Sunday, May 21, 2017

New RUM-V Wheels For Your Vehicles, Too

Per another user request (Thanks, Mr. Hamner), I sprued together six wheels from the RUM-V files, and put them up on the Shapeways store for Rebel Minis Digital Direct.

Here they are.

This will let you create a wide variety of vehicles, including some of the following.  New wheels are digitally mounted under the old pre-RUM-V Combat Flatbed hull.



New RUM-V Pods For Your Combat Flatbeds

Had a little bit of upload fever, and put three pods in the Rebel Minis Digital Direct store on Shapeways up for sale.

My thanks to Donovan Borman for the boot in the ass to get this going.

These are preview pieces for folks who want to jump the production line, and get their customization bits now now now.  ;)

We don't put a markup on them, for now, since the prices are already high enough.

First is the RUM-V Combat Flatbed APC Pod.

It's a 1/100 scale bit that fits on the back of the Combat Flatbed, and can carry a small number of troops.  It also has a RUMV-compatible top hatch, so it can also mount a weapons turret or cupola like the ones already sold by Rebel.

Next up is the RUM-V Combat Flatbed Turret Adapter.
No illusions of cramming troops in here.  It's just a riser pod that lets you mount turrets like the heavy gatling turret.

And last, but not least, is the "Winnebago-Style" overhead camper APC pod originally crafted for the Combat Flatbed.

This older pod isn't RUM-V compatible, per se, more of a prototype and vision of things to come.  It does fit on the back of the Combat Flatbed, though, and has a quirky look that I like.

So, there you go.  Order away.  Default materials are White Strong And Flexible, which doesn't give the best details, but does keep prices down.  If you want tabletop quality, try the higher definition plastics such as Frosted Ultra Detail or Frosted Extreme Detail.  The price climbs astronomically, though, so brace yourself.  :(



PS, here are a few variants and variations of the RUM-V Combat Flatbed and Civilian Flatbeds.

 Winnebago style pod on the Civilian Flatbed hull.

I went a bit wild with the combos.  You can too, with those adapters and other parts from the Animech Kickstarter.

I love the RUM-V system.

Saturday, May 13, 2017

Rhino3d Tutorial: Making Treads and Tracks, Part 1

One of the more odious tasks for me, as a digital sculptor, is tank tracks.
I can do them in my sleep, now, but at first, they were no fun.  Plus, they used to crash my more feeble sculpting computers, leading to much frustration.
I still carry some of that residual hate.  Damn you, tank tracks.  ;)

Now, I'm not going to get technical on you.  There are various types of suspensions, wheel and sprocket arrangements, and tread types.  You can research that on your own.  Here's a good start...
Everything Is In The Suspension
Sherman Road Wheels
M1 Abrams Suspension
Leopard 2 Suspension
WW1 Tank Suspensions

As you can see, there's a variety of approaches.  The simplest is the type used on the early British tanks in The Great War, and which has been emulated in WH40K Imperial Guard Designs and some charming Alternate WW1/Martian Invasion games for their steam tanks.

Also, the tank from Indiana Jones and the Last Crusade.  Tread units running all around an armored block. Simple, and no major complications.  Let's do that one first.

I work in Rhino3d, so adapt to your program and work process as necessary.

 First, a trapezoidal line.  A closed curve, actually.
 I fillet the four corners with a nice radius, rounding it out.
This is what I call my Main Reference Line.  Remember that.
 I extrude that closed curve into a shape
 I offset two curves from the main ref. line.  One larger, the other smaller inset.
 Rhino lets me use two closed curves on the same plane to make a hollow shape.
 I do that, making it slightly narrower than my main tread unit body.
 I subtract that large hollow collar from the main shape using a Boolean Difference.  Basically cut one shape out of another.  This creates a shallow trench all round the center of my tread unit.  Individual track links will fit in this trough.
 I chamfer the outside edges, because I'm a fussy git.
 I create the outline of my track link.  Nothing complicated here, but I want to make sure it fits inside the confines of my trough.
I mirror the line, and make it a solid shape via extrusion.
 I chamfer the edges of the blocky tread link.
 I rotate it 90 degrees, and see how it fits.  It fits!
 I then use a command in Rhino3d called Array Along Curve.  I select my link, select my Main Reference Line, and play with things until I have an evenly spaced number of tread links all around the outside of my tread unit.
 I end up with 57 tread links all arrayed around the edge of the unit.
 Rhino handles the orientation automatically.  In the past, on more complicated builds, I have had to manually rotate each tread link around the curved edges.  Nothing is perfect.
 Now, there's a number of gaps between the links, the trough, and the main body of the unit.  I offset the Main Reference Line a wee bit to the interior.
 And extrude a shape that will be a substructure, holding everything together.  The main details are still evident, but when fused, the unit will be one cohesive piece.  This is necessary for casting and printing.  Small voids equal death.  Lack of detail equals death, too.  A balance is struck.
 So, there's our completed tread unit, ready to be fused together.
 The tempation is strong.  Let's make a tank.  First, we copy the tread unit.
 Create another closed curve.  This will be the profile of the tank hull.
 We extrude it into a shape that fits between the tread units.
 A couple cylinders, one for the turret, the other for the barrel, and it's a tank.  Too squat and fat, though.
 I scale the hull along one axis, squishing it without changing other proportions, and move the tread units up against it.

You can put armored skirts over the top of those tread links on top, you can add any variety of rivets and surface panelling to it.  This is just a simple tutorial on making WW1 style tread units.  More advanced stuff later.


Friday, May 12, 2017

Grav Tank 4: CNC Machining The Turret

Well, today was a day well spent, I must say.

Here are a series of Youtube videos (and a few stills) showing the progress I made from a simple sample block of tooling board (courtesy of the nice folks at ) to a grav tank turret that is pretty close to being thrown into a mold.

Just so you know, these are loud videos of machining operations, so you probably want to mute them.

I'll also give you short attention span types the finished result up front, then explore the details farther down...

Nice, eh?  That thing is smooth, let me tell ya...

So, onward we go into the process...

Initial Roughing Pass.

Knocking down the unmachined columns of stock material.

Roughing Pass is done.  The finish, is, well...rough.  So, we change out bits, and start the finish pass.

Starting the XY criss-cross finish pass.

Those nasty waterlines from the roughing pass go away, right before your eyes.

Pencil pass, to clean up the inside corners.  Very cool to watch.

And, again, the finished product.

 I think I'm on to something, here.  Pretty cool.


CNC Machine Back Up And Running

I installed a new anti-backlash nut in the heart of the X axis of my CNC machine, and it seems to be travelling much nicer now.  No binding.

My thanks to John at Microcarve for making this happen.

Two holes, drilled and tapped for 8-32.  Easy peasy.  Assembly was a lot quicker this time, too.

On to machining!