red76ta

I have a formost 160, V2 and have everything ready to start the modification/build to make it turbine worthy. I recently found your thread and I am ineterested in your model, possible future purchase if availabale.

Thank you, Bill

red76ta

Now that I have the plywood and drawings for the mods, I've started looking over the kit and found that they have indeed made some improvements as suggested throughout this thread. (I haven't cut any parts of the model open yet to examine the inside). Most important (IMHO) is that they did not go to a one piece wing tube, rather they increased the od from appx. .625" to .750". I will modify the drawings from this forum and use a .750", 48" carbon fiber wing tube and the mods needed to accommodate same. I tried twisting the booms/vertical fins and they are very rigid. It feels as if they put the long spar inside the vertical fin. The nosegear is completely boxed in and very solid. The plywood used in the fuselage framing is not easily broken and definitely stronger than "ply lite". The glue used in this area looks like the junk normally used in ARF's, however, I couldn't pull anything loose like noted throughout this forum. The outer wing does have an aileron and a flap, guessing about half and half. They put a canopy on it that looks a lot like the custom ones shown in this forum.
All this said, my intent is to do the wing mod with the larger od, 48" carbon fiber tube. I will check the main gear mounts at that time. I will likely cut most of the fuselage formers out and replace as shown in forum. I will cut the booms and check their tail mod and add support if deemed necessary. I may leave the nose gear mounts, as they seem sufficient.
If anyone else has seen or built one with these changes, please let me know the mods you've done and flying results.
There was mention earlier in post that "160" was a misprint, however, my box, plans and decals all state Formost 160. (as info)

Thanks all,

Toolbag

So have you built one up for yourself, an update would be good. With interest I have reviewed your mould development I would be keen to know if you have made any and how they performed.

Rgds

John

izzy

while the foremost 150 could be a suitable turbine plane , it needs mods etc to make it turbine ready
why not go withthe new Xcalibur - i just got mine last week and this thing looks awesome , really nice and goes together quickly

i think at the end with the mods etc , the xcalibur will work out to be cheaper too

KJ-66

My Feedback: (1)

Hello John

Sorry for my delay in response - different Time Zone. I havn`t touched this project for a very long time,but will be going on with it sortly. I had an issue with the tailboom halve joint and couldn`t get a fibreglass tape to strengthen the joint from the inside. Just no space to get in there.This was bugging me for a few months,until recently,I came up with a solution to this problem. My solution to this problem,also enabled me to remove the rudder servos from the tail section. Much better and less nose weight for the C of G.

Regards
Craig

Toolbag

Craig

I am interested in your solution and would be keen to understand how your model finally comes together, your tail boom and rudder configuration sounds interesting maybe some pics when you get it done.

John

KJ-66

My Feedback: (1)

Hi John

I will post photos of that. The elevator will have one servo,which is mounted into the center of the stab (Fully symetrical stab airfoil,alows for this). Not that stab,which was flat and had a servo in the boom,to operate the elevator. At the same time,there will be more "lift" in the stab section. New stab also bolted down onto plywood block,which matches the profile of the stab section and is glued inside the boom.

Also trying to locate the holes inside fuselage,for the wing tube. Making a jig for the laser to "point" me in the correct direction.

Will get there for sure,but its hard work.

Regards
Craig

Toolbag

Izzy

At 5 x the price of the foremost it should be good, is there really 5 x more work in it, sadly it is getting harder to get good value for money these days.

I saw a new xcaliber just last week-end I must say it looked very well put together and the finish was excellent.

Such a pity that the foremost can't match the xcaliber for quality from the factory even if the price doubled or tripled it would still be a very attractive option if it were turbine ready.

There is a big market out there for that size model and very few low cost options that is why the foremost is a lower cost option for the home builder discounting the hours of work needed one can upgrade to turbine ready and out of pocket costs are somewhat less than an xcaliber.

My 2c worth.

John

Toolbag

Hey that sounds like a great solution for the stab, what are you doing with wings and wing tube / main wing aerofoil (symmetrical?) glassed or covering.

Possibly a larger diameter main wing tube with location pegs front and rear could be the go, a cut metal template of the aerofoil (with all holes in position) might be easier to transfer holes for alignment.

it seems like you have sweetened the design nicely, as you say more work to do and nothing good comes without effort.

I have to congratulate you for your efforts so far, it's been a journey.

I would be very interested in one of your Graig's Foremost Plus+ once sorted.

John

KJ-66

My Feedback: (1)

Hello John

Sorry for my late response.The stab and wing aerofoil is actually a "modified" NACA 2010 profile.Its the closest that I had to a fully symetrical airfoil.The wings and stab/rudders will be glassed,with a white base colour pigment added to the resin.Then colour scheme spray painted onto it.

Now the wing tube,is a bit of a concern,as I can`t locate between a 15mm and 20mm O.D. aluminium tube here.The next size up,is a 25mm O.D. and the original one was 16mm O.D. with a thin wall thickness.I have got 5/8" O.D. tubing,with a 1,6mm wall thickness here at home and it is stronger,due to the thicker wall thickness.I need advice here,as if I need to go bigger in O.D.,then I have to import it.Problem is,that I have both 25mm and 30mm O.D.,but heavy in weight.Otherwise I could use 20mm O.D. carbon tube and that has to be imported as well.Any ideas?

I was studying the wing on the original model and discovered that the wing tube,is on an angle towards the wing root rib.So this means dihedral is in it.This made me look at the fuselage photos as well and it looks as if there is definately dihedral in it.This is messing about with thw wing tube alignment - have to think about this.

Thankyou for your comment.Yes,it is a lot of work for sure and its my first mould that I have made.Who knows,you might have one of mine in your posession?

Regards
Craig

KJ-66

My Feedback: (1)

Hi Guys

I decided to buy a new transmitter for the Formost and Turbinator.Its the Spektrum DX18.I tested it in my Taurus plane and worked VERY well.

Regards
Craig

Toolbag

Craig

5/8" (15.875mm) x 1.6 tube would be ok at a pinch you may be able to locate some 3/4" (19.05mm) od alloy tube locally in SA that would be much better.

That being said then another wing tube socket will need to be sourced or made and the corresponding holes bored in the wing to suit, so you would have opportunity to position the hole in the best location for alignment and structural integrity.

Otherwise you may have to build new wings from scratch. More work bro.

John

Toolbag

Actually if you have 20mm tube on hand you would be better to use that a little more weight is a small sacrifice for some strength in the tube, 16mm tube is pretty small for a turbine jet especially if you pull a few G's, it's not going to last long.

John

Toolbag

I was looking at the DX18 also but
I bought a Futaba T14SGA only for turbine telemetry and SBUS compatability reasons.

Nice radio the Spectrum.

KJ-66

My Feedback: (1)

Hi John

Thankyou for your advice.I can get 3/4" aluminium tube and will confirm tomorrow,what the wall thickness is.The wings will be completely re-built,so the alignment shouldn`t be an issue at all.Just the alignment inside the formers in the fuselage,will be a bit tricky to do.Yes,I will make the wing socket tubes.

Regards
Craig

Toolbag

So Craig

Any progress did you manage to locate any 3/4" tube.

You know you are going to have to make two of everything cos I want one as well, after you have it sorted naturally...Lol!!

Off topic

I flew my Pantera over the week-end just fitted a s/h P120sx and OMG it was much fast-er (scarey actually) than with my ATJ 120Ti I will have to tame it down a bit and knock some RPM off the top and put a throttle curve in it, was doing well over the 160 kph at 60% throttle.

Anyway I have an (8 hr) old P80SE that I was thinking of using for the Foremost it needs a internal circuit board and likely a temp sensor as it came out of a crashed model some time ago, the starter, and housing and bellmouth are new and it just had bearings and a balance before it went in, fortunately the crash was in soft wet ground and it didn't have any dirt particles inside at all so it should all work ok.

Keep me updated on your progress bro.

John

KJ-66

My Feedback: (1)

Hi John

Yes,they have got the 3/4" O.D. aluminium tube in stock and it has a wall thickness of 1,6 mm. I believe this is ample strength? I will be making a tool,to use for the making of the wing tube socket. Won`t be a problem at all. You rekon 2 of each?

I was in bed since Saturday evening,with a cold and only returned to work today. So will collect a 5 m length of that tubing on Friday morning.

Be careful of high speed. We get too comfortable with it and it catches us out,when we least expect it. Your old P80SE will be ideal for it. I will be attempting my own scratch-built version of the prolink struts. Its mainly a lot of milling work,which I will do manually and later when my mill is a CNC version. My mill is the same as the X2 mini mill. Nice little machine it is.

Regards
Craig

Toolbag

Craig

I think 2 x 3/4" x 1.6mm alloy tubes should be sufficient (what grade alloy is the tubing).

Manual milling - I know all about that - spent most of my early years in a toolroom on a mill. Trouble with CNC machining it takes so long to program but you can make another with the push of a button..that is where the benefit really comes in.

I myself also could make a lot of stuff but I just have no space in my workshop for anything let alone machine tools.

Good luck with it - all seems to be coming together, I am keen to see how it all goes.

John

Toolbag

Craig

I just checked on a wing tube stress calculator - for the Foremost 2 x 3/4" dia x 1.6 Tube (if you use T6 Aluminium) it will withstand a bending moment equal to 6G and survive ok.

If it goes to 8G it could yield and bend if the tubing is unsupported through the middle of the fuse (not taking into account the strength of the fuse itself) with all things considered and given that the tube is supported through the fuse it will probably handle 8G's without too much trouble but probably not more than 10G.

If on the other hand you were to use 1" x 1.6mm tube for one tube it would handle upwards of 14G wing loading.

I would say that general sport jet flying one would expect to generate 4 to 8G's if competition or display flying you might push it upward of 12 to 14G's.

I think 8G max would be acceptable.

What do you think.

John

Toolbag

Criag

Are you going to glass your wings or just sheet and cover.

It seems like you have done so much work - you simply have to finish it.

Oh and build a second one for me - and maybe a couple more for other guys this side.

Am really keen to see her finished.

John

Toolbag

Craig

A footnote on the alloy tube - if it's gr: 6061 T6 - it will be fine, if it's Gr: 6063 T6 you will need to go to 1" dia. as it's yield point is too low @ 3/4" diameter.

I just checked the metalurgy from Wispeco Alum in Cape Town on their tubing - not sure which grade they have but I think it might be 6063 T6 which would mean you will need to go to 1" dia.

Cheers

John

blakeketcham

My Feedback: (61)

hi, I bought 2024 for mine, little heavy as the wall thickness available from aircraft spruce and specialty supply .062 figured I make it a flying tank. gluing them into the wings and extending them in also. I cut the end of the tube into a sawblade to drive it in further. the center attach will be a sleeve that will bolt them together from the underside. Blake

KJ-66

My Feedback: (1)

Hello John

I did get the 3/4" Dia. Aluminium tubing yesterday. It has a wall thickness of 1,62mm and I am not sure what grade the material is? I want to thank you for the information you supplied,regarding the wing load calculations. I feel more comfortable with the 1" Dia. tubing.

Now the wings will be fully sheeted and glassed with epoxy resin (Ampreg 21 laminating resin). In fact,ALL of the resin on this model,is the same epoxy resin. Not too badly priced,but surely the best that can be purchased here. So I`m just using quality stuff for the best result.

I have even thought about going for GRP wing skins too? Once the wings are built,I can make a mould of them and use the resin/cloth in place of the balsa sheeting.

I want to make a success of this whole project and once its done and tested,it will be a winner for sure.

Regards
Craig

Toolbag

Craig

You can use a 1" tube and a 3/4" tube - together they will take care of the loads and bending moments.

Another method would be to have a socket through the fuse as well but it must be rigid, this would also work with 3/4" but would most likely be heavier than 1" tube.

The difference in the weight of tube is about 100 grams / metre - not a lot for the added strength.

I must say your idea of GRP wing skins sounds excellent, a full glass model would be a great way to go and a real step up from what else is out there.

John

KJ-66

My Feedback: (1)

Hi John

My idea of a socket inside the fuselage,is compulsory. The socket will be glued to all of the ribs and flush with the outside surface,where the wing root rib is. The aluminium tube will be bolted into the one wing panel and then the panel is placed on the fuselage,with the other wing panel slid into position and also bolted down to that panel. I doubt that I will be able to install 2 wing tubes?

Regards
Craig