Wall-e U-Command Nerf Turret TerrorScout

In this Instructable, I am going to convert a very sorry looking Wall-e U Command into a RC Controlled vehicle for carrying a custom built Fusion 360 designed one piece 3D Printed multi shot Nerf Turret, the Nerf Turret is based on a cool design by Little French Robot on Youtube, I have made various changes one major one is a one piece design but the principle is much the same.

This particular Wall-e is twice as big as a standard Wall-e and unfortunately it's had quite a hard life, parts were missing etc and nothing worked, sold for parts only I need to give this bot a new lease of Life, The way the Nerf Turret works is this, there is a vertical magazine for the nerf bullets, there are 2no dc motors which spin in the same forward direction, the right hand side motor spins clockwise and the left side spins Anti-clockwise, it has a Servo driven shooter trigger which via an arm pushes the nerf bullets towards the spinning wheels, the wheels then grab the Nerf bullets and ejects them with gusto towards the Target, Multi shot or Single Shot. Its my first adventure with a RC Transmitter and Receiver so it's a bit of a learning curve as well, should be quite a nice little project putting all this together. Time to take a Wall-e apart!

Wall-e U-Command, preferably a broken one, or any vehicle really, Tracked or wheels.

MG996 360deg Servos x 2no for driving the tracks.

MG90x 1 Servo for the shooter Mechanism.

2 x DC Motors 3-6 Volts the cheapo yellow gearbox style available on Amazon.

5v Laser dot modules

Radio transmitter and receiver, in this case its a FLYSKY FS-I6 with 6 Channel Receiver.

Servo extension cables

RC 2 Way Switch for Laser

Hot Glue

CA Glue

3mm MDF

3mm Allen head Bolts and Nuts

5mm Allen head Bolts and nuts

1mm steel rod

Fusion 360

3D Printer

1.75 PLA

Cura slicer

This particular Wall-e is never going to work again as it should and with parts missing etc I decided just to strip it completely, all parts were unscrewed etc, all plastic parts which I can't use will be recycled, all the little screws etc I always keep, you never know when they will come in handy.

I removed the tracks and transmission, and cut the axles off then started looking at how I could install MG996 360 Degree Servos in place of what was already there, It means taking a Dremel with a cutting blade, offering the servos up and using a black felt tip pen to mark the areas of plastic to cut, and keep offering the servo up, until it lines up with the main transmission drive wheel, the transmission Locates on 2 pegs so its pretty easy to get this right, the same applies to both sides, doesn't matter if you cut too much plastic away either, hot glue is a great filler.

With everything cut away we can now on this occasion secure the crucifix Servo horn to the drive wheel the horn was centred onto the drive wheel and marked off in 4 positions and hand drilled, the horn was then screwed onto the Servo and the some clever alignment between drive wheel and Servo meant that the Servo could be screwed to the main drive wheel, with some 2mm screws

The only thing left to do is screw the drivetrain in position then Align each Servo and secure in position with hot glue, tracks can be re-fitted, they are flexible enough just to push over and onto the transmission

At this point I set up the FlySky FSI6 and the Receiver that came with it, and after a bit of a play had the Servos working, I will go into the transmitter and receiver later as it's a new venture for me, at this early stage it's quite satisfying to see the Servo's working, I'm not familiar with RC Transmitters and receivers but after looking at a few Youtube videos for reference, I could control movement with the right stick, right stick up for forward, down for backwards, left for servos working opposite to turn, same with right, then the diagonals just operates one servo to turn, awesome.

One thing I did notice when taking the Wall-e apart was some little stabilizer wheels at the back below the drive motors, these were cut away, the Wall-e is very rear heavy because of the batteries, I quickly sketched up some spring loaded Anti-Wheelie bars to counter act this thing wanting to tip over at every obstacle, its never going to climb over steep obstacles but it works a lot better.

To finish off the base I cut the majority of the component holding pegs away and created 2 level flat surfaces with 3mm MDF, cut to size and secured with hot glue, these will make ideal working platforms for components.

Main body is up next:

Very little to do the main body, its just a vessel to house the electronics, The arms on a Wall-e do very little apart from move up and down, it's a waste of 2 Servos, so I may just Hot Glue these into position, they move up and down with a ratchet type of action so this will do.

The original battery enclosure at the back, this housed 4 AA batteries, I cut this out using a dremel with slitting disk and filed the edges before cutting a piece of 3mm MDF and securing this in place with hot glue, the new 6v Ni-Mh Battery pack has 5 batteries, this will be secured with Velcro allowing it to be removed for charging.

At this point I screwed the body to the Base, the next process is designing a custom built Nerf turret with Fusion 360:

Now comes the tricky part, Instead of designing the Nerf Turret with separate components, my intention is to design it as one piece and 3D print as one piece, nothing ventured nothing gained so lets have a go.

Update, I did manage to design and 3D print the magazine as one piece but I was backwards and forwards with the design and it was a real head scratch at times.

I have attached a short video of the design process, it will give people some idea of how it was achieved, the most important thing here is getting the distance correct between the 2 motors and thinking about the size of spinners, I think originally I was thinking about the spinners being 20mm but ended up 23mm.

I got lucky with the 3D print, I printed with Cura and only opted for support from the build plate only, there were open areas where the print was sagging but it did it, I had to snip and file some of the raggy bits away and some filing after it printed but it ended up being a one piece print, I was well impressed, it was a near 10 hour print so I was hoping it would turn out well.

In my haste to get this thing from sketch to print, I had neglected to design holes for the motor clamps, I got round this later by just drilling some 3mm holes through the lugs, it worked, the motors can now be secured with 3mm Allen head Bolts, Nuts and Washers, (I've since modified the print file to include all the mods I made.

The magazine can hold 7 bullets at a pinch, 6 comfortably with the sprung lever down which applies a little pressure to the bullets forcing them down the magazine so to speak.

The motors I used for the spinners are the more common motors found on Amazon, they are attached to a yellow gearbox, just cut the plastic holding tabs, release the motor and pull off the splined gear on the shaft, with these motors the voltage range is 3-6V which is ideal as our voltage is 6v.

I sketched up 2 x 23mm diameter 10mm depth spinner knobs with a 2mm hole in the centre for the motor shaft, these are a very snug fit and have to be fitted in situ as they go inboard into the turret opening so they grip the Nerf bullets to fire them.

There is provision for a MG90 servo to the rear of the magazine, this is for the arm that pushes the Nerf bullets forward into the rollers, this was made out of 1mm steel rod, to the end which pushes the Bullets I applied different thicknesses of Heat shrink tubing at the shooter end and at the servo end of the rod I used a Z bend, much like the way a servo is used on an rc plane Testing this with the transmitter it worked really well.

To push the Bullets forward slightly in the magazine I cut a length of 3mm MDF and coloured it black with a felt tip pen, this was to stop the Nerf Bullets from interfering with the shooter, it was secured to the back of the magazine with CA Glue an afterthought but it does a job, if I was to design the magazine again I would give more thought to this area and how the bullets are in place for the shooter to push them forward.

I needed a way of applying a little pressure to the top of the bullets, this was achieved by 3D printing a lever and some afterthought lugs for an axis for the lever, an elastic band is then used to act like a spring, I would give this area more attention as well if I did a different design.

I will use the Wall-e for Pan movement, for tilt movement instead of using the original top off the Wall-e I'm going to cut a piece of 3mm MDF and cut a slot into it down the centre, I will fit a servo on the underside, from the servo horn to the base of the Turret I will use a piece of 1mm steel rod so its long enough to lift the Turret which will have a Fusion 360 designed hinged mechanism to the rear of the Turret, Ideas in action once again but it should work ok.

The final addition to the turret is a 5v laser pointer, if it all works it should make for an all singing and dancing Wall-e which most importantly will be a lot of fun:))

The FlySky FS-i6 is my very first venture into RC Control and Initially it was a bit daunting but there are some very good help videos on Youtube, my initial intention was to have to have the left stick controlling all movements etc, what I've ended up with is the right stick controlling all movement, I'm actually quite pleased with the out come as moving the stick forward moves the Wall-e forward, back to go back, right stick has it turning right on the spot with Tracks going in opposite directions, same with left stick, the diagonals stops one track, which ever direction its going in, pretty cool makes it really manoeuvrable.

Left stick up/down is the servo shooter mechanism Switch A turns the motors and laser on, Knob A operates the Servo to lift and lower the turret.

I did have to make some adjustments to the FLYSKY to get the movement that I wanted, in the settings in the mix settings Mix #1 Mix is on Master is channel 3, Slave is channel 4 Pos mix is -100% Neg mix is -100% there is a reverse section in the set up and channels 2 and 3 and 5 and 6 are reversed.

The turret Motors and Laser were controlled by a 2 Way RC Switch which is purely for lights on drones or rc planes etc working through the receiver, I thought I could get away with it for switching the motors on and off as well, the update is that these RC switches are only basically good for operating led's etc they switched on the motors for a while then the motors were on full time so I'm guessing something burnt out I wasn't able to turn them off, the remedy was to purchase a RC relay switch, see attached wiring diagram for connections.

I have the relay wired so it energises the Turret Motors and Lasers both at the same time when switched, the motors are running on a separate power supply but only 3 x AAA Batteries at the moment, more voltage makes the motors spin faster thus making the bullets travel further, I will up the power later but everything works I will settle for that.

I've enjoyed getting this bot back on its feet and also enjoyed my first experience with RC controls, there are still improvements which can be made, but I'm going to use this Bot as a platform for other things as well as the turret is completely removeable, so watch this space for updates...

I hope you enjoyed this Instructable and thanks for looking.