Triumph Tr6, 3d printed large scale

[François]

Yesterday I said that I would not be making a real differential, well I lied. I decided to try and see if it could work. So today, I designed the internal components that makes a differential do what it does which is to drive both wheels while permitting the wheels to rotate at different speeds. It's a beautiful feat of engineering invented back in 1827 by a French guy named Pecqueur.

I also redid the half shafts with more accurate universal joints along with the drive shaft. I incorporated the small bearing (which I received today and boy, are they tiny) in the front hubs. I had to find slightly larger bearings for the differential, I went with 4mm id instead of the 3mm id used in the hubs.

Redesigned half shafts

Differential internal bits

Working differential (in cad at least)

View attachment 20251117_194827.mp4

 

[François]

With the differential done, I'm slowly progressing back towards the front of the car. I did the rear brakes and started the transmission housing. It's composed of 3 parts. The tail housing, the bell housing and the shifter housing. Having restored this car for real, l have a ton of literature. One of these books (the tr6 maintenance book) is full of really nice hand made 3d drawings (remember that it dates back to the pre-computer era) and some just as nice cross section views. There's one of the transmission that I used to 3d model it. Combined with pictures from the net and measurements from my car, I was able to do a decent job of it. It's not finished but not to far either. I still have the complete shifter housing to do. On the hydra, I made a mecanism activated by the shifter to engage the rear wheels but it didn't work well. For this one, I would like to make the actual friction clutch and engage it using the shifter instead of the clutch pedal.

Cross section from maintenance manual

3d model of transmission so far

the transmission from my car after it was restored

And the rear brakes

 

[Marquinius]

Ehrmh … you will sell this to Tamiya or so? I mean … oh well. Just impressed beyond normal levels.

 

[MisterCA]

Amazing!!! Incredible work.

Below is a picture of the TR 6 prediceser. The American import called the TR 250 built only one year in 1968..

 

[François]

Wow, the 250 was the nicest of all TR'S.

For those of you who work with computers, you know that eventually something will go wrong. Well something did go wrong will my bell housing 3d model. After close to 8hrs of work, the file decided to become corrupt and could not be opened anymore. It's a very complex part to do so redoing it wasn't all that fun. The good side of this is that it went faster the second time around and that I'm more pleased with the result.

Bell housing V2. You will notice that the gearmotor has been placed where the starter motor normally is. Being a 1/6 scale model, I should have enough space inside the starter housing to hide the gearmotor.

I also started work on the engine, I did the pistons.

On a lighter note, I went to a model show last Saturday and picked up 3 prize. I brought the Hydra Coupe and the bentley blower. Both cars were in different categories which had close to 30 entries each. The bentley won first place in the 1970 and older cars segment while the hydra won first place in a movie vehicle themed segment. Plus, the Hydra won best of show!! It was a nice day.

 

[Peter Voogt]

Wow, the 250 was the nicest of all TR'S.

For those of you who work with computers, you know that eventually something will go wrong. Well something did go wrong will my bell housing 3d model. After close to 8hrs of work, the file decided to become corrupt and could not be opened anymore. It's a very complex part to do so redoing it wasn't all that fun. The good side of this is that it went faster the second time around and that I'm more pleased with the result.

Bell housing V2. You will notice that the gearmotor has been placed where the starter motor normally is. Being a 1/6 scale model, I should have enough space inside the starter housing to hide the gearmotor.

I also started work on the engine, I did the pistons.

On a lighter note, I went to a model show last Saturday and picked up 3 prize. I brought the Hydra Coupe and the bentley blower. Both cars were in different categories which had close to 30 entries each. The bentley won first place in the 1970 and older cars segment while the hydra won first place in a movie vehicle themed segment. Plus, the Hydra won best of show!! It was a nice day.

Congratulations, François. With the 3 prizes. Of course, you already had our appreciation, and now you'll be at that show too.
Sometimes computers go either way. In the latter case, there's often no other option than to start over. A great second attempt.
Regards, Perer

 

[jolia1450]

Well, I did some printing tests on the tire with a different anti aliasing setting and althought not perfect, it aided a bit. I also reduced the lettering height ftom .01 inc to .005 inc. But I will still need to sand. I did try to sand and paint a test tire. I can see that the end result will be good but since I had very little black rubber paint left and had to thin it a bit (read too much), I will not show you my test (I've have to much pride).
On another front, I have a first sub assembly done, the rack and pinion. Very pleased with the result.
View attachment 555522
View attachment 555521

Now before progressing any further with the frame and rear suspension 3d modeling of Red Interior Car, l will test print the front suspension components to see if everything fits and moves correctly.

Yes i see

 

[François]

I did the crankshaft today, it went pretty well.
View attachment 20251124_211253.mp4
I also started on the clutch. Unlike on the hydra where I had a geared coupling hidden inside the transmission to drive the rear wheels and that didn't work well, I intend to drive the rear wheels using a dry clutch just like on the real car.

Here's how I see it. The green part is the flywheel and it is bolted to the crankshaft so when the engine turns, the flywheel turns. In red is the clutch plate and it is coupled to the main transmission shaft that drives the wheels, it can slide on the shaft and has a spring pushing it off the green plate. The blue part is the clutch pressure plate that turns freely around the clutch plate (red). The idea will be to push the blue part against the red part that will in turn push against the green thus transmitting the torque from the engine to the wheels. I still need to figure out how to push the blue part by using the gear shifter. Aside from the 'using the gear shifter' bit, everything else is basically how a real clutch works minus a lot of fancy springs, shouldered rivets and a bunch of other stuff. I will probably make a cut-out of some sort under the bell housing so that all this stuff can be seen.

 

[Peter Voogt]

I wish you a Happy Birthday, François.
Enjoy this day!
Regards, Peter

 

[GIG1810]

Hey François,

I wish you a happy birthday too. Enjoy this day surrounded by your loved ones and have a wonderful celebration.

 

[François]

A few things happenned since monday. As mentionned by Peter and GIG1820, I turned 62 yesterday so that's a start. And after 58 years of skiing, I finally got to ski on my birthday, yeah for that!

On the Tr6 front, I finished modeling the transmission, the clutch and the shifter that will actuate the clutch. I also finished the starter motor with the gearmotor hidden inside.

Then I started the real meat, the engine bloc. It's about 95% done and 95% accurate. Like any engine bloc, it's a pretty complex part with lots of features. I took a few libertys such as adding ball bearings at the front and rear of the crankshaft. Aside from another Tr6 nerd like me, I don't think anyone will see the 5% innacuracy. I'll slowly model all the add-on parts but there are a bunch so might take a while. I would like to have a rotating ignition rotor in the distributer just for the fun of it. I'll see if it's possible but since the distributer takes it's power from the camshaft and I plan on having a rotating camshaft, it should be doable.

Completed clutch mecanism
View attachment 20251125_212837.mp4
Starter motor

With hidden gearmotor

Almost completed bloc

Vs a real one

And on the frame

 

[RussF]

A few things happenned since monday. As mentionned by Peter and GIG1820, I turned 62 yesterday so that's a start. And after 58 years of skiing, I finally got to ski on my birthday, yeah for that!

On the Tr6 front, I finished modeling the transmission, the clutch and the shifter that will actuate the clutch. I also finished the starter motor with the gearmotor hidden inside.

Then I started the real meat, the engine bloc. It's about 95% done and 95% accurate. Like any engine bloc, it's a pretty complex part with lots of features. I took a few libertys such as adding ball bearings at the front and rear of the crankshaft. Aside from another Tr6 nerd like me, I don't think anyone will see the 5% innacuracy. I'll slowly model all the add-on parts but there are a bunch so might take a while. I would like to have a rotating ignition rotor in the distributer just for the fun of it. I'll see if it's possible but since the distributer takes it's power from the camshaft and I plan on having a rotating camshaft, it should be doable.

Completed clutch mecanism
View attachment 560294
Starter motor

With hidden gearmotor

Almost completed bloc

Vs a real one

And on the frame

Beautiful work François! And happy belated birthday!

Not being critical here, but what are the two missing bosses on the cylinder head for, freeze plugs?

 

[François]

Yes Ross, they're freeze plugs. They are part of the 5% left to do. They're done on the other side.