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Armor/AFV: Axis - WWII
Armor and ground forces of the Axis forces during World War II.
Hosted by Darren Baker
Dueling Build Log: DML & Trumpeter Sd.Kfz.7/1
lesrogers
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New South Wales, Australia
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Posted: Monday, December 21, 2009 - 08:35 AM UTC

Bill could you tell me what technique you used to assemble the Dragon tracks.
I have mine in front of me and I am rather frustrated with their assembly.
Regards Les
Photos would help
bill_c
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Posted: Monday, December 21, 2009 - 09:21 AM UTC

Quoted Text


Bill could you tell me what technique you used to assemble the Dragon tracks.
I have mine in front of me and I am rather frustrated with their assembly.
Regards Les
Photos would help


Sorry, Les, I'm already past painting them, so no photos, LOL!

My suggestion would be:

1.) clean up the knock-out holes on the inside of the track (the side with the guide horn). Can't tell you how shocked I was at the amount of these holes and the work it will take to clean them up. They're very faint, though, and I didn't discover them until I had finished painting both sets (Trumpeter and DML). Grrrrrr.

2.) place a SMALL amount of styrene cement in the center of the track pad underside. This will soften the plastic and provide for a better "weld." Put the track pad aside. I did these in gangs of 6.

3.) slide two links together - the guide pins slip easily into the two grooves of the preceding track. Apply a SMALL amount of styrene cement to the "H"-shaped form, being careful not to get any glue into the grooves themselves. If you make a mistake, set that piece aside until the glue has dried completely before using it.

4.) re-apply a little fresh cement to the track pad underside, then CAREFULLY align it over the "H." Don't do more than a pair at a time, and LET THE SUB-ASSEMBLIES DRY THOROUGHLY!

The tracks will allow for NO torque until fully dry (usually overnight). You can then combine the dry pairs into "quads" until you've built up 2 equal lengths. As you lengthen the string, be sure the track pads both adhere properly to the tracks and are perfectly perpendicular to the line of the track.

Hope that helps. The Magic Tracks are about as much work as Friuls, but $35 cheaper, LOL!
bill_c
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Posted: Tuesday, December 22, 2009 - 03:52 PM UTC
One of the big problems with the Trumpeter kit is the inaccuracy of the drive sprockets. While waaaaay ahead of the old Tamiya, they simply stumble in several key areas. One is the tracks don't lie flat on the sprocket. Coupled with this is the drive teeth are backwards and don't show the small washer that allows the drive teeth rollers to rotate. Terry Ashley at PMMMS has this fix for the problem, and I have followed his lead.

You begin by snipping off the inside tabs of the ring on the left, being careful to set them aside. You will then glue each one into the grooves on the right piece. When the drive teeth ring is fully-assembled, you can then align the tracks.


I will post something tomorrow showing the final results, but you can check out Terry's photos to see the various steps.
c5flies
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Posted: Tuesday, December 22, 2009 - 04:16 PM UTC
Excellent builds so far, Bill....I've been following silently along with this one, and you've got me almost convinced into picking one of these up and attempting to build it!

Great tips on the track assembly also, wish I had them when I did my one and only HT. Not sure if these are the same style as the ones I did but, like Les, was getting frustrated with them. Slapping together a quick jig like this may also help......




lesrogers
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Posted: Tuesday, December 22, 2009 - 05:28 PM UTC

Thanks for the reply Bill it realy helped.
I ended up sticking the links to a length of masking tape and using Humbrol Poly Cement
glued them in two operations.
It worked and I did the 54 links in groups of 6.
A good Xmas present.
Regards Les
bill_c
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Posted: Wednesday, December 23, 2009 - 03:49 AM UTC
James, Les, those are both good solutions. Plastic tracks aren't my favorite, which is why so muych of my money belongs in Hungary (where Friuls are made).

Happy Holidays to all! Mine should be half-tracky, since LuckyModel tells me my barrels have been shipped. Yea!!!
panamadan
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Posted: Wednesday, December 23, 2009 - 05:41 AM UTC
Bill,
Just got around to looking at your builds and I'm finding it very interesting! Keep up the good work!
Dan
M_Wittmann
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Cluj, Romania
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Posted: Thursday, December 24, 2009 - 04:30 AM UTC
Hi Bill. Regarding the drive sprockets, I encountered the same problem when I built my Sdkfz 7 from Trumpeter, as I have red Terry's review who said the rollers weren't offset. Trying myself a solution to this problem, I started to search for photos of the sprockets and I found out that the rubber band covering them was almost circular, with no visible flat lines. As a consequence, I sanded the rollers until they became circular, and now the track sits flush on the sprocket. Maybe you should check the photos yourself, to see if that's one noticeable solution.
alanmac
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Posted: Thursday, December 24, 2009 - 07:43 AM UTC

Quoted Text

Hi Bill. Regarding the drive sprockets, I encountered the same problem when I built my Sdkfz 7 from Trumpeter, as I have red Terry's review who said the rollers weren't offset. Trying myself a solution to this problem, I started to search for photos of the sprockets and I found out that the rubber band covering them was almost circular, with no visible flat lines. As a consequence, I sanded the rollers until they became circular, and now the track sits flush on the sprocket. Maybe you should check the photos yourself, to see if that's one noticeable solution.



Photographys courtesy of Toadman's excellent site. Restored vehicle at Military Vehicle Technology Foundation in Portola Valley, California in September, 2006.




See gallery here.
http://www.toadmanstankpictures.com/sdkfz7.htm

Alan
M_Wittmann
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Cluj, Romania
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Posted: Friday, December 25, 2009 - 07:53 AM UTC
Hi Alan, I've seen the photos when I was building the Trumpeter kit. It seems there are some, let's say "flat" lines, but they are no way near as flat as depicted by Trumpeter. The ruber band looks more like circular, especially in 1/35. There are also some indentations on the sprocket seen on the restored vehicle, and in the kit they are too obvious to seem real, the same as the rubber band. Of course, I have puttyed them, the same way as I sanded down the rubber band, to obtain a more realistic look.
Cheers, Marius.
bill_c
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Posted: Friday, December 25, 2009 - 02:04 PM UTC
Gents, the Littlefield Sd.Kfz.7 is a restored vehicle. We already know the tread patterns on the tires are post-war. The drive sprocket looks worn or otherwise rounder than the period photos I have in my reference works. The DML kit also has flat indentations.

I will post some photos of the finished drive sprockets in the next day or two. Terry's "work around" does the trick.
H_Ackermans
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Gelderland, Netherlands
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Posted: Friday, December 25, 2009 - 02:55 PM UTC

Quoted Text

Hi Alan, I've seen the photos when I was building the Trumpeter kit. It seems there are some, let's say "flat" lines, but they are no way near as flat as depicted by Trumpeter. The ruber band looks more like circular, especially in 1/35. There are also some indentations on the sprocket seen on the restored vehicle, and in the kit they are too obvious to seem real, the same as the rubber band. Of course, I have puttyed them, the same way as I sanded down the rubber band, to obtain a more realistic look.
Cheers, Marius.



Well,that just shows you need PERIODTIME pictures as opposed to museum and/or restoration pictures.

While this vehicle is an SfKfz 8, the sprocket is build up the same as on the SdKfz 7 and SdKfz 9:

Sprocket
bill_c
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Posted: Friday, December 25, 2009 - 03:22 PM UTC

Quoted Text

Well,that just shows you need PERIODTIME pictures as opposed to museum and/or restoration pictures.

While this vehicle is an SfKfz 8, the sprocket is build up the same as on the SdKfz 7 and SdKfz 9:


Yes, and most definitely, no.

While I agree with Mr. Ackermans about the need to use period photos over photos of museum restorations, his point about the drive sprockets of the Sd.Kfz.7 and 8 being "the same" or even "built up the same" is not correct. The 8 has a string of rubber pads that handle the track feed (clealy visible in his example photo), while the 7 has a rubber ring with indentations or dimples that allow the tracks to sit flat against the drive sprocket (see photo below from the very excellent Allied-Axis #21, which I reviewed here):



Good period photos that show these "dimples" are hard to find. Perhaps someone else can provide better ones. It's also possible there were variations according to the place of production, or the dimples wore down over time in the field, but the photographic evidence is too poor to make generalizations.
M_Wittmann
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Posted: Saturday, December 26, 2009 - 12:25 AM UTC
Hi all. I also believe the dimples existed in fact on, if not all, at least the majority of the Sdkfz 7's, but what I wanted to say is that they were not as obvious as Trumpeter represented them. I found another photographic example of the sprocket which shows the dimples existed. The source is Panzer Tracts No. 12.
The most likely situation is, as Bill said, that they wore down over the time and that I think it's why they look circular. That's also why I made the choice to sand them down, to give them the worn look, which helped too to the fitting of the track.
H_Ackermans
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Posted: Saturday, December 26, 2009 - 01:15 AM UTC

Quoted Text

Hi all. I also believe the dimples existed in fact on, if not all, at least the majority of the Sdkfz 7's, but what I wanted to say is that they were not as obvious as Trumpeter represented them. I found another photographic example of the sprocket which shows the dimples existed. The source is Panzer Tracts No. 12.
The most likely situation is, as Bill said, that they wore down over the time and that I think it's why they look circular. That's also why I made the choice to sand them down, to give them the worn look, which helped too to the fitting of the track.



That may work, but then STILL the "teeth" with the rollers are not accurately offset, as they are on the DML sprockets.

And Bill, you're correct about the shape of the rubber padding, the SdKfz 7 has a solid run around the sprocket, the 8 has sections.
bill_c
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Posted: Tuesday, December 29, 2009 - 05:32 AM UTC
OK, here is the result of reworking the Trumpeter drive sprockets:

The track rollers now have their detail facing outward instead of inward (beats adding PE washers like I did on this build):


Now for the tracks. The Trumpeter version are a three-piece affair (track, pad and pad-base), while the Dragon version is two-piece. One problem with the Dragons is the knock-out holes:

Both build up well after a base coat of Tamiya flat black under a coat of Testors metalizer (the burnishing variety).



Remember, the track pads are rubber, so they will need a coat of oily black.
bill_c
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Posted: Tuesday, December 29, 2009 - 05:35 AM UTC
Because the chassis will be mounting a gun platform instead of a passenger compartment, I am pre-painting the chassis details now. This is the Trumpeter version with the tow line attached:



The Dragon kit is more simplified, so the front is already attached:

H_Ackermans
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Posted: Tuesday, December 29, 2009 - 06:01 AM UTC
Just HOW smart is the DML kit? Is it a case of indeed, very clever molding and no lack of detail?

I've got 2 88mm FlaK guns, maybe one in firing position and the other being towed, and I wouldn't know exactly what would be the best option, Trumpeter or Dragon.
bill_c
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Posted: Tuesday, December 29, 2009 - 06:43 AM UTC

Quoted Text

Just HOW smart is the DML kit? Is it a case of indeed, very clever molding and no lack of detail?


That's a very good question, Herbert. I think that for most purposes, the DML kits will build up very smartly and look quite good. If I were doing a DAK or repair dio, then the Trumpeter would definitely "trump" the DML because of detailing in the engine. The Dragon kit looks very good, but the details are just not as strong.

One problem with the clever molding is that things can get lost or damaged. The windshield mounting brackets are molded-on in the DML, and one broke off early in the build. I will have to replace it. The Trumpeter brackets are separate parts, so I can add them when I'm ready.

Quoted Text

I've got 2 88mm FlaK guns, maybe one in firing position and the other being towed, and I wouldn't know exactly what would be the best option, Trumpeter or Dragon.


Again, this is a matter of how you plan on doing your dio. If you are going to have the Prime Mover bearing branches and other camoflage, then the kit differences are not going to be as evident. And keep in mind, the Trumpeter's faults are mostly technical and often not immediately noticeable. Take, for example, the different lengths to the kits: the DML is more correct in overall length, but we're talking about 2-3mm. Same for the gun platform folding sides on these kits: a few milimeters. For the vast majority of modelers, that amount of difference or the higher mud guards of the Trumpeter kit simply don't matter.

This doesn't mean the Trumpeter kit is as good as the DML, but given the price differences (especially with rumors Trumpeter is re-tooling the Sd.Kfz.7 base kit), you can sometimes pick up the Prime Mover for as little as half the price of the DML. The Trumpeter's additional parts will be more-satisfying to detail geeks, too. The winch detailing (while it doesn't show) is simply not even close in the DML kit, and has some lovely PE wedges that aren't even rendered in styrene by the Dragon kit.
Wisham
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Posted: Tuesday, December 29, 2009 - 10:17 AM UTC
This has been fun to watch, I like the side by side build concept.
ted_hayward
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Posted: Wednesday, January 06, 2010 - 10:26 PM UTC
Great idea and nice build, Bill! Thanks!
bill_c
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Posted: Thursday, January 07, 2010 - 02:12 AM UTC
Thanks, Ted and Warren!
bill_c
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Posted: Friday, January 08, 2010 - 03:56 AM UTC
Here are the tracks with some "oily black" on the track pads:

bill_c
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Posted: Friday, January 08, 2010 - 04:04 AM UTC
Next in line are the wheels. I employed the QuickWheel masks I reviewed (click here to see the Dragon mask review; click here to see the Trumpeter mask review). I had to lower the rating on my review for the Trumpeter mask set after discovering it does not have a slot for the drive sprocket (the Dragon mask does). Considering the price of these masks, that's a real deficiency.

Anyway, here are the results. I'm going to have the vehicles side-by-side in a France, 1940 environment, so I'm using 1/3-2/3 disruptive Dunkelbraun over Panzer gray:





My lousy close-up zoom and these photos don't do the masks justice, but they REALLY make a difference is creating the "lip" of rubber that extends from the edge of the road wheels. I can't imagine painting German "box chassis" vehicles ever again without them.
H_Ackermans
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Posted: Friday, January 08, 2010 - 11:47 PM UTC
Does your camera have a MACRO-modus? My Fujifilm S3000 has this, and it enables you to really get close on a subject in the litteral way, thus by bringing the whole camera close to it instead of using the zoomlens.

I still have this opinion on the wheelmasks, that, take a compass, measure the wheels diameter, scribe plastic sheet with the compass and you have a homemade mask. What is the real plus of the wheelmasks, besides being pre-cut, so to say? I mean $14 is in itself not much, but it's kit-specific. Another brand or subject, you need another wheelmask set.

Are you going to paint the chassis before gluing it to the body?