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Lil Hacker Questions

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Lil Hacker Questions

Post  fredvon4 on Wed Mar 04, 2015 2:37 pm

I hope Ken and any others who have built the Phil Cartier (CoreHouse) Li'l Hacker will respond

We have bad weather here so building a few birds like the Mongoose, VooDoo, and a few Dawson "hawks".

On a whim I ordered and received a Gotcha Streak RST and Li'l Hacker double set from Phil.... a little disappointed with the wood (hand/machine hacked cutting vs laser on the RST fuselage but that is fodder for a different build topic

Of interest here are the Li'l Hackers,

Recently a thread was resurrected on the subject, but it sounded like Godsey decided to not buy the twin kit.

I absorbed a LOT of Ken's suggestions but once kits in hand, I see a few things I would do differently or other ways to reduce weight and yet have strong enough craft to survive my son and my efforts to prove that a figure nine not always end in the dirt.

I do not intend to waste time with Reed engines.

I intend to use Cox TeeDee .049, Norvel .049 short shaft, with Texas Timers screw in radial mount. Or a Fora .049 with nose block and arrow shaft tail: all having a vast weight difference

Ken Cook, I get it on how to set up bladder compartment in the wing but have a question:

You said you prefer the location you showed aft of the spars so the fuel was on the CG.  That begged the question: Is the CG on the plan wrong (about an inch forward of the spars)? Or simply asked, where do you balance the CG regardless of engine used?

Second idea/question:
Seems to me the top and bottom Fuselage ply is over kill and very heavy: So one idea is to bore lightening holes from firewall back to TE top and bottom to shed weight...or just trim the total width by 40~50% aft of the spars.....comments please

Third Question for anyone who built these:
Did you use the included PLY center section spar? If reducing weight is desired up front I envision using 1/64th ply or some of the very thin phenolic Roddie sent me.  But I can see not using this piece if nose heavy is gonna a problem. It really does not add any structural strength in the direction needed

To explain my thinking here...The vertical ply spar directly under the top and bottom spars is only 5" long-- or 2.5" left or right of Center line. To prevent high G wing folding, it is too short and would cause stress point right where the highest wing bend would be (out side of the already well supported center of the root by the fairly wide top and bottom fuselage plywood)

Further, I have never folded a 1/2a foam wing by high G force..... ON the other hand, when you firmly plant a combat ship in the dirt-- the sudden stop usually has the wing flex forward and break in the center.

I find that Carbon TOW on TE, strapping tape in an "X" from LE outboard/inboard tip to TE just beyond the inboard center, and attention to the center of the LE with glass or carbon veil will make a wing I can plant at 80 MPH and survive.... When I set up Dawson 1/2a birds I end up with a plane a bit heavier that Jeff does but they survive my learning punishment

If you have built a few, want to, curious, have advice please chime in.

If you want a fun 1/2a plane that looks to me like a very easy build, and durable 1/2a trainer---I highly recommend this double kit.

The cores on mine are real clean cut, the ply parts are a PITA to remove but near perfect in fit, instruction are a bit vague but adequate for a previous builder (this is easy to over come as there is CEF, Stunthanger, Stuka Stunt, RC universe, and RC groups internet forums for any help)  There are even folks who have done this bird in electrickery
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a few photos of the Li'l Hacker II kits

Post  fredvon4 on Wed Mar 04, 2015 2:51 pm

Not in the pics is the large qty of SLC...plenty to do both planes with a bit of screwing up learning to use the stuff

SLC = SuperLite Covering is a great and maddening product ...maddening in that you always need three hands and a draft free , dust free environment. More on this when I get to covering these kits



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Re: Lil Hacker Questions

Post  Ken Cook on Wed Mar 04, 2015 3:38 pm

Fred, here's my take. While I built many per Phil's instructions they never suited me well. I went over Phil's house a few months ago to get some problems sorted out for me. I feel the Hacker wingspan is too narrow. Phil just made me the same cores with a wider wingspan but same root and tip. I can now trim and shape the wing panels as desired and still have a decent wingspan. Keep in mind that Phil designed this plane for the beginner. When I did use the Ply fuselage body, I removed the entire center section of the ply top and bottom leaving only 1/8" of material  down each side. The plane will build tail heavy if you use a Norvel. You will need almost 1 oz of nose weight. I elected not to use weight and remove as much material I could behind the cg. The problem with engines like the Norvel is that you need to use a Dave Brown R/C mount. They vibrate and this not only robs tons of horsepower, the mount breaks all the time. I broke 6 of them. I had a mount made from aluminum to avoid this problem. If you build the plane like Jeff does, you can use aluminum Driskill mounts on the noseblock and try Norvel's, Stels, Tee Dee's all on the same mount.

Let's go to the parts. Use the spars to light your fire place as they have no place on a combat wing. Use hard balsa, you will find it easier to sand down and lighter. Just use strands of carbon tow under the spars like Jeff does and thinned white glue. Don't use Gorilla glue or epoxy. I only use Epoxy on the nose block for fuel proofing.  Phil only gives you sticks and pieces that fit into the box. You will find more than likely the spars he provided are too short. He will tell you it's not needed. I'm telling you they need to go wing tip to wing tip. One ground pounding and the wing creases directly where the spar stops. The elevator can also be trimmed waaaaaaay down as I feel it's too wide only adding to the tail heavy condition and it can be angled in to also lighten even more.

Using a small  Contadina tomato paste can, cut the rolled rim off of the top of the can. Heat the can up on the stove and using gloves core holes directly behind the spar. You can cut 3 holes on the inboard side and 2 on the outboard side. The outboard side will also have you bladder compartment. Obviously this is done in a symmetrical application. Coring the holes will save you almost 5/8 oz. even moving the cg more forward. Instead of using metal tubing for a replaceable tail, use the Dubro antennae housing like Jeff does. It's lighter than brass or copper.

My friend Larry I fly with eliminated the shear web your inquiring about upon my instructions. Larry's plane is built using the wood fuse in the kit. We slide the wing forward a bit and cut off the excess material that was behind the trailing edge. I'm thinking we almost cut 5/8" off the fuse if memory serves me correctly.  No wing  failure to date and it won't happen regardless. Look at Jeff's planes, none of them use that piece of wood. That can also be used as kindling.


Here is one I did with my modifications . I prefer the arrow shaft though.   https://www.facebook.com/PhillyFliersCL/photos/pcb.658021857601285/658021487601322/?type=1&theater   I only used the cores. I provided my own arrow shaft and I made my moments based on my Litehawk. I then realized I had to shorten the tail boom a bit to balance using the Cyclon. I'm not using that shear web inside of this wing and not too many planes around are as powerful as this one in the maneuvers. I used carbon tow under the spars and I used carbon veil and thinned white glue at the nose and tail .

Seeing that you have the Fora, USE IT. Put it on this plane and build it the way I did above. My version pictured here is based from Jeff's fast combat plane or AKA the Allenplane. 5/8" wide by 1 1/2" bass engine block drilled to accept carbon arrow shaft. I rough the shaft up and use Pro Bond or Gorilla glue to assemble the shaft to wing joint. Wing roots are white glued together .Here is a video https://www.facebook.com/video.php?v=1456292264595816&set=vb.513140418756097&type=2&theater  of my Lil Hacker in action with Neil Simpson of New England are. My son Shawn is flying Neil and it was crazy fast. The matched ended in a line tangle with Neil's plane just doing continuous loops eventually taking Shawn's plane in.


Last edited by Ken Cook on Wed Mar 04, 2015 4:07 pm; edited 1 time in total
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Re: Lil Hacker Questions

Post  fredvon4 on Wed Mar 04, 2015 4:05 pm

Thank you Ken

Based on your advice to Godsey I already cut Balsa Spars full length. I always use TOW under the spars and can attest this adds a bunch of strength in compression and tension

I have small hot wire cutter and templates to add the fuel cut out and any lightening holes. However the sharp hot soup can trick will be tried as it sounds a lot faster than my current method

Most likely will build a few of these with and without Phils fuselage.

The Dawson/Cook method of arrow shaft and nose block are simple and effective BUT: I hate cutting nose blocks as I never seem to get them square or the shaft holes 90 degrees...yada yada ---So for now I will concentrate on the strandard front end as I have the radial mounts for the TeeDees and Norvels...The Fora's need beam/nose block

The top and bottom fuselage ply---Your Idea is reverse of what I was thinking ... but I like your idea better, gives a better width for the stabilator attachment

In flying trim where does your CG balance?

Jeff is up to his neck in current orders so I think I will ask Phil if he will send me some of the longer span cores, thanks for all your ideas!

If by chance you have excess Fora sized nose blocks for this wing I would like a few
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Re: Lil Hacker Questions

Post  Ken Cook on Wed Mar 04, 2015 4:10 pm

Fred, those cores were pretty exclusive to me. I'm really the one doing the R&D with them currently. I have one started on the table now. The green plane I show in the picture is the same cores on your bench. Ken
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Re: Lil Hacker Questions

Post  fredvon4 on Wed Mar 04, 2015 4:31 pm

Great...crap----I e-mailed Phil immediately after your post

I guess Phil will tell me if I over stepped....apologies to you for jumping the gun.

Really got to get my stuff together to cut my own cores
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Re: Lil Hacker Questions

Post  duke.johnson on Thu Mar 05, 2015 9:20 am

Ken
How much longer are the cores? Maybe I'll cut a couple to try.
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Re: Lil Hacker Questions

Post  Ken Cook on Thu Mar 05, 2015 2:54 pm

Duke, a stock Hacker core is about 15 1/4" give or take a little. The tip is about 5 5/8" and the root is about 8 5/8". The other cores are a full 24" wing panel. Unlike what I mentioned to Fred, the root and tip dimensions have changed. The root is 9 1/2" and the tip measure 5". This is always subject to change due to the way the wire exits the foam. Sometimes you can have a pointy trailing edge and sometimes a squared off one. I generally sand them back or cut them to insure a solid continuous surface. Spar slot is 1 3/8" back from the high point of the leading edge. I switched over to high power ball bearing engines and I needed the wider span to keep the speeds under control. While 1/2A has no speed limit, the speeds are insane to fly. You need to have the plane under control eyes off. I suggested this core and I haven't tried it yet. Ken
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Re: Lil Hacker Questions

Post  duke.johnson on Thu Mar 05, 2015 6:27 pm

I've been thinking of putting something together for my sons. I have some big mig 061's I could use. I think they can handle the speed, they put them on fast planes at the Bladder Grabber last year after the contest each night. The plan is to have them enter the Grabber this year. We have a 1/2A contest a couple times a year and we are talking about allowing the big mig 061's to fly against all the high proformance 1/2A's. Let me know how the longer hacker turns out. I can always buy cores from Dawson or Buzz up here.
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Re: Lil Hacker Questions

Post  Ken Cook on Thu Mar 05, 2015 6:42 pm

Duke, there's no problem with the Hacker AS IS handling the speed or punishment. I requested longer wing panels to create a bit of drag to slow the ball bearing stuff down a bit. Over here, we allow the use of .061's to compete against ball bearing .049 engines. I can get the Norvel engines to fly as fast as the ball bearing variants. I can't keep the engine together though as I constantly break connecting rods. I fully switched to ball bearing engines last year. One thing to realize is that there can be a tremendous weight difference between engines. I use side exhaust Stels engines, these look like a Norvel externally but they're over a 1/4 oz heavier in weight based on the same size engine. The Hacker was designed for a integral tank Black Widow and it's really sticking out there. A Norvel even in a R/C composite mount is almost 1" shorter than the Cox. You will need nose weight if you build it in the stock configuration. Ken
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Re: Lil Hacker Questions

Post  duke.johnson on Thu Mar 05, 2015 9:44 pm

Are the Stels side exhaust a new engine? Are they ball bearing engine you mentioned? I have some Stels .36's.
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Re: Lil Hacker Questions

Post  fredvon4 on Mon Mar 09, 2015 2:22 pm

Ken I had asked before but most likely too many questions in my long post

In describing your fuel cell location cut out in the wing to Godsey: You said you prefer the location you showed aft of the spars so the fuel was on the CG. That begged the question: Is the CG on the plan wrong (about an inch forward of the spars)?

In flying trim where do your Hackers balance?

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