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Friday, May 31, 2019

1 hr. not actually accomplishing anything...  Oh well, it happens...

The factory says they fit, so we'll see....  Put on some very slippery hand soap....

... and despite my best effort, there was no way the 15mm Oetiker 2-Ear Clamp is going to fit over the... 

... over 16mm hose (as measured over the barbs).  That size is simply too small.  Off to hunt down some of the next sizes up...  And the process managed to gouge the hose, so I'll replace it.

Contemplating how to tie down this power line from the battery...  Would like a standoff that I can use a tie-wrap on.  I think...  Was thinking of using a clamp, but not happy with that idea at the moment.

I've been Googling for info on clamp positioning since I want to get it right and came across this page which confirms my thoughts on the positioning.

Another piece of info I came across was that the ear-type clamp ears should not be completely closed as that would indicate the clamp was too big for the application.  There should be a small space left.


I heard back from the factory regarding the ear clamps over the barbed fittings and they say those are the correct ones and just requires some force.  I'll try using some soap to help ease them over the barbs.

They also got me some photos of the pumps on the firewall.  I've also added these to the factory photos firewall page.



Thursday, May 30, 2019

1.5 hrs. on the fuel pumps.

Not fuel pump related, but was just looking through my box of harnesses that SteinAir prepared for me and was pleasantly surprised to see the connections for the shunt sense wires are already wired into the connector.

With the assumption that the drawing in the manual is proportional I calculated the lengths of the various hoses for the fuel pump assembly.  The circled lengths are the calculated lengths in mm.

This tool worked well for cutting the hoses (though I think a box knife would work just as well for this).

For the barbed connections BobZ recommended putting the hose ends in boiling water to make them more pliable.

The barbed connection in the vise...

And with a little wiggling it went on without much fuss.

Both ends done.  I cut them a bit long (50mm) in case my calculations were off.  I can always make them shorter.

But.... The supplied CRMP-302 (15mm) ear clamps won't slide over the barbs....  Hmmm....  No way...

While I contemplated that I moved on to the other connections.  Figuring out where to put the clamp for this connection.  I think close behind the barb makes sense.  In this case the clamp slid over the barb just fine.

Crimped and cut to length (the calculated length this time).  This was actually the second attempt to crimp that as the first time I completely crimped one side and when I went to crimp the other ear it pinched the rubber pretty bad.  So, I cut that off and tried again.  This time I went back and forth, crimping a bit each time until it seemed solidly crimped.

They recommend using worm clamps for the fuel inputs (to make it easy to inspect and change the filters later on).  But, I only have 2 of the proper size (12-22) and you need 4.  Also need larger ear clamps as I mentioned above.  I'll ask the factory about that before just going ahead and buying them.
UPDATE: I ordered these marine-grade hose clamps for inputs.  Those seem to be a step up (and slightly more expensive) than the "aircraft-grade" clamps they also sell.  Seems to be better corrosion resistance.

Note that for a lot of the critical component assembly it is a very good idea to consult the Sling 4 (or 2 or TSi, if that's what you're building) Maintenance Manual as it contains lots of info that the build manual does not.  For instance, there is a section on the fuel pump and one thing I learned is that the main pump in on the left and the aux is on the right (though it also shows ear clamps for the fuel pump inputs, but the factory now says to use worm-type clamps).  That info is not in the build manual.  So, print that manual out and refer to it often!


Wednesday, May 29, 2019

I was looking through my copy of the Aviation Mechanic Handbook last night.  It's actually quite good and is a quicker reference than AC43.13 for a lot of info.  It also has tons of info on tools that the FAA doc doesn't have.


Tuesday, May 28, 2019

1 hr. on the firewall pass-through.

Cut some 3/4" fire shield for the conduits.  I'll slice one side so it can be wrapped around the wiring.  There will be worm type clamps around the fire shield.

Cutting the heat shields.

Made cutouts for the screws, but I'm not sure I like the way that looks (not that that matters really...).  Was going to try just making holes for the screws, but it's not that easy to make small holes in it.  Maybe I'll try again using a punch of something for the screw holes...

Monday, May 27, 2019

4 hrs. fabricating the electrical pass-through for the firewall.

If you have to fabricate.... it takes time...

My parchment paper tracing to locate the screw holes worked well.

Making sure this is where I want to put them.

The holes need to be larger than the above parts, so a rough sketch will do.

Holes drilled out with a step drill bit and holes drilled and reamed for the rivets.  Line drawn for where I'll cut it in half.

And drawn on the pass-through pieces.

And on the heat shield I'll apply later.

A bit anxious about doing these cuts...

...because the cutting disks break so easily....  As it did within a couple of minutes.  Heads-up: Wear a full face shield, gloves, hold the Dremel firmly and keep yourself out of the plane of rotation....

These disks ended up being better than the thin cut disks.  Still need to keep the tool steady to keep the disk in the intended plane of the cut, otherwise it's more likely to end up breaking the disk.

Whew.... glad that's done!

Test fit to see where I need to cut the firewall to clear the holes and rivets.

This should do just fine.

This setup will make it easier to get in there and cut.  Heads-up: Much of the work on the firewall would have been easier without the mount in the way.....

Took awhile, but it's done.

Test fit and it's looking good.  Hope to finish this off tomorrow night.

Sunday, May 26, 2019

An hour starting to make the dual conduit pass-through for the firewall.

Cut the stainless steel sheet for the pass-through.

Probably going with this arrangement.

Used some parchment paper to transfer the rivnut locations to the blank.  Should finish this tomorrow...

Visited my bro in NJ this past weekend and checked out the airport I think I'll use to visit him (just 25 minutes to his house).  Lincoln Park (N07).  Looks nice.

Nice MU-2 in this hanger.


VFR route 6B6 to N07

Make your Flight Plan at SkyVector.com

Thursday, May 23, 2019

An hour mostly contemplating....

Terminals to use for the cap?

Maybe like this?  The cap certainly seems firmly connected to the terminals, but maybe it would be better to put the wires and cap into the same terminals for a more secure connection?  Some heat shrink too for better protection?  Hmm...  As Einstein would have said, "I must tink" 🤓😊

Trying to make sure I have the spacing right based on the appearance in the manual.  I'm a bit concerned about the clearance between the bottom of the assembly and the bottom edge of the firewall...

...So I'm thinking of flipping the mount so the slots for the mounting clamps would be on the top and I can slide the pumps up a bit and the clamps would be in the center of the pumps.  That would give me more clearance.

Side view showing what I mean with the mounts in place.  With this positioning the clamps are right in the middle.

Heard back from the factory regarding what the heat shrink in the throttle cable parts package is for.

Got it!

Wednesday, May 22, 2019

1.5 hrs. on the firewall.

Trying to figure out how to arrange the two wire pass-throughs.  Like this....

...or like this?  I have a piece of thick stainless steel (thanks Kerry!) that I will split in half, I'll split these pass-throughs and rivet them to the two sheet halves.  That will be screwed to the rivnuts shown.  That way I'll be able to pass through connectors and secure the wiring properly.

Meanwhile, I got connectors I can use for the battery sense wire.  Fits!

I could have sworn I had a crimper for insulated terminals, but I didn't.  I have crimpers for un-insulated terminals, and many other types, but not insulated.  So, I bought these.

Done!  Still needs to be tied down somehow though.

Enlarged the holes for the grommets for the fuel lines.  The grommets have an ID (hole size) of 1 1/16", but I made the holes 1" so they would be snug.  Test fit here, but I realized I needed to cut away the heat shield some more so it would seat right.

And both done!  Nice!

And a nice snug fit!

The big view.  Took the fuel pump mount off, which will make it easier to mount the pumps assembly to them.

These are the throttle cables.  Anybody know what the heat shrink is for?