RC Tank Warfare community hobby forum

Yes, we're back on lads!

Time to finish installing the power train. Completed:

- Glued in the styrene stiffeners in the front of the lower hull
- Installed drive shaft bearings (height was adjusted slightly as a result of switching to the Mato gearboxes)
- Gearbox attachment points were reinforced using aluminum tubing (1/4" ID, 9/32" OD, .014" wall thickness)...their lengths extend an extra 1.5-mm (total of about 5.75-mm long) to replace the washers that were used as spacers to raise the gearboxes.
- Gearbox mounting plate is secured with #4 (#0 drive) self-tapping, square pan head screws. They’re ½" screws that have been cut down to about 7 mm. (possible source: http://www.mcmaster.com/#tapping-screws/=10t9c2g)

I’ve put some lithium grease and 3-in-1 oil into the gearboxes following thecommander’s guide (http://www.rcuniverse.com/forum/rc-tank ... boxes.html). I tried using some M3 PTFE washers in gearboxes (source: http://www.mcmaster.com/#catalog/122/3251/=10t9gqc). But they didn’t seem to work. They seemed to cause the gears to bind.

Great to have you back on the job mate !
How do the gear sets look now with all the height adjustments for the track run ?

They look pretty good. Not quite level with the return rollers, but you have to look to notice it. I would have liked to raise them another millimeter. But, as it is there isn't quite a millimeter of clearance between the tracks and the forward edge of the fender. Any higher had them rubbing the fenders a lot HL should have made the fenders about 2-mm longer.

Photos are from a test run.

Okay...so, I'm ready to epoxy the lower hull and do the electronics. In the meantime, I'm considering some Mr Surfacer 500 to create a cast effect. But, I need help identifying the cast parts. Here's what I think is cast based upon the photos I've seen of surviving PzIVs. Up front, the German casting seems pretty smooth...not as rough as the US casting.

Sprockets (already metal with the look)
Road Wheels (already metal with the look)
Commander's cupola? (can't really tell...looks like one part, but very smooth metal)
Armored MG Ball mount
Rounded vents on brake hatches (flat hatches are rolled steel)
Signal port hatch
Suspension mounts
Port covers on side hatches
Side vision hatches (port covers)
Armored hinges
Driver's vision port cover/block
Front tow brackets (can be cast or welded)

Am I on the right track?

Some more work done. Some of it you can see and some you can’t.

- Glued in the battery cover and puttied the edges.

- Installed the return roller mounts with thread lock on the bolts. Clipped the bolts shorter.

- Test fitted the electronics to see how it would all fit. It’s crazy tight inside the PzIV.

- Put a small layer of clear epoxy in the bottom. It adds a little weight and stiffened it a lot. It’s almost like having an aluminum hull. I saw this from someone else...totally ripped off the idea. LOL I used about a half a cup total. Any more would have covered my gearbox lifts.

- Installed a front brace that will also be a splatter shield between the gearboxes and the electronics.

I put together the electrical. There are now small rocker switches on the switch platform for the power and the smoker. The volume knob is there, too. Cabling is tight, but the tube should keep it close to the side and away from the turret wiring.

Still need to tidy up the turret wiring...

Note: Switch source:

Also got a set of these, but they stuck down into the hull too far to fit with the smoker under them.

So, today was texture day. I tried my hand at creating a cast texture for the first time using Mr Surfacer 500. Using a brush in the tighter areas was a bit more difficult. But, I happened upon the idea of using Q-tips to stipple it on. It seems to have worked well.

The armor plates had a little texture added using a technique that was suggested by Herman Bix. Using a finger, I smeared gel-based super glue around on the armor plates. After it dried (and I removed a large growth of glue from my finger), I sanded it with 220-grit paper. The idea is to introduce some random patterns on the surface so that it’s not perfectly flat and smooth (rolled steel vs plastic sheet). Sanding it flattens it and gets rid of bumps and ridges. We’ll have to see if it still shows after priming and painting. This method was cheap enough, but I think if I were to do it again I’d try Testor’s Metalizer paint.

Still trying to figure out if the commander’s cupola was forged or cast. It looks forged in most of the photos I’ve seen.

Looks way better than the smooth plastic surface eh !
I thought of using a paint also, called "hammertone" but was real concerned it would affect the acrylic top coats.
I reckon the super glue will work a treat Mr Philipat.

From what pictures I have looked at for the cupola on the PzIV it was cast then machined.
The periscope block armour slides were milled grooves, and the rest was dress machined.
The real vehicles I have seen were very clean of normal cast texture but these could be due to degrees of restoration.
(Aberdeen PG, and the Littlefield Pz IV)up real close.
I have seen pictures that appear to show areas of cupolas that were missed by the lathe leaving patches of raw casting, but to fluke one again could take for ever.
Also, the picture could be just showing dirt, or any other detritus so I cant be sure.
Assuming the cupolas were also required to be fairly accurate in relation to the gun, the commanders vision block and manual rifle-sight gun aiming pointer it makes sense to machine them to a degree.
The Panther style versions were cast &welded but still must have had machine work on them to some extent.

I hope the super glue does the trick. First time trying...it certainly adds some interest and texture beyond the smooth plastic.

Cast and then machined...that makes sense. The part in the photos looks like a single part, which would imply casting. But, the surface is too smooth, which would be where the machining comes into play. Thanks for the info!

I looked up the hammertone paint. It's offered here by Rust-o-leum. But, in the photos, the texture appears to be too pronounced with large pits and the like. I'm not sure it would give the right texture. I looked at the Testor's Metalizer again and it's laquer based. That might be a concern, because I like to use acrylics as well...maybe a layer of primer between the metalizer and the base coat would do it.