ZNLine factory: Enigma Building
#251
And the cooling intake.
It is the builders choice whether or not to louver the holes or just make a pleasing shape. I prefer simply cutting a pleasing shape. No wondering about airflow on this one. The DZ shall get a nice dose of air right over the cylinder head.
#253
Drill the holes for the forward mounting screws
Here JP is using a lipped drilling guide to put the holes at the right distance from the edge to meet the hole in the mounting tab. We have placed these holes about 2" in front of the ladning gear cutout.
#256
While that dries, we move to the rear of the pan.
OK, the basic idea is a single cross brace with a screw in the center in the rear of the pan, two screws into tabs just forwards of the landing gear cutouts, and one screw on the front. This keeps the pan impeccably aligned and very secure.
For the cross brace, we want it to fit very flat so we use an angle grinder to flatten out the extra material where the brace shall sit.
For the cross brace, we want it to fit very flat so we use an angle grinder to flatten out the extra material where the brace shall sit.
#258
Drill the hole in the fuse
Center the brace in the position selected on the fuse and drill the hole. This postion will allow a ball driver to slip past the pipe and engage the screw. It will also stiffen the rear of the pan and keep it perfectly aligned.
#260
Not a great photo
I had trouble getting a good focus, but here the cross brace is screwed down, the belly pan is tape into place with perfect alignment and the cross brace is glued to the belly pan with 24 hour epoxy and microballoon. If you look at the lip of the belly pan, you will notice a black piece. This is felt tape which is used as anti-vibration/scuffing material and applied after the airplane is painted. It must be applied now to achieve the perfect spacing. The belly pans are cut to allow for a thin material for seating nicely against the fuselage. We use the felt tape for wing seating and anywhere that the bellypan contacts the fuselage.
#261
The rear is mounted.
We have mounted the rear in place and prepared the front of the pan with the ply screw bosses and taped everything into perfect alignment. Here, a serious JP displays his work. This will dry until tomorrow, and then we will mount the tabs to the fuselage and securely mount the forward part of the pan. All mounting hardware is in place and screwed down while the glue dries with the belly pan perfectly aligned. When all is dry and the tape is removed, the belly pan will remain perfectly aligned.
Again, tomorrow we will finish the forward mounts. I have been instructed to bring in my DZ too. Hmm, I think firewalls are coming soon.
The wings have the last piece of ply drying on the TE tonight and require no further pieces added. Just finaling any shaping of LE and tips if needed, and then sanding and filling and sanding and filling and sanding and, you get the idea I'm sure.
Goodnight.
Mark
Again, tomorrow we will finish the forward mounts. I have been instructed to bring in my DZ too. Hmm, I think firewalls are coming soon.
The wings have the last piece of ply drying on the TE tonight and require no further pieces added. Just finaling any shaping of LE and tips if needed, and then sanding and filling and sanding and filling and sanding and, you get the idea I'm sure.
Goodnight.
Mark
#262
On the the front of the belly pan
The glue has dried and the brace is securely mounted in the rear. So, we untape the pan, remove the rear screw, and now we will install the forward hold down tabs.
First , the tab must sit against the ply screw boss, so the belly pan lip is ground down to allow for clearence.
First , the tab must sit against the ply screw boss, so the belly pan lip is ground down to allow for clearence.
#264
Now we can mark the tab location.
This photo show the next few steps all at once.
Tape across the area so that you can mark on the fuselage. The distance from the fuse side to the slot is the thickness of the ply square and belly pan thickness. We use a drill to make three holes across the slot and then a needle file to open them nice and square. Allow a little play here; the epoxy/microballoon will fill everything nicely. Slide the tab up from the inside for a good test fit.
Tape across the area so that you can mark on the fuselage. The distance from the fuse side to the slot is the thickness of the ply square and belly pan thickness. We use a drill to make three holes across the slot and then a needle file to open them nice and square. Allow a little play here; the epoxy/microballoon will fill everything nicely. Slide the tab up from the inside for a good test fit.
#265
Prepqre to glue qnd glue.
OK, several steps at once here because it is sooooo easy. Roughen and clean the area around the slot on the inside of the fuse. Use a piece of clear sticky tape over the slot. Slice a slot in the tape just big enough for the tab to go through. The tape should fit tightly around the tab as this will keep the epoxy flush with the fuselage surface giving an incredibly clea appearance. Slide in the tabs and keep them in place with a piece of tape on the inside of the fuse. Mount the belly pan, screwing down the rear and the two front tabs. The rear will be perfectly aligned from the cross brace. Now, carefully align the front of the pan and tape it securely into place. Tape it SECURELY into place.
Flip the fuselage so it is sitting upright. Mix up a batch of epoxy with microballoon. Make this mixture a little bit thick. It should not run or spread. Using a long spatula (balsa stick or other suitable object for placing the glue), and cover the T portion of the tab with glue. Remeber the tape on the other side; the glue will go only that far and lock this tab into place.
Here is the tab with it's glue in place.
Flip the fuselage so it is sitting upright. Mix up a batch of epoxy with microballoon. Make this mixture a little bit thick. It should not run or spread. Using a long spatula (balsa stick or other suitable object for placing the glue), and cover the T portion of the tab with glue. Remeber the tape on the other side; the glue will go only that far and lock this tab into place.
Here is the tab with it's glue in place.
#269
The reward.
Here is what the result of this method. Perfectly fitting belly pan, and when the rear screw is engaged, the two forward screws turn in with absolutely no wiggling or jiggling. The holes have absolute perfect alignment and will stay that way for the life of the airplane.
#270
Still two small steps to go.
First, the side screw holes will be inset so the the head is flush (that is why the 4mm light ply instead of a thinner wood). Then, after the nose ring mount is installed, one more screw goes into the front to lock the front into place.
Again, this is only one way of many to do this job. The magic boxes from MK with guide pins in the rear and one screw up front, and various other clip or sliding pin or spring tension methods are also very good. If you prefer another method, then by all means use it. Me, I do not mind these four screws and it is probably the easiest (and least expensive at about 25cents for the screws) method there is to get professional alignment.
The motor should be next.
Again, this is only one way of many to do this job. The magic boxes from MK with guide pins in the rear and one screw up front, and various other clip or sliding pin or spring tension methods are also very good. If you prefer another method, then by all means use it. Me, I do not mind these four screws and it is probably the easiest (and least expensive at about 25cents for the screws) method there is to get professional alignment.
The motor should be next.
#271
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Blind Nuts
Mark, I've never seen blind nuts like you are using. Are the only made in metric size or are SAE sizes available too? (I wish the US would make up it's mind on get on the metric band wagon, it's much easier to learn being base 10 instead of 16 ) If available, any idea where we can get them in the states? gv
#272
MP Jet
George,
The blind nuts are an MP Jet product and are really nice. The stem is knurled and locks into the hole instead of making holes behind the piece. I do not know if they are avaialable in the states. Check with dealers of JR models and other exlusive Czech built line dealers.
At this time, JP is installing the first of several motors, so tonight the fun stuff will be posted.
Mark
The blind nuts are an MP Jet product and are really nice. The stem is knurled and locks into the hole instead of making holes behind the piece. I do not know if they are avaialable in the states. Check with dealers of JR models and other exlusive Czech built line dealers.
At this time, JP is installing the first of several motors, so tonight the fun stuff will be posted.
Mark
#275
The first motor is mounted.
I will go into a little detail here. This procedure is not hard and certaintly no witchcraft is invloved, although the "big chief" JP does express a certain mood when preparing for this step.
We use the YS DZ and the ZN motor mount and adapter. The ZN mount weighs about 80 grams, one of the lightest available mounts.
Here is the mount and motor with the mount adapter on the engine.
We use the YS DZ and the ZN motor mount and adapter. The ZN mount weighs about 80 grams, one of the lightest available mounts.
Here is the mount and motor with the mount adapter on the engine.