1947 FROG Jupiter build

[Danny Fenton]

Just cos we talk sense doesn't mean you have to take a blind bit of notice mate

[Richard Harris]

A couple of hours work and the fuselage sides have been made, not a lot to them really. These have been put together with formers 5 & 6 , the tops of these create the canopy frame.

Will cut out a few more formers tomorrow, in front of F5 the fuselage tapers getting thinner towards the bottom face which will be fun! may well end up like a banana if I'm not careful.

I have omitted the lightening holes as they will create weak points on the larger model.

 

 

Rich

[Steve Hargreaves - Moderator]

Posted by Danny Fenton on 07/12/2011 17:09:38:
Just cos we talk sense doesn't mean you have to take a blind bit of notice mate

Edited By Steve Hargreaves on 08/12/2011 11:58:17

[Richard Harris]

Cut out the fuselage formers this afternoon, front end was as expected..HARD! super glue and accelerator unfortunately had to be used around the front as it curves around.

Next I will trial fit the motor and gear box, then the top front can be planked.

 

On another note, when I was at work this morning the unit next to where I work had an accident where several chaps got injured. The air ambulance was called for and I watched it come in to land in all that wind, no easy task. It was all over the place as it descended. Cracking piloting skills! got me thinking about when the pilots train, I wonder what the maximum wind speed they are able to fly in?

 

Rich

[Richard Harris]

Well I eyed up the fuselage this afternoon and for some reason from the canopy forwards it had gained a twist. So I have had to hack it realign and glue back together, this time it is straight, phew!

 

Managed to get the top front covered in balsa, the wood was soaked for a couple of hours in boiling water.

Then the first side was added and trimmed on the centre line.

 

The second was added then rolled over and pushed against the first piece, this leaves a reference mark on its underside which I trimmed to. A bit of fettling and this was glued into position.

 

I have also started on the motor mount, epoxying three 1/4" birch ply formers together. The inner holes has been cut out and filed so that my gearbox is a nice fit. To this will be glued a final ply facing to which the gearbox will be mounted. The bolts for this will not be seen as they will be obscured from view by a spinner.

Then all that will be needed around this area is balsa block to form the front end, I have opted for a big cooling hole at the front. This is not to scale so to speak but I think it will ok, kind of Mothish.

Need to let everything dry out so I can start to sand things down.

 

The plan is to spin a biggish prop, I have tested this wooden 13 x4 and its only pulling 18 amps on a 3 s pack. It has way too much thrust so I may end up ordering a 2s pack.

Nose weight will be a big problem in that there will more than likely be too much. I have been scratching my head over the battery position. The plan is to have plug in wings which eliminates access to the normal hole where the wing seats. I am thinking of making the middle canopy removable to give me room. But will know more as things progress.

 

 

Rich

[Big Bandit]

Hi Richard,

 

I was just thinking around a solution to your tail feathers problem, and I'm not sure if it's workable but the old KK Ivory Gull had an all moving tailplane that I had my doubts about at first. The fin was hinged and the tailplane just sat on top. It seemed to have no effect on rudder when the fin rocked backwards and forwards, but it turned out to be very effective and I had years of slope soaring out of it. In the end I gave it to a local model shop to hang up and they sold a few from it. Just a thought.

 

Chris.

[Richard Harris]

Chris,

Sounds interesting, if I do go for the all moving tailplane this will mean the the fin and rudder will also move very much like what I think you mean about the Ivory Gull? The problem would be to some how couple up the rudder so that it is free to move whilst the tailplane is pitching back and forth.

The more wood I am adding to my Jupiter the more evident it is that it will be nose heavy due to the long nose. I may well have to end up fitting the servos into the rear end to help compensate this but will know more when things progress a little further.

The nose is just about done, it still needs to be shaped to suit a spinner. At the moment I cannot find one with the correct profile so may make my own along with a bespoke prop driver.

Have also made up the wing joining box and dry fitted it into the fuselage, its coming along slowly (very slowly).

 

 

Rich

[Erfolg]

Exquisite, beautiful workmanship.

 

I would like to see the plan of this one, so as to hew from planks a less crafted version.

 

I am impressed with your model, very SAM 35.

Edited By Erfolg on 14/12/2011 16:50:55

[Richard Harris]

Erfolg,

Close up it is not that great, I made a huge error with the ply motor mount. When first sanded down the ply mount was revealed which didn't look correct. If you look at the photo you can see that I had to get a hack saw to it and chop the top portion of the nose back horizontally to remove the revealed ply mount. This was then in filled with balsa, hopefully when covered and a with a bit of paint this odd joint will disappear. Or I could 'cheat' and make up a litho plate cowl!

 

The original shows 22 degrees dihedral, this has been reduced to around 18 degrees as it looked a bit to much. At this stage it is no hardship to make up another box as this is where the dihedral is set.

 

Now should I stick with the reduced or go with the original, what do you think chaps?

 

The UC on the original is a knock off type, I like this idea and its position as it will give it character. A block is set into the fuselage with brass tubes for each leg to slot into. At the front of the block is a tube to which a rubber band locates to the front of each leg. They can then pivot forwards on impact with terra firma.

I am not sure but I would hazard a guess that was the norm for this type of model back in the year dot?

 

 

Rich

[Erfolg]

I am certain you are correct in reducing dihedral.

 

I built a rudder elevator VC Tomboy, using the original dihedral. The model exhibited wild Dutch Rolling, with the slightest amount of rudder. The dihedral was reduced, making an improvement, not a cure. I finally almost made the wing flat, which resulted in a well handling model.

[Big Bandit]

Hi Richard,

 

I think 22 Degrees is a bit much obviously very stable for rubber power, but a bit much for controlled flight, like the folding under cart idea though, I recon they did those sort of things back then and they seemed to work.

 

Cheers,

 

Chris.

[Richard Harris]

Cheers Chris,

I will leave be then and get on with the wings, see what it looks like dry fitted.

 

 

I have made up that UC mount using 3 laminates of lite ply. Slots where cut into the middle piece which acted as pilot holes for the aluminium inserts that have been machined up. It was just a case of drilling through once the glue had gone off, the hole at the front is for a rubber band to run through which pulls the 2 piece UC legs together.

Have added lightening holes and will also add strengthening inside the fuselage where it fits in.

 

The prop driver that came with the motor and gearbox just wasn't quite long enough ! frustrating because I haven't another. So I have machined up a bespoke one to suit this model, just hope it spins true!

 

Well I have a couple of spinners, one to big and the other to small. I cannot justify going to the LMS for just a spinner so I had a bit of a thought.

I took the smaller one and wrapped it in 1/4" layers of balsa, made up a small mandrel and reshaped it on the lathe. The screw mounting clearance holes where drilled out first before whilst I had a flat surface to mount it on the pillar drill. The diameter is pretty close now, will have to give it a couple of coats of dope or varnish to finish it off but I am pleased with the results.

 

Rich

[Big Bandit]

I do like the spinner Richard, I must get myself some sort of small lathe when the new workshops finished. The whole build's looking very smart.

 

Cheers,

 

Chris.

Edited By Big Bandit on 15/12/2011 18:02:20

[Erfolg]

I am also impressed with the spinner.

 

The gearbox looks reminiscent of a Mole Technology item., is it?

[Big Bandit]

Posted by Erfolg on 28/11/2011 20:06:39:
I do not know if you know about the House of Frog. If not it may interest you.

Hi Erflog,

 

What a fantastic link, I've just spent half an hour skipping through it some great models in there just right for lazy summer evenings. Thanks for that.

 

Cheers,

 

Chris.

[Richard Harris]

Erflog,

The motor/gearbox and esc is a Hong Jobbie bought off Flea Bay, I don't remember the Mole Technology type?

 

 

Gearbox

 

Rich

[Robin Kearney]

Enjoying watching you build, Richard. It sure is one of the prettier Frog models.

Erfolg, I'm not sure if you knew, but the plan is up on Outerzone:

http://www.outerzone.co.uk/plan_details.asp?ID=2290

Sorry, making links doesn't work from the iPad.

If you havnt come across OuterZone, many a happy hour can be lost browsing their plan archive.

r.

[Big Bandit]

Thanks Robin, I'll do a bit of surfing to see what they offer.

 

Cheers,

 

Chris.

[Richard Harris]

I passed on my plans to Dereck Scott for his collection, HERE

 

Must get back on the Jupiter, I get distracted very easily !

 

On another note but still with a vintage feel a friend from the local club Martin turned up with a couple of home made diesel engines. I took a few photos as I thought it would be good to share.

Both Mills type, the first is a tiny .2cc version. He has made 4 of these and they run really well. It is tiny and the craftsmanship is superb. everything is bespoke, even the tank.

 

 

The second is a 6cc version which he turned up with today. He has shortened the stroke on the version and has used an OS carb. He says it needs a heavy 14" prop to maintain a run but throttles really well. This he is planning to fit into a Super 60 or his Smog Hog which is currently powered using a Taplin twin.

 

The photos do not do the engines any justice, they are a work of art!

 

 

Hope they are of interest?

 

Rich

 

[Big Bandit]

Hi Rich,

 

They are so sweet, it takes more than an engineer to turn out something like that, it shows real talent. I've seen a fair few home made small diesel motors in my time, but nothing comes close to those, they are a work of art.

 

I've took the liberty of sending the post to a mate of mine who is a classic engineer and I'm sure he'll be impressed.

 

Cheers,

 

Chris.

Edited By Big Bandit on 06/02/2012 19:05:48

[Martyn K]

Those engines are amazing. On my wish list is a small engineers lathe and mill (I am only 5' 6") - but seriously, I don't have space for an ML7 - which is what I really want.

 

Martyn

[Richard Harris]

I knew they would be of interest to someone, they are a work of art and he is very modest about his skills. Without doubt the best engineer I have ever seen, you want to see his 7 cylinder radial! The good thing is he flies everything he makes

I will check with him to make sure its ok but I do have the drawings for the smaller Mills, I can get copies of them made if he gives me the nod if your mates interested Chris?

 

 

Rich

[Big Bandit]

Hi Richard,

 

I'll give him a ring over the weekendand see what he says, he does a lot of work for motor sport and aerospace and what he turns out is a work of art to me.

 

Cheers,

 

Chris.