jrjohn

My Feedback: (24)

it really depends on who you talk too. I spoke to Duralite last week and they say they won't build a pack without it. Fromco didn't feel it was necessary. Duralite gets a lot of money for its batteries, if they didn't have the circuitry then they would have the same battery as everybody else and fighting for sales with less profit margin. Duralite charges about $40.00 more for their 4000 mah battery. I"m guessing the circuitry is worth about $5.00-$10.00 extra. Get the picture!

John

Maudib

My Feedback: (51)

I don't know if Fromecos have a PCB, I doubt it... the Duralite have a safe charge circuitry that prevents overcharging only.

The packs I make from new cells have no additional circuitry either and work great.

Personally I wouldn't try and fly a $2,000 aircraft with a receiver pack made from "an old laptop batterypack". It just isn't worth the risk is it?

Buy fresh cells from batteryspace.com for $5-$8 per cell...

You can go with three 2 cell packs if you wish... it'll offer you a little more redundancy.

All the redundancy issues have been hashed over earlier in the thread and it's still personal preference.

I prefer a 4 cell pack and a failsafe Smart-Fly regulated switch.

jrjohn

My Feedback: (24)

DAvid, I checked out batteryspace.com I'm wondering what cells your using, how many and what your total MAH ends up being. OH and what brand are the cells

John

Maudib

My Feedback: (51)

I'm currently using the "LG Li-Ion 18650 Cylindral 3.6V 2400mAh Cell --- New Products"

4 cells makes a 2s2p 4800 mah pack

I order these with tabs. Buy 20+ and you get a discount. ($7.90 ea)

These are LG Chem cells, the same cells being used by the other manufacturers.

Before these were available I used the 2000 mah cells... and they are just $5.70 ea. with tabs...

Since I don't make my packs in "bulk" I take each individual cell and top them off so they are all equal when I assemble 4 (or 2) in a pack.

Neat thing is... the Smart-Fly regs come with a deans lead and shrink wrap.

I first use silicone adhesive to glue two cells together with opposite ends... then solder one pair of tabs together.
The tabs are bent together like praying hands, soldered together using a good, hot iron (I think mine is a 60 watt).
Then the whole thing is bent over to one side

I repeat this to create another 2 cell in series. then these two packs are glued together and the free "like" tabs are soldered together along with the deans lead forming the 2p part of the pack.

A strip of fiber packing tape across the top to prevent stress on the wires and shrink wrap the pack.

So for $32 I have made my own 4800 mah pack and they are rated for 12 amp continuous (2.5c).

If I wasn't using smart fly, I'd probably get the Fromeco packs because of having to buy the deans leads and shrink wrap plus my time. But as it is I am saving almost $40 on the 4 cell and 2 cell packs required for my 50cc planes...

Aerosplat

My Feedback: (12)

A quick word about wheel pants and mounting. The Wheel Pants supplied with the YAK are very light-weight. Consequently, this makes them relatively more fragile as compared to some others I have seen. I mounted mine as per the instructions, with two 4-40 screws through the LG legs into the Plywood blocks. On a paved runway, or smooth grass filed, this will work well. However, my club field would not be considered smooth. [] After 6 flights there I noticed the wheel pants were cracking just past the plywood backing plates.

The suggested mounting procedure secures the wheel pants solely by the plywood backing plate. The pant is then free to flex, wobble, and vibrate, - eventually cracking the fiberglass at the pivot lines at the edge of the plywood.

I suggest you go here to the Bolly site ( http://www.bollyprops.com/wheelpantinstall.html ). This is an excellent method and description of Wheel Pant mounting.

I am mounting another set of Wheel Pants now, using this method. The only part I am not doing is the flat cut on the axel hub. The real key to this method is the plywood block on the inside of the outside wall of the Pant, for the end of the axel to fit into. This locks the outside wall in place and prevents the Pant flex and wobble mentioned above. Because of the rough nature of my filed, I am adding some additional supports. I will post some pictures in the next few days.

2rolls

My Feedback: (16)

Is there a problem installing the SWB elevator servo arms, and using their locking feature?
Seems the servos are mounted in such a way as to limit access to the locking bolt.

Aerosplat

My Feedback: (12)

With the servo hooked up and centered, slip the arm on so it is at 90 degrees to the servo body. Snug the servo arm retraining screw down, but not tight. Then turn the electrics off. Now rotate the servo arm so the locknut for the pinch bolt is down (away from the cutout), and the hex head is up. Hold the nut with needle nose pliers, and tighten the bolt with a hex wrench. Finish tightening the retaining screw.

Stratos

My Feedback: (4)

That's a pretty good guess John. Unfortunatelly it's even cheaper than that.
Batteryspace has a protection circuit module that does more than protect you against overcharging
for $4.99 http://batteryspace.com/index.asp?Pa...OD&ProdID=1083

$4.74 if you get 10 or more. Thanks for pointing out that site David.


Stratos.-

wgeffon

My Feedback: (4)

About the wheel pants...

What I did was Z-Poxy a strip of fiberglass tape 2" wide across the inside of the mounting side of the wheel pant.
It goes on top of the mounting plate and then down onto the side of the plate.
Much more secure now.


My left pant was shattered and cracked even before I flew the plane for the first time.
My flight box fell over in my Van and landed on the the left pant. I was more than pi$$ed. [>:]
I caked epoxy over it that day just so the cracks in the paint wouldnt flake off.
It looked horrible.

Last weekend I sanded it all down and Bondo'ed the cracks and re-painted it. Looks like new again.

Maudib

My Feedback: (51)

I strongly recommend you do NOT use the circuitry provided by batteryspace...

While it does protect against overcharging, it ALSO will shut the battery off in the event of too much amp draw.

I'm not sure what it is rated at, but it's probably on the conservative side and probably only designed for a single cell pack (no parallel packs that would double the amp handling capacity).

If for some reason you achieved that amp draw level in flight... you would MUCH rather have the pack just not take another charge than to simply shut off in flight...

The circuitry used by Duralite only provides charge protection... the power leads to the receiver bypass the circuitry and are wired to the cells direct... thus the two leads on the packs.

If you have a dependable charger that supports Lions there is no reason to require overcharging protection...

If a pack is overdepleted, it simply will not take another charge or won't fully charge.... but the circuitry will literally shut off power.. .putting your plane and people at risk....

Stratos

My Feedback: (4)

David,

I'm not too sure that that circuit will shut down the battery if the draw is more than 5A. It seems more likely that
it will just limit the draw to just 5A and no more. Maybe that's just wishfull thinking but they don't say explicitly
what it does when the draw is more than 5amps.

But if indeed cuts off everytime it sees more than 5A then I agree. It's NO good for us...;-)

Also that circuit is good for a 2 cell pack. Nothing prevents you from using 2 of them in parallel in a 4 cell pack and double
the current allowed.

Stratos.-

Stratos

My Feedback: (4)

Those are the specs for the protection IC the use in that circuit:

http://www.mitsumi.co.jp/Catalog/ic/...12/text01e.pdf

David is right. It shuts off when detects overdischarge.

Stay away from it...lol

Stratos.-

Ricmussman

My Feedback: (24)

According FEDEX, my package will be delivered tomorrow.

jrjohn

My Feedback: (24)

I thought I read somewhere that the Duralite kicks out when the amp draw it too hi as well. It would be interesting to know if it's true and if so at what amp draw this happens

John

jrjohn

My Feedback: (24)

did chris give you a tracking number?

John

Maudib

My Feedback: (51)

I couldn't be more tickled to see everyone start getting their Yaks... Can't wait to see the remarks and pics.

I'll be flying my Yak in the next few days weather permitting... (Monday looks pretty good if nothing else, but the weather is usually only accurate up to yesterday)

Maudib

My Feedback: (51)

I believe this was a misconception rumor that spread. The power leads bypass the circuitry... only the charge leads pass trough the circuitry...

jrjohn

My Feedback: (24)

DAvid, Your right, it does bypass the circuit on the discharge of a duralite. it's only used to keep the cells ballanced when charging.

John

DrScoles

My Feedback: (18)

Do we need to do any follow up with Chris? I gave him my CC info a while back.....

I understand making your own packs will save $$$, and if you have the skill/aptitude to do it cool, but man, that is one area I wish not to save $$ on!! I have used Duralite packs for four years, have been very happy with the way they work. You can't screw them up! Emory has definitely worked hard to design those packs to be bulletproof and mike scoles proof....<g>

Thanks, Mike

Maudib

My Feedback: (51)

You are absolutely right... Unless you are familiar and comfortable with proper soldering techniques, it's way better to rely on manufacturers for their expertise. And it's not that much more for Fromecos, and only a bit more yet for Duralites that do offer some additional featrues.

It only takes one cold solder joint to cost youa plane, so I only recommend making your own packs if you truly feel competent to do so. With that said... the cells from Batteryspace feature welded tabs and I can solder with the best of them. Add a little silicone adhesive and some fiber tape and I feel as comfortable (and perhaps more so) with my own packs as any others.

It's not about saving $40 (though it's a nice benefit to save that much and take a lady to dinner) but I enjoy building my own packs.

BBriBro

My Feedback: (2)

I agree, I have seen some "cheap" battery packs fail with just one tiny spot weld on the tab. If you use a braided strap, it will tolerate vibration better than a rigid tab, and a nice "puddle" of solder that flowed so nicely across the top of the cell and into the braid gives me a warm fuzzy over a single spot weld on a brittle tab.

Maudib

My Feedback: (51)

Now you are talking!

But, of course... these cells have 4 spot welds on each tab... we're talking quality... LG Chem knows their stuff...

jrjohn

My Feedback: (24)

I had a "super" pack fail and they used braided. Problem was the Nut (builder of the pack) wicked solder all the way through the braid and made it brittle.

Everything ended up real nice, he sent me two new packs too offset my $1200 of damage. (they were both made to fail as well)

John

I need a tracking number!

Maudib

My Feedback: (51)

Alright guys... we have some exhaust numbers...

First I set the sound level meter to "A" weighting and slow response.

I marked off 25 feet and in line with the prop.

This is as directed by the 2005 IMAC Rulebook.

I did not have a windscreen available nor did I tripod mount. I stood and held the meter at just above knee height and directly towards the prop.

Tho not exactly optimal, it was consistent.

The following results were with an MSC 22x8 prop. 41 degrees, approx. 700-800 feet above sea level, on soft, thick grassy ground. no cowling.

Stock muffler cut off to 1.5": 6700 rpm @ 98db

Stock muffler uncut: 6720 @ 97-98 (it jumped between the two a little but stayed mostly on 97)

Supersonic inverted pitts wraparound (pipe exits are straight, no swages): 6510 rpm @ 95 db

Bisson inverted pitts wraparound (swaged pipe exits): 6250 rpm @ 94 db

Chip Hyde Quiet Pipe: 6780rpm @ 93 db


As I mentioned, I can't invest the time to test the tuned pipe or RCS Silencer... (the stand I made ended up not usable for the task due to bolt placement)
so that's all I can do right now... this summer perhaps I'll get busy with it and do them all...

I tweaked the needle only slightly erring on the rich side due to the fact this is a brand new engine. (Which, btw on the very first start popped in 5 flips, and started in 3 flips.... this was after flipping it enough times to draw fuel visably to the carb the first time. Then every start thereafter was 2 flips choke off) AWESOME!

It sure was good to hear an engine purring and roaring again... it's been since last September that I've heard a gasser.

All the data above points to a few conlcusions... The wraparounds are quiet but at a significant power loss... especially the Bisson... but it was very quiet to the ear obviously pointing to the fact that prop noice is as a contributing factor as exhaust. The Supersonic actually sounded louder than it was.

The stock mufflers were loud... they sounded good to me, but the meter says they wouldn't pass IMAC noise requirements if they were sticklers. Cutting the exit didn't make all that much difference... maybe 1/2 - 1 full db... if it was "close" leaving it full length might get you just under the limit.

The Chip Hyde Quiet Pipe? Well... I was tickled to say the least. It provided the best RPM and the quietest sound of them all... Though I added a total of 8 oz of weight by going to it, I gained a little RPM to add 12 oz more thrust... Pretty much an even trade.

But it IS quiet... and sounded good to me... pleasurable. It also could easily have used more leaning out, but I just didn't want to push the new engine that hard.

The mufflers were changed out hot (had good gloves) and the engine was allowed to clear up and idle 30 seconds before tests.

I'm glad I made the decision to go with the Chip Hyde Pipe. It's a perfect fit, quiet and powerful....

I still believe that the tuned pipe would blow it away with probably another 200 rpm... but there will be the added cost of time, tuning, throttle response and balance issues to deal with.

If sound is of no issue, the stock pipes are the easiest to install and are powerful too.

Welp... hope that helps. It certainly makes me feel better about my choice and I'm raring to get this thing in the air.

Oh... one last thing... I did put the 23x8 NX on the cutoff stock pipe initially, but only got like 6200... I didn't want to load the engine that much this early. I'm thinking it's going to make a great 2nd 3D prop for the DA-50...we'll see...

TailTouch

My Feedback: (54)

Awesome David !!!
I think the final part in the muffler equation now is to measure the KS-1060 pipe...