Now I have had time to examine my twelve-year old build in detail there are some issues I see with the kit compared to the actual restored vehicle. There are three main areas that I felt needed addressing. One is making good an original build mishap, the second is a very prominent inaccuracy issue with the bodywork, and the third concerns the fitment of the body to the chassis. Then there will be some additional detail to add here and there.
Sprocket Issue & fix
The first main issue concerns the track fitment. Although my already fitted tracks appeared to sit snugly over the sprockets, I assumed I had resolved the well-publicised sprocket fitment issue. But whilst attempting to roll the tracks any further over both rotating sprockets it was revealed I definitely hadn’t! If the issue is not addressed only a few track teeth will locate between the sprocket rollers. Although barely just enough to allow a partial wrap around, its visualy obvious as the track links coming off both upper and lower runs don't engage and sit naturally. The actual vehicle sprockets were handed, and the rollers were offset differently on each side. This is not represented in the engineering on the kit parts so will cause a fitment issue if not addressed.
The non handed kit sprockets from the Trumpeter Sd.Kfz 7 kit (same issue as on the Sd.Kfz.8) showing the incorrect position of the rollers sat centrally between the track pads
You can see in the resto image below of the driver side sprocket that the rollers are sat slightly forward of the centreline of each track pad.
Nice clear side view image showing each track link sat slightly forward over each individualy bolted on rubber track pad. Notice how each track link also sits centrally over each sprocket reinforcing rib.
As my tracks are going to be removed anyway to improve the weathering on them, I figured the sprocket issue could be dealt with first.
The kit offers two types of sprockets, and I had already fitted the type with the smaller circular central face. After checking images of the restored vehicle it was obvious I should have fitted the alternative type with the larger face. Doh! As the photoetched step ring on one of the smaller faced sprockets I had built was looking pretty beat up anyway it was a no brainer to conclude these had to be replaced with the larger faced ones. This would necessitate removing the two-part circular moulded drive rollers from the already built sprockets, as the same parts are used on both sprocket build options. I could then solve the offset issue when adding them to the larger faced sprockets.
To fix the sprocket issue I would first recommend marking up each sprocket outer faces (parts B18 or B30) LEFT and RIGHT. Out of the kit when the sprocket parts are assembled they will be incorrectly identical, but we are going to make them 'handed' as per the real thing.
This is a sprocket and tracks from Trumpeters Sd.Kfz 7 (8T) but the issue applies to the 12T kit too. This image shows the best fitment (its often a lot worse) you could hope for without applying the fix. Notice how the track links do not sit flush on the track pads
The second step is to snip off the three keyway tabs on the ringed drive roller parts B22 that fixes to part B19. Out of the kit these key incorrectly into the rear of the sprocket outer face parts B18 or B30, leaving the track teeth unable to fit between the drive rollers as they should.
Here are the three inner key tabs (circled below) that need removing on part B22.
The kit sprocket parts incorrectly have the drive rollers sitting centrally above each reinforcing rib as per the red x below. This we need to change.
Step three is to carefully remove ALL the square tabs (track teeth spacers) around the inner portion of the sprocket parts B18 or B30. The fix on the original PMMS site (showing the same issue on Sd.Kfz.7 sprocket parts) then instructs you to replace all the cut off internal tabs back onto the sprocket into their correct re-orientated positions. (slightly forward of their original locations on your now handed sprockets) From experience this really is not necerssary. First up unless you snip every one off perfectly square they are not going to re-attach perfectly square. But more importantly, they are difficult to see anyway once the tracks are fitted. So I've never bothered.
Whether you re-attach the tabs or not bother (as I do) all that is left to do is refit parts B19 and B22 which are now (without the keyed tab) free to rotate into any orientation inside the sprocket outer face (parts B18 or B30) They can now be fixed in place so the sprocket rollers are visibly offset slightly forward on EACH side. This can be done by eye but I recommend building up two lengths of track runs (ensuring they are correctly orientated for each side) and to then use them to test the fitment before commiting to final fixing.
This image of a 8T sprocket shows the adjusted and now correctly oriented roller location (left image) See how the track links now fit snugly up against each track pad and the track run fits tightly around the whole sprocket
On this 12T kit the wheel on the left has been fixed to represent the port (drivers) side sprocket and the wheel on the right shows the remaining sprocket not yet fixed. The green lines show how the drive roller centre line has now slightly shifted forward. Compare this to the red line showing the roller sat in line with the wheel rib and centrally over the rubber pad in the unfixed sprocket assembly.
The fix process was made more hazardous for me as I had to first remove glued parts B19 and B22 from the alternative sprocket! It was pretty tricky as the ringed drive roller parts are extremely fragile. Thankfully it was carried out without too much visible damage. With the drive roller rings added to the new sprockets and fixed in place with the correct left and right-handed forward offset, they were marked and test fitted successfully to the tracks.
The rebuilt starboard side sprocket (without the PE stepring) with the track teeth now accurately engaged between the drive rollers showing the forward offset track links now sat snugly on the sprocket rubber pads.
Upper armour plate overhang issue
Now it was time to turn to the second main issue. The angled upper body crew compartment side plates were designed to overhang the lower plates. It's not by much but clear to see on both the original damaged, and the restored vehicle images. The upper plates over the engine compartment in the kit have a prominent overhang but unfortunately, just like in many a Dragon Model and Cyber Hobby Sd.Kfz.251 Ausf C & D, the upper and lower plates in the kit simply butt up to each other with no overhang. To remedy this on an unbuilt kit I figured there would be a few options. Adding a whole new extended upper plate, adding just the overhang portion, or reducing the thickness of the lower plate.
As the interior of the upper panel on my build had already been painted and weathered, I opted for option three. The stowage bins are positioned centrally on the lower side plate and as these were already fixed in place, I would only need to trim either side of them. Although this will involve the removal of quite a chunk of material, retaining the profile of the angled rear plate was of most concern. This needs to remain as straight as possible. After an evening of scraping and sanding I eventually got the look I was after.
Birds eye view showing approx.50% of the material at the upper edge of the left-hand plate between the stowage boxes removed.
The lower side plates either side of the stowage bins have now been reduced in thickness to slightly taper to a narrower profile at the top. The upper plate now displays a decent amount of overhang.
The upper plate overhang is much improved now. Maintaining the lower plate profile to look as straight as possible along its full length down to the lower back plate was important.
The outwardly leaning lower side plate profile has been retained.
Some further clean-up is required with finer grades of sandpaper before the upper sub assembly is added to the lower but I'm really pleased with how this process turned out.
The third issue to address is one that most builders will come up against early on in the build. I should have noticed much earlier but I did not follow the build steps. The bodywork assembly to chassis assembly connection is by way of several keyway connections and they did not fit at all precisely on my kit.
Here is how I tweaked the connection points when I got to this stage after painting assemblies seperately later on in my build. Bodywork assembly to chassis assembly fit issue
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