CriCri MC-15 in NZ

[MadRocketScientist]

Hi all,

I am currently building a CriCri and it has been suggested that I make a build thread. The project started in November last year when I purchased some CriCri plans but I have only been building it for the last few months.

I first saw Nev Hay's CriCri (ZK-LBW) at Classic fighters at Omaka airfield in 2005. I thought it would be a cool aircraft to own and build but was put off by the 2000 hour build time (I didn't even consider the cost at that point in time). I would not have been able to afford it anyway.

I purchased a CNC router early last year and realized that it would be good to build myself a homebuilt aircraft. It would also shorten the build time substantially. I choose the CriCri due to it being all aluminium and would utilize the CNC a large amount, The low storage size and relativily low cost were also factors. I have spent upwards of 300 hours converting all the plans into CAD format so I can CNC all the parts and pre drill all the rivet holes etc.

There are currently two CriCri's flying in New Zealand, ZK-LBW and Wayne's ZK-CRI. Wayne also has an excellent website on his build and flying.
Cricri aerobatic aircraft builders Page : Home

Edit again to include youtube link:


Plans are available from Mr Colomban, his address is:
Michel Colomban
37 Bis Rue La Kanol
92500 Rueil Malmaison
France
Fax: 0033 147 51 8876

I have put this info here because someone invariably asks how to get plans, Mr Columban does not use the internet and mail or fax is the best way to get in touch.

*edit* those in North America are outta luck when trying to buy plans, a certain US manufacturer copied the CriCri and made some design changes with fatal results. Mr Colomban now refuses to sell plans there due to the resulting undeserved lawsuit directed his way. The irony is that the certain manufacturer was up in arms when someone else copied one of his designs. Those in North America wanting to build would do well to check out CriCriDrawings Yahoo group (link below)*

There is also a wealth of info on the yahoo groups 'cricri' and 'cricridrawings'
CriCri : CriCri
cricridrawings : !Cricri-Electronic Drawings (ACAD&SW)-01

Next post some build pictures.

Shannon

[MadRocketScientist]

Here are some pics of my build, the aluminium part is a viability test I cut with my CNC sometime before I purchased the plans and at that stage had not decided to go ahead with the project. The part took about 15-20mins to draw in CAD and about 4 minutes to cut on the machine. Turning the machine on takes longer.

The next lot are of the landing gear and the mold I made to make my own. The mold is lined with acrylic as epoxy will not stick to it and it leaves a glass smooth surface. I also put a slight angle on the ends of the mold so I would only have to make one cut off each side (I hate fibreglass dust). I used a single strand of glass for the layup and wrapped it around pins in either side of the mold. I also used some woven cloth at 45 degrees to hold the lamination together. The original CriCri's in France had issues with the landing gear as they were just uni fibers with only the resin strength holding them together. When in use, they started splitting, adding reinforcing fibers through the layup solved the problem. The landing gear from France costs about 400 Euro, Mine cost me about NZD$30 for materials. I could have another one with about 6 hours labour now that I have the mold.

I had a few issues when molding the gear. The glass layup pulled down tight around the curves but tended to bulge up in the middle. I planed it down with the rasp shown in the photos. I have yet to drop test this gear but I think it will pass easily. I will be making another one for on my plane as this one has a few imperfections in the finish and I would like to get the layup in the middle to sit flat.

Next post brakes and wheel tests.

Shannon.

[MadRocketScientist]

Here are some images of the landing gear tests I did, I have not done any more on these since buying all my aluminium. I will be using Avid BB5 brakes, I considered getting the Avid BB7's but they are slightly more complex (ie: more to go wrong). I have purchased a set of Shimano cables to go with these, they come with boots and should make a smooth mechanical brake setup. The BB5's are slightly lighter than most of the hydraulic MTB brakes and there is nothing to leak.

The first photo with the smaller disk for the brakes is also a test cut out of aluminium, I may increase the size slightly but I would like to keep the weight down as much as possible.

I will be making my own wheel rims (because I can and the plane is a showcase for my CNC business/hobby) and the clear acrylic is a preliminary test to see if it is viable. I will change the tyres in the photo with aircraft types from Desser.com, they supply the right sizes.

If anyone has any questions, fire away.

Shannon.

[MadRocketScientist]

I bent the rudder cable tubes over a bit of Scaffold tube, the duct tape stopped it getting marked. I made the piece of 'modern art' then cut it up for minimum wastage. I think they turned out alright

The parts on the machine bed are various bits I made by hand. You will see them show up again in various pics. There is only a small amount of 4130 steel in the CriCri and I didn't want to fork out the $$$ for the CNC laser cutting. I enjoy making things with the bare minimum of tools (bandsaw and linisher in this case), just not ALL of the 100's of parts needed for the CriCri. There are around 2200 parts to a CriCri, including bolts and nuts etc but not the 4000 odd rivets.

I will be making a few changes (with careful consideration and engineers advice of course). One being the Ramp Armor used for the sliders on the bottom of the pedal tray, The plans call for Phenolic (or celeron, Tufenol etc) The ramp armor is a similar product that we use on our skate parks (see website) It is a much newer product that I suspect is phenolic based. Iten industries in the US makes it along with many other phenolic and composite products.

Here is some of the rudder setup, I cut the pedal tray on the CNC and took it out to the local airfield to fold it up. Came out almost perfect, even better considering it is my first folding attempt. The best part about CAD and CNC is that the bend radii can be calculated and allowed for exactly before anything is made.

The last pic is how I made the metal parts, glue a printout to the 4130 and cut it with the bandsaw. Then linish it to size.

Lots more pics to come.

Shannon.

[MadRocketScientist]

Here are more control parts I made, some of the finish work has to be by hand with a file and sandpaper. The second photo shows the smaller parts of the rudder setup.

Then its the ends of the flapperon tube, no zenair mods here

Lots more bits and bobs, Mostly CNC machined. Putting a vice on the CNC helps for milling parts, I also CNC drilled the holes in photo 13.

Shannon.

[MadRocketScientist]

Now to the spar construction, CNC is great for things like the web reinforcements, hundreds of holes without any fuss.

Mdf is great for spar jigs, offcuts from paying work cut on the CNC (of course).

The last pic is the wing and elevator spar (nissan serena for scale)

Shannon.

[Jman]

Shannon,

Thanks for sharing this with the rest of us. Looks like you are off to a great start. Is the CriCri solid rivet construction? Thanks.

[MadRocketScientist]

The CriCri is mainly 'pop' style rivets, the wing spar is one of the few parts that has to be solids. I am going to make as many of the rivets in mine as solids. I think they look better on the outside (mine will be polished)

Shannon.

[flyoz]

Good workmanship and clear pictures - i am sure you will have Cri Cri builders wanting to buy parts from you .
Flyoz

[MadRocketScientist]

Made the jigs for the fuselage buildup today. Cut out of scrap MDF (mainly). I designed them to fit together like a jigsaw puzzle. The plans call for the two concave jigs but I am CNC pre-drilling the skins so I need the convex ones to drill the aluminium angle corner reinforcements on. The concave and convex pairs also stack together for storage.

The hole cutout is for the lower nose vent, I can attach the vent and still put the forward fuselage on the jig.


Shannon.

[rtfm]

Hi,
Nice to see a fellow Kiwi building (and posting build pics and info) here. Where are you based?

Duncan

[MadRocketScientist]

Duncan,

I am in Rangiora, The local airfield has lots of homebuilt aircraft. I think it may be the biggest group in the country (would have to check up on that) the hangers are certainly packed with planes. There is also a shop that has a good supply of aircraft parts.

I have been keeping an eye on your build thread although I only discovered this forum recently.

Please don't hesitate to ask any further questions you may have.

Shannon.

[Mac790]

Shannon,

Beautiful work thanks for sharing with us. Personally I'm a little bit scare about a number of parts in this little plane, I've heard that on average people needs about 1500-2000h to complete Cri Cri, now I know why. Wish you luck, keep us up to date with your progress.

Thanks
Seb

[MadRocketScientist]

Seb,

I keep saying that there is no way I would be doing this without my CNC, there are just so many fiddly little parts to make. I am doubling up on some of the parts I am making, most notably the materials that need to be sourced in small amounts from the US (depending on finances I will build a second CriCri) I know it will come together really quickly once I have all the parts cut, drilled and folded. Its almost going to be like a Van's quick build kit. In the meantime I find that the drawing and working out the setup for the CNC takes far longer than actually making the parts.

I think by the sounds of things the 2000 hours is a fast build for a CriCri. I would not be surprised if it took up towards 3000 hours. Having said that I think I can do mine in about 1500, mainly due to the CNC making my parts for me.

There was one other person locally that was interested in building a CriCri, as of yet I haven't heard back from him.

I'm almost looking forward to building a bigger plane next, like a two seater STOL, I would not be surprised if they have less parts

Shannon.

[MadRocketScientist]

A few more pics, the first one is of the bits that make up the nose gear, no wheel rim as yet, I will make that later. I have also sorted out the steering clamp and made a welding jig for it (someone say jig) I have made enough bits to make three clamps. I will be sending these up to my brother in Auckland to weld up for me. The steering clamp is the only part in the CriCri that needs to be aluminium welded.

Also a few pictures of parts I have made but sneaked past me posting them. A few progress pics of the engine mounts that attach to the F1 fuselage former. I think I have a few more parts made for this since the last picture was taken, another photo of it might be in order.

Also sneaking in to the photos are the hinge brackets for the elevator.

Shannon.