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Chris's Vicomte 1916


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I've been eating even more strange 'things' in my travelling past, David. In your case, the "itchy" side of the delicacy could have something to do with the 'covering'... wink

At least, Paul seemed to manage it with 'a' (ie >one) glass of red Valsacro or Casa Safra. cool

Hakuna matata

Chris

BE - BRU / CTR Red Control

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Hello out there,

Not really much to show at the moment as I only had a short session, but the 3mm diagonals for the fuse went finally in without trouble.

163_vic_formers_dryfit01_900.jpg

Then it was time for a light sanding of the carbonized edges of the main formers followed by a dry fit. The JVM kit is - not surprisingly - really accurate and not a single correction is needed. yes

But before I can glue them in, I want to prepare F1 for the motor offset and drill the different holes and cut outs needed. I also have to draw the cowl mounting former to correspond with F1.

169_vi_formers_dryfit02_900.jpg

> note: apologies for the bad lighting of the pics but unfortunately my self-made ‘video-light’ did abandon us and ‘went west’, while the old desktop lamp isn’t up to the task. blush

So, the glue gets aside and the calculator is dusted off. cool

Mchana (= sunlight) matata

Chris

BE - BRU / CTR Calc Control

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Hello to all still out there,

Before going on with the fuselage, I have to prepare the firewall - a lamination of two 3mm birch ply pieces - by drilling the holes for some blind nuts, dowels and magnets.

A bit of calculation is needed to determine the offset required for the motor mount. So, it’s about time to get ready to dust off some old trigonometry. surprise

Then I thought that I would share it here as it could possibly help some ‘newcomers’ to the building hobby. If they still exist, that is. indecision Anyhow, here we go:

Motor offset

As I would like to obtain a 2,5 degree side thrust, the formula for measuring the motor offset is > Motor Offset = (total motor length) * sin(thrust angle). The value of Sin(2.5 degree) = 0,04361939.

Here is an example for Vicky’s 3536. The length of the engine from the back of the mounting plate to the back of the prop is 50mm, while I’m making my spacers 55mm as to correspond to the extra 20mm length added to the cowl (some info later about that), the total equals 105mm. If I want to have 2.5 degrees of right thrust built in then > Offset = 105mm * sin(2.5) = 4,58mm . In this case, I will need to move the centerline of the motor 4,58mm to the RIGHT (when looking at the firewall) for my spacers so that the axle of the prop is in line with the center of the firewall (or the designer/kit maker stated centerline).

Thrust angle

If we use the Tangent of ‘x degree’ formula, we can find out how many washers are needed or how much different to make the right spacers versus the left ones to get the right thrust you want. If the firewall has no side thrust built in, then you will need to have the right spacers of the motor longer than the left ones to put in right thrust (again when looking at the firewall). The equation to do this is > Extra Length = (distance between mounting holes) * tan(thrust angle). The Tan for 2,5 degree equals 0,04366094.

Note > in this case, 'Tan' has nothing to do with Paul's skin color after spending four weeks in sunny Spain... angel

With the Vicky, the distance between the cross mount holes on the 3536 is 30mm. As we want a 2.5 degree right thrust angle, then > Extra Length = 30 * tan(2,5) = 1,30mm. The right side of the motor will need to be extended 1,30mm more than the left to have a right thrust angle of 2.5 degrees. In Vicky’s case and as a first guess, a single M4 washer could already be very close. cool

Apologies to granny & to the eggs if / when needed…

Hakuna matata

Chris

BE - BRU / CTR Boredom Control

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Hi Chris not so much of a tan but more pink - bright pink 😱. It's been many years since I delved into log tables and the like, slide rules were the order of the day back then. No calculators were allowed at tech then nor were they affordable to us young apprentices, for some reason I could always get the numbers correct with a slide rule but could never get the decimal place right 😢.

I have tried washers for side thrust but always end up using more as they seem to crush into the ply, might just be me over tightening though

Recently acquired a wots wot now that has a hardwood 'wedge' attached to f1 for the correct side thrust, not seen this before but works fine.

My side thrust is now drawn out using a protractor, compas and squares don't trust my calculations these days �

Paul.

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Hello gents,

You're absolutely right, Mark. Being too heavily committed to my calculations, I didn't really realize it was Sunday. blush But then, I guess it's probably not a good idea to post it again today. Or should I? angel

I think "bright pink" is a totally brilliant colour, Paul. A truly lovely, vivid, young and living colour. yes

I have to admit I only saw a slide ruler once in my life, let alone being able to use one... frown

Regarding the hardwood wedge, if it is glued to F1, it should only be usable for a certain length of motor. Or not?

Your 'Pro-Com-Squa' method should work fine of course, but with the trig, the only instruments needed are a caliper and a T-pin to punch the wood at the offset location.

Hakuna matata

Chris

BE - BRU / CTR Cat Skinning Control

 

 

Edited By McG 6969 on 26/02/2018 10:02:43

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When you mount the motor, put sone two pack filler between the motor mount and firewall. Pull everything down finger tight, i.e. No crushing of wood. After the filler has set, tidy it up, if you are quick, cut it offf when it gets to its cheese set.

You end up with a solid, stable motor mount. Chris, don't forget to offset the mount so the prop is in the middle of the cowl.

Edited By Don Fry on 26/02/2018 10:14:47

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Thank you for commenting, Don.

I guess your answer was directed to Paul as I'll be using threaded studs to mount Vicky's motor.

Regarding the motor offset, no probs. I mentioned it in my 'boring' thread of last Sunday. Just have a look just a few posts ago. Anyhow, thanks for the reminder. yes

Not really something to show right now, but duty went on in La Grotte today. I started to draw the positions of the different holes in F1 and as foreseen I was making an attempt at the ali cowl to get it 20mm longer to aid with the CoG.

More to be shown soon, I hope.

Hakuna matata

Chris

BE - BRU / CTR Duty Control

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Hi to all,

Just in between those trig calcs, I started to progress with the cowl.

Two reasons for that:

First one > as I might have some CoG problems, as most of the EP Vicomtes do have, I decided to extend the cowl a little bit. My Lipo will weight about 200 > 240gr depending on the capacity, with a ‘center’ moment arm of 90mm to the CoG. The motor with prop and ESC will be around 210gr but with an arm of just under 190mm. So I’ll bring the motor even more forward by 20mm for a start. If it appears to be too much, I can always cut off the treaded rods for the motormount and shorten the cowl back. angel

Second one > I found a aluminium cowl in France - in fact the same one that came with David’s Baron Models kit - but I wasn’t pleased with the front ‘squarish’ curvature as I never saw a pic of a WW1 aircraft resembling to that. In fact, it looks like an old sauce pan with the bottom cut out. surprise

172_vic_cowlmod01_900.jpg

When I lately ordered some sheet balsa, it came nicely protected with some scrap bits of balsa at the ends to protect the corners of the parcel. As it was 10mm, I decided to give it a go even if I had to ‘puzzle’ a little for the bottom layer due to the small dimension of the blocks.

175_vic_cowlmod02_900.jpg

And I really mean ‘puzzle’ in this case. When I tried to screw it to the cowl, the wood just started to ‘decompose’ itself. I had to apply a quite large dose of Superphatic to convince the balsa to behave a little… frown

Indeed, 'totally bin’ bits, but at least ‘free’ bits… wink

Hakuna matata

Chris

BE - BRU / CTR Scrap Control

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Hi Chris good advice from Don, impressed with the jigsaw puzzle I usually end up with loads of cocktail sticks to hold everything together , having said that cocktail sticks are a very useful addition to your workshop tools.

Looking at the weather forecast , the beast from the east might cause us a problem getting home at the weekend might have to stay a little longer (Pam's devastated at the thought 😎😂🍻👍 hate to disappoint her 😉.

Really enjoy watching your build of the vicompt as it's not the sort of model I would build so new experience 👍

Paul.

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Hi Paul,

Good advice concerning those cocktail sticks. Since reading a lot of build blogs around here, I decided some time ago to start to collect 'possible useful' little bits. I now have a collection of toothpicks, skewers, square bamboo sticks, kebab skewers, popsicle sticks, tongue depressors and... round & square cocktail sticks. wink

The LotH is now also regularly asking... "... and, want to keep this one?"... cool

Regarding "the beast from the East" - or from wherever - please just keep in mind that Pam was, is and always will remain 'the Boss'... angel

Hakuna matata

Chris

BE - BRU / CTR Authority Control

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Hello again,

Thanks to the overflow of Superphatic, this time the screwing of the ‘sauce pan’ to the wood went just fine. I then decided to make a sanding jig to (try to) obtain a more accurate and steady curvature at the front of the future cowl. question

Far from perfect, but the “free bin bits” seem to look a little better already. angel

199_vic_cowl_sanding01_900.jpg

I also wanted to try the world famous Freddie B Sauce instead of some Isopon or P38 filler. First I applied a layer of WB varnish to close the balsa grain, sanded it lightly down and applied the Sauce. The latter is a lot easier to sand than car body putty would be.

210_vic_cowl_fredb_900.jpg

Now, a question please > when I was sawing the jig, I spilled some DNA to the wood. So, in accordance with that widespread fairy tale, does that count for getting a “nice flying model” or does the DNA has to hit the wooden bits of the model itself??? surprise

Hakuna matata

Chris

BE - BRU / CTR DNA Control

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Don't worry about dna unless you are a suspect in ncsis or Abby will be on your case and there will be no escape 😂 wink.

Pam's still a little concerned about the flight home being delayed but I am sure we will make the most of whatever transpires. yes

Don't take this the wrong way but your cowl is the spitting image of a lemon cheesecake we had last evening, dna/red wine excellent evening. wink 2

Paul.

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Hi again Chris .Back to the motor shaft overhang. Either make a clearance hole in the bulkhead or wrap the motor in cling film and cut the shaft with a "DREMEL" and a cutting disc. That would keep the filings off the motor O.K. as you can wrap up the film with any bits not on the floor. Good luck

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Hi again Chris .Back to the motor shaft overhang. Either make a clearance hole in the bulkhead or wrap the motor in cling film and cut the shaft with a "DREMEL" and a cutting disc. That would keep the filings off the motor O.K. as you can wrap up the film with any bits not on the floor. Good luck

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Hi gents,

@ Paul > if you bring a few mega XXL milkshakes to Abby, she'll forgive you anything. yes

On the other hand, not that sure if Gaston will forgive you to compare his beautiful cowl with a vulgar 'lemon cheesecake'... surprise kulou

@ John > thanks, but I won't need the Dremel, as mounted to threaded studs, the motor mount will be a sufficient distance clear of the firewall now.

Hakuna matata

Chris

BE - BRU / CTR Cheesecake Control

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Hi everybody,

Some progress with the sanding of the cowl which went really nicely.

216_vic_cowsanding02_900.jpg

Next some high build filler that I use for the first time. It comes in a spray can and is just 1K. It’s available at Brico - the BE equivalent of Halfords, I guess - and wondering how it will behave. I had to spray outdoors and it was very cold and windy, so I’m afraid I was a little greedy with the amount of layers. The black ‘misting’ on top is just a sanding guide, a very useful trick from the car body shop guys.

225_vic_cowl_filler01_900.jpg

227_vic_cowl_hbmcg_900.jpg

Ooh! Thanks, Gaston. That’s very attentive of you.

Oops… reminds me I have to get dressed to go out for dinner with The LotH.

Hakuna matata

Chris

BE - BRU / CTR HB Control

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Thank you for jumping in, gents.

By the way, birthdays seem to be very healthy.

After some long-term researches by different scientists & universities, it appears now that how more birthdays you celebrate, how longer you live...  cool...

@ Mark > you will find the FreddieB 'manual' by scrolling down on page 43 of the Bella build log. More pics to grab in my FredB album. I posted it on this forum several times already but I never received a feedback regarding what people think about it. I knew it works great on foam or Depron but now I know it also does for balsa as well. I only had a thin WB varnish layer first to be on the safe side with my 'bin quality' balsa. yes

892_fredb_test01_900.jpg

@ Paul > I'm pretty sure Gaston would have preferred something like 'Soufflé Citronné de Fromage des Pyrénées'... Sounds a lot more 'sophisticated'... wink

@ Martian > well, I hope it still will look "first class" after sanding... indecision

Hakuna matata

Chris

BE - BRU / CTR FredB Control

 

Edited By McG 6969 on 02/03/2018 11:22:13

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