luv2flyrc

My Feedback: (6)

Beautiful work Jeremy but, I am dismayed at how much re-engineering is required on a $10,000 kit!

I think CARF should have sorted this out long ago. I'm just about to start to assemble my Carf Hawk which of course pales in comparison to the Mig project but, I hope I don't have these headaches with it.

Mike

LGM Graphix

My Feedback: (22)

Mike,
I've seen a couple of the Hawk's and like the majority of the Carf stuff it is very good quality. I wouldn't hesitate to buy any of their ARF models. Reading back in threads from 7 or 8 years ago, the problems I have faced have been problems since the very first kits. It is my opinion that 10 years ago when this kit was introduced, there were aspects of it that were definitely rushed when it came to the molds and fixtures and those were never corrected.
I think this is in big part why with 100+ of these kits sold, there has only ever been a handful of them completed and flown. When the kit was introduced, ARF's were definitely not as prevalent in the jet world. There were primarily kits out there and the builder was expected to do extra work. But you are correct, on a kit of this cost, there should at the very least be no re-engineering required.

Having said that, despite all the head scratching, modification, and frustration, this is one massive and very impressive airplane. I am definitely looking forward to being able to put paint on this bird, it will be an awesome airplane, almost makes me wish it was mine!
Jeremy

Plautos

My Feedback: (5)

Jeremy!

We are catching you... build your MIG faster!!!

Plautos

LGM Graphix

My Feedback: (22)

Hi Plautos,
I was waiting on some parts, I also had a bunch of motorcycle work come into the shop so the Mig progress had slowed down a bit, but the bike stuff will all be out this week and I'll be back on the mig full time. I don't have a lot of building left on it at this point, need to locate cylinders and get the rear nacelles and tail cones completed, but then it's on to prepping for paint!

mr_matt

My Feedback: (10)

Hi Jeremy,

A question, what did you use for datum lines? I figured the rails that the turbine covers set on for the thrust line (0 degrees) but I am not sure about the other axis (looking at the top of the plane). Are the wing roots parallel and fore aft in the top view?

Sorry the question was not clearer, my brain is fried from work. Thanks again for posting the pics.

LGM Graphix

My Feedback: (22)

I am a little confused as to your question, are you asking what I am considering zero for the fuselage datum line to set wing incidence and stabs to?

For the wings, one wing aligned perfectly with the fuselage at the front, the other wing was way off, it was to high at the front. Both wings are slightly thicker than the root at the fuselage as well unfortunately.
For aligning the wing, I kind of have to give Comp ARF benefit of the doubt, neither wing is zero with the outside engine mounts, so I picked the wing that lined up best on the fuse, and set the other wing to match.
As for the the stab alignment, it is a major major hassle.
One stab sits square to the fuselage if viewed from above (in other words, the gap is equal from LE to TE, while the other stab is crooked, it touched at the LE and had a huge gap at the TE). The stab that was not square to the fuselage was also the stab half that sat way to low at the tip. Interestingly enough, the stab that sits square to the fuse from the top view also lined up at the LE and TE edges with the fuselage fairings and read the same 0 as the wings. As such, it was the other stab half that I cut out and corrected. The downside to this, is the stab half that is not square and doesn't match the wing incidence has the closer to correct anhedral in the stab. The fins and the stabs should be 90 degrees to each other, unfortunately, unless you cut BOTH stab bearing blocks free you can't get both perfect, I started splitting the differences and ended up with something that was so close you wouldn't actually know it was slightly off unless you measured the distances and knew for fact what the angles would be. To me, since Arnaud wasn't planning on this being a 100% perfect scale competition aircraft, I was most concerned with incidence and angles being true to the wing so that the aircraft will fly the straightest possible without having to tear apart everything. In the end, if I didn't say anything, I doubt anyone would notice the slight discrepancy in the angles on the stab and fins.

LGM Graphix

My Feedback: (22)

Here are some updated pictures since this thread has been seemingly abandoned (not really, I have just been really busy)

Pictures 1 and 2, just showing the insides, I have painted the inside of the jet with epoxy primer so that should there be any leaks of fuel or oil, it will not damage the foam sandwich of the composite constructions.

Picture 3. Just another shot of the speed brake with all cylinders in place.

Picture 4. Fin mounts glued in, I have done them slightly differently than the instructions suggest in that I glued carbon fiber sockets into the fuselage to give the stab spars full support when the fins are mounted.

Picture 5. Other side

Picture 6. More paint

Picture 7. Landing gear bay, once I had the gear mounted where I wanted I glued plywood strips around the mounting blocks so that when I need to reinstall I'm not having to spend hours realigning them.

Picture 8. Louver cutouts primed

Picture 9. Stabs, instead of Comp ARF's method of mounting the stabs, I have glued the tubes in place, the bolts are also glued, as are some steel rods into the stab to keep that spar pivot from ever rotating. The stabs are still removable, you just have to remove the custom horn I built from the inside.

Picture 10 and 11. Rudder horn fairings, these needed to be made slightly taller than what comp arf supplies in order to actually clear the rudder linkage.

Picture 12. The flap linkage fairing

LGM Graphix

My Feedback: (22)

Picture 1. I ended up cutting the rudder pushrod shroud free in the fins and moving it slightly so that I could have easier access to the servo's, servo horns and linkages

Picture 2. LE slats free with linkages installed.

Picture's 3 and 4, a couple of the detail parts for the mig, the radar dome and the nose gear skirt

Picture 5. Front equipment tray and the former that holds the nose cone on.

LGM Graphix

My Feedback: (22)

Various pictures of the gear door cylinder mounts, unfortunately, I installed all of these using COmp ARF's parts, then when I put the gear back in, I discovered that all of the supplied mounts are far to big and the wheel's hit everything, so I had to tear it all out and redo it with thinner mounts.......
There is also some pictures of the louver mounting, I kept all of that removable so that should anything ever need maintenance you can take it out to work on it!

LGM Graphix

My Feedback: (22)

I also finished up fiberglassing and priming the intakes, and added the lithoplate to the intake ramp doors.

LGM Graphix

My Feedback: (22)

Various pictures of the cylinder RE install including a picture showing the Comp ARF supplied cylinder mounts and the new ones, the difference in thickness was nearly 1/4".
Also test fitted the landing lights since everything fits so tight, I wanted to make sure they weren't going to interfere with anything!
The left hand gear strut also needs to be shortened, it's 3/16" longer than the right hand side and won't allow the wheels to clear the door hinges and cylinder if not shortened.

LGM Graphix

My Feedback: (22)

Update, I have the hydraulic system almost all installed and ready to test. Need a couple of festo's and it's good to go. It's virtually impossible to install all of this without getting oil somewhere!!!!!

LGM Graphix

My Feedback: (22)

More hydraulic install

Craig B.

Hi Jeremy,

Awesome work man! Keep the photos coming please. I am back on mine in a few weeks and am really enjoying watching yours come together. I have to do my gear next so that will be fun. Expect some questions!!!

Keep up the great work and photos!. I will post some pics of my progress so far a a few weeks.

Kind regards,

Craig.

mr_matt

My Feedback: (10)

Was someone flying one of these at FL Jets on an RCUniverse thread recently?

i3dm

My Feedback: (51)

Are the gear door cylinders hydraulic or pneumatic ?

mr_matt

My Feedback: (10)

Gorgeous work BTW and keep the posts coming. Great thread.

What do you use to point the interior? And do you spray it on?

LGM Graphix

My Feedback: (22)

All of the cylinders are hydraulic, gear, doors, and speed brakes.

Hi Matt,
the inside was all sprayed with a 2 part epoxy paint. I wanted to make sure it was all painted and sealed before installing the hydraulics and I'm sure glad I did, I don't think it's possible to install all of that without getting oil somewhere!

LGM Graphix

My Feedback: (22)

Today was one of those days of many hours spent, for what looks like not a lot of progress. I got the nose wheels fitted, got the steering servo in place, and did all the assembly of the nose gear. Would have been much faster except for a couple of parts that I found were installed backwards by Comp ARF. I got the nose gear doors hinged though I need to stiffen them up some.
The way Comp ARF does the nose gear doors, it leaves a 1" gap behind the doors for the wheels to clear, I cut back into the fuse a little further and glued the cutout back onto the doors so the doors are a little bit longer, but at least it looks better than a big gaping hole in there. It is going to be critical that the nose gear is always STRAIGHT when it retracts, there is very very little clearance on the sides, I am going to turn the resin hubs down a little thinner so there is a bit more room for error, but it is going to be tight no matter what.
I bent up a couple of aluminum strips for the nose gear opening as well to seal the gap on the edges, looks really nice this way.

mr_matt

My Feedback: (10)

I tried to post a pic, but how did you attatch the main gear "hub" to the strut tube? In the instrucions they say to glue it on (!)

LGM Graphix

My Feedback: (22)

I haven't figured that one out yet Matt. Right now I just have it being held on by a bolt in the end of the axle but as soon as the wheel turns it spins the hub off. These wheels and the hubs are the glennis parts, much nicer than the dubro wheels that are included with the kit. However, the brakes don't fit to the strut worth a crap, there is really no provision to mount the resin hubs, and the hubs have to be removable in order to install the wheel collar that holds the wheel on place. I also had to turn the axle shoulder back a little as it was holding the wheel to far away from the strut and the gear couldn't retract all the way. I need to thin the resin hubs down a little as well as they are hitting the top of the fuselage when the gear is retracted, but if the gear had been angled any differently, the struts and the oleo scissor would hit the gear door.
I think I might drill and tap a few small holes around the edge of the wheel and hub and just bolt the hubs on.

Craig B.

Hi Matt,
I have not looked at mine yet so I might be speaking out of turn but I seem to recall Peter Agnew from Intairco saying that he had his welded on once he had them all lined up properly. I think I will do the same.

Hope that helps?!

Kind regards,

Craig.

LGM Graphix

My Feedback: (22)

Hmmmm, now I'm wondering what parts we're talking about for sure. I assumed Matt was talking about the resin "hub" that glues into the wheel, but now I'm thinking what you are, the plug that the axle fits into mounting into the strut.
The problem with welding, is the main gear strut is steel, while the plug is aluminum. I was thinking of using JB Weld, but a friend of mine also gave me some Loctite 609 retaining compound. So I was thinking about using that, plus cross drilling the strut/hub/oleo scissor mount and putting a bolt through all of it. I would feel far better about it if that aluminum piece had a plug that was 1" long instead of that short ass little thing on it, I think it's only 1/2" long!!!!

mr_matt

My Feedback: (10)

Yes this is what I was asking about. I figure to glue it and then run a bolt all the way through. Pretty cheezy way to do this but as best I can figure they could not get the alignment perfect and you had to have this final place to tweek the toe angle.

And i agree I don't know how you could weld it, maybe some sort of brazing operation, not my strong point!

LGM Graphix

My Feedback: (22)

I have been thinking about this overnight (amazing how stupid little things will haunt you and keep you awake) and I think I'm going to machine some new plugs for the struts that the axles will fit into. I just don't feel good about the weight of that airplane sitting on those little tiny plugs like that. I want the piece that slides inside the strut to be 1" long, at that length it's not going to stretch the strut and pop out of there or get sloppy. The ones Comp ARF use are so short, it doesn't take any pressure at all to make them sit crooked in the strut.
If you want a set I can turn an extra set for you Matt.
Jeremy