A quickie...

Had a few extra moments today to play in the garage. Started work on the drive sprockets. The base is just a cone. To that cone a ring will be welded on each end. The actual sprockets will then be bolted to the rings.

Brummbär Progress Video Log

The Brummbär begins.

First off, a little of the back story.

This build is intended from the beginning to be a PAV (paintball armored vehicle) for use in paintball/airsoft games. It is intended to have a minimum crew of 2, though I am trying my best to cram three in the thing.

The Brummbär was selected as the model for this build for several reasons. First of all, construction is pretty straight forward and in line with my skill level. Second, it has a very high profile (unlike the Hetzer) making it easier it fit in the thing. Third, it has a big gun. What I mean by that is the original had a 150mm main gun with a short barrel. This gives me a lot of options for designing a scale version. And fourth, it is casemate (turretless) design. Though not having a turret will be a slight hindrance on the paintball field, it is safer without one. I have several ideas to make a turreted design safer, but that will have to wait for future projects.

This project will progress a little differently than the last one. The first items on the "to do" list is suspension, drive sprockets, road wheels, rear idlers, return rollers and tracks. After all of that is done, I will then start tackling the frame/hull and what not. Since this project will be much heavier than the Hetzer project, it is important to have all the suspension and tracks ready to put on the hull as soon as it is done so the lower hull can be moved around. How heavy do you ask? It is my goal to keep the finished tank under 5000 lbs.

I have had a couple days so far working on the Brummbär. So far, it is not very exciting. Just cutting up the little pieces that will get put together for the suspension. Progess has been slow as I am still learning how to effectively use my plasma cutter. I also had an issue with my circle cutting jig not fitting the torch of my plasma cutter. Everything was correct, except for some reason the diameter of my torch head was about 1mm too big. Just enough to keep it from sliding into the jig like is suppose to. I fixed that problem by carefully sanding the torch head.

First picture is some of the small pieces I chopped up last week.

The next is of some discs that I cut out. These ultimately will become the road wheels. 20 down, 16 to go. 

One other item of note: I have started a video log for the project. It can be seen on YouTube here:

Brummbär Progress Video Log 04-12-14

First video I have taken with my phone. Audio went in and out a little. I will try and correct that in future videos.

Every ending is a new beginging.

Everything in life does not end the way we thought it would. This is very true where my Hetzer is concerned. An ambitious project to be certain, but achievable. However, it will not come to fruition. My biggest mistake with the Hetzer was not fully articulating the projects goals. I said early on that I had no idea what I was going to use it for, I just wanted to build the thing. As I continued to work on the project, I began to realize I had some serious design flaws. No not in a mechanical sense, but in the capabilities of the finished project. It simply was not enough to just build it; I wanted it to be able to do more than it was designed for.

Specifically, I wanted it big enough for more than one person to fit in the thing. The Hetzer, even at full size, is not very big; knock it down to 60% and one person is all that is going to fit in comfortably. This "problem" is made worse by the fact there simply is no way to make it bigger without re-doing everything. So, several months ago I made the decision to scrap this project and start another. I used the winter hiatus (read: cold weather) to chose a new tank and work up the CAD drawings for it. I also made several key upgrades in my little tank factories capabilities. In the Hetzer project, I tried to use as many parts as possible "off the shelf" due to my limited fabrication skills/equipment. This made me make many compromises in how close to scale I was staying. I added a plasma cutter, metal bending equipment and a new welder to the arsenal. Moving forward, I will fabricate almost everything from scratch. Outside the engine/hydraulics package, about the only thing I am not making myself is the bearings and nuts & bolts.

So , last week the Hetzer was cut up for parts. I salvaged the longer pieces of square tub and will use the springs and bearings in the next project. The hubs, rims and wheels will be sold or traded away.

So what is the next project you ask?

The Brummbär......