Quandry

Made some progress yesterday on my Rebel build starting with the Elevators




The gel coat is a bit scuffed up on the insides but that will be corrected at painting stage, everything is a nice fit which is the main thing!

Quandry

Inside the Ele half, and with a standard size servo fitted






Cutting the horn slot is a little daunting, but at this stage we only need a 'roughly correct' size hole to get the linkage travel line. After the horn is glued in I can come back to this and clean up the slot to make it look a little better.

Quandry

I am using the Intairco 3mm ball link system, the horns just require a minor blip with the drill to accomodate the 3mm bolt and while I'm there I gave them a bit of a scuff up to make sure the Hysol will hold and the paint will stick later on..




Looks good and ready for glue...



Tonight's action will be to check fitment on the Rebel, hopefully it's all good (as I already glued one side :O ) and then finish the other elevator half before moving on to the wings...

Quandry

Well I checked the elevator on the model last night and it still fits even with the horns glued in (phew) lesson learned I'll check first next time. With that in mind I made up the second elevator and the glue is drying on that now.



The next step is to drill and fit the incidence pins, then make up the retaining bolt system. That sounds simple, but measuring and drilling these blind holes are not for the faint hearted. Finally after that I can make up the connecting rod, check the throws and trim out the servo arm slots to ensure they allow enough movement and make them a bit more aesthetically pleasing. The Ailerons are easier than this because they come with covers that already include the slots *relieved smiley*

As a side note, these are the dremel bits I'm using for cutting, they go through like a hot knife in butter so i've learned to run them very slowly and carefully

Desertlakesflying

My Feedback: (28)

Some jet people do not want the average guy, the "riffraff", affording jets.

Quandry

Well there's a good bit of work to do on securing the elevators, I've also found an issue regarding the control surface fouling on the body. There's a bit of work required there so I'm pushing on with the more simple stuff... for now...

The main wings come with cut out areas to work within, it's not just as simple as cutting out anything that is grey, we want to leave a small border there for the servo door to affix to. Therefore it's necessary to mark the cut out in pencil:


Which reveals very nice servo shaped holders already inset in the wing


Luckilly, the Hitec HS8335SH servos I am using just drop straight in no modification required


So just a quick drop of CA for the mounting blocks, drill the very nice carbon servo hold down (came in the kit) and fire hex screws through the assembly. The Hex screws go through the mounting blocks and in to the lower cutout but don't go near the outer wing skin (phew!). Disregard the fact that the paint looks bogey in this area, that will be fixed at a later date


Edit: Note that the servos fit fine, but the carbon hold down is not quite deep enough at the securing ends, a washer under each side will sort that out for me while still keeping the servo pinched in place.

RAPPTOR

My Feedback: (41)

How do i get one??

Quandry

I believe the US agent for Pirotti models is: http://www.eliteaerosports.com/?page_id=421

Quandry

Oh yes, one more update.... I received my Jets Munt Merlin 140XBL

Since the start of this month they are shipping with a colour touchscreen GSU. There's a lot of other great features also so quite the compelling turbine package for jets of this size.

Si_B

Looking at you cutting them out makes me sweat.....glad mine was done at factory. Would it be worth losing the sharp corners in the servo access holes. Not sure if it would crack but an abrupt corner is a big stress riser.

Might check my factory cut outs later and see if they have a radius in the corner.

Not got time to work on mine so enjoying watching.

Simon

Quandry

I know it looks pretty rough although this is only the first pass, good suggestion though Simon I might see if I can radius the corners on the cutouts.

Got a good bit done over the weekend, I decided to tackle a retract in one wing... first step is the cutout similar to the aileron.



I like the wood that they have used inside. I am not a wood geek so can't tell you what this is but it has a good quality feel to it. Hopefully should be light yet strong as most of my flights will be from grass.

The kit comes with a G10 plate to mount various retracts to, the idea here is that if there's a hard landing the plate should take the hit and be replaced without tearing apart the wing. I dropped in an Electron and a plate to see what we're working with.



Which then led to putting down painters tape, and measuring/drawing out the internal structure and leg cut outs etc. The manual comes with templates that you can cut out, but depending on the printer you use these could be scaled up or down. I'd prefer not to take a risk on this so just used the whole assembly as my template. Once it's all up and running I will take measurements and draw it all out again on the second wing.

Quandry

I found that the wheel well lined up fairly well for an 81mm holesaw and tried to make a start on the cutting with that. Unfortunately though the hole saw was a bit aggressive and kept jamming. I think for fibreglass you need a carbide grinding hole saw (which I don't have) so I went with the dremel and milling bit. Because I'm cutting by hand I'll need to do some cleaning up here later on to smooth out any jagged lines. On the second wing I'll try the Dremel circle cut attachment and see if that works any better. This is the advantage of working on a jet before paint



Next I marked out the leg pattern, and using a super thin tile cutting disc carefully made the cut. I am hoping to reuse this piece for a leg cover later on so wanted to keep the tolerance as close as possible.



Leg looking convincing, some minor trimming here and there still required to clean things up a bit.

Quandry

Then it was just a matter of drilling out mounting holes, putting in blind nuts and bolting everything down. A minor gripe here over the design.... The Eletron retracts sit halfway over the gear mounts in the wing, which means that the 'snap out' plate will most likely take the gear mounts with it anyway because the blind nut has to bolt in to them and not just the plate. Anyway, it all fits so I should just be a careful pilot!

Here's a quick video - click for HD in the bottom right.

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Si_B

Could you post a link to that cutting disc. How wide is it?

You are a braver man than me, it's looking fab.

Simon

Quandry

Cheers Simon, here is the cutting disc. Expensive but worth a look.
https://www.amazon.co.uk/Dremel-2615.../dp/B001DH7Z4I

I don't have any new photos from last night, I was just running through the same process on the other wing. Hope to finish it off tonight

Si_B

My retracts have been installed with self tapping screws. I can't confirm this is how they come from the factory as I didn't order it, but I know it came with the optional factory install of servo, wiring loom and retracts. I guess if I rip one out the next option is to replace with blind nuts so a little bit of redundancy. Like you say, it doesn't really make sense to have a sacrificial plate if the retract is also bolted to the rails?

It's the first time since I bought it a few months back that I've looked at the wings. They feel very heavy to me compared to a similar sized model I have. I'm hoping that's due to bullet proof construction !!

Also, the cut outs on my wings for the servo and retract look pretty rough. As they are not seen I'm not sure I will worry too much, but will put a radius in the corner to stop any cracks forming.

Simon

Quandry

Overall I prefer self tapping machine screws because if the retract takes a whack then they pull out of the rail and you just move up to the next size. Having blind nuts or wood screws greatly increases your chance of blowing out the landing gear rails and taking the wing with it. I'll just have to try and land lightly every time

Post up a pic of your setup when you get a chance!

number27

I use selt tappers as well. Rip straight out less damage. Same with turbine mounting.

Quandry

Well last nights work was to get the other main retract fitted and then put in the flap horns, the second retract was pretty easy having learned the forumla from the first one.


The flap servo is inboard on this model and there is a convenient servo mount in place and also port for the servo arm to reach the interal horn



I test fitted a servo and loose arm, then marked the horn direction, dremeled out a bit, sanded and drilled the holding plate of the horn and glued it home with a generous amount of Hysol. Quite straight forward.


Left to dry..


Until I get the rest of my servos the only thing I can do on the wings now is fit the rotation pins, but I'll do some other rudder/body work in the meantime and come back to that....

Quandry

I wanted to complete my control horn installation so last night took the body out to setup the rudder horns. Wow! I'd forgotten how big this is at 2.2m long..... I can only imagine what it's like working on the PRO size which is even bigger. Still this is big enough for me! - for now



The rudder is live hinged and the standard installation is very similar to the ailerons making this a quick and pain free install. I toyed with the idea of cutting the rudder free and installing with some centre hinges, although that would require woodwork, carpentry, and probably more skills and time than what I have at my disposal. I may yet come back to this idea at a later date.



After some grinding/cutting, the horns well glued home and left for the Hysol to dry...



There's a lot of effort involved in this kit but it is really satisfying watching it come together. Unfortunately with a full time job and city commute either side that leaves me only a couple of hours each night (even if I am being greedy) so the build is a bit like drip torture. Still, a dripping tap will fill a bucket eventually, and it means I have time to really think out my next steps..... which tonight I hope to get a bit of a look in at the nose retract and plan out how my doors are going to work....

Quandry

After considering a nose door system, I think it's probably beyond my abilities and am going back to the recommended setup of cutting a slot. There is likely to be a lot of stresses around the area of the nose retract though so I figured some CF tissue re-inforcing could be useful to apply. It's very light weight but dries solid and just laminates on top of the standard fibreglass layer:



It's pretty hard to get a square piece to look straight in a tapered fues, not to mention a piece that is folded in two! after a bit of fiddling I got it close to square.



Next I test fitted the front wood work pack, it needed minor dremel attention to get it to plug together cleanly. While I'm probably not going to spray the whole inside of the jet, I am not a big fan of bare wood look so decided to use the 'sand and seal' to convert these something akin to a brushed aluminium look.



The cradle has to be assembled inside the model to be glued, and will be hard set in place with Hysol, ready for nose retract fitting and *gulp* slot cutting...

Quandry

I had a pretty limited window available to work on the Rebel in the last few days so just a quick update...

The nosegear frame is glued in to place and hysol drying fully. I went to install my Hitec 5685MH servo in to the nose steering and found that the standard rubber mounts/brass bushings will not suit the pre drilled/tapped Electron plate. I toyed with the idea of making an adaptor plate, but then I realised that simplest solution was just to bolt in the servo directly to the plate with no rubber bushing and use washers under the bolt heads.



The required washers are very small (maybe M2?), anyway I raided some old helicopter spares and found what I was looking for. I've found that one or two good heli crashes gives a veritable treasure trove of hardware and fittings that are handy in jet builds

So the retract, plate, and servo combo looks something like this (note though that I had to turn the servo the other way around to get proper clearance for the arm when it's installed in the model):



There is a lot of associated griding and gapping to be done to make everything fit within the mounting rails. So if you're tackling this job get your Dremel ready...

Quandry

Took a quick in situ look at the turbine in the engine bay last night, useful to start thinking about how the brackets etc will work. Of course the pipe install needs to come first but the M140 looks great in there...



Just for a laugh I also checked out a K45 in the engine bay, looks kinda small!




Back to some more Dremel work on the nose retract plates tonight if time allows...

Quandry

Rebel build update. I made up a steering link, ground down some of the mounting plates and drilled for captive nuts. Here's a pic of the nose system loosely in situ, while considering the slot vs door options:



I know it adds more complexity to the whole thing, but I decided to go for a three door system on the nose as opposed to the slot. I accepted that this build is not a 'rush job' so I might as well take the time to get it setup the way I want it. I tackled a hinged nose on my F86 Sabre, but nose doors from scratch is a bit of an advanced project for me - anyway it's a great learning experience! The first part was to mark out where the doors would go, so after taping the underside of the model I sent down a couple of pilot holes from the inside to mark the back and front points and give me a starting point. The seam is pretty much centre and according to a length of string is nice and straight so my doors are all measured off the seam. The front door will be sprung with a leg skid and the main doors will be servo driven 'bomb bay' style



A buddy of mine held the fues while I took to the cut out, when all is said and done it went reasonably well. I guess no one is going to be inspecting the underside closely when it's in a 200kph knife edge pass LOL. I've glued on Tamjets offset hinges. These will be drilled and screwed also and then I'll build the sealing frame using some thin G10.



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Si_B

How do you plan to fit the turbine to the rails? Got a similar issue with a Jetmunts 100 which is to narrow to bolt directly to the wooden rails.

Simon