Author Topic: The Gotha  (Read 48727 times)

Offline Borsos

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Re: The Gotha
« Reply #30 on: March 18, 2018, 02:43:29 AM »
The Schwarzlose was the standard Austro-Hungarian Machine Gun:
sadly only in German:
https://de.m.wikipedia.org/wiki/Maschinengewehr_Schwarzlose
but here some information in English
http://www.hungariae.com/Schwarz.htm
Borsos
"Deux armées aux prises, c'est une grande armée qui se suicide."
Barbusse.
"Ein Berg in Deutschland kann doch einen Berg in Frankreich nicht beleidigen. Oder ein Fluß oder ein Wald oder ein Weizenfeld."
Remarque.

Offline GAJouette

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Re: The Gotha
« Reply #31 on: March 18, 2018, 10:12:00 AM »
 Steve,
Excellent progress my old friend. I really like you Becker 20mm too. Keep up the high levels of excellence.
Highest Regards,
Gregory Jouette
" What Me Worry"

Offline krow113

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Re: The Gotha
« Reply #32 on: March 22, 2018, 06:28:00 AM »
Thanks Borsos , that is enough info for me to go on.
Gregory thank you , always a pleasure
Not much in the way of modelling, still looking at a major cleanup of the work area prior to paint starting. The temperature around here is going up as well ...
I also finally got the Ma gauge I need before firing up my new laser engraver, installed and working.
Test pulse proves:

Some fooling around shows encouraging results:

« Last Edit: April 12, 2018, 06:06:11 AM by krow113 »

Offline krow113

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Re: The Gotha
« Reply #33 on: April 01, 2018, 02:08:18 AM »
First paying job out of the laser , a nice piece of island maple burl , a stainless plate and we have a cool display:



Immersing in the laser learning curve has taken up a lot of time lately, back to the modelling soon...

Offline GazzaS

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Re: The Gotha
« Reply #34 on: April 01, 2018, 08:56:50 AM »
That looks great!
There are only two states to be in:  Queensland and blotto.

Offline krow113

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Re: The Gotha
« Reply #35 on: April 05, 2018, 02:09:35 AM »
Thanks Gaz!

 Upcoming work on the Gotha includes the problematic Taurus valve train resin upgrade set.

I've been perusing other threads and the parts , as well as the instructions for the set , and have come up with a few reasons for the set being a bit of a pain. I have also set out to solve the problems and make it easier to understand as well as install the set.
I'll be laying out the parts and taking some pics in the next few hours , then I'll go into the details of the sets installation.
Thanks for your patience and 'wait for it'...
« Last Edit: April 14, 2018, 04:11:51 AM by krow113 »

Offline Europapete

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Re: The Gotha
« Reply #36 on: April 05, 2018, 02:58:01 AM »
Excellent!! thank you, I have a number of those sets but not used any yet. I have started on their  Gnome Mono engine for the DH2, and that is a real beauty. Straight forward to build with no issues. Regards, Pete in RI.

Offline krow113

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Re: The Gotha
« Reply #37 on: April 05, 2018, 06:03:21 AM »
Thanks Pete.

** THIS IS THE START OF THE TAURUS PROCEDURES**
I'll do the extended work on this posting, that means I'll be coming back and adding the information to this post , rather than a bunch of posts about he same work.
 The work involves Taurus' resin set # D3206 for the WNW Mercededs D IVa.
**There  will be whinging on this post , if this disturbs you , move on , I'll do my best to try and solve the problem rather than whine and do nothing**
Here are the parts:
[/url

 Whats all the fuss about?     
Its WNW for cryin' out loud , their stuff is perfect! ...isnt it?
Lol. Yes and some details are 'conveniently moulded' . Like the spark plug locations on the Biff's engine. Moulded to suit the injection moulding production process. Convenience moulding.

 I assume that's the reason, I don't really care , but close examination of the WNW valve spring mouldings shows an outwardly arcing spring shape , prolly to go with the new fangled arced valve stems ....and in conjunction with the '5 stroke' engine valve layout in the Taurus instructions.
More on that later...
THIS arced valve/spring layout is the whole reason for the replacement of the valves , rocker arms and camshaft housing . I can see no other outstanding reason for the work.

The two cylinder bank parts are the only ones at play from the kit.
Here are the Taurus parts:
[url=https://ibb.co/g2mZ6c]

 You get a camshaft housing , rocker arms , open/closed valve springs , and some other part that is undefineable at this point as to what they are and where they go!
Some actual engine pics courtesy of Bertyl on The Aerodrome forum:




 Some details of note;
- The valves are at a 15 degree angle. ** THE most important piece of information for this work ** Janes book supplies the 15 degree angle info.
- There are 4 valves per cylinder ! A performance engine trait that was nailed from the get -go on this powerplant.
- 2 valves per every intake and 2 valves per exhaust , 12 on each side , 24 in total .
- The look of the rocker arms suggests a front to back rotation, the rotation is actually from side to side; ie: In the pic directly above both of the valves will open at the same time, they are both intake valves.
I'll insert this here. I have this book:

It has the engine in a section on engines in the back. A complete breakdown with photos that answer alla the questions in this thread:


 Dimensions taken from all of the parts. Fed into Corel we come up with a nice drawing of the plan view of the valve layout . I used 'O' for open , and 'C' for closed valves.


The Taurus instructions are a little misleading in that they have the second from the right cylinder with all 4 valves open! This must be the mystical '5 stroke' engine I alluded to earlier. No 4 stroke engine would ever have intake and exhaust valves open at the same time , it is quite impossible , and thinking of piston position , would really make it hard for the engine to run. Shown here:

In reading the Janes book I find that this engine was equipped with an 'over compressed' mechanism which allowed for a set of exhaust valves to be open during the compression stroke . This was to ease the rotation of the crank during setup procedures by mechanics. The lever on the back of the camshaft assy is the way to do this , the cam would disengage and move a little , enough to allow another roller to bump open the exhaust valves just enough to relieve compression.
On Harleys we would pull the plugs.
My thought was that perhaps this is what is being portrayed in the double open valves on cylinder #2 in the drawing. However continued reading says nothing about intake valves being open , and you only need one set open to relieve compression. So it will be up to the model builder to determine their own course of action on this point.

Actual size printout reveals a good fit:


Next up is the crucial cuts to the WNW parts.

Best described as an angled cut, using the finest side of my UMM razor saw I begin with just a few careful strokes on the outside of the assy, laying the saw right on the top of the manifold landings ,which are a stable guide , and angling the blade down as the strokes are made. This is the finish cut that begins the needed angle and will meet up with the second cut.
The second cut begins betwen the rows of springs , you can see a moulded in lower spring cup , place your blade along these edges and cutting at 90 degrees at first , then angling the blade down to meet the first cut.
** KEEP THE CYLINDER ASSY FLAT ON THE BENCH** As it will flex a small amount during cutting , this was fixed on mine , but will throw off the cut.
Springs cut off , cut edges dressed with files and some thin glue , you can see a half round spring cup shape left:


I'm happy with this , cutting the springs off flat adds to the workload , already difficult enough , I have an angle , may not be absolutly correct but an angle none the less.
 I use jigs , understand them, and incorporate them easily and properly into almost alla my work, on signs . models, custom bikes etc , etc , for my whole life. So a jig must be made here , not only for a better drilling alignment , but also to hold alla those valve spring assy's while the glue sets. I'm thinking of a simple ,some jigs are simple , strip of material with the spacing and holes drilled to allow proper cylinder bank spring landing drilling and accept the spring top pins during final assy.

  **WASH THE PARTS THOUROUGHLY IN LAQUER THINNER OR ALCOHOL - DO NOT OMIT THIS STEP **
  ** DO NOT SOAK AS THE PARTS WILL ABSORB AND DEFORM **

 Getting input from fellow forum members regarding the 'T' shaped parts. I see exactly where they are to go.
 And I tried my best to get them there!
  Here is a setup for removing the tiny parts from the sprues. I letter sized sheet is folded for a 'safety net' background if any parts decide to take to the air.The razor saw and clamp work within the tray confines , the tray to catch the parts as they fall off:

I cut the sprue on a moulded in dividing line , and clamped the working piece:

Lay the saws finest edge on the tiny edge,it can be felt with the saw , and letting the saw do the work, held with the lightest touch:

And cut the parts off one by one, orienting the saw with each cut as any miscue ruins the part - this is where your patience is tested:

I had to cut the sprue a number of times to orient the saw better , watch for that. I managed to cut all of them off without loss this time. I recommend sawing the parts off as it has the least chance of installing force into the part, knife cutting uses a separating force installing energy into the part and upping the chance of it getting airborne. The gentle sawing motion separates the part and it falls away inertly into the tray.

 After cutting the parts off some problems show up right away. The landings are not all the same, and cutting them accuratly is near impossible. After cutting all of the glueing surface' must be dressed. Then the inside edge that goes against the camshaft housings must be rounded off in order to get them to stand up straight. These 2 operations are best done with a file , holding the parts down on the bench top with one finger and filing as needed . As for mounting there is no help to align them , its very hard to get all of them straight , did'nt matter to me any way , 2 broke in half and one of each size flew off somewhere. Even the opnes I managed to get attached in the 2 hours I worked on this are all at slightly different heights.  And the sickening application and re-application of cyano is something I hate.
View from underside:

This pic shows placement to good effect:

These are all I will put on as they are the only ones that made it this far. It will be enough to align the camshaft and establish a height.
So after installing the ' T ' s we see that the camshaft housing is raised too high above the top of the cylinder head. I can nip these off, at which point they will prolly fly , fly , fly away , or I can drill a hole in the top of the cylinder head to accept the 'stand'.
Checking the third drawing of the supplied instructions we see the 'T's are shown flush with the bottom of the camshaft housing. This leads the viewer to think that's the height they should be at , which is not the case as you will see further on.
 So with the 'stands' dried and confidence high , I plopped the assy on top of the cylinder/head assy. Of course the indefinite 'stand' length and other small factors made for a less than stellar looking and feeling situation.
Any way here is the assy:

Looks to be a bit of a gap:

With the cam assy placed on top and the camdrive (lollypop) housing in place and everything lined up , we got ourselves a gap:



Here is the final camshaft layout , I did mess up in that I had used some short 'T's instead of long ones for the placement of the cam. This can still be done and has to be done carefully to line up the rockers and springs. So here is the camshaft with the 'T' 's in place with 2 part epoxy:

 The camshaft and stands are proving to be the most difficult part of this set. Here it is again slathered in ca and kicker to try and get the parts to adhere , everytime I'm within 5 feet of this assy one or two of the stands flys away:

As the stands are all ending up different heights , which makes it tough to get it  properly mounted and spaced , I drilled some landings into the cylinder tops to seat the stands into. I think there is room for adjustment which is sorely needed to get this set up properly:

  Here it is in place now. The height being set by the 'lollypop' and by eye as there is no other way. At least I will be able to supply a dimension for the space between the cylinder head and the underside of the camshaft.
The amount of work and rework calls this set into question for me. slathering repeated applications of cyano, and epoxy are not getting things to stay together. I have it on now , I have the gear drive in place and found out that the camshaft is on backwards. The only way to tell is to look very keenly at the ends of the camshaft , one end has a collar that the other does not. I fashioned a s/steel replacement collar and will keep going. I'll try to get alla the little 't's back in place most of them falling off during the assy attempts. As well as the resin being unreceptive to adhesion to anything , it is also flexible , this may be also part of the problem:


** To update the 'gap issue' I have read ( in one of the supplied other builds at the end of this post ) that the modeller had shortened the cam drive , part # E 13 , by 1 mm off the bottom.** I'll look into this as I progress further. I did shorten slightly the circular collar for the bottom of the camdrive , no more than .5mm to fit.
I did not like the cyano mess all over the parts and got a little po'ed at this, so I cleaned all of the parts , losing some more in the process and re-did the work using the glue shown. It seems to be a little better and thinning it down  I can wick it down behind the 'T' s :


   
 I waited a while and when the parts were secure but flexible I mounted the devilishly tricky little part :

 Pretty evident what is at play to mount this all properly , I recommend the 'T' s get there little landings drilled:

Showing it all :



 Looks as if the glue has held, the parts are secure and inline. This is the way to go to me. The parts are fine , delicate and hard to handle , easily broken so the utmost care has to be taken right from the start. This is the first third of the work completed. The springs are to follow.

 Here is a set of templates realized from the research and help on this posting:

1) Layout guide for spring placement. This can be attached to the cylinder assy to layout the holes to be drilled to accept the springs.
2) Layout guide for spring spacing and mounting. These can be mounted on thin card , the centers drilled to accept the tops of the springs.
3) Layout guide for spring angle. These are used on the ends of the cylinder assy to align the springs to the correct 15 degree angle.

 Here are the templates in play.
 First template # 1:

Fits nicely with some cellotape on the end tabs.
Very lightly pricked:

Worked OK:

Template # 3 taped to the end of the cylinder bank , the kit parting line and the top of the cylinder to orient. This allows you to see the angle of the drill as you do the work:

Drilled for the springs:


I will end this right here as I don't know how much more I can put on one post. This ends with the camshaft mounted and secure. And enough parts to finish the job. Next up will be part 2 , the springs.

Three other builds on this forum with these parts:
https://forum.ww1aircraftmodels.com/index.php?topic=5786.0
https://forum.ww1aircraftmodels.com/index.php?topic=9381.0
https://forum.ww1aircraftmodels.com/index.php?topic=8284.msg153623#msg153623
Other forum build of note , superb engine work:
http://www.britmodeller.com/forums/index.php?/topic/235012686-wingnut-wings-132-aeg-giv-finished/

I'm sure there are others, these show the parts in play  , although not the whole procedure.

 I hope this is helping , its meant for guys who would struggle with the tiny parts and assy procedure.

 ** GO NOW TO PAGE 7 TO SEE THE CONTINUATION OF THE TAURUS WORK **


« Last Edit: June 25, 2018, 07:17:33 AM by krow113 »

Offline Michael Scarborough

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Re: The Gotha
« Reply #38 on: April 06, 2018, 10:25:25 AM »
Yo, Steve,

As for the unidentifiable parts, are you referring to the T-shaped bits??

Cheers from NYC,
Michael

Offline krow113

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Re: The Gotha
« Reply #39 on: April 06, 2018, 11:19:03 AM »
Yo, Steve,

As for the unidentifiable parts, are you referring to the T-shaped bits??

Cheers from NYC,
Michael

Yes I can find no evidence of where they go , most guys drop them from the procedure.
I cant even see them in the pics of the engine!
I think I can see the post underneath the rocker arms but I cant even figure out what they do. They must have a movement function as they are in 2 sizes...
Good to have you here.

Offline RAGIII

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Re: The Gotha
« Reply #40 on: April 06, 2018, 08:00:22 PM »
Your cutting looks very precise. I will store your method away for future use.
RAGIII
"A man has to know his limitations": Harry Callahan

"Don't slop it on" Lynda Geisler

Offline Michael Scarborough

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Re: The Gotha
« Reply #41 on: April 07, 2018, 12:13:33 AM »
Steve-san,

Engines are not in my wheel house of knowledge so the Taurus parts were a mystery for me at first. Trial and error started to clear it up but then, bless him, Jeroen Veen sent me pix of his D IVa engine in process and, without those, I'd never have figured this out. (I'd post pix here but have forgotten how to do so on this site.) So let me try to explain it, with sincere apologies for my non-mechanical lingo.

So here are my findings....other's findings my be different, but this is what worked for me:

- First, I removed all evidence of the cast on springs. I then made four holes per cylinder head to accept the nipples on the bottom of the Taurus springs. Do not fill the remaining slots on top of the cylinders.

- As for the T shaped pieces, I found them CRUCIAL for getting the cam shaft height correct. They fit directly below the boxes projecting from the sides of the cam shaft, with the vertical section pointing down and the horizontal sections spanning the gap between the shaft boxes.

- The four longer T's fit into the two slots on top of the cylinder heads. This leaves all the remaining T's sitting on TOP of the cylinder heads and, thereby, determining the exact height needed for the cam shaft above the cylinder heads and the exact height needed for the lolly pop shaped kit piece that fits at the aft end of the whole assembly. This also determines the height for the rocker arms to sit on top of the valve springs.

- I followed Lukasz' directions for which valves were open/closed, and, put the springs in next. Then, I inserted the rocker arms. Now, I don't think of myself as a particularly ham-fisted model builder, but the process of trying to remove the rocker arms from from the casting block, without breaking them or sending half of them into orbit tested my skills and patience...and both were found lacking. And when one is successfully removed, trying to sand it to clean any remains of the block.....well, let's just say it took three sets of pieces until I got an engine I wanted to mount on my build. But, once done....oh, my...yes, Taurus parts are hard to work with and expensive but well worth it once you get the hang of dealing with them.

I hope this helps. It's going to be a great build!

Do me a favor and post a picture of a D. IVa engine with all these pieces discussed labeled so I'll know what the hell I'm talking about in the future! "Lolly Pop shaped piece", indeed....I sound like a real sucker.

Cheers from NYC,
Michael

Online PrzemoL

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Re: The Gotha
« Reply #42 on: April 07, 2018, 06:42:25 AM »
Let me add a few words on MercD.IVa engine with Taurus bits. I can confirm what Michael wrote.(It is great to have you here again, my friend!) I talked with Łukasz three weeks ago on it. The T-shaped bits are the bolts holding the camshaft to the cylinders block. The longer ones are indeed meant to fit the holes in the WNW kit part to align the entire system.
However I found another problem. The cam shaft length did not fit the cylinders, it was too long. Drilling the holes symmetrically on all cylinders led to the misalignment with the camshaft elements. I repeated the drilling process three times, had to fill the gaps twice until I got it all aligned in an acceptable way. Some cheating was necessary. You can see the miserable result of my work, additionally exposed by macro photography in my Rumpler build log.
Needless to say, I also followed the springs layout from Taurus instructions. I will have to live with this error.

BTW, great work on your Gotha, Krow.
Ash nazg durbatuluk, ash nazg gimbatul,
Ash nazg thrakatuluk, agh burzum-ishi krimpatul.

Offline krow113

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Re: The Gotha
« Reply #43 on: April 07, 2018, 07:13:37 AM »
Przy ,Michael ; thanks.
 You and Michael have given me an answer to the ' T ' shaped parts that makes sense.
And yes the camshaft part is too long by just a very little , perhaps .5 mm , I figured I would average the difference and make it work.
 There was some contemplation last night , looking at the razor saw and the part , lemme tell ya!
Anyway I'll continue on with the work and continue adding to the previous posting.
Thank you.
« Last Edit: May 03, 2018, 02:22:16 PM by krow113 »

Offline Michael Scarborough

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Re: The Gotha
« Reply #44 on: April 07, 2018, 10:15:08 AM »
OK...I trust what Prze says (he's my hero, after all) but I will add that I found no problem with the length of the cam shaft. BUT, I will further add that my work may be a bit, how shall I put it......artistic.....that is to say, sloppy. Let me do a refresher in posting images and I will start a build log for my AEG.....which is actually just about finished. I think if we all put our heads together, we can get all the issues solved for future builds and builders. As Steve knows, I have a Gotha G.IV and a G.Vb waiting to be built and I want to be sure the engines are as right as they can be when I get to them.

Glad to be back.

Cheers from NYC,
Michael