EarthX battery

[Ksmith]

Good thoughts

 

[Gust Kalatzes]

I have a buddy with the Earth X experimental in his IO540 rocket... it cranks the engine like it doesn't have plugs.. its easily twice as fast as the old concord.. he has a #2 cable and a B&C starter. will be good to watch..

In the mean time, Kurt and I are wondering about replacing the concorde with the J16 odyssey, in the stock location.. I have the stock battery cranking the motor pretty well now with the new relay and rewired cables, but more is better .

I would do the J16 in a heartbeat. But depends on if Your rg25 is new or not though. The 8 lbs is not worth throwing a good battery out. I need one for the riding mower so not a total loss of a 2 1/2 year old battery.

 

[Gust Kalatzes]

Gust what I have seen before is Anderson Power Pole 200 amp plug capped off in an accessible place, and your jumper cables have an matching adapter.. I could also see using XT150 plugs with #8 wire, that is good for 150 amps. I built a Jumper once out of 8 A123 cells, 4S4P setup, and it would put out 150 amps at about 11.5 volts for 15 sec.. I used a EC5 plug and #10 wire.. That little battery would start a 4 cyl car, and it fit in the palm of your hand.. you get the idea. an accessible coverable high current plug

That would work great! Could you legally put an inspection plate or something like it down there instead? Might be a bad idea if I put my pod on.

Like Mike says, I believe the earthx or like is where we are going but probably not yet for me. Saving 20 lbs with the earthx or more is big...the conflict or risk to benefit.

Also, the tail on the C feels heavier than my B did but the extended gear and 4 lbs heavier rear baggage compartment didn’t help either or maybe I’m getting weaker. With Tom’s tail spring and moving the J16 battery to the inside firewall and removing some cable it will help a little. I’d like to run the numbers first and see what it does to loading.

 

[FW Dave]

Gust, PM me your last W&B sheet, and the modifications you are proposing.. I can run the W&B quickly.
What I need is weight off/station, and weight on/station. I forget what the firewall is..somewhere around 36 The tail spring is only 1LB lighter.. The extended gear moves weight to the tail wheel, but the cG forward, but we still need to calculate the flying CG with the pod, and moving the battery..
Moving a J16 to the firewall puts the CG very far forward, under the curve, and could affect the CG a lot. I think you could be too far forward on the base airplane.. just did a quick calculation tho. With the elevator stops, you could run out of elevator, and might have to put some ballast in the tail when solo. I have worked with a few guys on here getting optimum flying CG. I like the way it flies with the CG loaded 75 inches give or take solo. I still fly solo with my tiedown/hammer bag strapped down in the aft cargo.. the tail sets in nicely.. when dual, the CG takes care of itself.

If I put the J-16 in, stock location, it will only be about .5 inch movement, easily compensated for or ignored. I like that change.. but to move it to the firewall, I think that is too much, and will require ballast IMO.. I just went through this with a Rocket buddy.. we built a 50 pound ballast bag that straps in the rear seat for solo flight after he kept running out of elevator on landing. I used 20 pounds in my aft when learning the plane, so it would be harder to get the tail up, now I can fly it with nothing, but I prefer 5-10 in the aft compartment.. each plane is different, and the weight of the prop has a big effect..

As far as in inspection plate, I will defer to the knowledge base.. . The electrical mod would be a charging mod, so use it for double duty charging/jump. There are a couple guys on here that have electrical access ports as I recall

all my opinions of course.. FWIW..dave

 

[Gust Kalatzes]

Gust, PM me your last W&B sheet, and the modifications you are proposing.. I can run the W&B quickly.
What I need is weight off/station, and weight on/station. I forget what the firewall is..somewhere around 36 The tail spring is only 1LB lighter.. The extended gear moves weight to the tail wheel, but the cG forward, but we still need to calculate the flying CG with the pod, and moving the battery..
Moving a J16 to the firewall puts the CG very far forward, under the curve, and could affect the CG a lot. I think you could be too far forward on the base airplane.. just did a quick calculation tho. With the elevator stops, you could run out of elevator, and might have to put some ballast in the tail when solo. I have worked with a few guys on here getting optimum flying CG. I like the way it flies with the CG loaded 75 inches give or take solo. I still fly solo with my tiedown/hammer bag strapped down in the aft cargo.. the tail sets in nicely.. when dual, the CG takes care of itself.

If I put the J-16 in, stock location, it will only be about .5 inch movement, easily compensated for or ignored. I like that change.. but to move it to the firewall, I think that is too much, and will require ballast IMO.. I just went through this with a Rocket buddy.. we built a 50 pound ballast bag that straps in the rear seat for solo flight after he kept running out of elevator on landing. I used 20 pounds in my aft when learning the plane, so it would be harder to get the tail up, now I can fly it with nothing, but I prefer 5-10 in the aft compartment.. each plane is different, and the weight of the prop has a big effect..

As far as in inspection plate, I will defer to the knowledge base.. . The electrical mod would be a charging mod, so use it for double duty charging/jump. There are a couple guys on here that have electrical access ports as I recall

all my opinions of course.. FWIW..dave

I’m concerned you are right about the change moving to far forward. Another Husky friend did that and it’s on the edge he feels. Will send when able tonight or tomorrow.

 

[MTV]

Im plan to clean the wiring connections up on Kurts plane first, before we change any components, and see if it helps the starter hit harder.. trying to discern if its the wiring or is it the better relay that makes the difference.. The Tyco has silver posts in it, which in the spec says max voltage drop is 50mv.. thats excellent continuity.

I think you're headed in the right direction. I've seen so many "hard starting" batteries that just needed the wiring addressed, with the existing battery.
MTV

 

[tbienz]

Just a thought to ponder: I’ve spent much my bush flying times assuming that a heavy tail (rearward CG) is bad because you can’t raise the tail early in the takeoff run for visualization and the tail spends more time down in the rocks where it can get damaged. I still think that’s true, but I found it interesting in a new book I just bought at Oshkosh after talking to the author and watching him compete his C170 in the STOL event “Bush and Mountain Flying handbook, 3rd ed” I was surprised to read that he always tries to load the plane near the back of the CG envelope when doing backcountry ops. The argument he makes is that the empennage is working less hard to support the plane’s weight so there is less drag, and slower stall speed/faster cruise speed plus it allows for better braking for short landings. He acknowledges that lighter is still better (for the whole plane), but keep the tail heavy. And my friend just bought a 170 (the one I asked you folks about for an instructor) and I was surprised that it is lighter than my Husky (or at least that’s what the W&B says...not sure if its been weighed recently. Thoughts?

 

[Gust Kalatzes]

Just a thought to ponder: I’ve spent much my bush flying times assuming that a heavy tail (rearward CG) is bad because you can’t raise the tail early in the takeoff run for visualization and the tail spends more time down in the rocks where it can get damaged. I still think that’s true, but I found it interesting in a new book I just bought at Oshkosh after talking to the author and watching him compete his C170 in the STOL event “Bush and Mountain Flying handbook, 3rd ed” I was surprised to read that he always tries to load the plane near the back of the CG envelope when doing backcountry ops. The argument he makes is that the empennage is working less hard to support the plane’s weight so there is less drag, and slower stall speed/faster cruise speed plus it allows for better braking for short landings. He acknowledges that lighter is still better (for the whole plane), but keep the tail heavy. And my friend just bought a 170 (the one I asked you folks about for an instructor) and I was surprised that it is lighter than my Husky (or at least that’s what the W&B says...not sure if its been weighed recently. Thoughts?

Thomas, just had that conversation with Dave and makes sense!

I will address the wiring also but without question install the J16 for the 8 lbs. I’d rather carry an 8 lb first aid kit I have than a porky battery. I know the J16 is a better battery and lighter. Was hoping to remove some wire also for weight reduction but that’s ok. The new wing has its advantages and some potential issues I’d like to learn. Not moving the cg to far forward has some wisdom.

 

[FW Dave]

no expert, but have been in this aeronautical performance game for most of my career..

Drag on the tail that can be controlled is induced drag.. the less it lifts downward, the less drag.. The more the AFT CG, the less the drag on the tail.. Until the point where it becomes too pitchy, or unflyable. Largely a stall is a combination of when the tail gives up or the wing does, or both in simple terms.. I have seen alot of nose heavy airplanes stall before they should, and putting some tail weight or shifting the load solves alot of that. The pitching force required is less if the CG is back a bit. With the CG back, you can find the true points of the Wing's performance, without stalling the tail.. I mentioned this with a harmon rocket I helped a buddy with.. it had an RV8 tail(thinner and smaller Chord but faster). He largely flew it solo, and was landing hot to keep the tail flying, or it would run out of elevator.. But when dual, it was fine. So, he built a ballast kit that could be strapped into the seat and calculated the moments needed, and we took some equipment out of the engine bay, and moved the battery back as far as we could.. Now it settles in nicely on speed. Same with a Up-engined 172.. we put 8 pounds in the tail.. It flew ok, but now it flies better.

So I have been playing with the CG on this bird a bit. actually going out and flying it short field work with the mid and aft CGs, there is a sweet spot in the mid to high 70's that lets you lift the tail, drop it for a quick out, and hold it off for short field JUS work (just above stall).. Its much more stable in pitch there a few knots above stall.. It never really stalls, it just gets the big sinker going, which you can arrest with power for the most part.. BUT, when when you get down below 45mph or so, the New wing loses aileron effectiveness. take it up to altitude and see for yourself. so that is another handling thing to consider with 30 flap and power on.

I was able to drag the tailwheel with about 1000 rpm, keeping the mains off the ground, and so was my instructor, who has alot of time in cubs.. why, because the airflow across the tail keeps it flying longer..But with the CG in the back a little, it becomes much easier to hold the tail into and down on those short fields when you chop the power, and block the airflow largely with the prop..

So there is a sweet spot where Milne Pocock talks about in the book where you have command of the longitudinal axis well into the stall.. that is what Im talking about. and the nose wont drop unexpectedly on you before the wing gives up the ghost.. The airplane just settles into a sinker, and you have good pitch control..

All that being said, Thomas you mention rock avoidance.. of course that is a player too, so it cannot be so heavy it bangs down or cant be lifted.. for mine, I found mid 70's is that spot through practicing on my short grass strip with about 100 + landings on it in the last 6 months.

take it for what its worth..my humble opinion.

 

[Snowbirdxx]

Please be aware that later Huskys have a different angle if incidence on the horizontal stab. If I recall right the leading edge of the stab has been moved up about 1/4 inch.
That was done by simply shortening the attach tubes welded to the forward horizontal attach tube. ( PN 35086-501 Stab support Assy Patrs Cat Fig 10, Item 42) This can be done to older Huskys too, but the Handhole cover just beneath the LH Stabilizers leading edge of the LH side of the Fuselage, needs to be cut open and covered by a Handholecover.

 

[Carolina Husky]

I swapped my # 6 cable with #2 cable. In my Husky the voltage drop delta was pushing 35% with the number #6 cable and the #2. going to the #2 cable made all the difference in the world. Of course this was done after a new battery purchase and a new starter purchase to solve the problem. The number #6 battery cable should never have been installed. I am swinging a Hartzel composite trailblazer as well.

 

[Ksmith]

The factory extended gear (if I remember correctly ) moves the axles 3" forward, this moves weight of brakes, wheels and tires forward, CG comes forward. Weight on wheels and in particular, tail wheel (as previously pointed out) increases. My older A-1B had factory extended gear, 31's, MT prop, B-Bushwheel, standard Concord. Empty it never ran out of rearward elevator trim. My newer A-1C, 31's, trailblazer, std Concord, Scott tailwheel and without the extended gear, solo does hit the rear stops on three point landings.

 

[FW Dave]

I swapped my # 6 cable with #2 cable. In my Husky the voltage drop delta was pushing 35% with the number #6 cable and the #2. going to the #2 cable made all the difference in the world. Of course this was done after a new battery purchase and a new starter purchase to solve the problem. The number #6 battery cable should never have been installed. I am swinging a Hartzel composite trailblazer as well.

Nice..It should have been #4 to begin with minimum.. I was even looking at just putting #2 splices on the Batt to relay to Start relay.. that should help too. The starter wire is a bitch to get up to the front unless you pull all the lower panels. that's why I went the route I did for now.

 

[Flying Dave]

The factory extended gear (if I remember correctly ) moves the axles 3" forward, this moves weight of brakes, wheels and tires forward, CG comes forward. Weight on wheels and in particular, tail wheel (as previously pointed out) increases. My older A-1B had factory extended gear, 31's, MT prop, B-Bushwheel, standard Concord. Empty it never ran out of rearward elevator trim. My newer A-1C, 31's, trailblazer, std Concord, Scott tailwheel and without the extended gear, solo does hit the rear stops on three point landings.

How much heavier is the BBW setup over the factory setup? That would definitely help with the trim against the rear stop in the air I would think.

 

[Gust Kalatzes]

How much heavier is the BBW setup over the factory setup? That would definitely help with the trim against the rear stop in the air I would think.

I have the BBW and ran it for years, but have not installed on the C yet. If it started to shimmy I rebuilt the assembly and tightened the center pivot bolt. In 20 years I was also on my 4th tail spring. Tighten, then loosen just where it pivots smoothly and no more. If it’s loose it will shimmy! It really smooths out the beating the tail takes in rough terrain.

BBW is 11.8 lbs V’s 8 for the Scott 3200. 3.8 lb increase.

 

[Ksmith]

I believe there is also a weight gain from the 205 MT going to the Trailblazer, putting more weight on the nose.

 

[dogday]

I believe there is also a weight gain from the 205 MT going to the Trailblazer, putting more weight on the nose.

I think it is the MT Ultra that is a few pounds lighter than the Trailblazer. The earlier MTV-15 were a little bit heavier than the Trailblazer.

 

[johnaz]

I think it is the MT Ultra that is a few pounds lighter than the Trailblazer. The earlier MTV-15 were a little bit heavier than the Trailblazer.

MT Ultra 2 lbs lighter than Trailblazer, I hav e both and cannot tell any performance difference between the two. Hartzell to me is beefier prop. MT is like a toothpick in comparison, amazing they pretty much perform the same to me.
John

 

[FW Dave]

having flown both a little bit and in formation with them, I think the Hartzell likes a higher rpm in cruise for similar efficiency.. the Ultra seems to pull fine at lower rpm... but thats a general observation. something like 2000 on an ultra, and 2150 on a hartzell seem to yield comparable speed at comparable power settings for example,

but thats a very general observation.. not easy to substantiate

 

[Ksmith]

The Trailblazer is much more robust, will not get bubbles in the finish or delaminate like the MT