Airfix 1/12 Bentley Blower

[François]

Absmiami, is that a good sigh or a bad sigh?

[François]

I worked a bit on a more accurate tire model.  I might try to print it with a flexible resin to see if it could better fit the wheel.

I also reprinted the hood panels with a curing fixture ( on right side of print plate). The idea with this fixture is to try and conforme the curved panel while curing. 

[CabDriver]

Beautiful work on the CAD for those tires - and the curing jig is a great idea!  

[François]

Like I mentionned before, I've made so many modifications/add-ons on this model that I have to take certain measures to assure correct fit and alignment.  I tackled 2 of these measures over the weekend. 

Since I printed new thinner hood panels to replace the bulky looking ones from the kit, one problem I'm face with is to try and maintain the correct curvature of the 2 top panels. When a part come out of the washer after printing, it is still very soft and can be deformed a bit just by manipulating it. So I made a curing fixture to conform the panel during curing. The fixture has the exact shape of the top panel as there are once installed on the model. I incorporated holes that align with the hinges, that way, the panels are firmly held in place at exactly the correct relation. Here are a few pictures. 

 

The fixture worked perfectly and held the panels during curing. I'm designing a similar fixture for both side panels as well.

The second measure was a bit more tricky to figure out. It's the alignment between the radiator and the hood panel. I want to hava as close to an even gap as possible between them. But, since almost everything in this section of the model is new, the gap is not parallel. In the following pictures,  I want the angle show as close to zero as I can get it.

to achieve this, I designed a mecanism that will permit me to ajust this angle once the radiator and the hood are permanently in place.

I made a sleeve that fits inside the radiator cap. This part will be glued in place once the ajustement's done so it will be painted black to look like the radiator filler tube.  At the end of the sleeve, I added a small stud that as a .035in excentricity. This means that when the sleeve rotates, the stud move on a .07in diameter circle (2x the excentric). I also added a hex socket on the inside the drive the sleeve with a small allen key. To work, the excentric stud is engaged in a slot I made in the radiator core, the slot has the same width as the diameter of the stud.  By rotating the sleeve, the stud move the radiator cover in relation to the core and since the cover is mounted to the core via a pivot point at the bottom, the angle between the 2 parts varies. 

Here's the design 

The sleeve, you can clearly see the excentric stud.

The slot seen thru the filler cap

The hex socket 

And the key

Here you can see the stud in the slot

And finally, a little video showing how it works 

 I hope my explanations are clear. 

[absmiami]

Thats f’ ..in great …

[François]

Thanks absmiami 

I just painted the radiator cover,  not sure it's ok yet, I'll let it dry first.  I also started painting the 4 hood panels, still some sanding to do before the black finish. 

[François]

All 4 hood panels are painted,  I should be able to install then along with the radiator next.

[Moparman18064]

Fantastic! I love the eccentric idea, ingenious

[François]

Well, I really messed up this morning.  I didn't like the chrome on the radiator so I tried to remove it. By doing so, I sorta melted the plastic,  the part is now unsusable.  I spent many hours modeling the radiator cover and it is printing as I write this. 

I modeled a working hood latch. It consists of a tiny spring loaded cylinder with a finger ring at the of the piston rod. This thing is micro. I'll have to fabricate a .05in od compression spring.  I'm using a small brass nail for the rod (leftovers from a wooden ship build)

The real one

[Bugatti Fan]

This is really going at a pace now.   All the extra detail you have done is phenominal Francois.

The chrome sprayed radiator shell looks great with the corrected badge position. Well worth doing I think you will now agree?

Edited February 9, 2024 by Bugatti Fan

[François]

It took a few tries but I think I got the new radiator cover right.  Now all I need to do is to chrome it (gulp!!). Good thing I made 2...

Here are some shots. 

Before sanding 

After sanding 

And again,  model vs real car 

[absmiami]

Missed an earlier post - is flexible resin for 3D printers commercially available - ?? - is it water based ?
   Cool !!

[François]

Not water based but yes,  available and at different duro. It's quit expensive so I'll have to be 100% sure of the design before printing with it.

Being seldom satisfied with what I do right off the bat, I modified the radiator cover to better reflect the reality.  The nose radius was too small. 

Before

After

The reality 

Edited February 10, 2024 by François

[François]

I printed the new radiator cover.  I incorporated the bottom trim directly instead of being on a separate part. That way,  I'll be able to directly fit the front grill inside the cover. 

Here's the newest version. 

I also made the 2 hood clamps,  they are actually spring loaded and somewhat functional.

Exploded view of a clamp 

Both clamps assembled 

Test fit on the model

[François]

There's a saying that goes like this

" Third time's a charm"...

Well in the case of the radiator cover,  it's the fifth that charmed me!! I finally got the chrome right!

Now, all I have to do is install the front grill whitout damaging the chrome... yeah right...

Installed the hood clamps (I'm using a dummy hood while a new coat of paint dries on the good one).

 

Started work on the hood straps, made tiny buckels and the 2 top straps are done.

This is what the kit provides (black rubber)

[absmiami]

Haven’t tried the Revell chrome yet - what were the challenges ?

[François]

the bigger the part, the better the surface finish has to be to get a smooth surface, otherwise, any defect will show (lower red circle). And It can do strange things (upper red circle). Also, the quantity of paint applied per coat is a factor 2 to 3 light coats are better then one heavier, it's a auto leveling paint so don't panic at first and resist to put on too much. Hope this helps.

 

compared to good one

Edited February 14, 2024 by François

[François]

Finished the hood straps today. I'll let the radiator cover dry for a couple more days before handling it. So the front end should be pretty much done by the end of the weekend.  I also installed the foot step. Next up will be the 4 fenders. I still have the wheels to finish but that can be done just about at any time.

[oldrevellfan]

very nice!

the front strap seems a little angled, or whas it like that on the real one?

[bill-e-boy]

Amazing

[François]

Oldrevellfan,  I think it's a combination of 2 things. The anchor point for the strap is at a small distance from the side panel which creates a slight angle and the fact that the straps aren't tensionned. I'm making new ones with real leather that I'm skiving to .02in think. I should be able to stretch these new ones more than the other ones. It should help... maybe...

[François]

Finally finished the radiator and I'm very satisfied with the result. Even the angle ajuster mecanism I made worked great althougt I barely needed it. I'm redoing the hood straps one by one in real leather so once that's done,  the front end will be complete. Here are a few shots of the finished radiator along with a fun picture of the model next to the ref car.

I also did a test print of a tire. But since I don't have any rubber resin yet, I had to make it in 2 halves. It came pretty good for a first try. 

Here what the real tire looks like 

And mine

[oldrevellfan]

The radiator grill is wonderful !

Will you flatten a little the tire to give them a more realistic appearance?

[François]

12 minutes ago, oldrevellfan said:

The radiator grill is wonderful !

Will you flatten a little the tire to give them a more realistic appearance?

Thanks. 

If I do decide to print them, I'll use a flexible resine. If soft enough,  the weight of the model should compress the tires a bit. Althougt my original plan was to show case the model on 4 stands in which case a flat spot won't be necessary.

I just complete the new hood straps in leather. Much better than the previous ones. Now I can tension the straps for a more realistic look.

[oldrevellfan]

Way better indeed !