After seeing some MSE Droids running around Celebration this year, I realized that I needed to build one for my own. I mean, who doesn’t love a Mouse Droid? (notwithstanding Chewie) And of course, I will say I’m building this droid for my kids, but we all know who it’s really for, right?
I have no- I repeat no- experience building anything droid-related, so keep in mind that I’m learning as I go. I am using Gryffin’s Guide to Mouse Droid Construction as my road map, but may deviate from it from time to time. If you haven’t taken the time to download and read Gryffin’s Guide, then stop what you’re doing now and get to it! It’s literally a step-by-step guide for how to build a MSE-6 Droid, and well worth the read. So… still with me? Let’s get this droid built!
For now, here’s the shot of all my parts in their ‘before’ state. (I’m still waiting on just a few more greeblies, but I’ll be able to make good progress with what I have right now)
I’m using a Traxxas Bandit to power the droid (an anniversary gift from Mr. Cricket- he knows me well!). The only mod that I’ve made to the vehicle so far is that I removed the springs from the shocks. I cut and inserted some pieces of 1/2 inch PVC pipe (less than $2 for a 5 foot length at Home Depot) to lock the shocks.
I’ve read that you want the chassis to be as rigid as possible to avoid sagging from the weight of the top part of the droid. The PVC bits do the trick to stabilize it all. I may change this method later on, but it seems good for now. Here’s what it looks like at this point:
First, I began with the IC sockets and chips. I assembled them into the side panels I purchased from JoyMonkey at the Mouse Droid Builders Club.
I went into assembling the sides with such enthusiasm… which wore off after hour one. Still, I pushed through it all, and the boards are almost complete. Just waiting on a few tiny greeblie parts. This part of the build reminded me of working with LEGOs, only these can make you bleed if you’re not careful.
I highly recommend buying an IC Chip Straightener for this. I picked mine up over on Amazon.
Here’s how it works. I can’t remember how the pins on this socket got bent (I think I was pulling out a chip that I’d put in there by mistake), but they’re wonky. Just stick the pins in the straightener and squeeze it together.
And the result:
Just like new! This straightener also is very useful when putting new chips/sockets into your board. They line up the pins so that there’s no struggling or adjustment necessary. I used this tool a lot, and I know it saved me lots of time from wrestling pins into submission.
One trick I figured out when placing the IC sockets into the boards: insert two socket chips into the board at a time, then (while holding the two chips in place with one hand) flip the board over. Temporarily secure the socket chips by bending two pins in the middle of each row (I used a small flathead screwdriver for this). This way if you bump the board, you won’t mess up the placement of your chips. And when you’re ready to glue, solder, or secure your chips however you choose, they won’t fall out. I didn’t figure this out until working on the second PCB board- and it made my progress so much faster! (I’m sure that you more experienced pros here already know this trick!)
I had seen that some people use hot glue to adhere the sockets and other items onto the board. I was about to take that path as well, but then I remembered that I’m not a fan of how messy hot glue can get. I didn’t want to have to deal with cleaning out tiny PCB holes, either. So, I decided to pull out my soldering iron and get some practice with my soldering skills. The nice thing about this method is that you don’t need to solder every single pin/hole connection. Just solder the four corners of the chip, and bend in some of the pins in the middle. It’s more than enough to keep those chips attached. And once you get your solder rhythm going, the process is really quick.
Best part of this: no mess to clean up afterwords! Woo!
I made some daughter boards, which will be applied soon. Waiting on the little square capacitors for the upper right corners to arrive. And yes, that’s my blood on my chip diagram. It’s not really considered a build until blood has been spilled, right?
Next up: More greeblies! These are the top greeblies, using the 3D print files found in the Mouse Droid Builders forum. It was much easier for me to get these 3D printed than to search for the bits and pieces to assemble it (this build was done well before I owned my own 3D printer. 🙂 ).
I may add some more wires and whatnot to this, but for the most part, it’s good to go after I paint it. Regarding these top greeblies, there was a little debate about whether these should sit straight on top of the droid, or be installed at an angle. It seems like the whole angle thing was a result of storage damage. In the scene where Chewbacca growls at the MSE-6 Droid on the Death Star, it looks like the top greeblies are on straight. Consensus in the MSE-6 Droid Facebook group (for the few who responded) seemed to lean towards keeping the greeblies straight for better screen accuracy. I’ll be keeping mine straight. Ultimately, since there’s no official rule about how our little pet droids look, you can attach them however you like. It adds personality to them!
I added some extra greeblies to my 3d printed top greeblies. I picked up a big assortment of 1 watt resistors because they seemed like the right size. I didn’t realize that I would end up with so many!
I just strung them together like so…
Coming along…
Until they ended up looking like this…
Next I hit them with some flat black paint…
And there ya go.
Next up was the wood inner frame. This part adds support to the shell.
The only wood I could find that was close to the dimensions I was looking for was 1.25″ poplar. I cut it to fit, and placed blue tape under the joints to prevent the glue from oozing out. I didn’t want the frame to get glued to the shell just yet. And letting the frame cure in the shell kept nice pressure on the joints.
Once both halves had fully cured, I decided to make the inner spacer frame. Remember, I only had 1.25″ poplar to work with, so I decided that I could easily rip the lengths in half using my jigsaw. This left me with 3/4″ strips.
I cut the 3/4″ strips to lengths that would leave a 1/2″ gap on the outer sides and checked the fit.
I also verified that everything would fit squarely on its own.
Looked good, so I then glued the strips down onto the larger frame in the lower half of the shell. I made sure that there was approximately 1/2″ of space on each of the outer edges. Clamped it all together, and let it dry.
Next, I’ll be trimming the down edges of the shell. Very excited about this part, because after that, I think everything will really start looking more Mouse-droidy! 😀
Next up: Creating some heat sinks!
To assemble my heat sinks, I used 5/16″ angle styrene for these. I measured the length of the side of my PCB board, which is 165mm. So I cut 12 lengths of 165mm (three for each side of each board).
I lined them up on a thin sheet of styrene I had leftover from my Stormtrooper build. I used the outer straight edge as my guide. I glued them on with super glue once they were lined up correctly.
It was easy to just use the straight edge on each side. Less to cut when it came time to cut them from the sheet.
Once they were stuck on the styrene, I used an exacto knife and some Lexan scissors to cut out the group.
That extra lip on the outer edge tucks in nicely under the PCB board. See?
And here everything is all pieced together. I will be painting things later, so this is just so you can see how they look assembled.
I now can call the heat sinks “DONE”. Pretty happy with how this little part of the project turned out.
With those done, I moved on to working on the shell. I have fallen in love with my Dremel again. The Dremel with a cutting wheel makes super easy work of making “Mouse Holes” into the shell for the Bandit. My workspace looks like winter right now from all the ABS shavings.
I measured my cuts by placing the Bandit (with my big foam wheels installed) on the upside down part of the lower shell. Basically, I just traced around the wheels and cut. I kept trimming a little at a time until the wheels cleared the holes and the body of the Bandit was resting on the shell.
Then I realized that the suspension arms were preventing the main body of the chassis to sit flat on the shell. So I did a rough estimate of what I would need to cut out to allow the arms to float free (that’s what those marks are for).
Then a few minutes later…
Everything fits nicely, and the wheels have clearance in the front to move around.
Next I’ll be removing the wheels so I can mount the body of the Bandit to the shell. Then I’ll pop the wheels back on and then it’s time to test drive!
After test driving the little vehicle around today, I learned that it’s totally normal for the ESC (Electronic Speed Control) to make a high pitched whine noise when triggering the motor. It’s annoying, but normal.
And that due to the beefed up size of the wheels, I needed to trim off a LOT of the bottom of the shell in order for the wheels to have proper clearance when the chassis is mounted inside. This has been the most tedious part of the entire build, and I’m not enjoying it much. Building a TK is much easier! That said, I have been conservative with each trim of the wheel holes, so if I’d been more gung-ho on it, it would have taken far less time. Still, for this kind of thing it’s better to trim cautiously than go all Fruit Ninja on the plastic.
In the pic below, you can see how much I cut of the shell for the wheels. I ended up removing even more from the front wheel cutouts after this photo was taken. When I test drove it around, I noticed that the front wheels were rubbing on some spots (due to turning), so I had to remove that extra plastic.
Another discovery is that when the wheel holes are cut to the proper size (or so), the entire chassis and wheel assembly fits easily into the lower shell. When my wheel holes were too small, I had to remove the wheels in order for the chassis to sit in there. Progress!
Next was to figure out how to mount the chassis into the shell. My way is one of many methods to do this, so if it helps you, yay! There is no “perfect” way to mount it, so if someone wants to offer other suggestions my way, I’m always happy to receive them.
I drilled two holes in the chassis and two corresponding holes into the shell. I chose these locations because they were the easiest areas I could access.
Using machine screws, washers, and nuts, I mounted the shell to the chassis from underneath the shell.
See those extra holes there? That was where I drilled incorrectly. Gah! No big deal, though. I’m a pro with ABS paste (oh, yeah, don’t throw away your trim scraps! You may need them to patch mistakes like mine.).
Anyhow, here’s the initial mounting of the chassis to the shell. I will add supporting straps from the chassis to the wood frame, but that’s not done just yet.
If you don’t know what ABS paste is, it’s simply scraps of ABS and acetone combined to make a slurry to repair oops moments on plastic. Easy, cheap, and reliable. It also works as a great ABS-to-ABS glue.
Holes patched from the outside.
I noticed that my wood frame was getting awfully close to my front wheels when a little weight was added, so I needed to make some clearance for the tires. So my belt sander stepped up and said, “Hold my beer.”
Then I also decided that I wanted my frame to be narrower on the inside edges. It would allow for a little more room in there as well as reduce the weight (just a little, but every ounce counts, right?). A quick pass with my jigsaw, and I reduced the overall frame width on each side from 1.5″ to 1″.
Once I verify that my tire/shell clearance issues have been resolved 100%, I’ll finally get the shells trimmed.
Next on the build was figuring out how to add extra stability to the droid. I was having a very difficult time trying to wrap my mind around the cross braces. The Bandit will be mounted to the bottom shell, but I also wanted to have more stability/strength for my mouse. I looked into having the braces 3D printed, but I thought that maybe I could build them cheaper (and stronger) on my own. So then I was left to ask myself, “How?!”
I wanted to use aluminum, so I opted for C channel aluminum stock from Home Depot. Flat aluminum has flex to it, but C channel aluminum is very rigid. A 10 foot length runs about $10. They didn’t have it in shorter lengths (bummer, but at least if I made mistakes, I had extra to work with!). Aluminum is strong, but also easy to cut/drill for what I need. I measured the width of my frame and cut two pieces to overlap it. Here’s what one looks like:
Then with some tin snips, I made a cut in each side.
Here are what the cuts look like:
The cuts were made in order to easily make the lengths I wanted. I’m not exactly the strongest person on the planet, but I was easily able to bend and snap the aluminum to the length I want.
Using a drill press, I made holes for mounting the bracket onto the frame. I also made cuts into the aluminum using a jigsaw. These were very easy to do! (Bonus points if you can see where I’m going with this!)
Then I took a pair of vice grip pliers, and flared out the wings… and ended up with this…
Can you see how this is coming together? Here’s what it looks like on the frame…
I still have to trim the tabbed wings down a little and make the holes into those tabs. But overall, I’m happy with this.
After taking a look at how my Bandit sits inside the shell with the brackets, I think I may only end up using one of the brackets across the middle. I will probably make two additional chassis/shell anchor points at the back near the motor, but I won’t be adding the bracket in that place (other installed components are in the way). So my mouse will have four anchor points at the shell, with two of those also tied into the cross brace.
Another MSE-6 Droid builder came up with a brilliant solution of locking the shocks using a 1/4″ piece of pipe inside where the oil usually goes. I emptied out the oil from the shocks and cleaned everything up. Then I cut two 1″ pieces of 1/4″ pipe for the front pair, and two 1 3/8″ pieces for the rear. They work perfectly now, as in: they don’t budge and look great!
Next came time to mount the chassis to the shell. I used four 1/2″ machine screws and lock nuts right inside the battery case to attach the chassis and shell together. I also added an extra screw in the front (which goes through the gray part of the nose of the chassis in front of the steering servo box area).
Once everything was secured, it was time to mount the cross support to the frame.
I chose to use just one support bar. I placed it based on where it would clear the battery pack in the middle. Once the right spot was chosen, I marked the screw holes on the edge of the wood frame. This would help me keep things lined up if the bridge shifted before I got the mounting screws into place. Then I flipped the frame over, and attached the bridge using wood screws and washers (because I made the holes in the aluminum a little large for my liking!).
Here’s how it all looks after assembly to the frame.
Next I had to decide where to attach the bridge to the chassis. This was another thing that was just done by estimation. Looking at the bridge and chassis, I made holes where I could easily place a screw all the way through the shell, chassis, and bridge. Here’s what it looks like.
From there, I made a mark through those holes on the chassis plastic so I could be sure everything would line up.
And here is how it looks when assembled. I added 1/4″ pipe to add support between the chassis and bridge, and used coupling nuts for easy tightening.
And here is my mouse’s belly.
You can’t see any of the screw heads when it’s running. Everything is mounted together nice and snug on there. And I’ll be filling in those extra holes with some ABS paste soon.
Chassis/frame assembly has been the biggest challenge to me for the build, and so glad it’s done now.
I decided to secure my tires to the hubs with some adhesive. I picked up some double sided tape for this task. The stuff is called VHB tape, and let me tell you, it is sticky! I picked up mine on Amazon (3M VHB Tape 4910, 0.5 in width x 5 yd length). It’s not cheap, but a little will go a very long way.
I had a tough time removing the red protective film from it. I don’t know the exact ‘proper’ placement of exactly where it should go, but I figured that I would stick it on like so:
That’s a front tire, looking from the inside. I slid the tire over the hub in the same way that you would put a very tight sock on over your foot, kind of stretching the tire over the hub as I went. Some of the tape shifted outside of the rim a little (it’s really snug around the rim!), but I was able to tuck it back in. You can’t see it now, and those tires aren’t budging off of those hubs unless I pry them off. Nice thing is, that if the time comes where I need to replace the rim, my tire won’t be damaged when I remove it. Sweet! And so you can see the tires in their completed state…
I’ve also been doing some painting of the other greeblies today. Just a few coats of black primer so far.
I finally trimmed my shell! Woo! This was an easy task done with my Dremel and a reinforced cutoff wheel.
Once I had the rough cut done, I decided to sand the edges down with a sanding block while keeping my frame inside the shell. This made for an almost perfect edge between the outer shell and the inner frame.
I chose to use wood dowels to anchor the top into place at the corners, along with adding 12mm magnets to help ‘lock’ the top (six on the top frame, six on the bottom). The lid stays snugly closed with just the four dowels, but I wanted to add the magnets for just a little extra security.
The holes I drilled for the magnets were a little too deep, so I used a lot of e6000 to ‘float’ them in the holes. To make sure they didn’t sink while the glue cured, I covered them with blue tape and put magnets on top of them.
When dry, they are flush with the wood.
I did the same thing with opposite magnets to the top shell. Here’s what it looks like when put together!
Painting is happening today. Lots of it! Unfortunately for me, the weather here is hot and very humid, which makes for very slow drying times. I managed to apply two coats of black primer to both shells. Once those were dry, I sanded them lightly and applied a coat of black semi-gloss. I waited for that to dry as well, and I sanded again. I don’t mind doing the extra sanding steps along the way because I know it’ll make the finish look nicer when I’m done. Currently I’m waiting for the inside and inner edges of the shell to dry before I apply the final coat on the outside.
Here’s what my frame ended up looking like after three coats of black.
I have lots of these little magnets left over from my Stormtrooper build (I made magnetic closures on my shins), and I used them to mask off the magnets when I painted. This way, my magnetic connections will remain as strong as they can be. I didn’t want paint getting in the way.
All that’s left is to attach the greeblies, glue the top frame onto the upper shell, and secure the chassis onto the lower shell. I’ll be using Titebond II to adhere the top shell to the frame. I’ve heard it works better than Liquid Nails. The lower frame is attached to the chassis and shell with screws and the cross-beam. I will leave it like that so I can take it out to service the RC car when necessary. For the most part, both frames sit very snugly in their respective shells. It takes effort to remove them. The only reason I’ll be adding glue is for extra security.
Here’s my frame installed into the shells.
And I picked up a little 12 watt bluetooth speaker setup, which is an upgrade from the 3 watt speaker I had in there before. It cost just a little over $30, and puts out nice sound. Oh, and it has a slot for a micro SD card! So I can use the micro SD on its own, which I have currently looping the 17 minute MSE droid sound file, which is followed by the groovy MSE theme song. After testing the sound on this mouse, I felt that it would be better if I could get it louder. I mean, it’s quite loud while outside, and even louder indoors, but the sound was a bit muffled due to the thickness of the top shell.
Easy fix! I made a bunch of small perforations in the area behind the PCB on each side using a Dremel and a very small drill bit. Instead of making round holes, I made the perforations more like small vertical lines. This results in much better sound overall when the mouse is fully assembled.
final pics of my mouse. Soooo….
Left side.
During the Great Lockdown of 2020, we put this Mouse Droid to work! Three cheers for the Droid!
