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Nev's Mini Jazz


Nev
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Just a quick post to start the blog off. Don’t get too excited I haven’t done anything yet but I have finished off all the other projects. A Turbo Beaver for me and a V Trainer for my lad to play with, among other things, so the Mini Jazz is next.

This will probably be a bit of a lazy build. I’m not building for Greenacres, just for fun

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If you haven’t seen what you get, this is the CNC wood pack, probably worth buying, the wood is nice, I think from SLEC going by the packaging.

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This is the additional wood pack, which you probably wont need, in hindsight neither did I, mostly 1/16 sheet and ¼ square.

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The canopy and cowl from MHS and the undercarriage and skid from Carbon Copy. Most of this has been on the top shelf for the last 12 months, waiting for me to get my finger out, so thankfully I’ve forgotten how much it all cost.

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Electrical bits donated by a now deceased Whizzzer and I’m sure I have servos somewhere, that’s nearly as good as a free build.

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Need to think how its going to fit, there’s not much space.

Edited By Nev on 13/02/2014 13:39:27

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Looking forward to your blog too Andrew if your doing one, we can crib of each other.

The motor is an EnErG C3514 1100kv, probably a bit over the top for the Mimi Jazz but it’s spare and reading other peoples posts a bit of extra weight in the nose is not a bad thing. This one is good for 350, 400 W with an 11 or 12 inch prop. I don’t think we have that much ground clearance though so I’m hoping for around 250W with a 10x5.5 will be enough, if not I have higher kv one somewhere. The ESC is a Scorpion 45w Commander. I’ve found this to be a good one too but it is a bit bulky, I may have to downsize a bit. The battery is just a 2200mA, 3S, nothing special.

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Having had a look at the CNC pack and detached all the ribs, I suddenly realised that they are cut from 1/8 sheet not 1/16. I assume this is a mistake, I’ve had my pack for a long time so recent ones may not be the same. I wanted to try and keep the model light, I’ve built enough heavy ones. So I found a bit if thin’ish walled tube about 20mm diameter and sharpened the end with a dremel and went from this.

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To this.

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Which resulted in a massive weight saving of 6g !!

From 22g without holes to 16g with holes. Was it worth it, I’m not so sure. Whishing I hadn’t bothered with the wood pack now

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Another implication of the thicker ribs is that all the shear webs now need to be 1/16 shorter. So anybody in the same boat, reading the plan where it says cut 8 at 75 wide and 3 at 50 wide, remember to make them all 1/16 shorter or you will end up trimming them all down like me.

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Hi Nev

Now got a motor though it's not to hand,so can't tell you what it is now but smaller than yours. Hoping for 250watts on a 9x6 because as you say ground clearance is an issue. As for your ribs,with so few i wouldn't have thought weight an issue by going to 1/8th. Still a week or so from starting but i've almost got all the bits together. Keep going.....i'm interested in how you're going to make the battery hatch...

Andrew

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Hi, I did a little work on the wing at the weekend. First step to glue the ¼ strips onto the leading and trailing edge sheet and pin to the board. The ribs are on loose just to get the position correct.

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Next using the pre cut webs fit the centre ribs.

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Then carry on with the rest, I had to keep checking and trimming the webs so I didn’t overrun at the ends. The piece of ¼ square is just a scrap piece to make sure the webs are in the right place.

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Looking at the front of the wing, it seemed an easy next step to curve up the bottom sheet to the ribs fix with CA so that’s what I did. Starting at the middle and working my way out.

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Next I planed / sanded a slight chamfer onto the bottom of the false leading edge and fix in position. Followed by the top spar. A light sand over the top of the spare to knock of any corners and again sand down the top of the leading edge with a chamfer. Followed by the top sheet. Up to now I have only used CA but for the top sheet I used alphatic, to allow enough time for all the pins, clamps and bits of tape.

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So this is where its up to so far while it dries. This is a very quick build, another hour and the wing will be done.

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  • 1 month later...

Don’t know where the time went there, work and a few day hols, didn’t think it was that long though. Anyway, servos in and hinges cut.

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A little bit of sheeting in the centre section, once the wing dowel is fitted.

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OK, well it took longer than an hour but the wing is done.

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Now to the main bit. On the plan and CNC part set I have, the tail has a lot of positive incidence, as has been mentioned before.

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So rather crudely I admit, I filled this in on the pre cur fuselage sides and re cut the tail slot at zero incidence.

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You cant really tell from the photos but for CNC parts I am very surprised at the difference in the two sides. I have trimmed these to match and have taken off as much as 1/16 " in places.

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Now. As well as the tail, the main wing also has a lot of positive incidence, shown on the plan and the pre cut parts.

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I was going to take some of this out a bit by cutting the fuselage sides and raising the trailing edge. Having followed Kev’s and Mashers build, among others, who I think just went with the plan and both these two gents have reported excellent flying characteristics. I think I am just going to go with it and not worry, it is a very fat section after all.

More soon I hope. Nev.

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  • 2 weeks later...

Well, getting there. I apologies for the lack of commentary but I think its all been covered before.

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Usual build shots, I've gone for the thin ply doublers and also a cross brace for F3, although I may have put it at the wrong side.

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Both sides joined.

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sided glued and a small brace added to stop the middle bowing out too much

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Finally, undercarriage plate added

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Getting there, its too nice to be inside but i need to get it finished before October. The battery has an obvious place, not sure about a hatch yet, or where the ESC will go.

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  • 1 month later...

Slowly but surely, these bits are very simple.

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I elected to join the elevator halves and will go with single snakes for elevator and rudder.

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Although I’m not spending much time on the build it is very straight forward and would probably have been finished a long time ago. The thing that has slowed me down is trying to cram in all this electric stuff.

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Not much room to get everything in. Also I’m trying to shoe horn in a 2200mA battery, because I had them and didn’t want to buy something smaller just for this. Still I think its sorted now. Not much to do now.

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  • 1 month later...

Well trying to crack on a bit, made a start on the covering.

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fitted the elevator, rudder etc after covering and to make things easier, also fitter the horns before fitting the rudder in place, this is where i discovered my not so deliberate mistake.

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Still sorted now and just to keep the enthusiasm going a quick shot of where we are tonight.

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Fitting out next then I can position the motor to get the best balance, I'm hoping to be able to pack it off a bit so it moves forward into the cowl ( sure I'm going to be lucky there ! ). once the motor position is sorted then last job will be to fit the cowl, hopefully without too much hacking about.

Nev.

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