Oz build SS7

[Paul Z]

I built a scratch build Compost (AKA Composite) Construction aircraft. I’m very sensitive / allergic to the epoxy now!

[rosslr]

Hi Paul and Jim - thanks for taking the time to think about this. It is pretty much what I have in mind. I am thinking it will be a nicer, flusher finish if I can just insert it and then use poly fill to smooth it out. I will post the result.

cheers

ross

[rosslr]

No photos today but started on fixing the Narca vents, ran the fuel lines from wing tanks to header tank and low fuel warning tank and started soldering up the PTT units that will install on the stick. I hope I did some more but I dont think I did actually! Oh yes, I did have an email exchange with Airfox about cruise settings for an Airmaster and WW combination.
cheers

ross

[rosslr]

Well, first to the Narcs vent fix - I said I report back and here is the result. the hysol install appears to withstand a very firm tug so I am happy with that. So then I got to and polyfilled them in and sanded them off - I think they are pretty much as they should have been now ....(??)

[rosslr]

Beautiful Autumn day here in Mt Beauty - blue skies, no wind and dusting of snow on the hills. I got a friend to help place the windscreen in rough place so I can make more sense of the instructions. I plan to go slow as I have read many of the stories of cracking the windscreen. The instructions talk of using a band saw - that appears to be a little impractical, so what is the best alternatives? I was thinking a slow moving, fine tooth gigsaw (I have one with variable speed) - other suggestions?

cheers

ross

[rosslr]

I am a little apprehensive about stating to 'trim' the cowls given my recent past experience with my friend the fibreglass ....

So, here are a couple of photos. I have read and re read the instructions and am still not sure what to actually trim. It appears that I need trim the top cowl down to approximately the 'tape line' in the first pic in order for the front vents to line up ?? True??

And in the second pic, I assume that these two 'tangs' need to go inside the top cowl? no way they will at the moment but will they line up better if I 'trim the top cowl?? Any advice appreciated as always!

cheers

ross

[Dick B in KY]

Ross, For cutting the windshield use a die grinder with a cut off wheel. This will not give you a lot of vibration nor a chance for saw blade to hang up in the material. Be sure to finish off the cut edges rounded and smooth.

Dick B

[Dave S]

Ross,

On the cowl, this is an area of construction where a person can end up doing a lot of studying before making that first cut.....I recall re-reading & studying the cowl assembly instructions till it made sense...it eventually did make sense....but took some time. My opinion: it is critical to follow the sequence provided in the instructions for the entire boot cowl/cowl trimming.

You are correct - the tangs from the bottom cowl go underneath the top cowl flange.

Attached a couple photos, front & side, to at least show where I ended up. I thought I took so many photos; but, it always seems that I could have taken more. Seems I don't have any of the steps taken earlier on the cowl.

Sincerely,

Dave s
KF7 Trigear
912ULS Warp drive
St Paul, Mn

[jiott]

Definitely do not use a jigsaw on the acrylic. The instruction sheet that comes in the box with the windshield I believe says what not to use and what is acceptable. Like Dick, I used a die grinder (Dremel tool) with a thin cutoff wheel for the rough cut. Then a belt sander to get down to the final line, then hand file and hand sanding for final smoothing. I found the belt sander to work really well-removed material fairly fast and kept a straight line. The main thing is to not put any stress on the bend area at the wing roots during handling or work. My method to insure this was after first carefully (two people) setting it on the aircraft frame, I put a long strip of masking tape on each side, from bottom front corner diagonally to the top rear corner. This tape stayed on until final assembly. By keeping the tape taught during moving, handling, cutting, etc. I knew that the windshield was in its normal relaxed position with no stress on that critical bend area. Also, never cheat even once by using a standard drill bit; always use the special acrylic bits. Some guys have had success using step drills.

I also found the cowl trimming to be a real head scratcher. Think it thru carefully and then take small cuts at a time to work it down until the air vent holes match up. Those tabs fit very tight. I found I had to thin them up some and also remove some material on the inside of the mating area. It is alright to spring them a little to get them to go together. Fiberglass is much less prone to cracking than the acrylic windshield.

[rosslr]

Thanks Dave and Jim,

I feel more confident now in approaching both these (somewhat tricky) tasks. Dremmel and sanding it is! And like the suggestion of the strapping support Jim. I will be onto that first thing this morning.

cheers
ross