Masher's Mini Jazz Blog

[Masher]

Prompted by BEB's post (it makes a nice change to get a "gentle reminder" from someone other than SWMBO!!!) I thought I would make a start. The only reason for further delay is that I am way behind my build/restoration list and spring will be here in a minute - honest!

My build will be an IC version from plan without making use of commercial woodpack. At this stage I intend to build to plan - I have studied the build article by Malcolm Corbin and the message I get is - "keep it light" and don't beef up because there is no need.

So my first steps, after reading article and studying plan, is to copy some of the important bits for templates - these are so straightforward that it will be just a case of going straight to the bandsaw. Also copied Fin/rudder and tailplane/elevators so they can be built separately without holding other progress up.

Pic 1: Plan, cut out's, Build article and crude parts list taken from Kev etc

Pic 2: Picked up a bundle of Balsa from SLEC at Gaydon plus tank & mount. Engine is old stock. Bulk of rest will be from scrap box (where have I heard that before!)

So there is my pretty unexciting opening post, hopefully there will be a bit more of interest next instalment - trouble is I have this in the corner of the workshop which I have been working on for the last week:

I'll have to try and multiplex - never managed before. Oh and by the way, today is my 58th birthday and, as luck would have it, there was a 1/4 scale DB Sopwith Pup on BMFA ads yesterday - guess what my present is I'll have to limit myself to just looking in the box when that arrives.

[Kevin Fairgrieve]

A good start.

If you need any info just yell.

Make note of the "revised" tail incidence.

Kev

[Masher]

Thanks Kev, I've been following your build closely. I think the incidence shown on my plan (from MHS) is the same as you went with in the end?

[Masher]

Good progress today. Started with wing.

Made some templates:

Then cut out a set then sanded as a sandwich and fine tuned spar slots:

Resulting in a set of ribs - using 1/16th balsa makes everything easy to cut but needs care because it's fragile:

All my strip will be cut from sheet using the magic cutter:

Cut webs as a kit since they can then be used to space and square up the ribs. Make good use of cutting mat:

I don't like using cyano because I have an allergy to it so have to wear a mask all day. However, it means you can build a wing in one session:

That'll do for today - need to do centre sheeting, servo mounting, sanding etc but majority out of the way. Left with weight on top to settle overnight.

[Kevin Fairgrieve]

Looking good.

They do not take long do they. A wing a day.

Kev

[Tony Bennett]

i like that.

a wing a day.

nice build so far sir

[Biggles' Elder Brother - Moderator]

A smashing start - and nice neat work!

BEB

[Masher]

Thanks for the encouragement chaps - it's good to get feedback.

Bit more done today starting with a little maintenance. If your not achieving your normal sub-micron accuracy or you are getting marks in your wood when sanding, your permagrit may need a clean!

I don't use nail varnish myself preferring to go au naturel, however I have found quite a few uses for the nail varnish remover including cleaning your Permagrit:

Finished off the wing today. Only real issue is that my wingspan is about 1/2" more than it should be - my 75mm webs weren't quite 75mm - but "that's jazz"

Bottom showing servo mtg bearers and cut outs:

Note the obligatory string! Before sheeting, strengthening blocks were added to hinge & wing bolt /dowel locations. Hinges dry fitted for ailerons:

Then did a bit of tail assembly. Here are elevators roughed out. I like to keep everything oversize then sand to final profile. Plasterboard surface and clingfilm makes everything easy:

And here is tailplane/elevator assy taped together because I've run out of hinges:

And that's about it for today. Wanted to do Fin/rudder too but that will have to wait. I'll start the fuselage next and it's good to have simpler things, like rudder, to do in between jobs.

[Tony Bennett]

nicely done so far sir.

[Masher]

Thank you Tony - my progress seems quite feeble compared to your massive daily output!

[Tony Bennett]

the joys of retirement, i have nothing else to do these days.

looking like it will be a great little flier when finished.

[Masher]

I've got quite a bit of free time at the moment and have spent most of this year in the workshop! I must say that I struggled to choose a model from the mass build list so went with the Mini Jazz as a sort of "got to pick one" choice. Now that I am into it though it's growing on me and the design is very well thought out so I am looking forward to getting this one done and up.

[Biggles' Elder Brother - Moderator]

Cracking along there Masher and looking great too. I like the "barn door" control surfaces!

I must remember the nail varnish remover to clean Permagrit idea. They do tend to pick up a bit of "marking" after a while, I've used paint stripper on mine which works very well - but is a bit aggressive (human wise!) so acetone (cos that's all nail varnish remover is I think?) may well offer a slightly more "user friendly" approach.

BEB

[Masher]

Thanks BEB. Yes I have a little concern about the "barn doors" - in his article Malcolm says "Whatever you do, remember the elevator is large and the pitch control can very soon get sensitive."

Kevin will hopefully maiden his (2nd/3rd) version soon so I will be looking to his feedback on set up and that tail incidence. I won't be rushing in to fixing the tail section yet.

More good progress today, will post later. Malcolm really has created a simple to build design here, it's almost harder to document than actually build because it's so quick - not that I'm complaining!

[Masher]

And now my Avicraft Moronic has just turned up! What is a modeller to do - I haven't got any electric models at the moment so I ordered the Moronic (cheap, easy build, designed for electric, not foam and I love my old IC powered Frantic from the same stable)

With hindsight, I should have built 2 Mini Jazz's in parallel one each for IC and electric........... oh dear what a shame, yet another model to build, it's a hard life and I have a long way to get to Paul Marsh's level - but I'm trying very hard

[Masher]

Another good day on this build and I am liking the Mini Jazz more and more as I progress.

 

First off all knocked off the fin:

 

 

As BEB pointed out, the control surfaces are a bit big - gulp!

 

On to the fuselage. Cut out two sides - mainly straight lines and economical on use of 4" balsa. Formers don't really need templates and were cut out on bandsaw:

 

 

Didn't cut out the wing profile until later as the sides become quite fragile, especially as we are using soft balsa. Then started to assemble - this really is quick and easy:

 

 

And in no time at all we have a roughed out fuselage:

 

 

I've found some pre-used small servos and space is tight - I have chosen to encroach into the cockpit area because I don't want to foul the wing. I've also backed the servo tray with 1/16th ply since screws never hold in liteply for me:

 

 

I chose to stick with the original (smaller) fuel tank and there isn't much meat left on the formers! This is largely due to the fact that the SLEC tank has a welded seam which makes it about 1mm bigger all round. (I've just realised that I do exactly the same as Malcolm Corben does as mentioned is his assembly notes, we must be a similar age. I freely mix metric and imperial measurements without thinking about it!)

 

 

No workshop time tomorrow but next jobs are to sort controls (I hope not to use snakes), do undercarriage mounting, top deck and then think about cockpit and cowl. I won't be paying the massive price for these items from MHS so will be using my home made vacuum former. Bad news is I will have to make plugs, good news is that if they come out Ok, I can make some for anyone else who may want one. I may build the cowl from balsa a la Peter Miller method - this seems to be quite effective on my Charger biplane................rambling on

Edited By Masher on 17/01/2014 17:34:30

[Biggles' Elder Brother - Moderator]

Ramble away Masher - great blog, lots of pictures, just how I like them! It is coming together really quickly isn't it.

BEB

[john stones 1 - Moderator]

well you don't hang about Masher

looks great, maiden next week then

keep throwing your tips in, always willing to borrow good idea's

[Masher]

Few more hours today doing bits and pieces which all add up. Since this is quite a small airframe, I decided to make sure the add-ons were done before everything became too obstructed by balsa.

Fabricated an undercarriage out of reclaimed set - re-bent and drilled, seem Ok:

Mounted with M3 bolts then added extra bottom sheeting either side of U/C to "locate". Extra holes are because U/C has been re-modelled from larger set:

More struggling to get the fuel tank in then realise I am actually using the "larger" 4 oz tank! Very snug fit in there so I'm thinking it might be best to keep the front top deck as a removable hatch. Suppose main downside is reduced strength of fuselage. Also go to fit some batteries in there somewhere:

I have used 3mm Tee nuts for u/c and engine mounting - these are nice and small and a bit more secure than self tappers.

Mounted the engine (smallest I have is a 15 so that will be what I'm using! If you don't already have one, these centre marking tools are perfect for marking engine mounting screw positions:

So putting it all together we start to see that this plane looks like all engine and not much else!

Servo bay is very snug too. Next job is to sort some control lines - perhaps snakes will be easiest after all:

One tip: Glue the bottom sheeting from front former to wing seating in early on because the fuselage sides are very prone to be broken off at the wing leading edge. I haven't put in strengthening doublers between F2 and F3 according to the plan and the model seems quite strong even without cockpit sheeting. However, re-reading other people's threads and advice I think I will add some too!

[Masher]

Bit more done today and I am now fast approaching the covering stage. Fitted wing fixing plate drilled and tapped to M4 and strengthened with thin cyano. Cut out recess to allow 4oz fuel tank to fit and finalised wing dowel.

Nylon bolts usually need making shorter so I chop and finish off with pencil sharpener to ensure easy thread starting. Anyone else remember this set? This is not the one I had when I was 11 but still holds the same affection:

 

 

Hinges turned up today so I have dry fitted Fin/rudder and Tail/elevators. After much deliberation I have cut slots for tailplane at 0deg incidence. So time to have a look at how she comes together:

 

 

I am still thinking about detachable hatch so spent 10mins knocking one up. Made some bits:

 

 

Then a bit of heavy engineering to bend 1/8 balsa round and flood with cyano:

 

 

This can either be kept separate (access to tank, place to store Rx battery etc) or glued. After a very short time, like most of my work............. it nearly fits!

 

 

So getting there and as always, the next job is the control lines - guess which is my least favourite job! I can almost guarantee that I will get the tail section wrong when it comes to final assy and glueing - I've gone for the wire joiner to join the 2 elevator sections which has to be fed through the fuselage befor inserting and glueing the tailplane - one of thos jobs where you concentrate so much you are bound to get something the wrong way round!

 

On the covering front, I have a load of stock to get shot. My wife says there is only one choice for a "jazz themed" plane - black and white. I have some black but don't think I've ever seen it on a model - is there a good reason why you don't see it much?????

 

One mor view from underneath which shows that I should have read the destructions properly and gone with solid elevators - they look a bit silly with all the reinforcing blocks!

 

Edited By Masher on 20/01/2014 15:25:58

[Masher]

Just for my one loyal Mini Jazz blog follower, another little update. Not much time today so tried to make a canopy. I've previously knocked up a vacuum press and used it to make cowl and canopy for KillerWatt. For me, it's an "iffy" process but you can usually make good - let's see.

Guess what - I'm struggling to get text wrapping round pics - so pics have come out in reverse sequence at the end!!!!!

PIC 4: Tools of the trade and plug - cut and sanded out of 3x3 offcut - just guesswork really. I can't bear to use up thick balsa stock so prefer hard graft with the pine! The first result at front of picture is made from some old thin plastic from a box of chocs or similar - just to see how close it isn't:

PIC 3: Once plug is good enough, go for it. Start by stapling thermo plastic to vacuum press frame, then it's into the Aga at gas mark hot. As always, my jigs are rough and ready under the premise that I will re-make them properly once I've tried them out....................... and I never do:

PIC 2: Then swiftly out and over the plug, making sure vacuum cleaner is on. Since I was otherwise occupied, I didn't photo that operation so have to settle for a pic of the plug on the press (yawn):

PIC 1: It didn't go too well! I left it in the Aga for a few seconds to long and it caught causing an orange peel surface effect in white. After much trimming and sanding to fit fuselage, it's actually so bad that it looks quite good! Well it'll do for me anyway - the canopy needs to be opaque because servos and receiver will be in cockpit and there is no need for a pilot because I will be controlling the plane from the ground:

[Nev]

You have more than one fan Masher. I keep watching but I’m yet to start my Mini Jazz.

Nice canopy by the way, I think I may have slipped up by buying one.

[Masher]

Thanks Nev, I've just noticed that my no 1 fan is in the top right hand corner of the first photo!

[Kevin Fairgrieve]

Very nice.

Puts my canopy to shame.

Kev

[Masher]

One of the day's where it was necessary to get a crack on, I was starting to drag my heels on trivial decisions - so today was "go for it!"

Lots of bitty stuff. Added fuse doublers after all - should have followed Kevin's advice as it would have been a lot quicker and more effective if I'd done it at the start! Glued the front top deck - absolutely no need for this to be removable, for IC anyway, because there is plenty of access.

Bit the bullet and put snakes through - once again the design lends itself to straightforward easy routing - took all of 10 minutes. One little thing, if you find that the drill wanders when you are trying to drill through the fuselage at an angle for snake exit - knock up one of these simple jigs, only takes a minute:

Plenty of sanding then covering comenced. Not my top skill but there you go. I am trying for a Jazzy theme:

Next time I will stick to white and then add colour after! If anyone is wandering about orientation problems. look what I did underneath!

I have expertly implemented the illusion of a dog's hind leg at the joins - but I will cover those somehow. Fitted wing servos and soldered leads to make Y connection. Once again I have ignored Kevin's input and gone for a 4.8V receiver battery - a very diddy AAA version:

Finished off today by slopping the tank bay and front former with Poly C to fuel proof. Jobs left include:

Finish covering and make some decals

Fit a tail wheel then glue and pin all hinges

Find a place for the ON/OFF switch - I am reluctant to put it in obvious place because it would be making another hole in the weakest part of the fuselage

Put throttle control in

Fix canopy (that'll be fun!)

CofG etc etc etc