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Mannyroad12/02/2017 21:54:58
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185 forum posts
81 photos

Cheek doublers now glued up. These give it extra thickness for when its time to sand the fus to a round shape up front

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Edited By Mannyroad on 12/02/2017 21:56:00

Pete H12/02/2017 21:59:54
71 forum posts
58 photos

Looking good Manny.

Pete Willbourn12/02/2017 22:42:45
567 forum posts
300 photos

The speed measured with the 53 on a tuned pipe was 132mph !

I cannot verify the figure cos I was not there when it was done but I have seen it fly many times , from behind our steel mesh fence and I dont doubt the speed , !

its not aerobatic its just smoothly fast ,well a bit frightening really !!

cheers

Mannyroad12/02/2017 22:53:58
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185 forum posts
81 photos

Pete, mine is pretty damned fast at full chat so I don't doubt that speed one bit.

Mark Kettle 112/02/2017 23:01:48
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2117 forum posts
1289 photos

Mallard was only 126 mph !

Mannyroad13/02/2017 21:22:04
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185 forum posts
81 photos

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Ok, so I've now cut out the rear fus top sheet and glued on the balsa strips each side that will help support the fin when glued in. I've also installed the servo tray, made from some scrap oak strip and installed the elevator and throttle snakes. Had to drill through the engine mount for the latter.

 

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I 'm sure some of you are now thinking that the front end looks a tad wonky, but that's intentional. The firewall has been set to give 2 degrees right and down thrust and the engine mount has been set off centre the right amount so that when the engine is fitted the prop driver lies on the centreline of the fuselage, which will keep the front end symmetrical after I've finished the nose and balsa bashed it. Other plans often show the mount central but once side thrust is introduced I've often found that the spinner is off centre and the nose is never quite symmetrical. Rightly or wrongly this worked fine on the last Mirus I built so I've stuck to it. And the fuel tank still fits just fine.

Next job is to sheet the bottom of the fuselage, well, thats the bit I wanted to do tonight at least. The weights are just there to stop it moving around when I'm sticking pins in and to keep it nice and flat on the board while the aliphatic dries.

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You've no doubt spotted my 'poor man's Permagrit'. That block of wood with 180 grit glued one side and 80 grit the other has stood me proud for many years now, although its looking pretty tired now and has already been replaced. i've all sorts of shaped pieces with two grades of grit on each. You may also have spotted those multi-coloured glass beaded pins. Avoid them like the plague. I thought I'd spotted a bargin on that well know auction site and duly ordered a load, only to find all the glass beads come off. I now have the T pins; much much better.  By the way, in case there is anyone watching who is totally new to building, the reason the pins are all stuck in at opposing angles is that it keeps the balsa securely held down, like skew nailing.  hope that wasn't too basic.

 

 

 

Edited By Mannyroad on 13/02/2017 21:23:45

Edited By Mannyroad on 13/02/2017 21:31:04

Mark Kettle 113/02/2017 21:31:54
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2117 forum posts
1289 photos

It's coming on quickly MannyRoad.

Jim Carss13/02/2017 21:34:33
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1981 forum posts
42 photos

Mr manny

If I knew where you lived I would pop around for dinner one night,your kitchen cupboard is better stocked than mine.

Mirus is looking good.

Stay with it.

yes

Edited By Jim Carss on 13/02/2017 21:35:27

Mannyroad13/02/2017 21:40:10
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185 forum posts
81 photos

Haha! Cheers guys. As you'll know Mark, these birds are a fast build.

Alan Pennington14/02/2017 21:35:11
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174 forum posts
46 photos

Hi Mannyroad

How is the build going?

Mannyroad14/02/2017 22:49:01
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185 forum posts
81 photos

Hi Alan, done a wee bit more tonight.

I need to sort fixing the ply nose ring and liked how Peter Miller approached this with one of his recent projects, so am copying his technique. So I've fitted a prop and JP Accessories 2 1/4" spinner (perfect profile for thie Mirus nose) to the SC32 and measured how far, behind the face of the prop driver, the back edge of the spinner sits. Its a couple of millimetres. So, I've knocked up a ply plate, recessed on the back face by 3mm with a forstner bit, and fitted it to the engine. The rear face of the thick ply ring now represents a face 1mm aft of the back of the spinner.  To this I've masking taped the 3mm thick ply nose ring. Later I will drill the engine mount, fit the engine and see how the land lies, so to speak. Hopefully with the engine mounted in the best place, allowing for pipework to come through the firewall, the ring will sit nicely on the front of the fus cheeks, ready for glueing up.

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In the meantime, I've glued up the rear upper fus sheeting and the balsa triplers for the wing seat. All simple stuff really.

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Edited By Mannyroad on 14/02/2017 22:51:31

Edited By Mannyroad on 14/02/2017 22:53:23

Alan Pennington15/02/2017 22:26:55
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174 forum posts
46 photos

Just bringing it back to the top again.

Mannyroad15/02/2017 23:59:32
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185 forum posts
81 photos

Nice one Alan.

Ok ,well, slacking a bit tonight as all I've got around to doing is cutting the ailerons and fixing the wing TE's. The centre section of TE, over the width of the fuselage is removed and a balsa infill piece is added, whic I have radiussed the edges so they will blend into the rads that I will form on the fus corner edges later. Need to radius it now because I will be glassclothing the wing joint, so it won't be possible to rad it after that. Last Mirus I built I used wing bandage but reading forum threads suggests that glassclothing is better as it is less visible on the finished model.

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Before I glue the TE's I have to cut off the section that forms the ailerons; these will be tack glued to the false TE with 3 spots of cyano so I can sand them in to the false TE's later, once the TE's are glued on. Once the ailerons/TE's are all sanded up to blend with the wing profile I can add the 12mm med balsa wing tips and sand those in, before glassclothing the whole wing.

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Ailerons and TE's glued up, weights to keep everything flat on the underside and T-towels to prevent marks to the obechi veneer

 

 

 

 

Edited By Mannyroad on 16/02/2017 00:01:13

Edited By Mannyroad on 16/02/2017 00:02:44

Alan Pennington16/02/2017 18:10:03
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174 forum posts
46 photos

On the top again.

Looking good Mannyroad

Mannyroad16/02/2017 18:51:21
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185 forum posts
81 photos

Ok, so today I've done a bit more. Sanded the ailerons & TEs, so I thought I'd do a bit on the nose of the fus, but spotted I'd not quite got that right. Turned out that once I'd decided that the furthest aft position for the mounting of the engine, to give some room for the fuel pipes to come through the firewall, was just a bit too far forward for the ply nose ring to sit on the front of the fus cheeks, so had to add a couple of bits of scrap balsa to make up the shortfall. Once sorted it needs two short pieces of 9.5mm balsa fillets to glue the ring to the cheeks. Once they are dry I will add infill fillets top and bottom and infill between the cheeks at the base of the engine bay with some 9mm balsa, before completing the bottom sheeting of the fus through to the front. This will give me plenty of balsa to carve away to blend into the nose ring smoothly.

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The F clamp just squeezes the cheeks in abit to get a bit more glue area for the nose ring. It doesn't matter that the balsa isn't protected from the F clamp as a lot of this will be planed off.

20170102_183350.jpg

On my version of the Mirus i didn't want 3 bolt fixing for the wing, drilled down the centre of the wing. I'm having an 8mm dowel fixing up front and just th one wing bolt aft. So I marked up the F2 position and knocked off another 7.5mm for the 6mm hard balsa and 1.5mm ply laminate that will help strengthen the wing joint. The cut out width was widened to fus width plus 4mm to allow for 1.5mm linings to the sides of the wing pocket.

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In my excitement to crack on I forgot to add the 1.5mm lining to the front of the balsa before drilling, but no matter I'll add it later. Before drilling the wing for the dowel I stuck some foam tape onto the wing seats to set the wing close to the right height for when I put wing seating tape on the wing seats.

Mannyroad16/02/2017 18:53:42
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185 forum posts
81 photos

So, here is the front of the wing, with 30mm x 8mm dowel epoxied in and all ready for glassing. 1.5mm ply now added too.

20170103_102113.jpg

Mannyroad16/02/2017 20:30:30
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185 forum posts
81 photos

Bump. Did this because I've put an explanation re the Mirus plan on my other thread, below in the list.

Mannyroad16/02/2017 20:47:23
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185 forum posts
81 photos

Bench ran the new SC32 this aft. Prop lightly brushed my finger, at full chat, whilst adjusting the main needle. Close.

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Alan Pennington16/02/2017 20:50:11
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174 forum posts
46 photos

One nill to the prop.

Mannyroad16/02/2017 21:12:02
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185 forum posts
81 photos

Just weighing up the tank bay top sheeting, which is 9mm, and realised that this will get really thin close to F2, thickening up quickly further forward. So have added a bit of scrap balsa to the front of F2/2A.

20170103_111648.jpg

Also glued in the engine bay bottom sheet too and decided there isn't room for the 9mm fillet pieces I was going to add around the nose ring; not needed anyhow. Oops, photo missed that bit. So, ready for fuel proofing tank bay, fitting top sheet and then balsa bashing the nose.

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