I built 2 of the "FIVE-JETS",which were a Spanish design and one of them is still flying today. It glides forever on the landing aproach. The power was a home-built KJ-66.

Regards
Craighttp://www.rcuniverse.com/forum/atta...mentid=2002016http://www.rcuniverse.com/forum/atta...mentid=2002017http://www.rcuniverse.com/forum/atta...mentid=2002015

Nice work looks a lot like the Formost as well.

Back to the wing tube ... yes a 1" single tube should be ok as you are going to lock it into the fuse it should be more than ample to handle pretty high wing loads.

A single 3/4" tube would be very marginal.

The load calculations I used were wing span 78" and AUW of 25lbs - it's an imperial calculator, the wing tube / spar load is calculated as bending moment spread equally over it's length, with near rigid wings and fuse support the tubes bending moment is reduced greatly and you can get away with a lot less stiffness in the tube itself. To bend the tube you would have to effectively break the wing or the fuse....I don't see any issues at all with your arrangement, should be very solid.

John

Craig

To confirm your thinking, I assume 1 single wing tube right through and all bolted together, with 1" x 1.6mm wall alloy tube based on 76" wingspan and 25lbs weight the tube if loaded conventionally along its length will take 6G without yeilding. At 8 possibly 7G it will bend with that said and with your wings and socket mounting for the tube being near rigid it will decrease the bending moment greatly and whilst you may have some quite severe forces transmitted through the wings and tube sockets at extremely high G loads say above 10G it would be unlikely to bend the tube greatly if at all, the structure will almost need to fail before the tube bends. You will need a good thick wing tube socket in the fuse to be sure it wont allow the tube to bend in the middle, the method of attachment you have indicated should do the job nicely. By making the socket rigid you are effectivly increasing the tubing wall thickness through the middle of the fuse and increasing its load bearing capability, it would only be possible to bend the tube outside the fuse (that is highly unlikely even at very high G loading).

All good.

John

Craig

Read this link: http://www.rcuniverse.com/forum/rc-j...s-through.html

Thats a bit scary actually, recorded G forces on some jets sport flying up to 10G and some guys getting up to 18G in extreme manuvers.

Maybe get an 1 1/4" tube....Lol!

John

Hey

Carbon Fibre - tube shop USA - 1" x 1/16" Tube would withstand in excess of 20G based on the info available. Unidirectional fabric for longitudinal loading $113 USD / 72" (1524mm) length (An option for someone who wants the security).

John

Hi John

Thankyou for the information.Yes,carbon fibre tube would be the way to go.Pitty our Rand value is weak against the US Dollar.

Regards
Craig

Hi Craig

ANy progress bro from your side.

I have cast some wheel bays for my Pantera, silly ABS ones supplied started cracking up, keeps me busy.

I also have my eye on a Fox Cub jet complete with P60SE for a fair price over here I might just get that for a week-end flyer.

I had sold my baby boomerang several months ago and got bored with I had about 25 flights with it over a few months was no challenge to fly and land in the end.

I'll be keen to see your Formost++ in the sky when you have it completed, with all the work and thought put into it, should fly and perform well.

Are you expecting to have some washout on the wings or are you going to stick em straight out. I know you are making the new wings symmetrical.

It should be a really good flyer based on your thinking. Keep up the good work.

John

Hi John

No,No more progress done. My Mother had a mild stroke,last week Tuesday and is still in Hospital. We are also in the process of arranging a Frail Care unit for her. Its quite a bit of documentation etc that must be done. So as soon as that has been sorted out,I will go ahead full steam. I will also have the K80E this week,which will be going into it.

Regards
Craig

Craig

No problem, my mother went into frail care some time ago and I know exactly what you are talking about, hope it goes well for her.

Otherwise yes I am keen to see yours finally come together and fly, shold fly well with the K80.

Naturally we will need to see the video when you maiden it...

Cheers

John

Craig

Any more progress in between other things going on.

I shall pick up this Fox Cub saturday, just to have something I can fly every week-end as I have sold most of my prop planes now and just have a 3M YAK sitting in the garage which is just too big for a week-end flyer.

Also will be going to a big jet event early August at Maryborough on the bitumen and will take both the Fox Cub and the Pantera a 3 day event, not that I'll fly every day.

Anyway when you get a gap let me know the progress - when you have them some pics as well bro.

John

Just won this at my clubs raffle last month. Looked inside the forward section of the wing and the sheer webbing grain is horizontal. Kit was bought several years ago and was listed as Formost 160 V2. I am thinking of making it a pusher electric or EDF..Would the wing be strong enough without mod for that use? Would it help if I sprayed some low expansion foam into the forward section of the wing?

I had one several years ago and sprayed foam inside wing l. e.. Be careful as it will swell up the sheeting. Put expansion holes in area also and measure carefully. I had a turbine in mine so went extra effort. Opened up wing and reinforced L. G.. Some early models had ribs split after numerous flights(20?????) so I went inside wing and added balsa strips across rib grain. Nice flier. For electric I would only do the L.G. mod and add ply or dowel across fuse for main wing tubes and anchor in center of fuse. Also I foamed the booms after running servoe leads. Worth the effort.

David,

Most likely will reinforce the LG since I might add retracts. I will try the low expanding foam that is used around windows. Doesn't expand as much as the insulating type. Dowel connecting wing tubes sounds like good idea.

Don

Re: lg I opened up area above mounts (1/4 " in from wing joint ON WING LOWER SURFACE) about 2"X 4"+/- used f. glass matt or chopped up glass cloth with epoxy. Then made a 1/32 ply cover for area with small soc. hd. screws. And painted with gloss white paint. Check your booms as they may be twisty-- foam was easy to do but put an expansion hole in boom bottom if twisty(weak).Be sure and anchor dowel or ply spar joiner in center of fuse.
Good luck.
Dave

What retracts do you guys suggest/recommended for this plane? Not trying to break the bank, but looking for something decent new/used.

I have been using springair for 7 years w/out a failure on a boomerange intro. 20# wet and 300 flights. A bit springy but a good buy at approx $150. Air up spring down. Be sure to get 3/16" legs.
Dave

Thanks Dave!

Hello guys,
does anyone have the templates from RCISFUN? i can cut them myself.
thanks.

Post #1005 page 41
http://www.rcuniverse.com/forum/rc-j...-150-a-41.html

THanks Rich !
just print out, trace back and cut? everything is already sized?
Perhaps you have a file of some sort for a CNC cutter? (dwg or dxf or..?) i have access to CNC equipment.
this is the complete kit right?

Shoot me a PM with your e-mail

PM sent

Where do you guys purchase the high quality CF tubes for the wing mod?

I picked up a For most 150 new in box at a swap meet last weekend. I noticed in this thread that the wings were fully sheeted. My wings have open bays past the end of the wing rods. It also has the nose gear supported better. Is this a newer or older plane? Plan to put a 14lb thrust turbine in it.