dhal22

I have the Hanno liner/piston package from a couple of years ago. Is that what you used or are aluminum liners available elsewhere?

8178

My Feedback: (17)

Yes, the same one.

dhal22

what is the weight difference between the two? Or rather was it worth the time? Thx

8178

My Feedback: (17)

They are about two ounces lighter. Expect that is how I got away without tail ballast.

dhal22

That is a huge difference. Thx, I will look into that should my battery relocation not work.

doxilia

My Feedback: (3)

David,

as it stands, where does the battery need to be installed in order for the model to balance? If it is way down the fuse, you might want to consider removing those two ounces from the engine off the bat before installing your battery. The battery is in a sense your last weight to achieve balance without added tail weight. Of course, I assume all this is with the model fully assembled pipe and all.

Just a thought.

David.

dhal22

David, thinking about shifting the battery to behind the servos. I posted a couple of photos of the battery sitting approximately where it was 1st placed and then another photo of where it needs to go. The photos are on the previous page. I like Mike's idea of a long battery pack. He posted a link to his BA build a few posts ago as well. It takes your directly to how he handled the situation.

pacorro

My Feedback: (9)

Hi dhal22.
Really awesome work , i hate those planes that have no room to work but you make it easy.
Congratulations and go ahead, will follow your progress.

dhal22

Thanks pacorro.

dhal22

My new slim battery arrived. Will try to install it today.

dhal22

Working the battery deep into the fuse. Hoping the location is close as I went ahead and glued in a backplate/former behind the battery. Now to glue some support over the battery and restest the cg.

dhal22

Still about 1.5 oz needed at the tail to balance. Looks like I need to lighten the engine. How hard is it to replace the stock liner and piston with the Nelson set I have?

Thanks in advance.

Flyitorcrashtrying

if it is tail heavy then you need a heavier engine, or split the battery pack and move 1 or 2 cells forward

if its nose heavy by 1.5 oz then the liner would do it I think, but if you are saving 2 oz then you may need to move the battery a little also

dhal22

Edited the #737 post. Incorrectly said tail heavy but meant nose heavy. Sorry guys.

dhal22

I have an 'extra' pumped .61 SF. Going to start disassembling it now and investigate the liner and piston swap.

landeck

My Feedback: (1)

David, when do you plan to maiden it at the GMA field? I would like to be there when you do.

Bruce

dhal22

Bruce, that someone would want to take time out of their day to see my plane's maiden is quite a compliment. Thanks. Even better I have had at least 3 people request a maiden date for the same reason. At this time I have balancing the plane, running the engine and retract cycling left on my to do list. No idea when I will get these things done though. Now my concern is the summer heat. Probably wouldn't bother to try when the temp is 90 or 95. I need to stay focused.

8178

My Feedback: (17)

David,

I can’t tell for sure from your picture but I think my battery is about 4” further back than yours. I assume you have a pretty good idea of the header length for the RPM you want to run and you are checking the balance with the pipe installed?

dhal22

Mike, thanks, yes I am checking the balance with the pipe installed. However, I have not adjusted the header length. Of course any recommendations are appreciated. I'm sure you have an idea. [8D]

And the battery resides just behind the former at the trailing edge of the wing. That's as far back as I could get it.

dhal22

I shifted the air tank back about 2 1/2". It's not much but at least it's over the CG instead of in front.

8178

My Feedback: (17)

The header for the 61SF needs to be pretty long, about 18” from the center of the cylinder (glow plug) to the first baffle. My SF liked it a bit longer to keep it from falling off the pipe on vertical pulls.

dhal22

Excellent Mike, thanks, I will use that recommendation. I will take a measurement next time I assemble the plane.

dhal22

I moved the battery back about 3" more. Now within 1/4" - 3/8" from balancing as shown on the plans. I still need to block the battery in place so I would think the additional wood will finish the balancing issue. Now for lateral balancing. I put the plane on baby scales and she is exactly 8 lbs dry.

8178

My Feedback: (17)

Getting close now! Can’t tell for sure but it looks like your pipe header needs to be a lot longer for a OS SF.

dhal22

Mike, I think I ordered the header based upon your recommendation in your Blue Angel build thread. I'm sure it is a Macs SF 'long' header but i will check. Thanks for the heads up.