

I have all these at my disposal but wanted to try something else.  Using a remote needle is something I'd like to explore.
Fine Thread Needle Conversion P3190110
coxaddict
coxaddict
Gold Member
Gold Member

Posts : 429
Join date : 2013-01-27
Location : north shore oahu, Hawaii

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  batjac Fri Mar 19, 2021 9:15 pm

aspeed wrote:I don't see why the 80 TPI needles can't work.

They can work for hard tanks or balloon tanks.  But for bladders they are too coarse.  With a fine needle valve on bladder, you have adjustability.  I did bladder on an 80TPI needle once, and it was less than a 1/4 of a turn from too rich to run, to too lean to run.  You've gotta be quick and precise using a coarse needle on start, and tweaking it in to the sweet spot is almost impossible.  

The Rough Mark
batjac
batjac
Diamond Member
Diamond Member

2022 Supporter

2023 Supporter

Posts : 2356
Join date : 2013-05-22
Age : 61
Location : Broken Arrow, OK, USA

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  davidll1984 Fri Mar 19, 2021 9:44 pm

Sorry stupid question someone knows where to find the valves For these blue cap?? Y want To build m'y own modified parts I can easily reproduce the pieces if can find the components
davidll1984
davidll1984
Diamond Member
Diamond Member

Posts : 2302
Join date : 2020-02-12
Age : 39
Location : shawinigan

Back to top Go down

Fine Thread Needle Conversion Empty Re: Fine Thread Needle Conversion

Post  Sponsored content


Sponsored content


Back to top Go down

Page 1 of 2 1, 2  Next

Back to top

- Similar topics

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