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Turkish T-155 "Firtina" 155mm SPH conversion
KursadA
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Posted: Sunday, December 13, 2009 - 12:00 PM UTC
My latest project involves the conversion of Academy's new K-9 155mm self-propelled howitzer into the T-155 "Firtina"; a modified version that is licence-built in Turkey. The T-155 uses a slightly different turret design and a Turkish-designed digital fire control system.

Here are the two vehicles: K-9 first, and the T-155 second:




KursadA
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Posted: Sunday, December 13, 2009 - 12:02 PM UTC
I started with a detailed 2D CAD design of the turret based on photographs and measurements. I then had the parts laser cut from 1mm styrene, and started the construction:



KursadA
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Posted: Sunday, December 13, 2009 - 12:03 PM UTC
The base kit is the brand-new Academy 1/35 K9 kit. The kit has been out in Korea since late October, and it is easily available on Ebay. I am somewhat surprised we have not seen a review of the kit yet in any "mainstream" modeling Websites (or maybe I missed it entirely), but it is an excellent kit with good level of detail and quite a few extra goodies in the "limited edition" boxing that I got:

KursadA
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Posted: Sunday, December 13, 2009 - 12:05 PM UTC
After completing the basic "box", I added weld lines from Apoxie Sculpt and gave the turret a layer of primer:



KursadA
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Posted: Sunday, December 13, 2009 - 12:07 PM UTC
The configuration of the hatches on the vehicle are very different from that on the K9. I will be using the laser-cut hatches I designed; and latches & hinge hardware from the kit:



tankmodeler
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Posted: Sunday, December 13, 2009 - 02:00 PM UTC
Excellent "old school" scratchbuilding with a "new school" kicker. I have to ask where you can get 1 mm styrene laser cut and roughly how much you are paying for it. I have a good CAD system & can easily make flat patterns of stuff I design, just need to know where to go.

I smell a Mk VIII International in my future...
KursadA
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Posted: Sunday, December 13, 2009 - 03:56 PM UTC

Quoted Text

Excellent "old school" scratchbuilding with a "new school" kicker. I have to ask where you can get 1 mm styrene laser cut and roughly how much you are paying for it. I have a good CAD system & can easily make flat patterns of stuff I design, just need to know where to go.

I smell a Mk VIII International in my future...



Hi Paul,

Thanks for the comments. For laser cutting, I used the services of Pololu, a company that I have dealt with before for some robotics projects. Their laser cutting service is pretty fast and reasonable, I ended up paying $29 (not including shipping) for two sets of T-155 turret parts cut out of 1mm white styrene. They accept several different formats (I just sent them a PDF), and will e-mail you a price quote soon after you upload your design files. Their link is below:

http://www.pololu.com/catalog/product/749

Hope this helps,

Kursad
bison126
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Posted: Sunday, December 13, 2009 - 08:18 PM UTC
The K9 has not yet reached the shelves and you've already started a conversion ! That's fast.
Thanks for sharing your project. It's really an interesting and original one.
It seems you're mastering all the brand new modeling technique
HeavyArty
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Posted: Sunday, December 13, 2009 - 11:58 PM UTC
That turret looks great. Great idea with the laser cut parts too. I see this being used often for conversions. Any chance you could do the same for an M992A1 FAASV? It too has a boxy superstructure that would benefit greatly from this technique. I have no experiend with CAD to draw it up myself or I would.
tankmodeler
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Posted: Monday, December 14, 2009 - 06:16 AM UTC

Quoted Text

Hope this helps,

Kursad


It certainly does! Thanks a bunch.

Paul
C_JACQUEMONT
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Posted: Monday, December 14, 2009 - 06:20 AM UTC

Quoted Text

The base kit is the brand-new Academy 1/35 K9 kit. The kit has been out in Korea since late October, and it is easily available on Ebay. I am somewhat surprised we have not seen a review of the kit yet in any "mainstream" modeling Websites (or maybe I missed it entirely), but it is an excellent kit with good level of detail and quite a few extra goodies in the "limited edition" boxing that I got:



Thank you for all the information and tips! Fascinating project and this laser cut plastic open doors for many scratchbuilding ventures!

Could you please elaborate on the "extra goodies" included in that "limited edition" boxing?

Thanks!

Cheers,

Christophe
RichardM
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Posted: Monday, December 14, 2009 - 07:03 AM UTC

Quoted Text

Could you please elaborate on the "extra goodies" included in that "limited edition" boxing?

Thanks!

Cheers,

Christophe





In the Special Edition you get a tiny PE fret (engine grill), some camo decal for the figures and a small booklet.covering the K-9, K-10 and a few others things.

HTH
gcdavidson
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Posted: Monday, December 14, 2009 - 07:34 AM UTC

Quoted Text

. I then had the parts laser cut from 1mm styrene,



Wow. I think I just found a way to make the ceramic armor for my Coyote, Bison, Husky, LAV-III...etc etc

How good are the edges on the styrene, ie, is there a burr like when you cut with a blade? Is the cut edge itself quite smooth?

Very very interesting possibilities there. Thanks for sharing that with us, and the build looks great too.
C_JACQUEMONT
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Posted: Monday, December 14, 2009 - 08:45 AM UTC

Quoted Text





In the Special Edition you get a tiny PE fret (engine grill), some camo decal for the figures and a small booklet.covering the K-9, K-10 and a few others things.

HTH



Thanks a lot!

Christophe
KursadA
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Posted: Monday, December 14, 2009 - 09:30 AM UTC

Quoted Text


Quoted Text

. I then had the parts laser cut from 1mm styrene,



Wow. I think I just found a way to make the ceramic armor for my Coyote, Bison, Husky, LAV-III...etc etc

How good are the edges on the styrene, ie, is there a burr like when you cut with a blade? Is the cut edge itself quite smooth?

Very very interesting possibilities there. Thanks for sharing that with us, and the build looks great too.



Graeme, your books are the primary reason I got into scratchbuilding in the first place; and now I get my chance to contribute something in return!

The edges are very smooth and there is no sanding required once the parts are cut. Perhaps the following close-up photo might give a better idea, I can take better ones tonight:

http://s204665619.onlinehome.us/images/T155_project_02.jpg

The laser has its own "blade thickness", i.e. it eats away perhaps 0.2-0.25mm of material at the edges; and furthermore has a slight angle to it; so one has to account for this during the design phase. Some of my parts ended up being just a tad underscale in the end, but this was my first project using laser-cut styrene parts.

A more important issue is warping: the heat of the laser can warp 1mm styrene significantly; and heat-induced warping was a problem in some of the larger parts like the turret top. It does not seem to be an issue for smaller parts, though. I would imagine warping would be less of an issue with thicker styrene (2mm. etc.)

The laser cutting service's (Pololu) Web site has a brief introduction that covers these and other issues as well.

Kursad
gcdavidson
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Posted: Tuesday, December 15, 2009 - 08:39 AM UTC
Thanks for that info. I will check out their website.

The heat warping on larger parts is counter-intuitive. I thought that wee skinny bit on the turret roof angle would bend due to the heat, but it looks very straight. I would be using .020 or .025 sheet, with most parts being smaller than your turret hatches, so I think heat deformation would not be an issue.

I've already got the pdf of what I need. I think the next step would be to print them on paper to make sure the templates fit. Did you try printing out on card stock or paper to do a test assembly before sending the design for cutting?

I'm thinking about all kinds of slab sided AFV's now... CT-15 Armoured Truck, Otter Scout Car, Humber Mk IV.

I wonder if they could cut slat armour out of styrene?
KursadA
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Posted: Tuesday, December 15, 2009 - 10:36 AM UTC

Quoted Text


I've already got the pdf of what I need. I think the next step would be to print them on paper to make sure the templates fit. Did you try printing out on card stock or paper to do a test assembly before sending the design for cutting?



Absolutely: I first printed a copy on paper after arranging the parts to come up with a model that I can fold and glue into shape. I sent the design for cutting after making sure that the basic shape was all right. I obviously had to tweak the CAD model a little bit to convert it into a printable paper "model"; because the CAD model assumed a wall thickness of 1mm.

gcdavidson
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Posted: Tuesday, December 15, 2009 - 12:28 PM UTC
as your avatar would say, "fascinating"
chrisj
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Posted: Wednesday, December 16, 2009 - 05:06 PM UTC
Laser cut styrene, 3D printing - Tamiya, Dragon you better watch out. I've never seen such clean cuts from styrene.

The smaller guys in the resin business selling $200 dollar resin kits better change their business plan and get some new machines.

Good work, I'll be watching your progress.
tankmodeler
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Posted: Tuesday, December 22, 2009 - 02:41 AM UTC

Quoted Text

Laser cut styrene, 3D printing - Tamiya, Dragon you better watch out. I've never seen such clean cuts from styrene.

The smaller guys in the resin business selling $200 dollar resin kits better change their business plan and get some new machines.

Good work, I'll be watching your progress.


Chris,

Well, it's not as simple as all that. Sure, these technologies do a lot to help the scratchbuilder (and patternmaker for the resin companies) but for the average joe, these technologies will still cost more than $200 to make an entire kit and you will still be left with at least the clean-up work and likely the need to add more detail, produce etched brass drawings not to mention the time & skill needed to create the CAD files to drive all this cool tech.

No, the $200 kit doesn't have to worry for quite a while yet. When downloadable CAD files and the rapid prototyped parts for an entire kit can be had for less than the $200 of a resin kit, then they need to be worrying, but that's a ways off yet.
TonyDz
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Posted: Tuesday, December 22, 2009 - 03:00 AM UTC
Tips is at again.....
KursadA
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Posted: Tuesday, December 22, 2009 - 09:21 AM UTC
Time for an update. I've been studying the photos of two vehicles feverishly; scratchbuilding the many bits and pieces that are peculiar to the Turkish version. Needless to say, this takes quite a bit of time. But we're getting there..



I also started building the hull and making the modifications necessary for the Turkish variant. Some differences between the K-9 and T-155 can be traced to a desire to reuse Turkish-built components as much as possible: the headlights look very much like M-113 or AIFV headlights, and the commander's cupola ring might have AIFV origins as well. Many small parts such as the tow hooks are also different. The tow hooks looked like a good starting point as any:





KursadA
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Posted: Tuesday, December 22, 2009 - 09:24 AM UTC
An interesting find is that the attachment of the rear sprocket: The configuration on the Turkish variant looks very simplified to me. The Turkish variant has some additional sheet metal to separate the connection point and the rear gate area. Here is a comparison picture.



I scratchbuilt this area accordingly:


trahe
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Posted: Tuesday, December 22, 2009 - 09:57 AM UTC

Quoted Text

That turret looks great. Great idea with the laser cut parts too. I see this being used often for conversions. Any chance you could do the same for an M992A1 FAASV? It too has a boxy superstructure that would benefit greatly from this technique. I have no experiend with CAD to draw it up myself or I would.



Exactly what I was thinking!
KursadA
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Posted: Tuesday, December 22, 2009 - 11:40 AM UTC

Quoted Text


Quoted Text

That turret looks great. Great idea with the laser cut parts too. I see this being used often for conversions. Any chance you could do the same for an M992A1 FAASV? It too has a boxy superstructure that would benefit greatly from this technique. I have no experiend with CAD to draw it up myself or I would.



Exactly what I was thinking!



I took a look at photos of FAASV when I first read HeavyArty's message; and indeed the structure looks somewhat similar. Unfortunately I neither have an M109 kit (for measurements on the base vehicle), nor detailed 3-view photos of M992A1 to come up with accurate drawings. If I had these I could design a basic set of CAD drawings for the FAASV fairly quickly.