Noris - Bachem Ba349 Natter - Build Thread/Review

Well I got home two days ago to find the Norris Modell Bachem Natter on my doormat. This has had a round trip from Germany via Austria to my door as the German shop selling them doesnt deliver to the UK for some strange reason (come to that they dont deliver outside of continental Europe !!).

Anyway after its long trip it arrived unharmed by the rigours of international travel and tonite I finally got to unpack it.

Those familiar with Daddyisbars thread on thismay recall I promised to do a build thread so I am ready and waiting now and all prepped up. While awaiting the Natter I bought myself a brand new cutting mat, X-Acto Knife, Air Brush, Squadron Putty and a few other items which I felt may be of use in building the Natter.

I thought that given the questions asked about Noris on a recent thread the kit contents may be of interest and my opnions on it so before the build starts lets take a look at the box and its contents.

Below are some pics of the box (yes a box - alien I know to US suppliers who prefer poly bags but here in Europe a box is de-rigeur for anything that costs more than a dollar ) and its contents.

The contents as tipped out on the floor do not consist of anything that even remotely resembles a rocket but do resemble something that looks like hard work ahead but surpisingly not so bad as I had feared and with some surpising quality touches.

The basic parts consist of;

• Instructions - in German but with a step by step pictorial guide (this is not for the faint of heart).
• Two vacuform sheets consisting of the nose and tail assembly.
• Cardboard tubes, rather glassy in finish and quite lightweight.
• Bag of parts of the rear boosters
• Bag of heavy card parts for wings and tailplane plus body formers/centering rings.
• Bag of parachutes and odd and ends.
• Bag of modelling clay (that hadnt gone hard.....yet !).
• Some weird fluffy material which I cant decide whether its packing material or some kind of weird ejection baffle material,
• Two sets of peel off stickers (one with the sun ray pattern of the Natter prototypes and one with two small crosses plus the wing numbers for the ill fated first manned attempt of the real thing).

I will cover the small bags of bits below, the cardboard tubes in the main elements are quite light and squishy but not as bad as I had expexted. The vacuform parts are quite heavy duty and seem very good.
The instructions have a step by step pictorial guide but my feeling is without some serious skill and experience this kit would be a nightmare. I feel I have the skills, the know how, am running with the Uberwoman inside and am ready to join the master race of modellers capable of 'Doing a Noris'

Whats in the teeny bags below.....

Make sure to use no less than 30g of nose weight!

So whats in the smaller bags then ???

The first bag has a pile of parts cut from some kind of thick card. These are the parts of the wings, tailplane and the body former/centreing rings. Overall they are fine - the centring rings seem a bit off centred and are not symmetrical to each other so they will need some attention on build. But on the upside no balsa to mess up (errrr I mean make perfectly formed aerofoils from).

The second bag contains two parachutes (although the model instructions seem to suggest a single chute recovery) together with shroud lines, sticky discs for the chutes rather than the ubiquitous hole reinforcers, an engine hook, cut outs for an Estes style shock cord retainer, a length of tubular elastic for shock cord, a swivel and surpise, surpise two metal launch lugs so the quality aint bad really.

The final bag contains the elements of the rear boosters which are small cardboard tubes, some end caps, plastic booster nozzles (hallelujah so no card to roll) and some weird hollow papier mache balls which form the front rounded sections of the tube.

Initial impressions - its good in parts....nice vacuform, some metal bits, two chutes and plastic nozzles, on the downside squishy paper tubes and some Heath Robinson (you yanks would say Rube Goldberg) ideas - like the bizarre mothballs made of paper but lets face it the real thing was hardly a model of sane and sensible design so hey ho.

Am I scared ? No not really - its going to be a challenge and this is certainly no kit for a tyro or anyone scared of more than a shake and bake kit - we'll see as it unfolds and see what sort of horror this builds into. I am quietly confident (other half says smug) - Let the build begin !

Also, you might want to consider making the motor tube to fit 18mm engines for use with Klima D9-x model rocket engines.

Because these engine are lighter than 24mm engines the CG will move forward for more stable flights.

Leo said:

Also, you might want to consider making the motor tube to fit 18mm engines for use with Klima D9-x model rocket engines.

Because these engine are lighter than 24mm engines the CG will move forward for more stable flights.

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Leo - round these parts its almost impossible to get anything other than Estes unless you move to reloadables. I lose too many rockets to make reloadable a practical proposition so its Estes or nothing. I was planning on using D12s for this but I will see what sort of weight I end up with. Getting an 18mm might be quite good to keep the height down.

I was wondering whether building it to glide after burn out might be possible

You will be just fine, no worries. My centering rings looked somewhat symmetrical, but look closely, there is a front and a back! Looks like they have sharpened the blade on their tube cutter. Maybe they upped the quality of the tube, mine was not "glassline" coated, it was matte paper with a big spiral. Squishy tube is good for this kit! You have to take down that 25mm engine tube to 24mm or it will be a lot of tape on the mighty D12. Metal launch lugs! WOW! I would go at least 3/16", a 1/4" lug worked well for me on the long rod. If you are going to use only D12s then you can put the motor hook in. My next flight will be on a D12 3 and if I don't like it then it is an F 44 for the final countdown.

Luke told Yoda he was not scared, then Yoda responded "You will be!" Flying the Natter is quite as bad as facing Darth Vader, it might however, be about the same as the Imperial Mind probe Princess Leia faced in the first movie.

Astro-Baby said:

Leo - round these parts its almost impossible to get anything other than Estes unless you move to reloadables. I lose too many rockets to make reloadable a practical proposition so its Estes or nothing. I was planning on using D12s for this but I will see what sort of weight I end up with. Getting an 18mm might be quite good to keep the height down.

I was wondering whether building it to glide after burn out might be possible

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I got a high speed and long glide with nose down ejection on an E12 4. Using the word glide is also very generous. More like a powered shallow dive to oblivion. This chubby little fella has no wing area, so like Buzz Lightyear all he can manage is to fall with style.

:surprised: I was just getting ready to post a request for info on any Natter kits folks may have. I have a rocketry magazine somewhere from a few years back that had an article on a Natter kit from Germany, I assume its the same as yours, Astro-Baby.
I gave some thought at that time to a scratch build since I have a nice book (Schiffer?) on the Natter with some nice scale drawings.

Daddyisabar, you are in Colorado, where might a Yank gets his greedy mitts on one of these kits?


Astro-Baby, maybe they give you two parachutes so you can recover the body and nose separately, sort of like the original?

Sierrafox in Italy have the Klima motors and they do post to the UK. As you no doubt know it's easy enough to adapt a 24mm. tube to 18.

Klima motors are not yet legal in the UK. (Note the optimistic use of the word "yet". ) Take no chances, fit a 24mm mount, then if we ever do get to use Klima motors you can always make a 24mm-18mm adaptor.

I agree with supersteve - the real thing dropped off the nose, which recovered on one parachute while the rest of the aircraft recovered on a second and the pilot recovered on a third. For added realism, then, you could put a small parachuting action figure or toy soldier into the model!

The fluffy stuff is Noris' idea of permanent wadding. Dump it and use proper wadding if you want the parachute(s) to survive.

It sounds as though the body tubes are better than the one I got with the Noris Ariane 5, which was thick, heavy, and had such a wide deep spiral that even I had to fill it, and I don't normally bother! The Natter body tubes probably have to be a bit squishy since part of the assembly process will probably be to squish them into an oval cross-section.

Good luck with the build!

supersteve said:

:surprised: I was just getting ready to post a request for info on any Natter kits folks may have. I have a rocketry magazine somewhere from a few years back that had an article on a Natter kit from Germany, I assume its the same as yours, Astro-Baby.
I gave some thought at that time to a scratch build since I have a nice book (Schiffer?) on the Natter with some nice scale drawings.

Daddyisabar, you are in Colorado, where might a Yank gets his greedy mitts on one of these kits?


Astro-Baby, maybe they give you two parachutes so you can recover the body and nose separately, sort of like the original?

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You can order them directly from Noris in Germany. I believe they are a bit pricy in Euros with shipping, and good German linguistic skills a plus. I got mine off EBAY where they do come up for sale occasionally.

Astro-Baby, you never fail to impress me with your ambition. I, who am too faint-hearted for vacu-form, will be watching this one with great interest and no small amount of admiration.

Just so you dont all think the Noris Natter has driven me to eating my dinner with a rubber spoon while locked in a padded cell I have made quite a bit of progress over the last few days and will post up a step by step build thread to the point I have gotten to in the next few days. Time has been a bit tight and its been a choice of moving onwards with the build or posting here (tough choice ) so the build has taken priority.

Early expectations have been met - the vacuform was easier than I had expected but as Daddyisbar pointed out if your building this kit take the instructions as no more than a general guide. Dimensions are often out by quite some so you need to check and double check everything you are doing. The biggest embuggerment on the instructions so far has been the dimensioning for the centreing rings/body formers with relation to the body tube/motor tube. They would probably be correct IF the body tub e and motor tube were the right lengths but the body tube is a bit longer than stated and the motot tube is a bit shorter. If you went by the instructions you would fine the motor tube was short of one of the centreing rings by about 10mm !!!! As I was forewarned and also because I am a tweaker by nature who constantly checks this came to light early.

My one is being adapted to use a 24mm Motor - I have a 24/18 adapter if I need it but 24mm seemed more sensible to me as I have a supply of D12-3s.

Definitely not a kit for the beginner but I am having fun (in a good way) with the kit and in a few days I hope to be able to share the first part of the build with you all - I am building it with little regard to the instructions so hopefully can bring something new to the party.

Please show us how you close the seams in the vacuum-form shell...I've never seen it done

You folks may want to stand back now cos the dangerous bits with sharp modelling knives and sharper wit are about to get going to pull this Nazi Warbird in miniature together.

The first thing to do was make a small addition to the kit which was a Fliskits 24mm Motor mount. The Noris kit is designed to use a slightly fatter German motor thats now out of production. You could probably friction fit a 24mm motor into the supplied tube but you would use a lot of tape and I don't like friction fit on stuff. Its hard enough getting the motors out at times with a hook let alone worrying about whether the thing has heated up and caused the glue in the tape to stick to the tube.

So first thing to do was to check how good a fit the standard 24mm motor tube was to the supplied Noris tube - the answer was it was OK(ish) but I like better than OK so decided to glue a paper wrap of copy paper around the 24mm Fliskits tube, wait for it to dry and then glue it into the Noris tube. This worked ok but its not for the faint of heart. You need to get the glue on and then press the motor tube in using a flat surface to force the outer tube down. No time for second thoughts because if you have a moment of weakness you will end up with one nasty big problem. So steady nerves and a steady hand with the sureness of knowing this DOES make sense is whats needed here.

The pics show the Fliskits motor tube WITH its motor block being assembled and pushed together - the arrow marker is to indicate which end has the motoir block because getting this wrong would not be good news. The final pic is down the tube showing the pre-installed motor block.

A point here - the Noris kit does not supply a motor block and relies only an an engine hook that pokes into the tube to stop the motor pushing forward. I like the idea of a motor block as a bit of security against a motor blowing up through the model later on.

Next up was to install a dead motor and get the positining right for the Fliskits motor hook. I did it this way because at this point I was unsire which hook I would use - Noris or Fliskits - the Fliskits one was more discrete but I wanted a test fitting to make sure its hook end was long enough to hold onto a motor with double the motor tube thickness.

A slot was then cut into the twin motor tubes and the hook glued in and then covered with a cardboard cover and a piece of masking tape run round at the halfway point of the hook. This is all pretty standard stuff but as this kit is a bit weird I thought I should cover everything.

After all was dry the tubes internals were given a coating of aliphatic glue forward of the motor block. Obviously NOT in the area where the motor will be but forward of that. This thing will be flown on D12s and I was nervous about the heat going up such a tiny tube so the interior was given two coats of aliphatic inside. I just CANT build light - it goes against the grain

So that completes the motor tube itself.....time to move on to other bits.

Time to think about the main body tube.

The Noris instructions would have you mount the centreing rings for the motor tube into the body tube and then push the motor tube in. This is the opposite of any other kit I have built where the centreing rings are applied to the inner tube and then pushed into the body tube.

The Noris rings are oval and act as body formers so alignment would be critical to make sure that they are square aligned to each other AND square to the tube. I was far from convinced that this would be a good thing to do and decided to try various other methods firts. Whatever I did I would need the body tube marked up inside and out so heres the tube getting some alignment lines put on from a home made alignment guide.

You will notice that the alignment lines run INSIDE the tube as well for the reason that the elliptical centreing rings/formers will need to be true to each other.

WARNING - Ignore the dimensioning given in the instructions for this bit and do some dry runs and measurements yourself because if you followed the instructions the motor tube would be 10mm short of the second ring and that would not be good news.

Fear is the mind killer. After the first two steps on the Natter you have no fear of cutting and joining vacuform, or glue locking up on big tube couplers. Now the third trial awaits, getting the centering rings in straight and positioned properly with measurements in the directions and actual part sizes that may be a bit off. You must look well into the future to avoid the GOTCHYAS on this kit.

I considered a whole range of options to get good alignment on the elliptical formers/centering rings. These included building some stringers between them like a balsa wood plane, putting a 'key' of balsa down the tube and cutting a slot into the formers/rings so that they were forced to align but everything seemed to add weight and/or unwanted complexity.

These rings are very loose on the inner motor tube with about .5mm gap so that would make the task even harder.

I didnt even try to do it the way in the instructions as I just couldn't see any way to get the rings in and be aligned - especially as they are not perfect and when the tube is squeezed into the shape the rings tended to fall out very easily. The tube would have to be squeezed onto the flats of the elliptical rings/formers to get the body shape right. I knew this would be so because while all of this was going on the rear part of the kit made of vacuform had been assembled and here's another tip - don't do any final assembly until you have all of the sub components made up (ie front and rear vacuforms and the motor tube because you will find problems with fitting - for instance the vacuform elipses are much tighter than the tube would naturally form with just the centreing rings formers.

Whatever method I chose I would need to get the rings marked up so that I had alignment guides on them and something I could base a sensible approach on. I pondered on this for a fair few days as to the best way forward and I believe I have come up with the best approach I can.

Heres those wretched rings being marked up - they are probably supposed to be symmetrical but aren't and have a definite front and back so you need to fiddle about to get pair to be identical with respect to each other before you mark them up. A lot of hassle trying to get vertical lines onto an ellipse more irregular than it should be but I got there in the end - the pic shows a photocopy of all the card parts (in case of disaster) and also to be used as marking guides.

The final approach came to me at last which was to use some old fibre rings I have cut to size and use those glued to the motor tube to act as guides for positioning the rings with respect to front and back plus an alignment line on the motor tube. You can see in the pic the motor tube has the first of the fibre rings (these were made from cut down Fliskits parts). The ring on the tube has the kevlar (also Fliskits spares) run underneath it. I opted for the kevlar shock cord running outside of the motor tube to keep it away from the extra hot gases near the motor on ejection.

And heres the rear most centreing ring/former on the motor tube. The fibre rings holds it in place and also locks the shock cord down.

I am not stating dimensions here - you will need to check these yourself as each of these kits may vary but the rear most former needs to be at least 12mm inside the main body tube to allow the rear vacuform part to fit. The front former needs to be at least 50mm from the front of the main body tube to provide space for the chute and recovery gear.

The fibe ring is nice and tight and acts as method to secure the body formers and provide a good square fitting on the Noris rings/formers which are very loose. In my original plan I was going to epoxy these on to take up the slack but this method seemed easier and adds little weight.

The second (front former/ring) was then slipped over and just left loose while the front fibre ring was added. Once the front fibre ring was glued down the front centreing ring/former was slipped down and glued into place using the alignment marks to get it both square to the tube and to the rear ring/former.

Once dry each pair of rings was given a quick run over with some glue for added strength and to make sure glue had penetrated into any gaps.

Alignment was very good, given that the rings/formers are hardly perfect to start with. You can see the shock cord runs under all of the rings so it should be pretty secure with its knot at the rear most point and held in place by two sets of rings.

Once dry this was test fitted to the body tube and the rear vacuform tail. Test fitting showed the motor tube to be at a very slight angle so the elliptical formers/rings were sanded a little to give the motor tube a perfect fit with respect to the body tube/tail assembly.

With this kit you constantly need to dry run, test fit, think ahead of what issues may arise.

The vacuform tail was marked round with a CD writing pen, then gently scored with a sharp knife. I dont like my X-Acto and did this with my standard craft knife. Once free of the backing plastic each part was gently sanded in a circular motion on a flat surface until the edges were nice and flat. You dont want to overdo this. Once each part mated well it was time to break out the glue - the vacuform with this kit is quite thick. The last vacuform bits I had were with a balsa plane and the plastic was about as thick as paper and felt like foam the merest whiff of plast glue was enough to dissolve it as I found out to my cost. This stuff is quite tough and feels more like porcelain.

I did some test runs with epoxy and also with basic plastic cement (Revell) and the Revell stuff seemed to work well. Not too melty though I hate the smell of the stuff.

Some strips of plastic 5mm wide were cut from the scrap plastic, I then drew a line right down the middle for good alignment of the plastic strips and a strip each side of the tail parts was added and left to dry. Dont run these strips too close to the very end of the tail as they will foul the motor tube later on and try and get this strips as thin as possible - dont have them too large or else they will foul the other half of the tailplane.

Once the strips were dry glue was added to the strips and the other half of the tailplane was added to form a whole and gently held together with some elastic bands until the glue was dry. Finally the seam was sanded to remove any edge and the whole assembly was given a light sanding to provide a good key for the paint later on. Sand this stuff carefully because it will score quite easily.

The tail element wont require much, if any filling, as the seams are very tight with no obvious gaps.

Heres some pics of one half with the strips added and the rear end completed plus the motor tube with its formers in the background.

Finally - and heres thinking ahead for you - when I was pondering the centreing rings issue I realised that the centreing lines should all mate up - the rings, body tube, motor tube and these should be along the lines of the vacuform halves to give a common reference (yes yes thats obvious). What was more critical as it turned out was that I considered at that point where the engine hook would be. Not at the top or bottom because there will be fins there and there will be no space to get my mitts in and remove the engine so it would have to be at the side - in line with the wings.

So the tube was marked up for that and just as well because when the rear vacuform part was test fitted theres no space to release the engine hook - it fits too tight. As a result a small cut out had to be made to allow the engine hook to come back so the motor can be gotten in and out.

Having a nice regular position away from the seams of the vacuform part made marking this up and cutting out the slot a lot easier and also shows you how you need to be on your toes with this one.

heres a pic of the cut out for the engine hook on a test fitting.

Thats it for tonite - the next job is finishing the nose assembly and moving on to assembly of all the major body components.

Most elements of this kit are being built in parallel but rather than the thread bumbling around I am trying to keep it in some semblance of a logical order so its a bit easier on the brain - mine as well as yours

Wow. I can't believe it! A Noris kit that is looking more Flis like than ever! A fancy Kevlar harness where I just cut the supplied bungee cord in half with 2 trifold mounts and tied on snap swivels. Golly, it would have been nice to have all this good stuff available back in the day when I built this little monster. This is required reading reading for anyone even thinking of building this kit! The vacuform nose cone is open so there is more space if needed for recovery gear. But the nose cone shoulder in mighty thin. And then there is the question of nose weight and getting the wings on solid and true, and getting the launch lugs alined, and getting it painted nice and purdy. OMG! I am scaring myself again!

Thanks AstroBaby, good stuff..I'm learning a few things here.

LOL - its all taken of - I have a plan

Actually the nose cone shoulder is a headache and I have yet to come up with something thats a good approach for that. I am thinking of cutting the shoulder off and replacing it with a formed piece of basswood but until the main body is ready I dont want to make work for myself.

This one will have 45gm of nose weight (Noris suggest this) and I will be putting in a small bulkhead near the nose to hold the weight in place and provide a secure fitting for the nose ring/recovery harness.

I am not a fan of the trifold mounts - I lost an Estes Long Tom in part due to failure of one of those. The nose flew away on its parachute never to be seen again while the body fell to earth in some scrub and without the chute we had no hope of spotting it.

I have your excellent Noris Natter to look up to for this and my thanks for your advice on building this as well. On giants shoulders etc.

mrichhcirm said:

Thanks AstroBaby, good stuff..I'm learning a few things here.

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Me too

The posts are coming fast and furious. Lots of good work and technique on the vacuform up front will cut down on messy filler use and sanding later. The tail cone is cake, but the nose cone is a bit harder, can't wait to see what you do with it. Nice cut out for the motor hook. I didn't use one with the E12, but you will be nice, safe and secure with your D12 3, much to the delight of any RSO.