Shelby Cobra Coupe by DocRob - Model Factory Hiro - 1/12 - multi-media - Le Mans

[DocRob]

16 minutes ago, Canute said:

Riveting parts? WOW, I haven't had to do that since I built an old Bowser/English locomotive kit. They did include a riveting tool in the kit for peening over the rivets.  You two are heroes, in my book.

Well no, no riveting tool for the Cobra. There are about 300 to 400 tiny rivets made from cast white metal with the kit. They have different heads and diameters, but the ones, I have to apply in heavy doses now possess a 0,5 mm shaft, which means, there need to be numerous holes drilled with a 0,6 mm diameter. To add to that, most of the holes shouldn´t be drilled through, which makes it a bit more awkward. The tiny buggers will be glued in then with CA glue, not too easy with these little thingies, sometimes hard to pick with pointed tweezers.

Cheers Rob

[Canute]

Rob, good luck with those rivets. I salute your endeavors. 🙏

[CDW]

When it comes to something as small as those rivets, have you tried using a pointed dowel with some bees wax to hold the rivet rather than tweezers? My luck with super tiny parts and tweezers is terrible. The parts go flying off where I cannot find them. You have a long, tedious task in your future. 

[DocRob]

17 minutes ago, CDW said:

When it comes to something as small as those rivets, have you tried using a pointed dowel with some bees wax to hold the rivet rather than tweezers? My luck with super tiny parts and tweezers is terrible. The parts go flying off where I cannot find them. You have a long, tedious task in your future. 

Tweezers can be awkward with these rivets, but I still prefer working with them. I also have a wax pencil, which should be similar to your bees wax method. The difficult part is releasing the tiny rivet from the wax. With tweezers this is guaranteed, one way or the other .

Cheers Rob

[DocRob]

I dreaded the day, but it had to be done. I speak about final test fitting of the main components, in this case the body to bonnet fit. This is quite delicate, as so many parts and sub assemblies are involved and the process is painful with some loosened parts, etc. and takes hours.
First, I screwed the body to the chassis. All doors and internal parts are only fixed preliminary. Then I mounted the bonnet to it´s hinges on the chassis and got that:



When I force the bonnet down, it will more or less fit, but without locking it somehow, it will open like shown.
I tried to identify the protruding parts and attempted to look, where they interfere, not an easy business, with only two tiny openings to see through on the sides of the bonnet.

As I identified the possible culprits, I dabbed some liquid mask onto them and closed the bonnet and bingo got the interfering locations.









In an iterative process, I removed the material as much as I dared and now the bonnet is paper thin, where the front funnels sit. It closes a bit better now, but not near as perfect as it should. At some point, I have no more possibilities to enhance the fit, as I also thinned the part in front, where the hinges meet the bonnet, to raise the bonnet a tiny bit. I will make a final try and then, I will add two tiny bolts, which force the bonnet into place and can be removed to open the bonnet.

Cheers Rob

Edited January 17 by DocRob

[CDW]

That looks like surgeons work, it’s so delicate. In the end all your tedious work will pay off.

[DocRob]

2 hours ago, CDW said:

That looks like surgeons work, it’s so delicate. In the end all your tedious work will pay off.

I hope so Craig, there are limits about what I can further do. I may end with a bonnet, which not falls into place by itself, but needs a little push and two tiny rivets for fixing it closed. I could live with that. This is a very critical phase of the build and I don´t want to rush it, but I feel, in the end everything will come together sufficiently.

Cheers Rob

[mtaylor]

Since I doubt you can remove the motor and lower it, I think your solution is a good one.

[Egilman]

This is one of the things that scares me with MFH kits, they are beautifully made yes, meticulous details and assemble much like the real thing... But if they are off in any way in the first sections, it shows up way down the line...

 

The interference issue seen here would have easily been handled with shaving the engine parts to lower the carb and intake profile just a few portions of a mm... Then it would make it an easier job to shave the bonnet to fit...

 

I know back seat driver and monday morning quarterbacking... But I have faith that You will get it right my friend...

 

You skills are far past anything I've seen before...

[DocRob]

On 1/18/2025 at 2:18 AM, mtaylor said:

Since I doubt you can remove the motor and lower it, I think your solution is a good one.

Thank you Mark, I will not alter the fit of the engine, if I can find another way to solve the problem. The chassis engine combo is one unit now and there is no way to separate these without destruction.

Cheers Rob

[DocRob]

On 1/18/2025 at 8:07 AM, Egilman said:

This is one of the things that scares me with MFH kits, they are beautifully made yes, meticulous details and assemble much like the real thing... But if they are off in any way in the first sections, it shows up way down the line...

 

The interference issue seen here would have easily been handled with shaving the engine parts to lower the carb and intake profile just a few portions of a mm... Then it would make it an easier job to shave the bonnet to fit...

 

I know back seat driver and monday morning quarterbacking... But I have faith that You will get it right my friend...

 

You skills are far past anything I've seen before...

Thank you Egilman and you are absolutely right. If there is something minor off, it will haunt you later. I had the same with the Crocker, where I had to seriously tweak some sub assemblies to get everything together. 
With cars, it´s even more difficult, as tolerances are tight and there are more parts potentially obstructing involved.
One difficulty with these cars is, you can´t foresee all the possible implications, which can arise in earlier stages of the build and you can´t really test fit early on. You have to build as precisely as possible and hope for the best.
Thank you for believing into my trouble shooting skills. I´m sure, I can sort out the problem sufficiently, maybe with a bit of improvisation.

Cheers Rob

[CDW]

One of the MFH kits I wanted to acquire was the Porsche 917. After watching build videos and seeing the numerous fit issues with the doors and other body components, decided to pass on it. Some fairly extensive work is required to make that one come together although the end result can be magnificent. I am sure Rob will overcome this inconvenience with the Cobra very soon.

[DocRob]

I read about the issues with the 917 as well Craig. I think, it´s very difficult to produce extremely high detailed kits and then everything has to fit under the hood literally. The resin bodies are thicker than the real thing and everything has to be assembled absolutely error free with tightest tolerances.
I was about to buy the actual re released Alfa Romeo Tipo 33 Stradale, but shied away, because of the swing doors and huge bonnet and rear body.
The only log about an Alfa build was a series of YT-videos, actually a double build. With both, the rear end wasn´t fully closed and that put me off.
I hope F1 cars are a bit more forgiving, as I plan to build some soon from my stash. At least, there are no working doors or bonnets to take into consideration.

[mtaylor]

Food for thought on the hood closing.   You're right about destroying things to remove the engine.   How thick is hood?  Maybe sanding the inside over the intakes?  Worse case... file/sand down the injector intakes and paint with chrome paint.    Just some thoughts.

[DocRob]

7 hours ago, mtaylor said:

Food for thought on the hood closing.   You're right about destroying things to remove the engine.   How thick is hood?  Maybe sanding the inside over the intakes?  Worse case... file/sand down the injector intakes and paint with chrome paint.    Just some thoughts.

Thank you for your thoughts ,Mark, I already sanded and grinded the bonnet paper thin (the last pic of post #65), where it obstructs. The intakes are made from aluminum with an insert of stainless steel tube. I will not reduce the height of these.
It looks worse on the pictures, but with only a tiny bit of force, I can push the bonnet into place and there, I will secure it with two nearly invisible aluminum rivets of 0,5 mm diameter.

Cheers Rob

[DocRob]

Poco a poco (little by little, like they say here where I live. I forgot to include the engine firewall into my final? assembly check. Getting everything together with the firewall, is extremely delicate, like a 3D puzzle, but after a lot of shuffling and breaking some pats off, it fits.
Next, I reworked the areas of the bonnet, which connect with the chassis hinges for a better fit. Some modifications of the existing parts were needed.

I also tested, how I could fit my first vac formed window in place with double sided transparent adhesive tape, which didn´t look promising at all. I need some better tape and luckily my wife flies to Berlin next week, where it is easier to get hold of better stuff.

Finally, I found another method to lower the obstructing first cylinder funnels a tiny bit for a better bonnet fit. 

I removed the PE seal? under the aluminum funnel with a sharp blade and deepened the holes, which accept the funnels first with a 2 mm drill bit, then the outer diameter with a 3 mm drill bit (left side without PE and drilled out).



As you can see, the front left funnel sits a bit less than a millimeter deeper, than the others. Not a lot, but it sure helps.



I reglued the funnels and the rivets besides and like the result. You have to know, that something is missing to find it.



Cheers Rob

[CDW]

An excellent adaptation to suit the need. Well thought out and performed, Rob. 
 

MFH advertises on their website a new model offering will come out in February. Have you heard any rumors on what this new kit will be? I have not heard anything at all.

[DocRob]

Thank you Craig, I hope the fix will allow a good fit along all the other measures I took.

The Februar kit is not a rumor anymore. It´s published on the MFH site.

https://www.modelfactoryhiro.com/pic-labo/llimg/12_131_000.jpg

Cheers Rob

Edited Friday at 04:11 PM by DocRob

[CDW]

4 minutes ago, DocRob said:

Thank you Craig, I hope the fix will allow a good fit along all the other measures I took.

The Februar kit is not a rumor anymore. It´s published on the MFH site.

https://www.modelfactoryhiro.com/pic-labo/llimg/12_131_000.jpg

Cheers Rob

Thanks! Will wait to see what gets offered in March and following months. The Fiat doesn't interest me.

[CDW]

Rob

 

Is this the tape you tried?

Amazon.com: Kaisiking 1mm x 50M LCD Repair Tape for Phone Screen, Adhesive Tape with 1 Tweezers for Cell Phone, iPad, Tablets, Laptops, Camera : Electronics

 

I saw good reports on that tape from the MFH builders Facebook page.

[DocRob]

16 hours ago, CDW said:

s this the tape you tried?

Amazon.com: Kaisiking 1mm x 50M LCD Repair Tape for Phone Screen, Adhesive Tape with 1 Tweezers for Cell Phone, iPad, Tablets, Laptops, Camera : Electronics

 

I saw good reports on that tape from the MFH builders Facebook page.

Thank you for showing, Craig. The tape, I used was the only I could find on my island. It´s thin and transparent, but when applied not transparent enough to let the body color look through undisturbed. I will check the tape you mentioned, but as it´s black, I can only use it for the tailgate, where the frame is black.
It is difficult to find good double sided tapes here, even through the big A. Many articles doesn´t get sent here, but my wife is in Berlin next week and I will use my chance.

Cheers Rob

[mtaylor]

I'm glad you got the bonnet to fit properly when closed.   Looks like a perfect fix..