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About this blog

My adventures in building the Skyreach Bushcat LSA kit

 

But first, time for some indulgence!

 

Thirty five years ago, I was given a copy of National Geographic magazine. The cover story was on ultralights. I was besotted by the idea of these 'personal flying machines', particularly the Pteradactyl and Quicksilver MX, but I had a funny mindset back then. Even to the extent of thinking that since we didn't live in the USA, ultralights were out of my reach. Not just that, I lived in Darwin, Australia which as a 14 yo felt like an even less likely place for ultralights. Where were the green forests and New England architecture for me to soar over!

 

Ten or so years later, having pretty much forgotten about ultralights (as I knew them) I learnt to fly in a Piper Warrior. I got as far as GFPT and then ran out of money, and steam.

 

A couple of years ago I started thinking about the 'real deal' again and the idea of constructing an ultralight and did some investigating. And lo and behold, Quicksilver (and the MX) were still around! But only just. They were going through the process of changing hands, and also Rotax had stopped making the engines used for them. Anyway, I discovered this new type of licence (RA-Aus) and decided to re-learn to fly and convert my GFPT. You get a lot more value for the price. At the same time, I was pointed to the Skyreach Bushcat as a possible kit to build. You might think the Bushcat is a far cry from an MX, but it is still aluminium tubes, brackets and fabric. Just with a Rotax 912 swinging the propellor instead of a chainsaw motor! But it will totally scratch that itch I had all those years ago. And also, I can take my partner up with me, and it doesn't just have to be at the break of dawn 😀

If you are starting out building the Bushcat review this blog from time to time to see where I’m at.

 

So let’s build a Bushcat kit!

 

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Entries in this blog

 

15. Section 49

Installing the firewall.   In section 23 I mentioned you need to leave the wooden fairing spacer in place. This is why! Without it, the firewall pieces are not the right shape and won't fit. Which I didn't realise so I experimented by trimming off about 2mm from where the firewall pieces meet the top of the engine mount thinking it might shift into place. It still didn't make sense so it was time to email Eddie the Engineer at the factory. He then told me the fairing spacer should still be in place. Oh and you can trim the edges a bit but whatever you do don't trim off the part of the fairing that sits on the engine mount as it helps keep the fairing in shape when the spacer is removed! DOH! I came up with a solution to fix my screwup however and checked with Eddie to see if it was ok. Pretty simple, I just made a shim from some aluminium angle and pop riveted it place. I used some epoxy putty behind to hold it in place while I drilled the holes for the rivets. And from the front when it was fixed in place I used epoxy resin in all the seams to finish it off. Stronger than the original design I reckon 🙂   When riveting the firewall pieces in place, I found one or two of the holes I drilled didn't hit the inner lip, or was very close to the edge. So instead of the little washers supplied, I used some of that ali angle to make some 'mudguard' washers. Talking of washers, some of them were really hard to get in place. See my special tool 😄   Note in the pic of the attached firewall pieces I filled in the edges with some Sika fire retardant silicon, from Bunnings Aerospace. Will it help? Who knows. But I figure it will at least help take some of the stress off the rivets.    Last pic is of the finished flame retardant foil/fibreglass. I used water based contact adhesive purely because it is rated for 160 C while the regular stuff is rated for 130 C. Again, will it make a difference when the fuel fire is 1600 C or whatever? Who knows. But 1600 C on one side of the fire retardant material will be much lower on the other side, so that could buy me a few more seconds! I have decided to try hard not to have an engine fire 😄

danny_galaga

danny_galaga

 

1. Without further ado!

Note: this build is for the taildragger version of the Skyreach Bushcat, so bear in mind some sections may be a little different to the tricycle version.   So I won't be posting every time I screw a nut onto a bolt. Mostly I will highlight points of interest, tricks and solutions and general thoughts. Also I am discovering that I am needing 'special' tools sooner than anticipated, so in this first post I will list any special tools/materials and the section of the Bushcat build I first needed them in. That way if anyone else is building a Skyreach Bushcat they can see when they have to spring for them without having to buy them all at once. At the time of writing this, I was up to section 17. I would suggest it won’t take long to get that far.   Torque seal                                - Section 1 Pop rivet gun                             - Section 2 (not really a special tool as such, but I didn't have one handy so it goes in the list!) Loctite 243                                - Section 12 Cable tension gauge                 - Section 14 0.82 safety wire                         - Section 14 (choose any unit of measure you like- miles, parsecs, cubits. I myself went for millimeters as that will have the best fit in the hole) modified pointy nosed pliers     - Section 17 M6 taps (through and bottom)   - Section 25 special wheel bearing grease    - Section 29 loctite 572                                  - Section 53      

danny_galaga

danny_galaga

 

13. Thoughts so far, or great expectations

I have not been enjoying this build.   but I need to elaborate.    A programmer friend once told me that I would be an excellent beta tester because I always seem to find that combination of inputs that seizes up the computer.   I am also a creative person. Often if i make something, it comes out of nowhere. The last major thing I built was this arcade machine:   http://forum.arcadecontrols.com/index.php/topic,144934.msg1506839.html#msg1506839   this gives you an idea of the skill set I have. Not a master craftsman by any means, but able to come up with novel ideas and solutions. In my mind then this is at one end of the creative spectrum. Another sort of creative pursuit are things like LEGO or Mechano. In the case of making one of those models the goal is clear, and there are explicit instructions to get you there. This is at the other end of the spectrum.   So, sometimes I like the OCD hypnosis of something like LEGO (I have a kit ready to start on actually) and sometimes I want the immersion of creating something from scratch, like my arcade machine with glass control panel and touch controls. With the Bushcat kit I was really expecting a giant Mechano set. But it’s not that. How can it be? Mechano have made millions and millions of sets and had maybe a century to perfect their system. My Bushcat kit however is number 231. And a hell of a lot more complicated than a Mechano set! This ‘model’ is a continuous work in progress. There are typos in the instructions, missing or wrong sized bolts. There are sections where you really have to use your initiative and work out what it is they are trying to tell you.   so then, this is not a scratch built arcade machine, but nor is it a Mechano set.    But Mechano is what I was expecting. Every step perfectly defined. Every part present and correct. So I am struggling because of my false expectations. So each time there is a problem, I really start to get down about it. Maybe because then I’m not sure what the right thing to do is. With one of my scratch built projects, the right thing to do is whatever comes to mind. The solution is correct so long as I am happy with that solution.   However, I have been told this kit is one of the easier ones and the manual one of the most complete. I think if you are a prospective buyer, be clear about what you expect. For most people, it will be all you expected it to be. For those rare few Beta Testers like me, you may struggle.          

danny_galaga

danny_galaga

 

11. Section 23/24

The fairing is a bit of a struggle to put on. You will need to ‘stretch’ it on. Note here that the bolts that weren’t fastened in section 6 should be removed before fitting the fairing. The manual doesn’t mention this. If you thought it was hard putting the fairing on, wait until you realise you need to take these bolts out and have to take the fairing off again 😄   Note: once i fitted the undercarriage I found that the slot it fits into on the fairing was not even. Hard to know if it was me or it’s not that accurate. I ended up cutting a couple of mm off with a Dremel. Just as well you can’t see both sides at once, eh! Time will tell if the alignment of the fairing will be a problem...   NOTE!  There is a wooden spacer you use to set the fairing up. I assumed you take it out when you are finished. Not so! You must leave it in because it changes the shape of the fairing and when you get to section 49 where you fit the firewall panels in you will swear black and blue that this panels must be for a different airplane because they wont fit at all! You will also just swear 😄  

danny_galaga

danny_galaga

 

14. Section 44

I had a hell of a time setting up the throttle arms. This was part of my tantrum in the previous post!   But basically you can avoid a lot of time and stress by being really careful fitting the armrest plates. I didn't make them conform closely enough to the curve and they sat a millimetre or two off the armrest. The problem there is that the throttle arms have a bend in them and there isn't much leeway for error. Where the arm bends, it rubs on the plate, causing way too much friction. I ended up drilling out the rivets (TWICE on the left hand arm!) . I filled the holes up with epoxy putty and redrilled. I took care to push the plates as hard as I could. But what I also did is redrilled with a smaller drill bit. Through the hole in the plate but as low as I could. Therefore when I drill that hole the correct size, the hole is maybe a millimetre lower. That helped pull the plate just a smidge lower again.    Pic shows how far the plate was off when I first attached it. 
 

12. Section 43

As good a point as any to post an updated picture. The battery was a dam tight fit and im not looking forward to having to replace that one day!    Putting on the undercarriage and wheels was pretty straight forward. Be aware that some of the items come pre assembled even though the manual has assembly instructions. Things like the disk brakes definitely need tightening up and Loctite used.   the seat backs had a hole too small for the clevis pins so I needed to drill them out  

danny_galaga

danny_galaga

 

10. Section 22

You need to put ten grommets into the fairing at this stage. Go to the bedroom and grab yourself some water based lube, some of these are tough little buggers to insert 😄    so tough in fact there was no way I could get the two medium sized grommets in the holes. They were 10mm holes. I ended up drilling them out to 12.5mm and they were still the hardest to get in! Those two are for the battery cables.   I should add that that at this point (kit # 231) they still have instructions for drilling the ten holes. This is probably legacy from when they offered a version with a rotax 582 and thus presumably you would drill holes in different locations compared to the rotax 912. Mine came pre drilled

danny_galaga

danny_galaga

 

8. Section 17

Detail section 17   installing the first bit of trilam on the skyreach bushcat.   ive never been good at lacing my shoes so this will be a challenge 😄 but at least I can make it easier to thread the lace with some superglue on the end and rolled between wet fingers to make a ‘needle’. I’ve now perfected my technique. Ignoring the fluffy end of the string I soak about a 10mm section with superglue. When it has set I cut it on about a 45 degree angle. Then a bit more glue on the cut end.   also, save the leftover string! On a later section you need to lace the aft end up with a short length of string. Mine was too short! Luckily the leftover string from this section was longer 🙂     When the the covering is done, you will need to get a nut and washer inside the covering and onto a thread. I found by sitting that part onto a torch pointing up, I was able to do this without too much trouble.

danny_galaga

danny_galaga

 

9. Section 20

To lace up the fuselage sail I stuck with my ghetto work bench. By strapping the front down, I was able to lace most of the way from back to front. The last quarter or so I was able to reach from inside the fuselage. I concede that I may have to put it on a stand soon but for now this let me crack on 🙂   Note that the lacing is only done loosely at this stage.

danny_galaga

danny_galaga

 

7. Section 11

Detail section 11.2   In my correspondence with the contact engineer he told me I will have to trim a little off two bolts on the tailwheel spring so that the rearmost diagonal braces will fit. I used a Dremel so took the barest possible amount off.   I corresponded a lot with the engineer recently because there was a lot of head scratching with those fuselage diagonals. It should be that you may have to coerce the pieces a couple of millimetres to get them in place. But I found my first diagonal was 36mm short! Had everyone scratching their heads. Finally Errol, the Bushcat dealer came over (luckily we aren't too far from each other) and he found himself scratching his head too. He called the factory and talked to the engineer and the manager. A light bulb went off for Errol though and while undoing the bottom longeron to see what the diagonals would do without it, he realised that loosening off the bolts let it fit properly. The bottom longeron has two bolts. Taking out the second bolt lets the longeron swivel a bit. Once everything was aligned it all fitted beautifully and the second bolt can be put back in.   A programming friend once told me I am the perfect beta tester because I always find that combination of things that no else has tried that will lock up the computer. Looks like that 'talent' has transferred over the airplane building because this is the first time this phenomenon has happened with this particular kit 😂   I still don't quite understand why it did it, but my own thought is that if I were to build one again I would leave those two bolts loose until all the diagonals are in place and then tighten everything up. It may well be that by the time you are building this kit, the manual will suggest that also.

danny_galaga

danny_galaga

 

4. Workspace

I am building the Bushcat in a two car garage. Skyreach recommend something a bit bigger. So not heaps of room. Right now I’m using two of the long crates as a bench. They are sitting on some mini castors so I can move them around. Once those two are decanted they can go out and the fuselage can stand on its undercarriage in the same location. There will be an awkward phase though because the wing components are in the larger of those two crates. Jo doesn’t know it yet but her car may have to sit outside for a bit 😄 once ive built as much as I can, I’ll have to look at renting a hanger of course...

danny_galaga

danny_galaga

 

6. Section 9

Detail section 9   left side upper fuselage tube has two threaded holes. Also, make sure you put the turnbuckles in in step 2 before you do step 3 (which ties the two tubes together aft) otherwise you won’t be able to put the Clevis pin in. How do I know this? 😄

danny_galaga

danny_galaga

 

5. Section 8

Detail of section 8.2   there are bushes that go inside the bottom tubes where the tail wheel spring mounts. These are a tight fit so what I did was wrap the tube in thin card and then get some vice grips. I wound the vice grips up to just touch the card. And then just enough more to just compress the tube. Not enough to even see. Then I placed the bushes in place with pointy nosed pliers and put the bolts in to hold them in place. When the vice grips were released the tube springs back into shape and holds the bushes 🙂   Note in in the background is my bike. By strange coincidence it shares much the same specs as the Bushcat- 100hp, 305kg (yep he’s heavy!) and about 180 km/h top speed! Mind you, you don’t want to be going top speed on a cruiser for any length of time, while you could do it all day in the Bushcat 🙂

danny_galaga

danny_galaga

 

2. Section 2

For this section you need to rivet some aluminium strips along the bottom. Later they are used for lacing the fabric. I can tell you now a ten dollar pop rivet gun won’t work!   So I got this bobby dazzler for the rivetting. Kingchrome, forty bucks. Does the trick and should see me through this build since there are only a few rivets here and there in the Bushcat  🙂    

danny_galaga

danny_galaga

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