Building my new Fournier RF-4

[Peter Miller]

The problem with that is A) the wheel is quite a bit too small. Stormtrade sell it in this country.

 

The other problem is that it would end up well forward in the tank bay. Either that or you have to make a huge cut out in the front of the wing.

 

It might work reversed retracting forward.

[David Thorpe 2]

hi Peter,

 

I love this model and would like to build one when I have a bit more time. I am likely to electric power it .

 

The only other mod I'd be interested in would be to fit a retract for the main wheel ~ do you know if this has been done, or is possible, if so is there a "unit" out there that would be suitable. I have noted the previous threads and think the full size glider wheel retracts forwards anyway and (I'm no ic. man) the electric set up might allow modding of F1 and a rejigging of tank space to accept a Lipo on its side next to the wheel unit

 

David

[Peter Miller]

If I were going to do it I would try and find the old drawing of Mick Reeves big Fournier and copy his retrtact unit. IT was made from bits of bent wire and could be duplicated.

 

I have seen a picture of it when I googled Images for Fournier RF-4.

[David Thorpe 2]

Thanks for advice Peter, I have seen one he sells for his 1/4 scale RF4 but it seems to be a different construction to the one you mention.

 

David

[Peter Miller]

As I said.soemwhere in this thread. Look on Google in the Imagaes for Fournier RF-4 and you will find a picture of the Fournier model retract.

 

But then it depends how interested one really is.

 

For those who can't be bothered to look here it is

 

Picture of Fournier model retract unit

[David Thorpe 2]

Many thanks again Peter, the "bits of bent wire" you mentioned fooled me as I had previously seen the unit you refer to so now know what you meant.

 

Just one final question before I mock up a similar retract to test for viability ~ is the fixed 2½" wheel you specify about scale or have you gone for a size which has the best ground handling characteristics?

 

best wishes David

 

 

 

 

[Peter Miller]

The U/C in the original kit was all bent wire, this looks far more practical for the average builder. I am not a fan or complicated wire bending.

 

I think the wheel is just about scale.

[David Thorpe 2]

Many Thanks, off to see if I can create a unit that fits, isn't heavy and most importantly WORKS otherwise it's the fixed leg for me!

 

David

[Ron Harrison]

Peter,

 

Does the Engine installation require Thrust adjustment please, or should I just fit, and hopefully, forget?

 

Ron

[Peter Miller]

Mine is set up 0-0. Works fine.

[Ron Harrison]

Thanks Peter, just thought I would ask, even though here was nothing on the Plans, I surmised that 0-0 would be the answer.

Not having built from a plan before I am quite enjoying myself. Also giving my brain a bit of a work out, as I am Retired.

Ron

[Peter Miller]

I find that for most models the 0-0 set up is fine. A few need some down thrust or side thrust. These are the high wing models. The Slingsby needs quite a lot of both. Low wing models should not need any down thrust. any turn should be corrected with rudder as it will vary depending on the power used and the pitch of the propeller.

 

For this reason I always start off with no side or down thrust and put it in if needed and that is very rare.

 

Of course there will be people who say I am wrong. All I can say is that it works for my designs.

[Daniel Meurer]

Hello Peter

I´ve just completed my Fournier following your plan and instructions. It has been a real joy, every minute ! I learnt unexpected building methods ( washout = so simple. so efectif ! ) and finaly got the nicest plane in my "hangar"

Will maiden it tomorrow, and re-reading all your threads and article about the RF4 I can only see that you handlaunched it. I´m a bit concerned about handlaunching her as the fitted engine ( Saito Fa30S ) is new and had only three tank fillings for break-in, it runs smoth and seams to deliver the promised performance, but you know...

Any tip for ROG ?

BTW: the final ZFW is exactly 3 lbs 10 Oz, pure casualty. Will try to upload some pics as soon I read and understand how.

[Peter Miller]

I am glad that you are so happy with the model. I know that you will love flying her.

 

If the wheel is in for forward position and your flying site is smooth with very short grass you should be able to take off. Plenty of up as she starts to roll and then take it off at lift off.

 

For some reason my RF-7 will take off fairly easily on grass. The RF-4 is more reluctant not to tip on her nose.

 

However if you have someone who can hand launch the model you need have no fears. Just make sure that they launch level. You will have plenty of power. She will fly at less than full power quite safely.

 

Once trimmed you can hand launch by yourself by holding the wheel in your right hand.

 

I will look forward to heariung how your first flights went

[Peter Miller]

It has been drawn to my attention that in my Fournier construction article in the wing construction section there is an error

On page 74, column 3, paragraph 3, it states, "Add the dihedral brace and then, with the root of the wing and leading edge firmly pinned down, insert the washout wedges as shown." From this I conclude that with the wing pinned thus the washout wedges are inserted from the trailing edge of the wing. In the next paragraph starting "!Once all the glue has dried,.........(and the paragraph continues)........Only then should you add R1, fit the washout wedges under the leading edges, and glue the top Sheeting,....".

Yes, the wedges should be fitted from the trailing edge,

[Peter Miller]

I was pretty sure that I had not got it wrong. so I called up my original text and this is what it said.

The second wing is built in the same way but R-1 and the top sheet is not fitted yet.

With the second wing pinned down join on the first wing making sure that the dihedral angle is correct.

Now add R-1 and continue with the washout wedges and top sheeting etc to complete e the second wing.

The wings can now be taken off the board. And the tip blocks fitted. Note that the tip sections are still quite flexible in spite of the D-box construction of the leading edge.

No mention of leading edges etc.

I am afraid that the editors like to do some "sub editing" and as sometime happens, they louse up my perfectly correct text to every ones annoyance

[Graham Ashby (Editor)]

Peter, I'll not get into an unprofessional open debate on the job of a sub editor and why he's so essential but I can assure you that his work is a very valuable part of the production process and I wouldn't be without it. We all make mistakes and clearly one has been made here for which I apologise. Has your text been loused up? Absolutely not. Nothing is ever 'loused' up here, material is treated with the upmost care and respect. When our sub editor finds sections of text that aren't easy to understand or particularly clear, we'll have a discussion about them and he'll often tweak them to sort them out. This is a common occurrence during which odd mistakes can sometimes creep in. All the time I'm here, the sub editor stays.

Edited By Graham Ashby (RCM&E) on 02/11/2011 11:37:41

Edited By Graham Ashby (RCM&E) on 02/11/2011 11:38:19

Edited By Graham Ashby (RCM&E) on 02/11/2011 11:39:06

[Steve Dibb]

My Fournier is coming on slowly (I am a very slow builder) So, I have nearly finished the fus and am looking forward to making a start on the wings.

Having read the magazine article and studied the plan, the position of the wedges is clear and the text error in construction for the second half of the wing fairly obvious. Peter's pictures above make things crystal clear but it is worth pointing out for clarification purproses, if only to confirm that washout is appropriate to both halves of the wing!

What is interesting about Graham's response is the apparent "tweaking" of constructional text without reference back to the author. Perhaps if this had been done prior to going to print the issue would not have arisen.

[Adam Reay]

I have just bought the plans for the 1880mm Fournier RF-4 but before I commit to building one with an electric motor I just wonder how a folding prop can operate without hitting the very wide cheek radiators.

I believe that the prop will fold OK when power is cut, but when power is opened up again and the blades start to spin once more I think they will hit the radiators before centrifugal force had a chance to swing the blades clear.

I have a Radian and it seems that the spinner and prop are exactly what I need for the Fournier so I built a mock up of the radiators and stuck them onto my Radian and that is when I first spotted the potential problem.

Can anyone put my mind at rest?

Edited By Adam Reay on 07/11/2011 15:54:21

Edited By David Ashby - RCME Admin on 07/11/2011 16:03:54

[David Ashby - Moderator]

Just tidied up a few posts here and added Adam's new query (welcome Adam by the way ).

 

 

 

 

 

[Peter Miller]

Why fit a folding prop? The model has an undercarriage and I have no trouble with the prop hitting the ground.

 

On this model a folding prop will not make a significant difference to the glide.

[Adam Reay]

Good. I'm going to start building right away. I have been flying ready made foamies for the last two years but I started to feel an urge to get glue on my fingers once again.

[Adam Reay]

Thanks for the welcome. You'll find me chipping in quite often in the days to come.

I have one gripe to get off my chest, speaking as an Aberdonian. I have just paid more than £12 for a set of plans for my Fournier but if I had bought a back issue of the magazine it would cost less than half. Also, by buying the plans without the mag I can't follow the comment "See text" on the drawing. I seem to have missed a trick somewhere!

[Peter Miller]

Just as a matter of interest. Are the plans that you paid £12 for the same as the magazine plans, i.e. on two sides of a singla A1 sheet? Or are they on spread out on bigger sheets.

[Adam Reay]

There are 2 sheets with the model shown full size. I hadn't realised that the magazine plan is a single sheet. I have an image of the right wing only and I intend to trace the image onto the back of the sheet to build the left wing. I couldn't do that easily with a double sided plan, so you have answered my question.