Ace R/C Throttle question

From what I've read and heard over the years, its a good design and works well. Hopefully it would make you money.

Hey guys how is this coming, very interested in one of these for my Lady Bug.

These RC needle valve assemblies were available from Ace R/C in the 1970's and early 1980's, but reason why I never went for them and opted for their exhaust restrictor throttle was needle and servo set up interfered with the battery compartment of the nose of most RC airplanes. Battery compartment for 1/2-A aircraft is tight. Exhaust restrictor throttle ring allowed for a conventional RC pushrod setup through wire cable Nyrod along side the battery compartment, so I had room for the battery.

I had great success with the exhaust restrictor throttle and thus stuck with it.

GallopingGhostler wrote:These RC needle valve assemblies were available from Ace R/C in the 1970's and early 1980's, but reason why I never went for them and opted for their exhaust restrictor throttle was needle and servo set up interfered with the battery compartment of the nose of most RC airplanes. Battery compartment for 1/2-A aircraft is tight. Exhaust restrictor throttle ring allowed for a conventional RC pushrod setup through wire cable Nyrod along side the battery compartment, so I had room for the battery.

I had great success with the exhaust restrictor throttle and thus stuck with it.

George, that makes total sense. Back in the 70's/80's.. receiver battery-packs were the standard AAx4 NiCd one's that came with the radio. An aero-modeler could fly 1/2A using them.. but building a full-house controlled model light/strong enough to perform well, was a challenge. There was the option of using a AAAx4 alkaline pack (6V) to save a little weight.. but at the expense of having to buy batteries often.

Today there are rechargeable Lithium (LiFe) receiver packs available that weigh less than a standard-size servo. The pack-voltage is 6.6V (3.3/cell) so.. depending on the receiver; a regulator may be needed.

A couple years ago, I purchased a "LiFe-Source" (Hobbico) 200MAh receiver-pack and some "nano-servos" for a 1/2A RC flight-pack.

Here's what my 4-servo/receiver/battery weighs in grams.. along with an "Ace throttle candidate" Babe bee engine.



That's 130gr. (which translates to 4.6oz. dry) Compare this to x4 AA/NiMh cells.. that together weigh 100gr. (3.5oz.).. and you can really understand the weight-savings of going with modern technology for 1/2A powered RC flight. Granted.. the Babe Bee is not a powerhouse.. but it's going to be a whole lot more capable with a radio that weighs just over 60gr. That's less than the engine with a prop weight, by almost 10gr.

Thanks, Roddie for the details of your radio installation. Being 60 going 61, I guess although young some time back, the older I get find I am still old school. Much of my equipment is a mix of old school with new and still using NiCad receiver packs.

There is merit to use of the newer LiFe / LiPo batteries, as you show they are lighter weight and considerably smaller for the same current output. Since I still have exhaust restrictor throttles, will still continue to use them. I may opt for Bernie's choke tube throttle some time down the road.

Facing reality, with the proliferation of the newer electric technology and drop in battery prices, I may opt for electric power down the road. One plane I am thinking particularly of is my venerable 1953 DeBolt 34" (864mm) span Livewire Kitten build. It was designed to haul the heavier tube (valve) receivers and 67-90V B-supply (for valve amplification), 1.5-3V A-supply (for valve heater elements) and 1.5-4.5V relay/escapement supply. A sufficiently powerful battery could potentially provide me with up to a half hour of flight time.

This is all speculative on my part, and of course as human sentiments are a toss between common sense and nostalgia, may just simply mount my old RC Bee engine or perhaps a Cox 290 with exhaust ring throttle.

But the rear Cox tank engine venturi restrictor needle does have merit. I could see it used on say, Ken Willard's 1964 Virus 34" (864mm) span model with pod mounted Cox .020 Tee Dee, substituting a Cox .049 tank engine instead.

http://www.outerzone.co.uk/plan_details.asp?ID=5713





Some revisions to the pod would be required of course due to the longer length of a Cox tank engine, but such with a throttlable engine say with 5" prop to fit would be exciting, IMO.

GallopingGhostler wrote:Thanks, Roddie for the details of your radio installation. Being 60 going 61, I guess although young some time back, the older I get find I am still old school. Much of my equipment is a mix of old school with new and still using NiCad receiver packs.

There is merit to use of the newer LiFe / LiPo batteries, as you show they are lighter weight and considerably smaller for the same current output. Since I still have exhaust restrictor throttles, will still continue to use them. I may opt for Bernie's choke tube throttle some time down the road.

Facing reality, with the proliferation of the newer electric technology and drop in battery prices, I may opt for electric power down the road. One plane I am thinking particularly of is my venerable 1953 DeBolt 34" (864mm) span Livewire Kitten build. It was designed to haul the heavier tube (valve) receivers and 67-90V B-supply (for valve amplification), 1.5-3V A-supply (for valve heater elements) and 1.5-4.5V relay/escapement supply. A sufficiently powerful battery could potentially provide me with up to a half hour of flight time.

This is all speculative on my part, and of course as human sentiments are a toss between common sense and nostalgia, may just simply mount my old RC Bee engine or perhaps a Cox 290 with exhaust ring throttle.

But the rear Cox tank engine venturi restrictor needle does have merit. I could see it used on say, Ken Willard's 1964 Virus 34" (864mm) span model with pod mounted Cox .020 Tee Dee, substituting a Cox .049 tank engine instead.

http://www.outerzone.co.uk/plan_details.asp?ID=5713





Some revisions to the pod would be required of course due to the longer length of a Cox tank engine, but such with a throttlable engine say with 5" prop to fit would be exciting, IMO.

Hi George, I actually see either the "Ace or the Cox" type throttles being used to power much smaller "scale models". Granted; RC piloting these would not be for the beginner.. but the models would be a lot more "nimble" with such lightweight radio components. I envisioned "Lieven" (Overlord) installing such a system in his Pee Wee powered Guillow's P40 FF job that he built last year.

Too many modelers don't like to build anymore. I mean "build".. as in taking a "kit".. a "plan".. or a design of their own, that incorporates framework with "well thought-out" reinforcement in key areas. There are many Sterling "Six-Way" scale model kits that would be great candidates for 1/2A RC. Stronger bracing/struts, spars and L/G legs would be in order.. but today's radio-gear is so small and lightweight.. that it's easier to install and the model is much lighter.

It "used to be".. that tiny 1/2A RC airplanes had to scream wide-open with no throttle.. just to keep the model in the air with the heavy radio.. A throttle-servo was the last thing anybody wanted to add. This is no longer the case. The engine doesn't have to work nearly as hard to keep the lightweight scale-model in the air. One can perform R.O.G.'s.. touch and go's.. and better scale-like maneuvers. Combine this with a modern spread-spectrum radio-system.. and fly anywhere.. anytime!

I guess that I really like "little" airplanes powered by "real little" engines.. which is what originally attracted me to this forum!

roddie wrote:It "used to be".. that tiny 1/2A RC airplanes had to scream wide-open with no throttle.. just to keep the model in the air with the heavy radio.. A throttle-servo was the last thing anybody wanted to add. This is no longer the case. The engine doesn't have to work nearly as hard to keep the lightweight scale-model in the air. One can perform R.O.G.'s.. touch and go's.. and better scale-like maneuvers. Combine this with a modern spread-spectrum radio-system.. and fly anywhere.. anytime!

Roddie, Back in the late 1970's, I built a 36" span Sterling Minnie Mambo as rudder only and auxiliary throttle. I used the Ace R/C Pulse Commander flight pack with Adams Stomper magnetic actuator and KRD Quick Blip sequential throttle connected to a Cox .049 R/C Bee engine. This radio setup was comparatively light, making for a rudder only stunt plane that was full joy to fly. Wing was clear doped yellow silk, contributing to its light weight.

Since the Minnie had a short coupled elevator, it would loop like crazy after about two spiral dive turns. I could get two loops out of it after about 3 spirals. Multiple barrel rolls were possible, too. It would putter around at half throttle, climb at full throttle, glide at idle. To get the half throttle, I set it up so that at full servo travel it would idle, at full servo travel the other way would crack open the throttle about 3/32", and middle at full throttle would leave the throttle sleeve roughtly mid way at full opening.

Now that we have the modern flight packs using lithium technology and smaller, lighter micro servos, digital servo technology has become practical.

I guess that I really like "little" airplanes powered by "real little" engines.. which is what originally attracted me to this forum!

I have never lost my fondness of the small engines. I still find them a joy to fly, although some modelers disdain that fact thinking it is nothing unless it has at least a .40 or larger motor in it. They miss the whole point, it is the fun of flying that I enjoy. I just love to see a model in flight, even if it is not doing competitive stunting. I still get thrilled by watching flight. I could entertain myself for hours just doing rudder only aerobatics, seeing how close I can land toward myself after each dead stick. Getting the model to flare on landing by kicking a touch of rudder incrreasing the speed after the nose drops, then greases in for a landing.

It doesn't have to have gobs of channels or controls to be fun. Sometimes the simplest is the best (at least for me).