Marty d's CH-701 build log

[Marty_d]

If they do the hinging the same on the sav for the fin and rudder my advice is to fit the rudder to the fin BEFOR you put it on...its a nightmare if you dont...you need 15 fingers and 3 tongues to hold while you are trying to do it. That way you only struggle with the bottom hinge while on the ground not standing a on a step ladder

 

One of the ways that the 701 differs from the Sav is that the rudder is all-flying.  Hinged on 2 bolts at the rear of the fuse.  The "fin" is simply the extended strake at the top of the fuse.

 

 

[bexrbetter]

Put the rudder back on and got onto the rudder cables next.  Had to enlarge the fuselage slots substantially, not sure why the plans show them so small - would have rubbed the cable to buggery.

 

 

 

Just if you need Marty, not saying you do, but info for others as well, run the cables through fixed small diameter copper tube where rubbing might be an issue.

 

[Marty_d]

 

Just if you need Marty, not saying you do, but info for others as well, run the cables through fixed small diameter copper tube where rubbing might be an issue.

 

[ATTACH]42123[/ATTACH]

 

Probably would have been a good idea - there's a nylon fairlead on the outside skin with a formed half-cone fairing over where the rudder comes out.   Works ok now.

 

 

[Marty_d]

Finally got the rudder cables tensioned up and hooked up to the pedals.  On the first attempt I wasn't getting full authority so moved the pedals back 10mm, re-tensioned (different holes in the 0.040" plates) and it's now getting to the stops on either side.

 

Today I deburred and filed all the fin pieces, primed the edges and riveted it all on.  Looks a lot better with those bits done!  Also adjusted the rudder cable slots again, ended up riveting a bit of nylon INSIDE the fuse on either side too.   That was interesting trying to reach everything through that hole at the top of the fuse, which is only just big enough for my arm going in and scraped the hell out of it going out.

 

Also had to come up with an innovative solution to file the fin rivet holes at the top of the fuse - couldn't reach the inside either from the back hole or the bottom hatch.  Ended up cutting a long dowel on an angle and attaching a file to it using electrical tape.  It worked!

 

 

 

 

 

 

[bexrbetter]

Geez that's a nice build Marty, not every Zenith builder can get 0.016" looking that smooth.

 

 

[Marty_d]

Thanks Bex!

 

It's funny, I look at the perfect builds in the US being made in perfectly clean LINED sheds and think mine is shite. 

 

 

[bexrbetter]

and think mine is shite. 

 

Well Ashley, Heinz slipped me a 20 to say something nice ...

 

 

[Marty_d]

Had to take the rudder pedals off twice tonight - lucky the "bonnet" is not riveted on yet, it'd be a 2 person job to unbolt the centre holder then.

 

Noticed after I'd bolted it back the first time that the driver's side outside mount was visibly out of alignment.  Turned out to be 5 mm too far forward.

 

So, off with the pedals again, re-drilled and bolted the mount in the correct position and back on.

 

Hung a plumb bob off the rudder trailing edge and adjusted til it's in alignment with the black line that's still on the underside of the fuse.  Now the noseleg needs adjustment with the rods from the pedals, and looking at the nosewheel I think the arch needs to come off and be redrilled so it's square with the steering rod mounts.

 

Never-ending adjustments!!

 

 

[bexrbetter]

 

 

 

Never-ending adjustments!!

 

Look at the bright side, just think of how much lighter it will be after drilling all those holes!

 

 

[eightyknots]

 

Here you go Hank!

 

[ATTACH]41979[/ATTACH]

 

Hi Marty,

 

For some reason this is not downloading for me :-|

 

 

[facthunter]

Tassies weather is even more changeable than Melbourne's.( but being a MANIA has me concerned) . The weather Keeps you on your toes and the little school kids down there only wear shorts all year round so be NICE  to them as they are bred TOUGH.. right from an early age. Paradise?? That's a station waypoint in the Northern Territory between Mt ISA and Katherine.. Didn't look much like Paradise from the air. Suppose it's all relative. maybe PARADOX they mean. Just a small typo. Nev

 

 

[Marty_d]

Hi Marty,

 

For some reason this is not downloading for me ?

 

PM me your email address and I'll send it direct.

 

 

[Marty_d]

Today I wormed my way as far into the rear fuse as I could, and attached the bungee that keeps the elevator cables separated.  While in there I put in some brackets with cable holders for the elevator trim, to keep it all tidy and not fouling the rudder cable.

 

On the front end I finally got to test fit the engine mount rubbers, sleeve, washers and the big AN7-40 bolt with castle nut.  One down, 3 to go!

 

(Split pin is just sitting there as a trial fit for now.  Obviously the ring frame needs to have an engine bolted to it before it goes on for real.)

 

 

 

[Marty_d]

Got the other 3 mounts done this morning.  It's a tight fit to the ring mount, so I'm thinking I may have to mount the engine in situ.  I'll build a little workbench on wheels that's exactly the right height so I can wheel the engine back to the mount.

 

Any suggestions?

 

 

 

[IBob]

Sure: leave the coolant pump housing off, it makes fitting the engine to the mount a whole lot easier.

 

(And you'll probably have to rotate the pipes from the housing a bit once the engine is in, so the coolant hoses run out through the mount okay.)

 

Fitting the housing once the engine is in is no problem in the Sav, and looks to be okay in your 701 also.

 

 

[Marty_d]

Thanks Bob!

 

I was a bit worried about this - I'd bought the Homebuilt Help DVD on engine installation and they hooked up the engine to the ring mount before installing.

 

I can understand it'd make it easier when you can rotate things around and get behind the ring mount, but I guess I'll just have to do it in situ.

 

 

[Kyle Communications]

Marty did they give you any engine offsets in the plans?....The sav kit comes with the ring mount on the engine mount already lined up with washers for the correct offset

 

 

[Marty_d]

Marty did they give you any engine offsets in the plans?....The sav kit comes with the ring mount on the engine mount already lined up with washers for the correct offset

 

Hi Mark, yes the 701 has 3 degrees right and zero vertically.  I designed that 3 degrees into the mount so the bum of the engine is to the left of the centre line and the prop flange should be on the centre line.

 

 

[bexrbetter]

This guy is doing a 30 day Zenith 750 challenge, maybe some tips/hints, or just motivation for you ... 

 

https://www.youtube.com/channel/UCY8yl9St6jNAZSx2i_FNBcA/videos

 

 

[Marty_d]

Engine is in position!

 

Took off the water pump housing (ripped the gasket unfortunately, even though I took great care not to), and the rear bolt of the electrical assembly.  

 

I haven't got the short bolts yet but test fitted the long 110mm one back through the ring, works well.  Need to get some shim washers too to pack out the spaces between ring and engine.

 

One worry I have is the tightness of those cables in the second picture - they're really quite taut when the engine is in the right position.  I tried making a longer clamp (see picture 4 - original vs replacement) but it's still bloody tight.

 

Anyone else had this problem?  How'd you get around it?

 

Cheers, Marty

 

 

 

[IBob]

I don't think it's usual to run those cables round the back of the ring mount....

 

 

[Kyle Communications]

no it not  the cable goes bet the ring mount and the engine,,,i am surprised it even fits the way you have done it

 

 

[Marty_d]

Only reason I did it that way is because that's what they did on the HomebuiltHelp DVD.

 

I'll take it off and go between engine and mount, at least I can use the original clamp then.

 

Thanks guys!

 

 

[Marty_d]

Sorted.

 

 

 

[Marty_d]

Question regarding air filters - I'm about to put in an order to Bert Flood for a couple of the conical style air filters and a new water pump gasket.

 

Has anyone used the 912 with that setup (air filters straight off the carbs)?  Most installations seem to use an airbox.  Any advice either way?  I'm not too concerned about the reputed 4% power gain from the airbox, a 100HP motor in a 701 has bags of power anyway.