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Mini Jazz builders hangout.


Kevin Fairgrieve
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Posted by Ian Southerton 1 on 02/09/2014 21:06:48:

Nicely finished, love the colour schemes!

I built 3! One I've flown once, one is 90% complete and the third is still not covered.

Having a lesson toward my licence this s week!

Noticed your aileron servos are on top of the wing, am tempted to do this one of mine as my lo all flying area is too rough for landing gear.

Yep that is why I put my servos on top of the wing to. It's a small plane and Uc may not even go on my one. I think unless your patch is like a bowling green it'll dig in. My patch where I go would be pointless with small wheels.

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Well I test flew the Mini Jazz tonight again laugh...

All is still intact and boy is this thing a floater !!

I am quite surprised lol but I do have a problem...small one lol.

Last night I test flew it to find that my prop was under sized and the CoG was back to far so after an exciting flight I took it home and put a small amount of lead up front. Tonight it was much less pitchier and easier to handle. I think it needs a small bit more weight in the nose and it will be a pleasure to fly but when I give it half throttle it pitches up and in the glide it is perfect level attitude. I fitted the F1 bulck head perfectly sq to the front of the fuselage as per plan but should I try a few washers under the top fixings of the motor to give it a little down thrust ?? Or would a CoG slightly to far back still make it pitch up under power ?? But behave in the glide. Well pleased with this wee model. Glad I built it now yes

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Sounds like it might need a touch of downthrust Jamie.

Maybe try an "alternative approach".... trim it to fly at about 1/2 power & fly a straight horizontal line then chop the power. What happens? If it immediately pitches down then you need some down thrust (Reason...the motor must be pulling the nose up). If it pitches up then you need a touch of upthrust.(reason the motor is pulling the nose down)...

The model should just continue in a straight line & gently lower the nose as the speed decays.

To check the CoG try a dive of 45 degrees or so with no power. If the CoG is correct it should carry on diving or slowly pull out of the dive....too far back & it will tuck into a steeper dive. Too far forwared & it will pull out of the dive....

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Posted by Steve Hargreaves - Moderator on 03/09/2014 22:02:31:

Sounds like it might need a touch of downthrust Jamie.

Maybe try an "alternative approach".... trim it to fly at about 1/2 power & fly a straight horizontal line then chop the power. What happens? If it immediately pitches down then you need some down thrust (Reason...the motor must be pulling the nose up). If it pitches up then you need a touch of upthrust.(reason the motor is pulling the nose down)...

The model should just continue in a straight line & gently lower the nose as the speed decays.

To check the CoG try a dive of 45 degrees or so with no power. If the CoG is correct it should carry on diving or slowly pull out of the dive....too far back & it will tuck into a steeper dive. Too far forwared & it will pull out of the dive....

Ahhhh Steve thanks for the dive test. I will try that tomorrow night. It definately need a couple of washers behind the motor to by the sounds of it. Ill get the CoG sorted first then try the washers. Thinking about my next build now....Going through a mad phase of considering a Spitfire build ........I think I should go into a dark room and have a word with myself!!!

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Posted by Jamie sawyer on 05/09/2014 21:51:36:
Posted by George Pickering on 05/09/2014 15:13:23:

can you still buy these kits? if so where sells them and how much are they.

Welcome to the forum George, you get them here and also you can pay for a CNC wood pack etc. Just search for the Mini Jazz **s chose my first name for the forumLINK**

Thanks Jamie, for some reason it has chosen my first name I go by my middle name (Brent), iv saved the details of the website because it is one model iv always like due to the size, its small and easily put in the boot of the car and probably would make a great model to convert to electric making it even better that a flight box is not needed also. trying to find out some projects for this winter because im out of work due to health issues (chemo and awaiting large op) and I don't want to be just sat at home awaiting it all so decided to return to the hobby for a 4th time lol. Now I have all this free time on my hands im also planning on having a dable with a 1/4 scale cub because I do like scale models for the nice warm lazy spring and summer afternoons and evenings. Will see about ordering it next week so at least when I finaly get out of hospital I have something to build while I recover from my first session of chemo. thanks for the help Jamie

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Its a very easy build Brent, I've flown my one 3 times now and planning changing the motor for a more powerful one plus I had to add lead to the nose for cog. I'm finding a motor of about 150 grams is about the required on my Mini Jazz.....

Sorry about the health issue. I hope it all goes well with you and look forward to hearing from you in the future.

Good luck

Jamie

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thanks Jamie, As for the health its one of those things. As for the mini jazz it will be an easy but quick build to quickly brush up on my skills as well as flying skills. not flown for 4 years but will not have a problem there because i have been flying since i was 11 and im now 28. I am looking for a 1/4 scale project to learn scale building techniques because there's allot of aircraft out there I like and would love to build replicas of and i love attention to detail by going as far as replicating the aircrafts structure to take the build to a higher level where some modeler's don't. Going to keep it simple to start with, 1/4 scale cub should be a good bassis to start from for the ease of building and to learn how to fly them scale also.

But from what i saw of the mini jazz's down my local field years ago they were heaps of fun and great flyers too.

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Hi Brent and welcome to the Mini-jazzers

I finished building mine in the end of July and have flown it several times. I use OS 0.15 and it has quite enough power for everything I´m capable of doing.

I made a build log at **LINK** It is in Icelandic but you can choose a translation on that page that uses google translate. Not perfect but helpful if you don’t speak Icelandic.

I followed the plans pretty much. I used mini servos with plastic gear but would recommend using metal gear, at least for rudder. I’ve already broken one but abandoned take off so no harm.

If you are taking off from a grass field, using a little bit bigger wheels might be wise, and if you are using a tail wheel you should take that into account when building the undercarriage so the take off angle is the same.

Welcome again and best wishes for your road back to good health.

B.

Edited By Birgir on 06/09/2014 14:03:50

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Posted by Birgir on 06/09/2014 13:35:46:

Hi Brent and welcome to the Mini-jazzers

I finished building mine in the end of July and have flown it several times. I use OS 0.15 and it has quite enough power for everything I´m capable of doing.

I made a build log at **LINK** It is in Icelandic but you can choose a translation on that page that uses google translate. Not perfect but helpful if you don’t speak Icelandic.

I followed the plans pretty much. I used mini servos with plastic gear but would recommend using metal gear, at least for rudder. I’ve already broken one but abandoned take off so no harm.

If you are taking off from a grass field, using a little bit bigger wheels might be wise, and if you are using a tail wheel you should take that into account when building the undercarriage so the take off angle is the same.

Welcome again and best wishes for your road back to good health.

B.

Edited By Birgir on 06/09/2014 14:03:50

Thanks Birgir yes our field is all grass unfortunately, I decided to try helicopters back in January but never finished the one ibought off. I ended up buying the Beam E4 heli and it is only short of a gyro and receiver and transmitter. all the servos in that are mini's and all are metal gear so will use the servos from that with a cheap plastic 9g one for the throttle if I don't chose electric. I bought an align speed controller and motor and 3c 11v lipo along with balance charger its 450 size and was wondering would the motor be suitable for this model. I cant quite remember the details of the esc and motor because there not with me due to being in hospital for the last 3 months. but if the power plant from the heli can be used in this model it will certainly be a better start for me. thanks guys for making me feel welcome and I will check out your link Birgir to your build

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I did the exact same Brent regards to the 450 motor & Esc. By any chance is the motor an Align 430L outrunner. I have my one in my hand and it is 3550 Kv lol which is a bit mad for an electric aerobatic 3d plane. Small 450 hellis run on high Kv motors where as planes are down normally around the 850 upwards unless I will be corrected lol. BUT I did what you did and fitted the motor to a plane I built and it worked just fine with a 3mm prop adaptor for the propeller.

Everyone has been going on about getting a watt meter for testing the watts being drained from the battery while the motor is at full throttle. I will be getting one because they are only about £12 and they will save a lot of burnt out motors and Esc, I suggest you get one to.

Hope all this help chap thumbs up

Jamie

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I think it is very close specs to the motor but im sure mine is just under 4500kv. im not used to this new ratings on electrics im used to the old ways such as speed 400 540 and 600 etc. so im learning on that side of things because iv always loved engines but now im at the point where I hate having to tune engines etc. so the smaller stuff will be electric and the large scale will be petrol engines as they are more reliable and efficient then glow. il try get hold of my house mate and see if he will go in my room and check the box the motor came in and same for speed controller because if they can be used it will save me allot and I can use that money I save for a good second hand 2.4ghz radio. I figure a second hand 2.4ghz transmitter is fine and il just buy new receiver's rather then trust 2nd hand ones. I just cant wait to get out of hosi so I can start and build a building bench. a trip to wicks or b&q will be in order for a nice flat skinned door as a surface. just need to find out where I can get some thin cork to cover the top of it in so pins will go in well for building. a door will be a perfect size for any model I wish to build because anything bigger then a door will be too big a project, excluding wings .

From what iv seen of these new electric setups im very impressed because years ago the motors were no where near as powerful and usually the battery's weighed more then an engine and fully fueled tank laugh

Can you over size props on this type of motor to stop it from being too powerful or would it be too much strain on the lipos esc and motor itself. im dumb with this new electrics job. may have to go read about it on the elec forums and see If I can find any beginner's guides to make things clearer to me lol.

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**LINK**

There's plenty reading in link above for you Brent lol. Your thinking the wrong way. The prop has to be made smaller, this reduces the load on the motor and esc/battery. That's exactly where the watt meter comes in to work....

I'm like you, oil and smoke guy and all this electric stuff is mind boggling for me surprise......

If your buying Rx try one of the Frsky 2.4 ghz rx or I just bought 2 of these for my 2.4 ghz futaba fasst system

**LINK**

that Rx are brilliant and binding is instant to your Tx......very cheap to thumbs up

Regards Jamie

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Cheers forv that. As soon as net comes back on il go on laptop and check the links out. Keep looking at thev hitec aurora 9 it seems like it will be a good all round tranny to go with. Last trannyvi had was a sanwa / airtronics rd6000 then I got american airtronics version with 2.4ghz. What others is there thats a good tranny. I was warned ti stay away from spectrums because there troublesome.
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had another 6-8 flights with my mini jazz today, she flies so well and I'm delighted that my flying is improving.

Then it all came to a sad end when she went in nose down dive HARD, dry ground but the engine was buried crying

My post mortem has revealed that both aileron servos have stripped.

Wings almost untouched, tail & fin no sign, just needs a new fuz. I'll re-build with metal gears.

Big lesson learnt!!

image.jpg

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