My Dig Switch Box!
 

I wrote this for my site, www.ncrccrawlers.com, but thought I would share it here... easy how to with photos of doing a enclosed dig switch for the Berg or any other MOA righ.


MOA (Motor On Axle) Axles are great alternative to the Shaft Driven rigs out there on the market. Both seem to have there place in the comps and such. Here we will make a dig switch box for both front and rear dig.


You will need a few tools:

• Solder Iron and Solder
• Allen Wrench
• Philips Screwdriver
• Drill and 1/8th Drill Bit
• Dremel with Cutting Wheel

Other Items:

• Radio Shack 1x2x3 Project Box
• Radio Shack 275-0016 Switches (2)
• Deans Plugs
• 16 Gauge Wire
• Heat Shrink
• 4 M3x8mm Button Head Screws
• Micro Server
• Velcro and Servo Tape

We will start off with Modifying the Project Box. There are a few raised screw posts in the bottom that will need to come off. Use a Dremel cutting wheel to cut away the posts. These posts are on the bottom of the box and are very short. Don't mistake these for the longer posts that the lid screws to.

http://ncrccrawlers.com/gallery2/d/7005-3/dig_0020.jpg

Should look like this:

http://ncrccrawlers.com/gallery2/d/7006-3/dig_0022.jpg

Next lets place the switches. Put one of the switches in the box with the open end up and against one of the longer walls of the box. Mark the top lip with a sharpie where the notch in the switch lines up. Leave a little room for the posts on one side in the box so that you have room for the wires. You don't need a lot of space.

http://ncrccrawlers.com/gallery2/d/7007-3/dig_0023.jpg

Now line the marks up on the out side of the box and on the switch and mark where you will need to drill 2 holes per switch for mounting. Repeat for each switch noting the direct each switch needs to be. Both of the metal tabs of the switch will face each other.

http://ncrccrawlers.com/gallery2/d/7008-3/dig_0024.jpg

Now you will need to drill the holes you just marked for. Use the 1/8th bit to do this.

http://ncrccrawlers.com/gallery2/d/7016-3/dig_0039.jpg

Next you want to cut the lip from the lid to ensure clearance of the switches.

http://ncrccrawlers.com/gallery2/d/7018-3/dig_0042.jpg

Now that the box has been prepped, we can move to soldering the switches.

The following diagram was found on RRCrawler.com and should show you how it will be wired.

http://ncrccrawlers.com/gallery2/d/7023-1/OCMDig.jpg

Lets start with soldering the ESC Positive Lead. When soldering wires to the switch, be sure to tin the posts and wires first, and don't let the switch heat up too much.

http://ncrccrawlers.com/gallery2/d/7002-3/dig_0007.jpg

http://ncrccrawlers.com/gallery2/d/7003-3/dig_0017.jpg

Now Note which side will be agianst the box and which won't. You will need to solder the wires so that the will stick out from the side and not straight off the back of the switch. This will ensure maximum clearance from the inside of the box. Solder the wire to the NC or #2 Post.

http://ncrccrawlers.com/gallery2/d/7004-3/dig_0019.jpg

Eyeball the length of the wire and cut it. Solder it to the NC (#2) post of the second switch. Allow cooling between soldering to ensure the switch doesn't over heat.

http://ncrccrawlers.com/gallery2/d/7009-3/dig_0027.jpg

Next solder the ESC Positive lead to one of the switches (doesn't matter which, but remember that will be the switch that the negative lead will come from for the ESC as well to help keep it clean).

http://ncrccrawlers.com/gallery2/d/7010-3/dig_0028.jpg

Now cut a peice of black wire the same length as the red wire that joins the 2 NC (#2) switches. Solder one end to one switch on the NO (#3) post on one switch and the other end on the NO (#3) post on the other switch creating a jumper.

http://ncrccrawlers.com/gallery2/d/7011-3/dig_0029.jpg

http://ncrccrawlers.com/gallery2/d/7012-3/dig_0031.jpg

Now we will solder on the 2 motor positive leads to the switches. Each switch get one red wire soldered to the C(#1) post.

http://ncrccrawlers.com/gallery2/d/7013-3/dig_0033.jpg

Now we will need 3 peices of black wire to run to each motor lead and the ESC lead. The switch that has the ESC positive lead will get 2 of the 3 pieces solder to it and the other switch will get 1. all get soldered to the NO (#3) post on the switch.

http://ncrccrawlers.com/gallery2/d/7028-3/dig_0036.jpg

Now the switches are done. We will now mount them to the box.

Start by reaming the holes on the switch a little (not all the way through) with the 1/8th drill bit. You don't want to go all the way through, but enough to get the button head 3mm screws to start and tap them selves going in to the switch.

http://ncrccrawlers.com/gallery2/d/7015-3/dig_0037.jpg

Now place the switches in the box with the metal tabs of the switch facing each other and screw in the screws to hold them in place.

http://ncrccrawlers.com/gallery2/d/7017-3/dig_0040.jpg

Solder you favorite ends onto the leads. The red lead coming off one switch on the NC (#2) post and one of the 2 black leads coming off the post NO(#3) to a plug that will go to the ESC. Then solder one black and one red from each switch, posts NO(#3, black) and posts N(#1, red) to plugs for each motor.

Now its time to mount the servo. I used a micro Spectrum S75 and servo tape and placed the servo in the box with the arm set to nuetral and facing up in the box like in the next photo. You will also need to cut 2 slots oposite each other on the short 2 inch walls for the wires to exit the box. You will run your Motor Lead out one side, and the ESC, Motor Lead, and Servo Wire out the other.

http://ncrccrawlers.com/gallery2/d/7019-3/dig_0044.jpg

With the lid off the box, adjust you end points on the servo so that you ensure proper travel as to not burn out the servo. Also you have your servo set on the transmiter in the desired direction that the switch travels. Also once you have your servo set, label each plug for each motor (front and rear) and go ahead and label your ESC plug so that you don't get things mixed up.

http://ncrccrawlers.com/gallery2/d/7020-3/dig_0047.jpg

You are now ready to put the lid on. Screw the philip head screws in the lid and test to make sure noting is binding or hitting the lid. Make any modification needed if it does hit the lid bu cutting or filing the lid for clearance.

http://ncrccrawlers.com/gallery2/d/7021-3/dig_0048.jpg

I used the Radio Shack Superlock velcro style fasternes to attach the box to the skid of my rig. Place a strip on the lid between the screws, incase you need to get back in the box at a later date.

Now mount your electronics to the bottom of the box and install in your rig upside down. Your Now ready to Dig!!

http://ncrccrawlers.com/gallery2/d/7022-3/dig_0051.jpg

Any questions on this, feel free to reply to this thread. If you find anything wrong, or know of a better way to do somthing in this How To, feel free to reply to this thread and let us know!

Thanks

Nice write up, and great pics"thumbsup"

Great Thread!!!!! thanks !!!!!

nice write up, thanks for sharing that with us

Dude that is a GREAT wiring diagram. Thanks;-)

Good write-up, looks just like mine.

I'm going to Radio Shack tomorrow to get the box and some more switches to change mine...Nice write up Thanks"thumbsup"

Thanks guys!!! I am glad you like it ;)

yes very nice!!!

sticky????

I have this box sitting here on my desk, I have been looking at it for a week thinking I need to build a dig, and then you up and show me what to do. Great work.

man........that is one clean way to install a dig"thumbsup"

Very nice write-up and great pics. "thumbsup" Looked at doing the same before making my dig units but that project box was too big for my liking. It takes up too much space in the smaller chassis's of today, got my whole dig unit in 1" x 1.5" space.

I do have to agree with ya on the space thing. I had to trim it to fit in my chasis. I am running a 45mm skid, and the box is a tad bit to wide. I will look at making this smaller at some point, but my biggest goal here was having a back up dig unit incase I burned a switch and this made it pretty easy to swap out. You can consider this v. 1.0 :) Thanks on the comments!

nice write up with clear pics"thumbsup" goin to have to try this out:)

Very clean. Cleanliness is close to Godliness. Will have to try this one too.

Sorry if this has been asked before, but I'm just now starting to get ready for MDA/MOA's. In the diagram, it shows the positive lead from the ESC eventually going to the negative side of the front motor. Is that correct? And is there a brief way to explain that?

One of the motors will have to spin opisite the other inorder to rotate in the same directions. Since the axles are reversed and not really mirrored one moter would turn backwards and one forwards. So if you wire the one that goes backwards backwards, it will run forwards... now did I confuse you?

Nope makes sense. Especially since the axles are pretty much interchangable from front to rear.

how does that work, in the diadram it shows when the switch is activated the positive is disconected and then the neutral is engaged. does this still give you dig or just free wheel . i am a bit confused here because i have seen it reversed with the positive activated to both positives and disconnecting the negitive wire. dont mind me i am just a bit confused here :?:

Basicly what I am reading with the switches and all is this... when the switch is open, it allows the power to run down the red wire, allowing the motor to turn. When you close the switch it dead shorts the motor which breaks the line of power running down the red wire. The motor locks, doesn't really free wheel due to the magnets in the motor. Open the switch back up and the motor is now running. Trip the other switch and the same thing happens.

All the switches do is break the line so that power can't reach the motor.

With this set-up, your tires will not freewheel, unless you have weak motors!

i was going to use the same switch but to actually make a short on the motor. the way its set up it shows exactly that, it kills the power to the motor and unless there are volts going in the neutral it shouldnt lock up. i could be wrong and still havent tryed it that way yet but i do know if you put the positive to the negitive like you would wire a capacitor to the motor it will stop and seize. idn maybe i am over analizing the diagram but thats how true dynamic brakes work by resistors till its a dead short to the motor.
i guess it comes down to what the esc is doing when you throw the switch , i need to get my volt meter out and see whats going on.

Actually it does lock it up. When the switch is engaged, it basically hooks the positive and the ground together inside the switch. If the ground wire was not going into the NO position, then yes, it would only free wheel.

i just meterd the switch, it is c=closed, no=normally open , nc=normally closed.
when the power is going through the red wires it flows power to the motor , then if you hit the switch it transfers power to the center (no )and totally disconects the positive. i need to see what the other motor is doing with the esc because i am still scratching my head here. maybe with a doubble pole doubble throw it may work that way heck it may even run the motors in reverse. i need to finish what i am doing if i cant get it to work i am gonna go the other rout and short the motors with the switch.

Look at the diagram a little closer. When the switch changes state the NO becomes closed which makes the + and - become DEAD shorted. it is exactly what you are saying except there is no need for a resistor and it is as much resistance as posible

is it because of the second motor , i didnt hook up the second motor to the esc yet. when i hit the switch all it does is switch the c from the nc to no and that isint connected to the red wire anymore , once you hit the switch. all that did was give me a second negitive and free wheel

It has nothing to do with the ESC. Take a motor and put a pinion on it so you can spin it. Now take a peice of wires and hook the + to the - and try it again. Feel the difference? now add the gear reduction of the axle and WALAAAAAA dig.

yes i got that part but when i hook up the other motor too it shuts off too if i short any switch or motor. this is too complicated i am going to use a transister and a diode to lower the voltage and slow the motor when i hit the switch. this way the diode wont let the current flow the opposite direction and the transister will drop the volts to 5 volts and 1 amp

Then you are not wiring it like that diagram. I am not sure what you are doing different but I know of about 6 trucks that are running this EXACT set-up and they work perfectly. Wish I could help you but with out seeing what you have I am not sure how to.:-(

Uroplatus, Thanks for the write up and pics. i will deffinatly be trying this out on my new super and new 2.2 moa rigs :D

ill let you know how it goes.

VERY CLEAN btw.

-tre

sorry to steal your thread, great write up . sorry again .

I like it too. I think it will have be used to power my rig in the future. I think I'll only need "on" and "off" so this will do just nicely

thanks again

Thanks guys... I have to say there are some things that I want to improve on... making a smaller box for one. The other is getting the electronics a little lower.

Thanks for all the compliments!

Thats great . Thank you for Clarifying that.

IS there a way to have:
freewheel and locked and Drive :?:

the locking works in both Brushless and brushed motors :?: but the holding power depends on the type of motor used ..?

Normal operation is without the switches, or is that closed position :?:

Answers are in red in your quote.

Thank you

One last thing
Those Micro switches are rated for 5 amps. so doesn't that mean that the voltage gets extremely cut down when the switch is activated :?:
Also over heating the switch ? How is it holding up...:roll:

When the switch is activated? Do you mean when the servo is hitting the switch or when it is in the normal state?

If you are refering to when the servo is hitting the switch then the voltage is not reduced it is ZERO (0).

But really why does it matter? There are a lot of trucks running this same set-up with no issues.

dig switch
 

just wanted to tell you your idea really helped me i built one today was really easy with your directions and pics thanks:shock::shock::shock:

i wish i would have read this before buy my new dig unit! nice work!"thumbsup"

So the servo should stop when it makes contact with the metal flap?