My Savannah S model rebuild Blog

[Head in the clouds]

3.2639 mm they are well thats what #30 is...that may increase the hole size a bit wouldnt it or are the specifically for 1/8 rivets...just seems a bit larger. 1/8 is 3.175mmBut hey I dont do this for a living so the airframe fitters would be right not me

Rivets should always be set into holes that are 'a bit' larger than the rivet diameter. Otherwise the rivet doesn't have the opportunity to expand and properly conform to the shape of the holes in the materials which may, or may not, be perfectly matched, but the rivet can take care of that. A slight mismatch actually make the rivet grip a little better and prevents it wanting to rotate with vibration. Not that you should aim to have a mismatch of course ...

 

More importantly the rivet needs to deform into the larger hole because as it does so the rivet work hardens, making it more durable in service.

 

 

[M61A1]

3.2639 mm they are well thats what #30 is...that may increase the hole size a bit wouldnt it or are the specifically for 1/8 rivets...just seems a bit larger. 1/8 is 3.175mmBut hey I dont do this for a living so the airframe fitters would be right not me

HITC explained correctly.

#40 for 3/32

 

#30 for 1/8

 

#20 for 5/32

 

 

[Kyle Communications]

Ok thanks for the info...I appreciate it..it also makes sense

 

 

[Kyle Communications]

Got those #30 and the equivalent for the 5/32 rivets today from bunnings. They work really well. Got the rivets out of the firewall and its now off...not that hard really. A few more bent rails which I will replace at the front section. You can see them in the pictures attached. The torn part of the Omega I will make a new piece up about 300 long like I thought and just fit it. Next I will take the rudder pedals out and do my extension mod to them...pilot side only though same as the girlfriend. Starting to get a little pile of bent parts but again not really a drama and shows actually how strong the airframe is. Picked up the 0.025 sheet yesterday so will take it to work and start looking at cutting it in the guillo at work and bending the new longerons up. I think I will make a drill jig up on my CNC out of flat steel 6mm so I can drill the longerons before installation so they fit the frames when they come. I can do almost 600mm on the CNC so I will make it up and use it to make life easier. Its too much mucking around and expense to get the longerons lasercut

 

Mark

 

 

 

 

 

 

[dan tonner]

Hello Mark;

 

With reference to your entry #47 (lower fork leg support), here's a couple of pics from 2015 following a sudden nosedrop on final. (I'm not talkin' ... all's well now.) The poor bugger had already replaced the stock lower support with the new style support after a noseleg collapse in 2014. Given the forces that were involved in the 2015 "landing", the new model stood up remarkably well - still had to be replaced though. I think its greatest asset is that it seems to prevent (delay?) cracking at the elbows of the "L" support caused by the uncushioned rebound of the fork leg.

 

'Best

 

Dan

 

 

 

[Kyle Communications]

Looks like yours punched straight on. On mine the noseleg wheel fork ripped off the bottom of the nose leg sideways which pulled it all sideways and back. The SS brackets I made didnt even bend hardly any. Infact those original brackets are still now in the girlfriend I didnt make new ones as they are fine. The new bracket is still alu and can bend the firewall. My SS brackets stopped the firewall from bending infact I am still using the same firewall. I just think even with the "new" bracket it is still too weak at that point at the bottom of the firewall as its just 1.6mm alu. Mabel will have a nice new set of SS brackets made as I can attest that they work and do the job I made them for which was not to crack like the originals it also helped the firewall to stay intact and all the load actually went to the nose leg and the nose leg fork...very little went into the front of the aircraft

 

 

 

 

 

 

 

 

[Kyle Communications]

Mabel has had the nose leg ripped off previously I found it in the maint log for the aircraft back in feb 2013. You can see when they did the repair they missed a part. The pilot side stringer is actually broken..they either missed it doing the repair or didnt worry about it which is a bit concerning. This is what happens though when you dont repair your own aircraft and you rely on someone else to do it. When my bum is in the seat I make sure everything is fine and dandy and safe. You can see the break in the picture and where the rivet through to it has been working in the panel.

 

 

 

 

 

 

[Kyle Communications]

Well Jim has looked at my engine last week as a precursor to see if the prop shaft was bent. The engine was stopped at full power when it hit the nose which of course is worse case scenario. There was a oppertunity to buy a "spare" engine for parts so needed to find out if the main shaft and or prop flange was bent so Jim pulled that part down to see and sure enough it was bent a little. A new shaft from Floods is a big cost about 1800 I think so this parts engine was a god send. We grabbed the engine it is a complete engine with the later ignition modules and even a oil tank. it has everything with it totally but looks like the cam crapped itself a little and this basically cause the valve in head to rattle and break off and into the piston. The engine has been through 1 full life and was rebuilt but obviously the cam wasnt and didnt last the next 500 hrs. The main shaft that is in it had been replaced as the spline was a little raggedy so the main shaft and flange is still perfect. So we got the gearbox off that engine tonight and Jim will put that shaft into my engine. The upside of course I we have lots of engine bits like carbs and starter ,flywheel , crank etc etc for a absolute steal of a price. Pics are of the gearbox from the parted engine. and the cylinder that was broken. We put the cylinder outer and head back on because now we have a "blank" to be able to make up any new exhaust systems without having to do it on the aircraft like I had to do on my Sav for the Rotax muffler...which I have to get back to. I just have to get the new bottom cowling made from the mold I made then I can trial that muffler system If it all works then I will make another to fit to Mabel

 

 

 

 

[Paul davenport]

You seem to be in the right place at the right time ,first a savanah then a rotax . Where do I sign up for this program

 

 

[Kyle Communications]

Yes Paul I have been very arsy for sure. Usually I couldnt win a naughty in a brothel with a fist full of dollars but its been pretty good for a change. The reason I got the aircraft from a whole heap of people who wanted it, was according to The owner I was the only one who wanted the aircraft and the engine to rebuild it. Everyone else who contacted him wanted just the engine and would scrap or part the aircraft out. He loved the aircraft and would have preferred to see it reborn in some way so thats why i got it especially for the price. This parts engine was a score....and its a not what you know but a who you know thing. I have gone halves with Danny in this engine so it was extremely cheap when you keep it for spares this way. Mind you I dont think we will be robbing too many bits as the rotax's are pretty good the only real thing that could be a issue is the sprag clutch so there is a spare there and also the coils . Just good to have spares really...I like to have spare parts..probably why I am a bit of a hoarder :)

 

 

[Paul davenport]

Yes Paul I have been very arsy for sure. Usually I couldnt win a naughty in a brothel with a fist full of dollars but its been pretty good for a change. The reason I got the aircraft from a whole heap of people who wanted it, was according to The owner I was the only one who wanted the aircraft and the engine to rebuild it. Everyone else who contacted him wanted just the engine and would scrap or part the aircraft out. He loved the aircraft and would have preferred to see it reborn in some way so thats why i got it especially for the price. This parts engine was a score....and its a not what you know but a who you know thing. I have gone halves with Danny in this engine so it was extremely cheap when you keep it for spares this way. Mind you I dont think we will be robbing too many bits as the rotax's are pretty good the only real thing that could be a issue is the sprag clutch so there is a spare there and also the coils . Just good to have spares really...I like to have spare parts..probably why I am a bit of a hoarder :)

Some people would say (rather unkindly) that I am hoarder ,just cannot find it in me to throw out that item that could be usefull .

 

 

[Kyle Communications]

Your the same as me then Paul :)

 

 

[Admin]

I am as well which is why next week my wife and I celebrate our 20th wedding aniversary

 

 

[Paul davenport]

Admin This is thin ice here

 

 

[Kyle Communications]

Iain You are playing with fire there mate with that

 

 

[Bernie]

Beat you by thirty years Ian 50th coming up next month . .

 

Sorry for contributing to thread drift .

 

Bernie .

 

 

[Kyle Communications]

Next weekend hopefully going to see Reg Brost and pick up parts for Mabel as they should be here now from Italy. Mainly the rear frame replacements. I am making the longerons for the rear. They are made from 0.25 thou so took the full sheet I had to work last week and used the plasma cutter to slice off a 3.6 mtr long strip 450mm wide off the sheet incase I need to make 2 new spar webs for the wings as I havent got there yet just mainly concentrating on getting the fuselage done. The wings will be the easy part.

 

The rest of the sheet I sliced off 600 mm from the end to I have a 3 mtr long sheet. Our guillo and cnc folder can only do 3.2 mtr long so decided to make the longerons 3 mtrs. The offcut I have cut into 40mm wide strips so I can use them to setup the cnc V folder to give me the correct bend and also radius in the bend. Then just a matter of cutting the 3 mtr sheet into 40mm wide strips and the folder will do the longerons in one hit. The holes in the longerons I will make a drill jig on my cnc from a 19x3mm steel bar and radius one edge so it fits neatly into the bent longeron then I can just use this as a drill guide for the longerons so it will all fit nicely just like a kit except there will be some joins in some of the longerons.

 

The joins will be between a set of frames and they will have a smaller piece of longeron on the inside which is riveted together with the outer longeron on the plain side and also will go between the 2 frames so where there is a join there will be 2 longerons riveted to those frames. It will actually be much stronger than just having a standard fit of the longeron

 

Will take some pics this weekend I borrowed a set of the cabin frame jigs as I can only find 1 set of mine to check that the cabin frame is not twisted. The cabin frame looks good at this stage but I have to check the cross measurement across the top yet I just have to remove the top lexan to be able to do it.

 

Mark

 

 

[eightyknots]

I am as well which is why next week my wife and I celebrate our 20th wedding aniversary

Well done Corinne and Ian

 

 

[Kyle Communications]

Hopefully crossing fingers I may get some parts from Reg on friday. Got some time at work today to setup the CNC V folder and to slice up the rest of the 0.25 sheet into 40mm strips so they can be bent for the longerons. I had to compromise a little on the bend in the longerons as I had to use the 32mm V and this gave me about a 2.8mm radius bend in the longeron. Its a little tighter than the original but well inside the specs for bending radius for 0.25 sheet 6061T6. All in all I am very pleased with the way they have folded and now just need to make the drilling jig up. On the weekend I will get the lexan off the cabin roof and do the cross measurements to confirm the cabin frame is all ok.

 

 

 

 

 

 

 

 

[Kyle Communications]

Parts!!! we have parts.... Now I can start to do a few things although I still have a lot to do but at least I can start on the rear section now.

 

I have started drawing the main side skin so hope to have that finished soon. I have the wing spar pretty much drawn and also the nose Dskin for the wings

 

 

 

 

 

 

[Kyle Communications]

WEll it doesnt seem much has been happening but it has...well frustration has been happening. I have been trying to draw up the side skins and have had a lot of issues with getting the hole spacing correct. I can tell you that those good pull out metal tapes etc that are 8 mtrs long are NOT accurate they are out by about 1mm per metre so by the time you get to 3.5 mtrs your out. So you add up all the hole spacings and the end bits and it should all add up to the same amount and the same when you draw it..well sorry that doesnt work when 3 of your pull out tapes are wrong. Ended up using my dial calipers and a steel 1 mtr rule and proved each other against each other. Some of the holes in the skins are just off and they actually calculate off as well for example 90% of the holes are at a 40mm spacing but 0.5mm is difficult to tell. So I ended up making a jig on my CNC machine to make sure that I can guarentee which holes are spaced at 40mm. So I drew up a block with pins 40 mm apart and being done with the cnc I can make sure of the accuracy and the 3.2mm shafts at the 40mm spacing are round and square to the block. Trial fitting to the original skins works a absolute treat so now I can confirm all the 40mm spacings and then work on getting the ones that are not. I can now get back to doing the drawings. I found a guy who has a printer that can print any length I like so once the drawing is done I will get it printed and lay the original skins over the drawing and this will confirm the file that goes off to the laser cutter guys is perfectly correct

 

 

 

 

 

[IBob]

Big job, Mark, good to see how you're finding a way through. I can tell you that most of the rivets in the S rear fuse were very well aligned, apart from the the round corners of some frames under the corner skins (and these weren't too bad).

 

When it comes to printing, what will the medium be?

 

Years ago I had some curved glass cut to a large paper pattern and it did not fit, and we realised that ordinary paper expands and contracts considerably with humidity. There used to be a super-stable plastic medium for printing, but it was expensive, and I haven't seen it for a while.

 

 

[Kyle Communications]

It will be printed on paper of some kind. The guy next door its his business he should be able to help me with that. Was talking about the measuring issue to a friend of mine. he tells me his somn just got a guy in with some special camera/scanner and they scanned a motorbike frame to they could get all the bits cnc'd..apparently this is accurate in the result in the thou range. It wasnt expensive either he said. So there maybe another avenue for the other skins if its cheap enough and they can get the accuracy. That will make life really easy then. Hope to start on the rear section this weekend

 

 

[Paul davenport]

It will be printed on paper of some kind. The guy next door its his business he should be able to help me with that. Was talking about the measuring issue to a friend of mine. he tells me his somn just got a guy in with some special camera/scanner and they scanned a motorbike frame to they could get all the bits cnc'd..apparently this is accurate in the result in the thou range. It wasnt expensive either he said. So there maybe another avenue for the other skins if its cheap enough and they can get the accuracy. That will make life really easy then. Hope to start on the rear section this weekend

All very interesting can't wait to see it all coming together, keep the pictures coming

 

 

[rankamateur]

So there maybe another avenue for the other skins if its cheap enough and they can get the accuracy.

Well stealing the cd from ICP isn't an option because since the Classic got away on them and morphed ever so slightly into the Land Africa they are a lot more careful about things like that.