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Aug 23, 2006, 06:28 PM
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The 4Q

The 4Q Build thread
Last edited by UAVPilot; May 24, 2008 at 03:52 PM.
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Aug 23, 2006, 06:29 PM
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Introduction And Plans

Hello all

The 4Q was developed after the Hydro Foam was first introduced. The story on it can be read on this page of a thread. In post #44 (note who posted right after me)I said that I would give away the plans for free. Well, After a long wait, and a lot of work, I am finally able to do it.

The 4Q does not use the same aero dynamic principles that the original Hydro Foam uses, and does not fly near the same. Believe it or not. A properly built and setup Hydro Foam can be used as a trainer, because of it's self stabilizing ability. The 4Q does not do this at all. It goes where you point it and stays where you left it. It flies like a pattern plane in most ways.
What the 4Q does well is , smooth pattern like flying, snap rolls that will freak you out. Great vertical performance if built as shown. And some of the best water handling of any Hydro so far IMOP. It will harrior real nice and slow down just fine. Not much on hovering.

So this is definitely not a plane for beginners to fly, much less build.


This design was first draw on poster board. I built a couple from the templates, then took the templates to my good friend Dick Rankin. He scanned each part and traced it into CAD for me, then used a machine he has at his work to cut a few kits. After a few changes and a lot of work we finally have the plans. He did a great job with them, and took him much longer to do all that then it did for me to design it in the first place (look back at the thread and see the time difference between the time I said I would draw the plans and the time I said I was finished).

This is why I ask that all that download them at least donate a few dollars to His PayPal account at [email protected] . I am not getting nothing for this but I at least think that he should for his hard work. Cause i didn't pay him nothing ( he did of course, get to keep a kit )

I also ask that the plans DO NOT be posted any where else. You are free to post a link to them and this build thread but please do not re post them.

Also, you may take the plans and have someone cut them for you if possible, But under no circumstances are the plans or any kits to be sold to the general public. Tim from E-foamies has the right to cutting kits from the plans and they will be available soon.

So good luck to you and happy flying/ boating

Can you figure out why it is called The 4Q?

Download plans below

Last edited by UAVPilot; Apr 15, 2011 at 10:37 PM.
Aug 24, 2006, 04:35 PM
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Foam forming and Parts list

Short tutorial on foam forming. If you are not able to do this then it will be pretty much impossible to build the 4Q. Grain direction is important, especially for the formed parts. And sometimes, Depron will bend smoother on one side then the other.


Parts and supplys that will be needed to build the 4Q.

1. Two sheets of full 3mm sheet depron 27 x 39

2. 3/4 and 2 inch blue #2080 3M scotch painters low tack tape.

3. Glue . I design around useing medium and thick foam safe CA and accelerator.

4. Wrapped Straight Tubes ,WS-36-18, 36" long .295" 18.1 gr (only need about 11" of it)

5.Carbon Fiber Pull-truded Tubes - 36" long .125" * ferrules .070" 1/8" 3.00 mm 7.6 gr

6. Flat Carbon Fiber Rods - 36" long .020" x .120" -- mm. 2.2 gr

7. CF Flat Strip .039(1mm) x .118(3mm) x 40"

8. Round Carbon Fiber Rods - 36" long .040" 3/64" 1 mm 1.0 gr

9. Round Carbon Fiber Rods - 36" long .050" 3/64" 1.25 mm 2.4 gr

10. 6 x 12 inch sheet of 1/64 plywood or .010 carbon sheet.

I'll post more if I forget something.

Lets get to work


Last edited by UAVPilot; Dec 30, 2010 at 08:21 PM.
Aug 27, 2006, 03:21 AM
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Fuselage Construction

Last edited by UAVPilot; Aug 30, 2006 at 02:13 AM.
Aug 27, 2006, 04:08 AM
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Motor mount

The tube itself should be perfectly straight. The type of tube mount that I normally use is slightly larger than the tube itself, and I usually hot glue or CA it in place with a little right thrust , but no up or down. Then I drill a small hole through the tube mount and secure with a small screw. The motor needs to mounted as far back as possible with out chopping the nose off.

.................................................. .......
Last edited by UAVPilot; Sep 01, 2007 at 05:48 PM.
Aug 28, 2006, 04:20 AM
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Bottom of the Fuselage


Last edited by UAVPilot; Aug 29, 2006 at 04:48 AM.
Aug 28, 2006, 05:11 AM
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Sponson construction.

Do I need to say make sure and build a left and right side?

*note* some pics switch from side to side depending on clarity.

Last edited by UAVPilot; Sep 24, 2006 at 07:53 PM.
Aug 28, 2006, 08:53 PM
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Getting some tail

You will need Two 7 inch long pieces of .040 carbon rod or similar.

And a piece of .020 or .040 x 3mm x 11 5/8 flat carbon.

Aug 28, 2006, 10:15 PM
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At this point in the build , The Servos can be installed. This is to minimize damage to the top surface of the model before the scope is glued on

There are a few ways to do it but here are some pics of a previous one I did.

The servo installation show is for a single aileron servo. I highly recommend running two separate servos for each aileron. This will give it flaps and really slow it down for landing without having to bring it to a hover. You can also dial a little up in them for running on water with out fear of it lifting off. The dual servo setup has been done on two other 4Q's after this pic.
The ailerons servos can be mounted on there side with the top sticking out of the sides. This will also allow for a large area for the receiver of give the ability to move the battery farther back. This might be necessary if your motor weighs more than 1 oz.

The carbon rods used to connect the two surfaces together are held together with heat shrink tubing.

Last edited by UAVPilot; May 14, 2008 at 11:13 PM. Reason: added more pics
Aug 29, 2006, 06:27 AM
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Intake and exhaust.

These parts are purely for decoration, but they sure make it look cool!

Aug 29, 2006, 04:17 PM
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Skids and stuff

The bottom skids can be made out of Carbon fiber, 1/64 plywood or what ever you want.
If you don't plan to run on asphalt much, you can just use packing tape with the over lap of the two strips down the center.

You can also just glass the bottom of the sponsons with dry cloth and epoxy.

Ether way there needs to be a replaceable part toward the rear of the skid that can be easily replaced.

I am going to mount my skids later as I hate this part. It is messy and time consuming. You will need a way to blow off the carbon dust after sanding the bottom of the skids to fit. Wiping the dust off doesn't really work well.

Last edited by UAVPilot; May 24, 2007 at 08:47 PM.
Aug 29, 2006, 09:56 PM
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There are only a few motors that will work for the 4Q, and only a few props.
Here are a few that I have tried.

First, my 12 turn of 24 awg home made CDrom motor, still my all around favorite. I buy most of my parts here > <

Strong also carries a HFM motor that works real well at the bottom of the page here > <

Basically the same motor can be bought from Custom CDR here > Custom CDR < Or you can buy the kit and build your own here > Custom CDR kit <

Another great motor that we have tried on the Regular Hydro Foam that worked really well but on two cells instead of three is from E-foamies here > Micro Dan < I am really interested to try that motor on the 4Q with three cells and a smaller prop.

The 4Q really grooves well in the air with a LittleScreamers "Park Jet" Micro OUTRUNNER and a APC 6x4 or especially a APC 6x5.5 prop.


Props that work are the GWS DD 7 x 3.5 . My motors will over drive that prop and make it sing (literally) at full throttle. If your combo doesn't do that , then your not getting enough RPM out of your setup

For more speed but less thrust the APC 6 x 4 is a great prop. Gives more ground clearance also. This one will not cavitate at full throttle like the 7 x 3.5 prop does.

The APC 6x5.5 prop will really make the performance shine with a motor and speed control that can handle the extra current draw of that prop (about 18 amps). The 4Q really grooves with that prop well.

8 inch props will not work. They apply to much torque to the fuselage and do not give enough ground clearance.

Last edited by UAVPilot; Jun 08, 2007 at 12:59 AM.
Aug 29, 2006, 11:49 PM
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Test Flight

At this point, I like to do a quick test flight to check things out before I commit to a paint job.

The more control deflection the better. Doesn't really need any Expo except maybe in the elevator.

The CG is 2.25 to 2.75 inches back from the leading edge.
It really has a large range in the CG so feel free to experiment. If it take a lot of forward stick to fly inverted , then it is to nose heavy. A small amount of forward stick inverted is normal though.

AUW should be around 8 oz's without the battery

I have flown mine up to 12.5 oz's with the heaviest battery and it still flew fine with no bad tendencies.

Everything should trim out level to start with. The 4Q really likes speed and grooves real well. The tail will tend to wag in windy conditions, that is normal. The 4Q will also fly slowly in a nice harrier mode, but the ailerons become almost useless and it requires rudder to turn well.

High speed snap rolls are outrageous, fact is, you can make it spin so fast with full control deflection you would think that the sponsons are going to fly off!

Water handling is by far the best of any Hydro out there IMOP.

The 4Q does not have any roll stability built in to it, so you will always have to be on top of it when you are flying. It goes were you point it and it stays where you left it.
Last edited by UAVPilot; May 28, 2007 at 10:12 PM.

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