Airfix 1/12 Bentley Blower

[François]

Alot was done today.

-All wiring and plumping of the bulkhead assy is complete

-the engine and bulkhead assy are installed, and when connected to a battery, the engine turns along with the drive shaft differentiel and rear wheels 

   -speedo drive housing installed on transmission and wired to dash,

-inclined floor board (the one just in front of the pedal) installed.

here's a link to my build album

https://photos.app.goo.gl/p2DahEAtoFRgju8eA

Edited November 23, 2023 by François

[François]

I thought it would be fun to show some comparison pictures.

1930

2023

1930

2023

[oldrevellfan]

Impressive !

[François]

I few more details were done today. 

Hooked up the steering 

 Attached the gas pedal to throttle linkage 

 Added the blower manifold copper oil line 

Added the starter ground cable 

[absmiami]

Ooph

[François]

Only did a bit of cad work today.  I decided it was time to tackle the blower unit and carburators.

The blower itself is ok, adding some nuts and bolts plus a few fittings for oil connections will bring it to par. The problem is with the carburators. I'll have to print the throttle bodies and the float chambers. The damper pots should be ok. I'll add a throttle shaft with a few levers and springs and spring mounting plate.  Again,  if all goes to plan,  the throttle shaft should rotate by depressing the gas pedal. 

Here the real deal

The kit's carburators 

And my 3d model

[François]

I got a new 12k resin printer for my birthday,  I can't wait to try it out.

[Big John]

Amazing work on the wiring and close up details, as always François!  Those chrome pens certainly work well even up close.  Looking forward to seeing parts from the new printer, does it have an even higher resolution?

Thanks, J

[François]

I've been very busy at other things this week.  Didn't even touch the new printer yet. But I did take a few hours here and there to 3d model the head lights and horns.  The stock head light outter buckets are ok, they will do nicely. Same goes for the inside bucket ( they will need new chrome) and the lens.  The protection grill will have to be redone. The mounting brackets and horn will also be new.

This is the kit's horn. 

My modeled front end

the ref car's front end 

The head light mounting bracket 

A tool I printed to form the bracket 

A full view of my 3d model to date

Same view of ref car

[François]

Still quite busy at other things but managed to try out the new resin printer I got for my birthday. I still need to make some type of enclosure with an exhaust fan, the resin has a powerful smell and I really don't want to be breathing those fumes.

Here's a picture of my firts prints.

From left to right,  first pair not too bad, second pair printed good but I forgot to ajust the scaling and last pair is a nice print.

The real part

[François]

Hello everyone,  I took a break from the Bentley these past few weeks in order to concentrate on my new resin printer.  This thing is really hard to dial in but I'm slowly getting the hang of it, and I do mean slowly! My first try at the begining of december was promissing but since then, the results were "ok" at best. Today, I finally printed a few parts that are worthy of being used on the bentley.

The horns have been glued to the kit's head light bracket 

And the throttle spring plate (thats the triangular plate between the carbs) has also been glue to the blower. The carbs aren't quite ready yet. It's kinda hard to see but they are 2 small lever mounted on the aluminium rod that will eventualy connect to the triangular plate via 2 extension springs. And they should (maybe) be actuated by depressing the gas pedal. 

[Bugatti Fan]

Fascinating progress.  The working steering and throttle linkage videos were most impressive to watcn.

[François]

I installed the horn/ head light bracket combo today, farly satisfied with the result.

Here's what I was aiming for

And here's the 3d model

And here's the result so far

I also assembled the carburators (all 3d printed on my new resin printer) and installed them on the blower which is now connected to the engine. I just need to make the 2 brass fuel lines that go from the carbs to the fuel hoses and to add a oil feed line to the front of the blower and it will be complete. Next on the list will be to model and print proper looking lever shocks.

Here are some pictures of the carbs and blower.

The real thing

The real thing

[absmiami]

as an early adopter of 3D design and printing - - I am curious 

how many different printers have you bought so far - and which on have you just purchased ??

thanks

[François]

Absmiami,

I have 2 printers and both were gifts. The firts one I received for father's day  is an Ender 3 filament printer,  very easy to use but not all the precise.  I mostly use it for jig and fixture.  The second one I got for my 60th birthday last month is an Anicubic photon m5s resin printer. At 12k resolution,  it's alot more precise but much more complicated to use. I still have alot to learn but I'm able to print some parts. 

Today I 3d modeled the front shocks. The kit's shock are very basic and if not installed at the very begining,  they just don't fit. So I made mine from multiple pieces like the real ones. That way they can self adjust when I install them.

The components 

 

My shock (top) vs the kit's shock (bottom)

 

The real thing

 

The 3d model

Installed on the car, this is only a prototype.  

I have to figure out the best way to position the parts in the printer and how to support it in order to get a good print. That's what I find is the most challenging aspect of resin printing. 

[Bugatti Fan]

I would guess that the only way to get each of the separate arms on the shocks more to scale thickness would be to fabricate them from thin sheet metal brass or plastic card instead of 3D printed. You are probably pushing the 3D print to the limit of what it can reproduce of this item. But having said that the 3D printed item looks far better than the kit offering.

[François]

On 12/21/2023 at 4:04 AM, Bugatti Fan said:

I would guess that the only way to get each of the separate arms on the shocks more to scale thickness would be to fabricate them from thin sheet metal brass or plastic card instead of 3D printed. You are probably pushing the 3D print to the limit of what it can reproduce of this item. But having said that the 3D printed item looks far better than the kit offering.

It would certainly be a way to do it but I would need to fabricate close to 30 separate plates, all identical. If I had a laser, it would be doable but I don't (yet!!). The prototype had .025" thick arms (.3" scaled up). I've reprinted the parts with. 015" thick arms (.18" scaled up). It looks a lot better but I think I can still improve it with better print supports and a bit more details. 

[Bugatti Fan]

They're looking better Francois.

I made some up the hard way for my scratch built Hispano Suiza a few years back. Not too difficult. I prepared a number of blanks with two holes equi spaced on all to screw together. I rough cut each to shape slightly oversized and screwed them all together. I could then put them in a vice to finally shape with a file. Once taken out and the screws removed each plate edge just needed a slight clean up. I then had a number of identical pieces by making them together. The circular pieces that went on between were made in a similar fashion but screwed together with one screw and a nut. The screw was long enough so that the protruding end could be mounted in a chuck and the outside diameter turned to size on a small lathe.

Edited December 23, 2023 by Bugatti Fan

[Big John]

I was also going to suggest stacking the shim stock to shape in mass.  The friction discs would be a simple 3D print.

It seems like a shame to cover up all those amazing details with a body François.

[François]

Ha but that's where it gets interesting Big John, my plan is to have a removable body that would be on it's own stand beside the car.  That way I wouldn't lose any of the frame details.  A bit like this.

The completed body mounted on a stand

 

 

and the completed frame on jack stands

[François]

Finished the shock absorber,  I think they turned out pretty good. 

Front shocks

compared to the real thing

Rear shocks

[CabDriver]

Beautiful, inspiring work.  You’re a real craftsman!

[Bugatti Fan]

Those shock absorbers look much more to scale now Francois.

It must have taken you a number of prototypes to get them looking just right.

You mentioned that you would need a laser to make individual parts for those shock absorbed parts in metal. When I worked as a school technician just before retirement the kids did a lot of work on it, but it was only powerful enough for working plywood and acrylics. I would imagine that a laser powerful enough to cut even thin metal sheet would be very expensive to justify for domestic use. But having the ability to etch patterns on the surface as well as cutting through the metal could replace parts that might otherwise have to be photo etched, but I have yet to see it done on model parts.

Edited December 24, 2023 by Bugatti Fan

[François]

You can get a laser cutter for around 1500$ which is still quite expensive but I'm hopeful that, like with 3d printers, the prices will go down in years to come. As a side note, my very first encounter with 3d printing was back in 1995. I was designing an in line skate assembly machine for Bauer and they gave me a prototype wheel hub that had been 3d printed on a very big printer.  The tech back then resembled todays resin printer in the manner that the part gradualy came out of a vat filled with a resin of some sort. But the major difference is that this big printed cost 1000000$ (yes, than many zeros) and the print quality was to 1995 standards.  I can print the same part on my 500$ printer with a much better result. So yes, I am hopefull that laser cutters will be affordable.

The shock absorber being done, my next task will be to run some micro gage wires from the head lights and gearmotor/starter all the way to the back of the car and eventually out of the still to be determined showcase and into a, also to be determined, electrical cabinet where there will be batteries and switchs to activate the head lights and the engine.  

[absmiami]

And i love the detail on the wheel hub …