Creeper 6x6 part4

Guess what?... I decided, in the end,  that the body I was making for this project didn't really look right on this chassis, it was too tall and proportionally too short. I also found that I had not captured the essence of the thumbnail in styrene, particularly with respect to the  cabin area which suggests an expansive area of glass. The one I ended up making has a small constricted windscreen which was not  what I had originally intended.
I have stored that version away for some future project and for a front end re-build and substututed a new design, making it the third and definitely final attempt at a body that suits this chassis. In fact it is similar in proportion to the first version but in my mind much better realised.

Here is the version 2 thumbnail for reference;

 And here is the version 3 thumbnail;

I further reduced the height of the body when doing a rough CG model.

I then cut up the CG model into thin strips at the points I wanted to make bulkheads and deleted the rest of the geometry. A screen captured front view is then used as a tracing guide for a 2d Cad drawing that is then printed out and stuck on 6mm foamed PVC sheet and cut out making frames and bulkheads for the real model.

Here are some pics of the frame construction which is then skinned in styrene sheet.

You can see I have attempted to make the frame as lightweight as possible, it will still turn out pretty heavy once all the styrene skinning and the detail parts go on. It is however a pretty strong structure.

Here is the old version 2 body on the chassis, showing to me at least, it just does not seem to fit followed by the new improved version 3 body on the chassis.

And here's the detailing so far;

Look carefully below and you may spot some keys from an old computer keyboard and some heat bent bits of green plastic knitting needles.

 I have also partly done the cockpit and re-assigned the 1/16 scale Bruder figures from the Moon Bus project. The seat padding is made from bits of 3mm Foamed PVC sheet and the headrests from 6mm. There is also a magnetic cupboard catch in there above the crew door holding a roof access panel down.

 I am in the process of making a wooden form to heat shape some perspex sheet to make the large area of curved front and side windows that will go in the gaping hole that's there at the moment.
I have also got a back end of a 1/35 scale tank kit which will become a centre control console which will house some LED lighting.

Hopefully more soon...

Toy Bash truck part 4

Part1, Part 2, Part 3, Part 5

I wired up and installed the Pololu rc switch using some cut up servo extension leads as plugs. These switches work a treat. They have an onboard flashing surface mount LED that blinks mostly off when the switch is off and mostly on when the switch is on. I covered the tiny board with clear heat shrink to insulate the contacts and to be able to see the led indicator working. The switch defaults to off so when you power up the RC receiver the switch is open and a push of the required control (in this case a button toggle) activates it. Pressing the button again switches it off. The button on the controller of the 3 channel wheel radio is usually employed for such tasks as changing gears on a two speed electric vehicle. If you put a servo on that channel, toggling the switch makes it travel from the equivalent of fully rotated right to fully rotated left. Toggling the switch again has the reverse effect.

I decided to add some rear red LEDs for tail lights. The forward voltage drop on these clear red LEDs is about 2 volts each, I have a 6 volt supply. I used the handy online led resistor calculator provided by the company I buy the LEDs from, to calculate the required resistor for the two LEDs in series at 6 volts. This was a 150 ohm 0.5 watt resistor soldered before the LEDs in series on the positive rail.
The LEDs are mounted in chrome bezels. They are retained in the bezel by a poly ethylene plug which goes behind the LED and just pushes into the back of the bezel relying on friction to stay in place. This is not a very satisfactory system as you can easily push the LED back out of the bezel from the front. I put a couple of blobs of hot glue behind to prevent this from happening. I made a removable styrene cover to hide the wiring underneath. It attaches with a couple of plastic thread screws salvaged from a disassembled toy.

The cockpit console also has a couple of bright white LEDS buried in the cockpit console. The bright whites drop 3 volts each so didn't need any resistor. A model kit part was used as a dual screen console with a bit of thin acrylic (perspex) sanded with fine wet and dry to frost it on the back, glued in behind. Some silver paint was added as a bit of a reflector before gluing in place.

 The console illumination is wired up to the same feed as the headlights.

The screens throw up a small amount of light onto the driver figure. The photo below is a longish exposure and shows it much brighter than in reality.

The driver figure has a plastic thread screw through the chair into his coight to keep him seated.

The Bruder toy's clear plastic windscreen has a wiper blade molded into it. It will get painted or may have to be detailed with some styrene strip.
 

I also removed the old push switch casing that was on the side of the cab and covered the hole with a kit part or two.

I've added a few more kit parts here and there, mostly at the front.

The lower sides of the cab have been paneled and I added some smaller tanks on top of the larger ones to more fill the truck toy's rear wheel arches.

The piping for the smaller tanks is made from some single conductor electrical wire. It is cheap and easy to obtain from a hardware store by the metre. It is also easy to bend, stays bent, paintable and the pvc outer insulation is able to be securely glued with either thick or thin superglue. It can be straightened by just clamping one end in a vice and pulling the other end. You can get a few different sizes, the two pictured below are 4mm and 2.75mm in diameter. Multi strand wire is no good as it cant hold a tight radius bend. You can sometimes find this stuff in skips on building sites, though with the price of scrap copper these days it is harder to find for free.

There is an empty space on the chassis between the wheels that I am toying with filling with some detail or other. I would also like to do a bit of work to the driver before finally cranking up the primer and beginning the paint process. Mechanically and electrically the vehicle is complete and working.

More soon...

Creeper 6X6 part 2 chassis

Creeper 6X6 part 1 is here

The original post for this from 2011 got accidentally deleted while I was trying to add a link to the next part, so I am going to recreate it here for a part 2.

Here is the Venom Creeper as it is supposed to be, a rock crawling RC vehicle supposedly to compete with the Axial  Rock crawlers. It was not as successful and has since been discontinued and for a little while back in 2011 they could be had new quite cheaply. I got a couple of the kits thinking I could attempt to make a 6X6 chassis. Others had already done this reasonably successfully so I had a go. One thing I particularly liked was the anodised aluminium beadlock rings which are very sci fi in design. The other aspect to the Creeper axles that i liked is they have a switchable diff lock, which means you can either have a working diff for tight cornering or a locked diff for better traction on rough terrain. As I have little regard to the "crawling performance" of these vehicles I thought they would suit my application just fine.

 I started by designing the chassis framework on a CAD program Deltacad.

This design was then printed out onto paper twice and spray glued to some 1.6mm thick lengths of aluminium angle. All the radiuses were then drilled out, after center popping them, using the radius centers marked on the printout. Then using a scroll saw and a lot of blades really designed for wood I cut out the rest of the material that made up the holes in the truss structure. Much careful filing later I had a pair of frames that the rest of the venom assemblies could bolt to.

 What you see here in these pictures is circa 2011. I eventually swapped out the shocks and their mounting positions many times over until I had a suspension system that could hold the weight of the top heavy body without flopping to the side. The added on rear axle is connected to a creeper frame cut in half, with many spacers made from 6mm aluminium rod on my Unimat 3 lathe.

It was quite a fiddle to get it all to work without binding or fouling, especially the front wheels which are turned for steering.

More recently with the new stiffer shock setup there is not the same amount of articulation as shown in the previous photos.

I then turned my attention to the body design and did a number of rough thumbnail sketches. After choosing the one i liked ( at the time, but ultimately abandoned and replaced) I roughly modeled it in Maya to get a sense of the volumes and proportions.

I then built a wood and plywood frame as a basis to start hacking into some 2mm styrene.
However I didn't really like what I had done and it sat around till this year 2015 when I did another thumbnail sketch that got me enthused and cutting plastic.


more soon...