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Building a HAS


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So the other night someone asked what the wingspan of the TR-1 is.  So I measured it at about 67cm.  And it isn’t as wide as the Herc

 

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She really is more like a kids action man plane than a model aircraft.

 

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So so it would be wrong not to add to her.  Maybe turning props & internal & external lights?  She is simply too big to try & do fine detail.  It would never get finished or would drive you nuts.

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Turning props & lights would be really impressive. I read somewhere that the motors for the buzzers in mobile phones are good for this sort of thing - although 1:48 Hercules nacelles have probably got plenty of space for something larger. If you want to do fancy things with lights, I can recommend Arduino controllers as they're surprisingly easy to set up, so flashing strobes and switchable navigation/landing lights are eminently doable.

 

Looking forward to watching this one progress.

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I have looked at arduino before - would be cool to have a start up sequence & flashing anti collision lights plus on or off internal lights @Kirk. Plenty of room for wires, lights & motors.  Main problem seems to be some issues with the kitchen t shape in some places, especially the engines.

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Had a look at a couple of websites & a couple of Herc things need an update.  

1.  RAF Herc photos of the era I am looking for are not plentiful.  The kit comes with decals for XV200 and so far I have only found one photo of her in grey green

 

https://www.airhistory.net/photos/0042248.jpg

 

and one pic of refuelling by a Victor

 

http://www.victorxm715.co.uk/victor-support-of-hercules-air-drops-during-the-falklands-conflict/?LMCL=ME7mTD

 

but none of her in late 80s wraparound camo & black numbers like 215

 

1252262-large.jpg

 

So maybe need some new numbers ( the decals are a little shot anyway)

 

2. Kit shape.  It seems there should be a bit of a flatter side behind the cockpit but ahead of the sponsons.  A strip of plasticard & some filler should fix that if it looks necessary.  However the sponsons themselves are from an AC-130.  You can buy resin ones but a bit of scratch building will be needed

 

attack_48039_parts.jpg

 

And then the engines - again AC-130 & too short.  Rather than throw them out & spend £30 on resin ones I think they can be reworked.  They are too short so about a 10mm plug at the back & make the end shape a little more oval - however still has to attach to the wing mountings so some shaping needed.  Also, looks like the ring behind the spinner is too deep.  Sure that will sand off though

 

attack_48046_parts2.jpg

 

Then have to complete the inside details, find & fit a motor & check it runs the right way.  What could possibly go wrong?!

 

 

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11 hours ago, bar side said:

I have looked at arduino before - would be cool to have a start up sequence & flashing anti collision lights plus on or off internal lights @Kirk. Plenty of room for wires, lights & motors.  Main problem seems to be some issues with the kitchen t shape in some places, especially the engines.

Don't forget the operating loading doors. That really would be cool in a start up sequence....😎

 

A little servo or two, perhaps?

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So now thinking about how to raise & lower the rear ramp.  Must be doable

 

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The Landrover fits ok & looks at home and it would need to drop the ramp about 40 mm

 

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But the mechanism will be visible.  Simple turn or l-shaped servo arm is probably going to look wrong and not lift far enough.  So some kind of actuator - someth8ng like this

 

https://www.ebay.co.uk/itm/123267362550?ul_ref=https%3A%2F%2Frover.ebay.com%2Frover%2F1%2F710-53481-19255-0%2F1%3Fff3%3D2%26pub%3D5575376664%26toolid%3D10001%26campid%3D5338268676%26customid%3DCjwKCAjwlovtBRBrEiwAG3XJ-0NsUxcEEq4RjW8TRsO03pe-lpXC6GFvUBT7XE8oyetiNIJ_LP5swxoCBkEQAvD_BwE%26lgeo%3D1%26item%3D123267362550%26srcrot%3D710-53481-19255-0%26rvr_id%3D2143032475111%26rvr_ts%3Dc69e69b416d0aa413573c2fcfffa63da&ul_noapp=true

 

any other bright ideas? 😁

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4 minutes ago, Kirk said:

Is there room for the linear actuator under the floor?

Probably - what are you thinking?  Rotating rod with a bend in it?  Another thought would be a 90 degree plate at the pivot point with a pull rod to a single actuator set nearer the cockpit?  And the the second half of the ramp that has to lift....

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Haven't really thought it through yet but was thinking of a bit of slightly springy wire or strip (e.g. from inside a tape measure) extending from the actuator to the tip of the ramp so it could both push and pull.

Neither have i thought about the top door at all, or about how to work in some limit switches. Has to be possible though. Top door should drop under gravity, so the primary problem is lifting it. I wonder how the real thing works?

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23 hours ago, Kirk said:

 I wonder how the real thing works?

Pair of hydronic rams on both I suspect.  The main ramp rams extend down when the ramp is open

 

20390116494_a2efa7bf80_b.jpg

 

Found these nice little ‘linear screw actuators’ on ebay - you can get them for about £1 each.  Short throw, but what about hiding one above the top door to push / pull a tag at 90 degrees to the ramp end?

5PCS-6mm-DC-3V-5V-2-phase-4-wire-Micro-S

 

And then could you hide one under the main cargo bay floor? They are only 6mm high and if a pull on the underside of the ramp ‘deck’ would sit high enough above the pivot point it might work

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You're way ahead of me. At one point this morning, I scribbled down something based on a Teleflex cable but your screw jacks have much more potential. You also put me on to @Jamie @ Sovereign Hobbies's amazing project - which means of course that you simply must have turning props as all the hard design & prototyping work has already been done (!).

A little bit of code could have the engines starting in turn on your apron...

 

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There would be a lot of wires coming out of the beast:

5 for the props (common power & 4 independent feeds)

2 for external lights

2 for internal lights

6 for ramp actuators (maybe 5 - common power in, forward & reverse feeds)

 

well a common power bus bus would reduce it to just 12 wires.  What point would this stop being a model kit & start being a science project?!

 

Will be looking at model rail doc decoders next.  They can do a lot....

 

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Progress is going to be slow on the Herc - lots of planning thinking before it gets going.  That & heading off for a bit of holiday time.

 

Anyway, latest thinking.  This is the back end & ramp held together with masking tape

 

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So what conclusions today?  Well the idea of an actuator under the floor looks a no go.  Not enough space.  I did wonder about a brass plate vertically upwards from one side of the hinge with a pull rod on it. Trouble is it would stand out a mile & the pull rod would probably cut across the side door to a hidden actuator above the wheel well.  So that’s a no.  The hinges look way to skinny as well

 

Below is the front end of the ramp & you can see the hinge lugs.  Not a lot too them

 

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So I am back to the idea of pull strings from the lugs on the side of the ramp in the position of the rams/dampers on the real thing.  Above the lugs / cut outs there is a round looking lump that the kit rams/dampers would fit on to.  So a tube down from there, chord running down to the ramp.  At the top a tube running forward holding the string & lost in the roof pipe work.  Strings converge in the mid upper section below the wing spar where there is a nice little boxed off section.  Looking from the other end

 

pKLg_45US4HPacKxJQCeYrN2XjqU7Zub-4DIqZNz

 

Yes above that bit.  Then improve the hinge on the ramp a bit, add some weight to it & gravity will pull it down when the actuator runs one way& the strings pull up.  Don’t think it could combine with the top ramp from the same actuator though.  That might need to be driven separately.

 

now why is it most nice cheap actuators seem to come from the US?  

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Quick mock up with a plastic tube and a nail

 

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Now imagine the nail had a length of cotton attached to the top of it & that cotton ran to the circular moulding above the tube & turned 90 degrees & ran another tube up to the roof spar you can see behind.  If you pulled the cotton from there the ramp would lift.  Some weight in the end of the ramp and slackening the cotton would lower the ramp. 

Needs a thinner brass tube but other than that - thoughts?

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And the kit ramp has large lumps on either side at the end of the rams/dampers that don’t seem to be on earlier model ramps like this one

 

images?q=tbn:ANd9GcTal8HB8h46UW3wXwo7ZhT

 

would make it easier to attach the struts in to the side of the ramp.  That will be stronger

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Playing with some bits today.  The engine nacelle is so big you can fit a hornby train motor inside with space to spare.  

 

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and I found a nice tube that fits in to the back of the prop sticking it out of the back of the wing & taping on the motor gives a rough idea

 

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So some bigger cheap motors could do the job.  Or some of those nice little ones.  Decisions decisions

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On a short break away at the moment.  Flew in to Verona airport on a Ryanair flight, and looked out of the window.  Nice set of first generation NATO HASes and possibly even a Tornado pared up outside one (didn’t look very operational though) - will see if I can sneak any pictures on the way out as the Italians are not keen on having their bases photographed

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So @Kirk this arduino kit, what do you need to get started?  I have seen starter kits for about £30 but the base seems to be a usb connected board.  What code it uses I am still not too sure on, but I can have a go at most things.  Done small bits of Unix, messed about with basic html & used Scratch and a little Python before so hopefully I can cobble something together.  Then I spotted this on. Ebay

 

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F113929372618

 

at that price its worth a punt if that is what will get things started

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Whilst hat one will do you fine, the standard boards are a little big to bury within the model itself, so I was thinking of the Nano. These are about £3.50 a pop on eBay (compatibles are generally fine). If you can program in Scratch then  Inno (the language for Arduino boards) won't present you with any problems. You download the dev environment to your pc from http://www.Arduino.cc and plug your board in via USB. It's worth following a tutorial to get started but the gist of it is write code to switch things on and off and squirt it down to the board, after which it will run whenever the board is powered up. Starting simply might be just get some lights working(there are countless sellers of tiny led multi-packs on eBay), then add a flashing beacon. This will give you all the skills you need to get the engines starting in order before tackling cargo doors etc. The biggest problem I'd anticipate is running out of io ports on a single Nano. Seasoned widget makers would probably use a "breadboard" to prototype everything on the bench before soldering it permanently, but to some extent you can get away with poking wires into holes during development. I forgot to add that the completed "circuit" can (depending on the power you need for the motors) probably all be powered from any old USB power supply - it doesn't stay plugged into your pc. Actually, you don't even need to retain a usb plug, so if you wanted to power it say through a model Houchin type ground power cart, you could use the real aircraft's ground power connector to stick a +ve and -ve in.

Hope that helps get you started.

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