Author Topic: LVA Fokker D.III using 3D prints designed by Bo  (Read 8346 times)

Offline Alexis

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #30 on: June 11, 2019, 10:52:44 AM »
Really like what you are doing here so far , those belts look great !



Terri
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Offline IvotB

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #31 on: June 13, 2019, 05:41:49 AM »
Hi guys, perhaps you can help me. I think I remember that Lukasz (Taurus Models) posted the build of one of his resin Oberursel engines. I'm building his 14 cylinder U.III and I'm looking for the detail on the cylinder head. There you can imitate open and closed valves, but I'm not sure what the differences are at the back end of the cylinder head.
Does anyone also remember these posts by Lucasz and could you help me find them? The Search option doesn't seem to direct me to any of those posts.


regards,
Ivo

Offline IvotB

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #32 on: June 14, 2019, 06:11:29 AM »
I've started with the U.III. To get a good impression I've built at first the main parts of the WnW Oberursel. Then I started with the version of Taurus Models.



The centre and the carter covers on which the cylinders have to be attached. One cylinder is shown. All these parts have to be separated from their casting base. I drilled a hole through the carter from the front to get a good centred hole with which I can attach it to the firewall and still be able to turn the engine with the propellor in the end. If you use a drilling machine with a good clamp it is possible to do this.

These are the cylinders with castings of the cylinder head with the base for the valve lifters:



Here you can see the WnW and the Taurus engine next to eachother. I didn't count them, but I have the impression that the Taurus version has all cooling ribs on the cylinders. It is amazing that this can be casted flawlessly:



Next step will be to install all cylinder heads and the lifters. I need to make up my mind whether I'm going to paint this part first in steel before the next steps.



Here you see the spark plugs to the right, the cylinder heads in the middle, the valve lifting gear to the left and the parts for the pushrods at the centre near the camshaft (?). Although it is not so much a camshaft but more a cam axle. I'm not sure about the correct word for this engine part. It is invisible in the model.


regards,
Ivo

Offline RAGIII

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #33 on: June 14, 2019, 06:36:05 AM »
As good as WNW engines are that is a Huge difference in quality! I am sure whatever decision you make on painting will work out fine! Looking forward to your next update.
RAGIII
"A man has to know his limitations": Harry Callahan

"Don't slop it on" Lynda Geisler

Offline Juan

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #34 on: June 14, 2019, 07:49:23 AM »
Amazing comparison of the two, agree with Rick, that Taurus is incredible (you get what you pay for).

Offline IvotB

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #35 on: June 14, 2019, 08:45:15 AM »
Hi guys, perhaps you can help me. I think I remember that Lukasz (Taurus Models) posted the build of one of his resin Oberursel engines.

Found it:  http://www.taurusmodels.pl/pdf/3216%20DetailedInstr.pdf

regards,
Ivo

Offline uncletony

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #36 on: June 14, 2019, 02:23:47 PM »
This is looking great Ivo.

Amazing to see it go together in another pair of hands!

Offline uncletony

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #37 on: June 14, 2019, 02:28:59 PM »
Ivo -- if you are on FB, I did a step by step on building the Taurus U.III. The tricky part is assembling the lifters. I ended up inventing a tool (sort of) to assist.

The thing looks fairly amazing when put together...


Offline uncletony

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #38 on: June 14, 2019, 02:38:17 PM »
I think if it was me I'd build the structural model with a second modified (where necessary) Fokker D.II from Special Hobby (Kit 32065).

I have had a closer look at the D.II from Special Hobby to see if what you suggested can be done. And the answer is yes, but there are a number of issues. First of all the surfaces of the wings and fuselage are very dull and do not reach the standard I'm used to from for instance WnW and what I hope to achieve with the Shapeways prints. But the other issue might be more important. It seems that this D.II is not correct in 1:32 scale. I didn't measure it yet, but it is larger than the D.III prints from Bo and it should be the other way around. Also the fuselage apart from the engine cowling for which I can use the surplus D.III print the forward part has some distinctive differences. When looking at your Fokker pair project I know this can all be solved, but due to time constraints I expect to stick with my original plan.

Hi Ivo,
I must admit I've not looked into comparing the two but if what you say is correct, then one or the other is not in scale.
My WNW and Bo's Fokker D.VII's match up pretty well, so I'm guessing, as you said, that the Special Hobby kit is too large.
That said if the two were displayed together but not too close to each other, the viewer probably wouldn't notice the difference.
Unless of course they are a modeler!!!

Mike




If the suggestion is to substitute parts from the D.II to the D.III -- unfortunately, although the two aircraft are very similar in concept -- they differ in almost every dimension, and in myriad detail: larger wings on D.III with wider chord and more ribs, deeper fuselage, the fairing are different, undercarriage also completely different -- perhaps the empenage bits were shared but that's even a little doubtful. Chalk it down to to the way they did things back then, i guess.

Offline IvotB

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #39 on: June 14, 2019, 05:04:04 PM »
Ivo -- if you are on FB,
No, I'm not. Perhaps finally a good reason to subscribe. Although I have the impression it is going downward with FB. It seems that Instagram is getting more popular.

regards,
Ivo

Offline IvotB

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #40 on: June 16, 2019, 08:18:18 AM »
Small update  ;)  again.

Today I added the cylinder head and the valve lifters to the Oberursel U.III

First I have cut all the parts of their casting blocks:



So now I have 14 cylinder heads and 15 valve lifters (the last ones are on a casting block with 5 lifters)

The cylinder heads are then glued inside the cylinders with epoxy. Not with CA as it will be impossible to correct their position once inserted as it is a tight fit. In test fitting 2 cylinder head lost the fitting of the valve lifters, but I hope to be able to attach those tiny parts again. One valve lifter is eternally lost to the carpet monster and 2 others are broken. These I hope to be able to fix as well. But the other parts have been connected to the engine. While doing that don't forget to cut a tiny piece of the actual valve end which is casted in the middle of the cylinder head. Thus creating 4 open valves and 10 closed ones. While I did that I have gotten a better idea about the functioning of this engine. Because there are in the U.III 14 cylinders (2 in a circle around the crankshaft) it is now possible to make the iginition sequence in a perfect boxer mode, thus reducing the vibration of the engine. The opposing cylinders however are never in thesame circle so they are unfortunately a little bit shifted along the crankshaft. But this engine should have less vibration when compared to the U.II .

It is also nice to realise that this must have been a 14 cylinder 2 stroke rotation engine, which must have produced a huge a amount of noice and dirt, as there is no exhaust, just an opening of every cylinder with a valve. Well all is well known to most of you here I guess.

My engine is now almost ready for its first coat of paint. I just have to fix the 2 cylinder heads and valve lifters. And of course adding a spring of a piece of 0,1mm brass wire on every valve lifter. And in the meantime not destroying any already placed parts. All is extremely delicate and there is almost no safe position to store this engine apart from putting it on the Fokker itself protected by the cowling.

It's state so far:



regards,
Ivo

Offline uncletony

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #41 on: June 16, 2019, 08:37:15 AM »
Nice work -- assembling those lifters is tricky -- heck, cutting them off the block  without destroying them is tricky. Congrats.

my technique was to assemble them with the cylinder heads still on the casting block -- I made a little helper tool that was really nothing more than a stack of styrene with a piece of two sided tape stuck to it. I'd put the block int position, then gently roll the lifter into place -- then CA it.


Offline RAGIII

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #42 on: June 16, 2019, 07:50:18 PM »
Really looking great in spite of the lost and broken parts. I am certain you will pull off a beautiful result!
RAGIII
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"Don't slop it on" Lynda Geisler

Offline IvotB

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #43 on: June 17, 2019, 08:24:02 PM »
I tried to repair the broken parts, but crashed and burned.

So I contacted Lukasz last night and he promised to send me some spare parts. In the meantime I can try to bend and fit some springs to be made from 0,1mm brass wire. Is also a fiddly job.


regards,
Ivo

Offline Manni

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Re: LVA Fokker D.III using 3D prints designed by Bo
« Reply #44 on: June 19, 2019, 04:38:08 PM »
My respect for the courage for such a build. The complete build looks great, can't wait to see the engine ready.
Bye,
Manni
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