Question about my TeeDee 09

What size Shoestring are you using? I didn't know there were plans for a Junior size SS. But a Tee Dee .09 is supposedly great for that application, and I have heard it will do the job as well as most older .15 engines. I still have an .09 that I have never used. I want to get a Jr plane soon.
Rusty

Bandit,

You may be better served by running a bladder, problem is finding a NV that will work. I assume you are talking about the SIG shoestring. If so, being a speed plane with careful tank placement and tank plumbing you may get it to pull fuel well enough on it's own.

Ron

I'm with Ron on the bladder vs. the crankcase pressure, but I'm prejudiced because that's the only type pressure I've ever used. You can buy a fine thread NV and spraybar from Texastimers.com and make a remote NV out of it. Use a wheel collar to house it with an outlet tube soldered into the setscrew hole and solder a mounting plate on the side.

Ken Cook recently mentioned an OS needle that works under high pressure as a remote for one of my bigger engines, but I have searched all over and can not find that thread. Maybe an OS 2 NV? But I'm not sure. I think it's part of an OS carburetor. I don't know if he reads this thread but if you're interested I'll ask him again.
Rusty

Cribbs74 wrote:Bandit,

You may be better served by running a bladder, problem is finding a NV that will work. I assume you are talking about the SIG shoestring. If so, being a speed plane with careful tank placement and tank plumbing you may get it to pull fuel well enough on it's own.

Ron

You are correct, I'm planning on building the Sig SS I've had one before and liked it so might as well build another my last one had that Rossi R15 on it. That's the reason I'm going with the tap in the back-plate "Hard to find a fine thread NV. I want to mod the engine as little as possible and the back plate is easier to get if I mess up. The pressure works just as well as long as you put a check valve inline with the pressure line. I would like to try a bladder if I can find a NV. (Bandit)

RknRusty wrote:I'm with Ron on the bladder vs. the crankcase pressure, but I'm prejudiced because that's the only type pressure I've ever used. You can buy a fine thread NV and spraybar from Texastimers.com and make a remote NV out of it. Use a wheel collar to house it with an outlet tube soldered into the setscrew hole and solder a mounting plate on the side.

Ken Cook recently mentioned an OS needle that works under high pressure as a remote for one of my bigger engines, but I have searched all over and can not find that thread. Maybe an OS 2 NV? But I'm not sure. I think it's part of an OS carburetor. I don't know if he reads this thread but if you're interested I'll ask him again.
Rusty

I might try that and yeah if he knows the thread type I would love to know thanks! (Bandit)

Just to clarify, when I said I couldn't find the "Thread," I meant the forum conversation, like this one which is referred to as a thread. But yeah, I can'r find the thread in which we talked about that particular NV.

The threads of a Cox or Texaxtimers.com NV are 128 threads per inch(tpi), so any NV with a high thread count like that will work. But I will ask Ken to remind me the part number for that OS part which might be easier to install without having to solder things together.

In the mean time, here are some links that might be helpful:

Main page:
www.texastimers.com

The valve I reccommend:
http://texastimers.com/accessories/retrofit_needle_valve.htm

The order form
http://texastimers.com/accessories/needle_valves.htm

One way to use it.
http://texastimers.com/accessories/remote_needle_valve.htm

All about bladders:
http://texastimers.com/accessories/pressure_bladders.htm

Here's one we use for a Tee Dee .049
http://texastimers.com/accessories/precision_%20nva_for_td.htm

My how-to videos:
https://www.coxengineforum.com/t3317-pressure-bladder-how-to-videos-parts-one-and-two

They also sell the bladder tubing and all the bits and pieces. Look down the left column and click links on various pages, the site is not well organized but there is a lot of good how-to info. You just have to pick through and explore. The guy's name is Hank Nystrom and he's an avid freeflight enthusiast.
Rusty

In another thread it was mentioned that an old way of making combat planes fly on bladder properly was to use a few inches of refrigeration capillary tubing to restrict the fuel flow prior to the needle, then use the regular needle.

Capillary tubing is pretty easy to get, just stuck buying a 20ft roll of it (that is a typical amount used in a cooling system)

Phil

A well designed tank would work better in this application. I certainly would give a rectangular tank  re plumbed for uniflow a go. If uniflow can be made to work properly it will yield the most reliable and replicable runs over and over. I personally wouldn't use crank pressure if I didn't have to. There's just too many problems that occur when using it. I never had the need to use a one way valve in my crank case pressurized engine setups. Seeing your familiar with the way crank pressure works due to your successful use on the Rossi I'm quite sure your familiar with the idiosyncrasies of using it. The Cox TD .09 doesn't come stock with a fine needle. I can't say how well it would work or wouldn't work, I do know it's certainly not an award winning unit by any means. It certainly isn't a Rossi assembly. I've found some needles in stock form work quite well but others lack. It boils down to experimenting. One click however can result in too rich vs too lean on the stock units. If a remote needle is desired, the OS #1A is a unit I use for many bladder applications. A Cox 128TPI though could be made to work. You would require a method of getting the fuel into the venturi. I certainly wouldn't put it through the stock spraybar after running it through the remote unit. The thread size of the OS #1A is a M4 x .5. Ken

Ken Cook wrote:If a remote needle is desired, the OS #1A is a unit I use for many bladder applications. A Cox 128TPI though could be made to work. You would require a method of getting the fuel into the venturi. I certainly wouldn't put it through the stock spraybar after running it through the remote unit. The thread size of the OS #1A is a M4 x .5. Ken

OSMG7164 21181902 Needle Assembly #1A/#15 Now I have it saved in my OS Engines folder for future reference, Thanks Ken.
Rusty

Hey Bandid, just curious.. did you use a check-valve with the Rossi? (or on another engine?) There's a YouTube vid of a modeler who successfully used one on a Cox Reed-valve engine running case-pressure.. along with very small ID tubing like Phil mentioned. The valve is necessary for the reed to function.

I like the Uniflow/hard-tank idea also.. assuming that you were Speed or Race flying with the SS/Rossi combination.. and will be doing same with this model?

I started a discussion (thread) about making an in-line fuel regulator recently. If you're determined to run any type of pressure-feed, it might be worth reading. This could in theory, avoid the need for a fine-thread NVA by lowering the pressure at the needle-seat.  

https://www.coxengineforum.com/t7431-thoughts-on-a-homemade-regulator?highlight=regulator

RknRusty wrote:
OSMG7164 21181902 Needle Assembly #1A/#15 Now I have it saved in my OS Engines folder for future reference, Thanks Ken.

I've stocked up on those needles before, bought a batch of ten I think....

They are for the OS .10 FSR engine and they show up fairly frequently on ebay.

roddie wrote:Hey Bandid, just curious.. did you use a check-valve with the Rossi? (or on another engine?) There's a YouTube vid of a modeler who successfully used one on a Cox Reed-valve engine running case-pressure.. along with very small ID tubing like Phil mentioned. The valve is necessary for the reed to function.

I like the Uniflow/hard-tank idea also.. assuming that you were Speed or Race flying with the SS/Rossi combination.. and will be doing same with this model?

I started a discussion (thread) about making an in-line fuel regulator recently. If you're determined to run any type of pressure-feed, it might be worth reading. This could in theory, avoid the need for a fine-thread NVA by lowering the pressure at the needle-seat.  

https://www.coxengineforum.com/t7431-thoughts-on-a-homemade-regulator?highlight=regulator

Yes I did, the check valve is necessary because in order to provide positive pressure using case pressure the pulse has to be "one way" that's what the check valve does, it makes the push/pull action into push/push. on a reed its critical because the reed relies totally on the positive/neg. pressure signal that's created by the up and down movement by the piston "piston goes up, neg. signal and Mr reedy opens tha door, piston goes down, positive signal and Mr reedy slams tha door. Put a pressure tap in the case now you have an air leak and while the reed will close it will have difficulty opening properly unless you put a one way check valve in line so when the piston goes up the valve closes off the leak so the reed will work properly. It will only open with positive pressure. The timed port on the side of a tee dee or medallion, a check valve is not required though since it's controlled by the rotary valve on the crankshaft.

Sorry for the essay i know you all here know this, I just did this so those who don't may get an idea.

I flew my last SS with the Rossi mainly in club events and I used a dubro tank. As far as NV go, I've used stock assemblies in the past I just removed the ratchet spring and made a friction collar but fine thread needles are much better on my rossi the needle is locked by a jam nut.

RknRusty wrote:Just to clarify, when I said I couldn't find the "Thread," I meant the forum conversation, like this one which is referred to as a thread. But yeah, I can'r find the thread in which we talked about that particular NV.

The threads of a Cox or Texaxtimers.com NV are 128 threads per inch(tpi), so any NV with a high thread count like that will work. But I will ask Ken to remind me the part number for that OS part which might be easier to install without having to solder things together.

In the mean time, here are some links that might be helpful:

Main page:
www.texastimers.com

The valve I reccommend:
http://texastimers.com/accessories/retrofit_needle_valve.htm

The order form
http://texastimers.com/accessories/needle_valves.htm

One way to use it.
http://texastimers.com/accessories/remote_needle_valve.htm

All about bladders:
http://texastimers.com/accessories/pressure_bladders.htm

Here's one we use for a Tee Dee .049
http://texastimers.com/accessories/precision_%20nva_for_td.htm

My how-to videos:
https://www.coxengineforum.com/t3317-pressure-bladder-how-to-videos-parts-one-and-two

They also sell the bladder tubing and all the bits and pieces. Look down the left column and click links on various pages, the site is not well organized but there is a lot of good how-to info. You just have to pick through and explore. The guy's name is Hank Nystrom and he's an avid freeflight enthusiast.
Rusty

Cool thanks! and sorry I misunderstood ya, I though you were referring to thread type.

Just for kicks 'n' wiggles heres a pic of the NV assembly on my TD .051 it's been a while but I think its a KK unit. (Bandit)

I'm just curious as to your need to run crank pressure on this plane. The only reason I ever run crank pressure is due to having too large of a venturi. This isn't the situation with a stock TD. Ken

TDbandit wrote:Just for kicks 'n' wiggles heres a pic of the NV assembly on my TD .051 it's been a while but I think its a KK unit. (Bandit)

Could be but I've never seen a KK with round corners. But I've never seen a black one of any kind. Take the needle out and compare the thread width with any regular Cox Babe Bee needle and it's obvious.
Rusty

Rusty, I believe thats a KirnKraft as opposed to KustomKraftmanship.
128tpi. I sent one to Ron a while back.
Bob

Ken Cook wrote:              I'm just curious as to your need to run crank pressure on this plane. The only reason I ever run crank pressure is due to having too large of a venturi. This isn't the situation with a stock TD.  Ken

I have a couple of venturi's that i modded a good while back and I want to try them out which is the reason for wanting to run case pressure.

dckrsn wrote:Rusty, I believe thats a KirnKraft as opposed to KustomKraftmanship.
128tpi. I sent one to Ron a while back.

Bob

You are correct, it is KirnKraft. I was trying to remember but couldn't to save my life thanks! I got it at my local hobby shop in Stockbridge Ga called "The Hobby Shop" back in the 90's. He used to sell lotsa 1/2A stuff untill the electric craze came in and mashed the small model market like a bug.

i think those blue ones were sold thru ACE (an old model airplane company marketed for the smaller planes) they're Dale Kirn's design, but not sure who made them for ACE, likely Kustom Kraftmanship or Kirn Kraft.

Speaking of ACE R/C they used to market an old R/C 1/2A kit called the GLH if you fly RC and find one of these kit's, grab one they are fun to fly and fast! GLH stands for "Goes Like Heck" and it lives up to it with a TD on a bladder.