DAK Pz IV Ausf G Build

[philipat]

One of the problems that came from raising the sprockets is that the outer edge of the tracks were rubbing the edge of the fenders. I’m using Impact tracks and the have a rounded knob on the end of each link that creates the closed-pin feature. The fenders have a small vertical face on the outer edge that represents the metal being bent down on the real thing. But, because it’s plastic, there is more thickness to this lip than there would be if the fenders were metal. So, I’ve tried a couple of different ways to make this work correctly and still look right.

First thing I did was ask my brother to lathe the drive shafts in order to shorten them by 2-mm (original length: ~60-mm). That worked. The tracks were no longer rubbing the lip. But, they seemed to far from the edge of the fender. Photos of the real tanks showed that the tracks pushed a ways away from the hull. In fact they went all the way to being just inside the bent lip of the fender. So, the next attempt was order some more drive shafts from MatoMart (sold in sets of two) and lathe them down by 1-mm. To make the drive shafts work that only had 1-mm removed, I sanded down the inner lip. Stock it is 2-mm thick. After sanding, it is 1-mm thick. That should leave sufficient strength in the plastic and let the tracks come a little closer to where they are supposed to be. Comparison photos are attached. I like the second effort better (1-mm from plastic and 1-mm from the drive shafts).

One thing my brother did for me while we had the drive shafts in the lathe was to deepen the hole for the bolt that holds the sprocket in place. For whatever reason on all of my drive shafts (I have three sets), the M3 bolt that secures the drive sprocket won’t screw in all the way to the bolt head. It stops about 2/3 of the way into the shaft. It will still hold the sprocket as is, but I like to be able to screw it in all the way to bolt head. So, he drilled that out and tapped it all the way in.

One added benefit to lathing the drive shafts is that the sprockets seat better. The stock drive shafts have a slight beveling around outer edge of the shaft at the ends. It was just enough to let the sprockets wobble slightly on the end of the shaft, even if tightened down. Shaving off a millimeter or two eliminated the bevel leaving a sharp, 90o junction at the end. The sprockets don’t seem to have that slight wobble anymore.

[philipat]

So, I’m waiting for a few materials to arrive. But, in the meantime, I’m getting closer to be finished. So, I played with a color mixture that I found. I plan to use acrylics to paint the tank and I want to paint in the RAL 8020/7027 camouflage scheme. The closest single paint that I could find that approximated what I think the RAL 8020 should look like is the Vallejo paint. (http://www.armorama.com/modules.php?op= ... 708&page=3 or http://www.acrylicosvallejo.com/en_US/g ... ily/17/133).

I’ve been using Tamiya paints; so, I figure I’ll stick with them. Their paint mixture calls for a 5:2 mix of Flat Flesh (XF-15): Red Brown (XF-64) to make RAL 8020 and using Buff (XF-57) to make RAL 7027. [References: Tamiya Manuals for “German Steyr & AK Infantry at Rest” (35305ml) and “PzIII Ausf N” (35290ml)]

I mixed them and painted a piece of scrap styrene. I’d say they came out pretty close to the Vallejo colors. I might add a little Deck Tan to lighten them. I’ll have to see later with some smaller parts, like the backside of the road wheels.

In this painting, I only used a few drops to make the RAL 8020 and thinned it so that I could brush it onto the styrene. The Buff was brushed on without thinning it. There also isn’t any primer behind it. So, the color contrasts are a little more than will happen later. Overall, what do you think?

[HERMAN BIX]

I think its fine, but is hard to be certain without seeing how it looks over primer.

[philipat]

Been doing some test runs on the tank, particularly focused on the alignment of the suspension and the tracks to ensure that everything runs straight. Those test runs have been successful, with the exception of losing an outer wheel to one of my road wheels. But, I was able to source a few new ones.

One problem that keeps popping up is with the leaf springs. The mod I made gets the wheel spacing right. But, now there is nothing to keep the leaf spring in position. So, I’ve had a few slip out while test driving it. I knew this would eventually happen, but I thought I could get away with a few runs before it did. Maybe I shouldn’t have done test runs on the lawn.

Anyhow, I saw two approaches for this on the internet. Unfortunately, I can’t remember the links where I saw them or who did them. So, I can’t give credit where it is due. Maybe they’ll chime in and post a link. One approach was done with metal boggies and the individual fixed the problem by dragging solder across the opening to block it. The other approach used plastic boggies and the individual drilled holes on either side of the opening and glued a wire into the holes that also blocked the opening.

I went for the wire approach. I drilled 1-mm holes into the bogies and used wire cut from a destroyed spiral-bound notebook. I soldered the wire into the holes. The leaf spring can be inserted through the slot and then screwed into the other half of the suspension.

One note: I tried to do this with my Dremel using the drill press attachment. If you do this, make sure that your alignment is good and that you have started the holes already with a pin vise. There seems to be some play in the system when you start to drill and the bits end up getting a little stressed. I broke all of my 1-mm bits before it was done. I had to drill a few of them out from the other side using a slightly larger bit. It was faster than using a pin vise for sure, but also a bit frustrating. Oh, and go slow when using the press.

[HERMAN BIX]

Wise move. I can see how they would come out. My metal bogie units dont have your bent up spring in the leaf pack, my ones are flat.
All advice tells to replace the new ones with the stock H/L leafs, so I will try that first.

[philipat]

Going with the stock HL leafs was an option and I still have the plastic suspension. So, I could do that. But, I chose this option because, out-of-the-box, the wheels sat too far apart and rubbed against the wheels from adjacent trucks. They also didn't quite look right. This mod brought the wheels a little bit closer together and gave more space between the bogie sets.

If you don't have that problem, then the HL leafs are the easiest improvement to make.


BTW...thanks for the feedback on the paint colors. I'm still playing with the mixture a little bit. But, I'll make a final decision after I try it over some primer. That was a great idea that I hadn't thought of.

[strmnd54]

Happy to see that the suspension mod. I suggested a while ago works well for you too...http://www.rcuniverse.com/forum/rc-tanks-369/11604422-winter-project.html
Now if I only could find the time to finish my Panzer IV; I'd be happier...
Too many movings...

[philipat]

I totally borrowed your idea with the bent leaf spring. But, admittedly, I forgot that it was your posting where I saw the modified plastic suspension with the bent wire. Thanks for the reminder.

Yes...I'd love to see your finished PzIV. That said, I need to finish mine, too.

[HERMAN BIX]

Any updates Mr Philipat ?

[philipat]

Sorry...I've been a horrible slacker.

Actually, been caught up in work and spring projects. Hope to get back to it in a couple of weeks. Warmer weather will be good for painting and I'm just about there.