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Old Aug 20, 2006, 01:19 AM
The Revegetator
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Melbourne Australia
Joined Jun 2006
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Hobbico Ventura/Venom Freedom Flyer Mod's

After seeing some interest with people modifying the Hobbico Ventura, or the Venom Freedom Flyer as it is known here in Australia, I thought I would share my modís.

This was my first electric RC model after over 20 years absence from the hobby, (I used to slope soar a 2 metre sailplane back then). I was so happy with the Freedom Flyer that when I started to get bored with it (probably at least a couple of hundred flights) I decided to start making it more exciting without spending too much money. I had by this time moved on to other models, but the Freedom Flyer is a great size to take on holidays and trips.


Hereís what I did:

After removing the motor and speed control/receiver, I bought the following components that fitted into the model perfectly.

Dualsky XM400A brushless outrunner
Towerpro 15 amp brushless speed control
Jeti Rex 5 channel Rx and crystal (to suit my my JR Tx)
3s 11.1v 1800mAh lipo (same dimensions as the original nimh pack)
A middle piece and 10x8 Graupner CAM prop (the largest diameter that will fit)


Most of the above was purchased off ebay.

The tail plane was pretty tatty by this time too, so I traced it onto some paper and made a new one out of balsa and covered it one of the shrinkable plastic covering products available at the LHS. This has been extremely durable and Iíve had no trouble with it.

With the above modís I get the figures below, which give me about a 60 degree climb and easily up to 50 minutes duration on one battery pack.

11.57 volts
7.2 amps
83 watts
5145 RPM

I couldnít believe it the first time, but I easily did it again. About half my flying comprises climbs to high altitude (almost spec height) and gliding to low level. The other half is just hooning about doing stall turns, spins, loops and very barely barrel rolls.

Not having much spare money about at the time to buy a light electric thermal sailplane, I decided Iíd have a go at making a 1.8 metre wing for the Freedom Flyer. The all up weight with this wing is 550 grams. Not bad for such a cheap model. It climbs the same as with the original wing but stays up much longer without power. Catching thermals is very easy with this wing, and Iíve specked out many times with it. The only problem is that turning takes a lot longer, but it didnít take long to get used to that.


After the 1.8 metre wing I thought it would be interesting to make an aileron wing so I could really throw the Freedom Flyer about the sky. I used a couple of cheap $10 servos off one of the ebay stores and a $15 Ubec so I didnít burn up the bec in my esc. The model flew incredibly fast and was incredibly maneuverable. The under-cambered foam wing the model comes with creates a lot of drag. My problem with this setup was that the Ubec was too close to the Rx and caused glitching. I lost control of the model and it disappeared into some very long grass next to the creek behind my house. I didnít find it until the next day, but to my surprise it was undamaged except for the lipo that had discharged and puffed.


The Freedom Flyer has been a great model in so many ways. A trainer, a high performance Park Flyer, a 1.8 metre electric thermal sailplane and an aileron aerobatic sports model. I plan to move away from the Freedom Flyer as I will make a new fiberglass fuselage big enough to separate the Ubec from the Rx so I can use the aileron wing with no glitching. This has given me the idea of using one fuselage for lots of different flying which will save me heaps of money!

Anyone interested in my modís? Iím happy to share the finer details.

Chris
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Old Aug 20, 2006, 04:36 AM
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Chris,
I used to fly a Ventura until losing it to the ether a while back. I've moved on to bigger/better airframes, but it's always good to have a fall back flyer when conditions don't suit the other stuff. I found my Ventura to be a capable flyer with a 3 cell LiPo. I have another in the closet that could surely benefit from the aileron wing mod in your post. If you can, post the mod or send me a pm with the info.

Thanks,

Mike.
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Old Aug 20, 2006, 09:55 PM
The Revegetator
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Melbourne Australia
Joined Jun 2006
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Aileron wing for Ventura

Hi Mike,

I donít know if you have done this before, so forgive me if Iím trying to explain what you already know. Although I have made a few kits in the past (over 20 years ago now) I only started scratch building wings recently, so Iím no expert and Iím sure there are other ways of doing this. I got all the info I needed off websites, some of which Iíll provide links to in case you want to plot your own choice of aerofoil.

Here is what you will need:

∑ I plank of balsa sheet 1.5x100x915mm (preferably quarter grain)
∑ 2 lengths of spar wood 3x6x915mm (I think it was spruce but the guyís at your LHS will help you out)
∑ 1 length of trailing edge stock 7x25x915mm
∑ 1 length of square (about 15x15x915mm) for the leading edge that you will sand to shape.
∑ Some CA glue
∑ Some iron on film
∑ 2 micro servos

These measurements are approximate. I found out what sizes of wood to use by taking my plotted aerofoil to my LHS and the guy suggested the right sized bits and pieces.

You can use my aerofoil in the photo and scale it to the chord (leading edge to trailing edge) of the Ventura (13cm) with your computer, or plot it yourself. The easiest to understand info I have found on this is at http://www.mh-aerotools.de/airfoils/...otairfoils.htm I think I used the aerofoil at http://www.mh-aerotools.de/airfoils/ As they say, try and be as accurate as you can, but there will always be inaccuracies when building with balsa so donít stress too much. My wings fly well enough for me and I consider them as pretty rough.

Draw a plan to make your wing on. Decide your wingspan and rib spacing. My wingspan is 1.115m and my rib spacing is 5cm except in the middle where I have them at 2.5mm. This area is planked and needs the extra strength for the rubber band wing attachment. Draw two parallel lines for the leading and trailing edges of the wing and put your leading and trailing edge stock inside these lines. Use them as rulers and draw along the inside as close as you can to the wood. Space lines out where you want the ribs to go. Decide where you want your ailerons. The ribs where the ailerons are will need to be cut slightly shorter along the trailing edge to allow a strip of balsa. I made a simple building board out of an old door with some cork tiles stuck on it. Make sure it is flat and level. I lay it on a table and it gives me plenty of space. I can also hack into it with my tools and not worry about damaging anything else.

Trace your aerofoil onto some ply and cut two templates. Make sure they are the same dimensions. You will also need to cut a notch in the top and bottom of the to fit the spar. I find the highest part of the top of the aerofoil and cut the groove the same size as the spar wood, and the other directly beneath it. Make sure your spar is in a position that will allow enough room to fit your servos. A square edged file works well for me. Clamp them together and drill 2-3 holes in them (see picture). Cut the number of ribs you want out of the plank of balsa sheet. Put them between your ply aerofoil templates and carefully drill again through the holes. Put the nails through the holes to keep it all together and start shaping the balsa to the ply templates. I start off with a sharp hobby knife and finish off with sand paper. For tapered wings plot (or just make one up like I did) a smaller aerofoil. You can see I drew one inside my plotted aerofoil in the photo. Make a ply template for it with the holes drilled into it so it lines up the way you want and shape the balsa ribs between them. You will end up with ribs with angled edges on them, but sanding them strait is easier than cutting them separately. Once you have shaped the ribs, you will need to cut the leading and trailing edge off them so they fit onto your plan. Make sure they are all stuck together well (I use a clamp) and make sure you donít cut too much wood away. You will have to start over again if you cut too much and they donít reach the leading and trailing edge stock. The ribs in the middle of the wing will need the thickness of the planking removed from the top and bottom to the planking does not protrude from the aerofoil shape (see plan). You will also need to decide how you want to make the wing fit the wing saddle on the Ventura fuselage, as itís made for the under cambered wing. I was slack and cut a slit out of the plastic on each side of the fuselage so the humped wing saddle became flat. Just be careful not to take too much out so you have enough clearance between the servo arms and the bottom of the wing.

Once all these bits are cut and ready, I start placing them on the plan keeping them in place with pins except the leading edge. The trailing edge needs to be cut where the ailerons will be. I only pin along the edges of the balsa so I donít damage it. The area of the aerofoil between the spar and the trailing edge is fairly flat so the bottom spar and the trailing edge stock can be pinned to the building board. The leading edge will sit above the building board, so I glue it on later. I glue the ribs onto the trailing edge and the bottom spar, lining them up with the lines on the plan and using a small plastic set square to make sure theyíre vertical.

The middle ribs should have been sanded to allow for the balsa planking. Cut it to size. There should be 4 pieces and the spar should sit flush with the planking like in the photo below. Glue a square of balsa plank between the ribs and spar where you want to mount your servos (see photo below). Make some holes in the ribs and the bottom of the central planked area and pull your servo leads through. Glue in your servos, cover the wing and your finished.

I hope you managed to get through all this and decided itís not too hard. If you already have a work surface, some ca and epoxy glue, the wood, covering and servos should cost you less than $30. Once you have done it once, I can almost guarantee you will want to do it again. My 1.8 metre wing took me about 5 evenings, and this aileron wing only took about 3. Once you get the hang of it, it takes almost no time at all. Iím going to try foam core wings and fiberglass fuselages using the lost foam method next. I might never have to buy another ARF again.

Good luck and let me know how you go. Let me know if you have any questions.

Chris
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Old Aug 20, 2006, 10:04 PM
The Revegetator
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Melbourne Australia
Joined Jun 2006
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Mike,

After clicking on the second link, click on the sailplanes button on the left hand menu. I used the MH42 aerofoil. All the coordinates are there, and the first link shows you how to scale them to your 13cm chord.

Chris

Good luck
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Old Aug 21, 2006, 04:47 PM
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Old Aug 23, 2006, 04:27 PM
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I happen to have two of these birds also, one is in desperate need of repairs or better yet mods. Found another wing mod incase anyone here is interested. http://www.rcgroups.com/forums/showthread.php?t=510062
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Old Sep 09, 2006, 07:50 PM
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Old Oct 25, 2014, 01:31 AM
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What frequency was the original receiver and transmitter on? I found in my garage an un-flown one hanging on a wall in a room I haven't been in, in years, because of health issues. Now I am feeling like flying again I'm wanting to fly this little plane. Can you tell me anything about it stock right out of the box and how it did for you, and what you did the first time you got it ready to go? Also what does the red button do? I have no printed material on this and am trying to find out everything I can about it. If you wish direct e-mail I am good on QRZ.COM for an e-mail Thanks! Jimmy, ARRL TS, WX9DX
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Old Oct 26, 2014, 04:13 PM
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Melbourne Australia
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Hi Jimmy,

Wow, it's been a long time since this thread has seen the light of day!

The model flies well out of the box but is light on power. I flew it stock many times before upgrading the power system. When you feel like you want to upgrade the power system it is probably best to get a new model as there are so many cheap brushless LiPo powered planes to choose from. Back then such things were cutting edge!

I'll try to find what still remains of mine tonight to answer your questions.
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Old Oct 29, 2014, 03:24 AM
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venom freedom flyer

I love this little plane and now I need a battery as mine is lost with the charger some place while my wife was cleaning up things in the garage. So now I have been looking for two weeks for the battery and charger. The hobby shop don't even know what to sell me for it. Mine has a orange rx3s receiver in it with stabilization. Flue amazing even in the wind. But thanks to others I now cant fly it cause the battery and charger are gone. Help please with some original battery specs and chargerl


The mod looks amazing I'd. Like to see how you put the motor in it.

Thanks for the help I'm. Lost without the book... And replacement parts.
73
Jimmy/ ARRL TS/ WX9DX
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Old Oct 29, 2014, 07:34 AM
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Melbourne Australia
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Hi Jimmy,

Sorry but I haven't had time to have a proper look yet, I have too much going on at the moment.

A 2s LiPo might work ok with the stock brushed motor if you can find one the right size. You will need a charger capable of safely charging LiPo batteries though. Most of these chargers also charge NiCd batteries too.

The brushless motor was a direct replacement, it fitted perfectly. If you upgrade to brushless you will also need to replace the esc, but they are very cheap.

I'll try and find what's left of mine tomorrow.
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