Oh, if you try loading the thing up in Eagle, it won't find the relay.
I added the relay to my copy of relay.lbr

 

Thanks Sarge,

I had to attempt making that footprint 11 times. I have learned more about board design doing this project than I had in 23 years in the Navy.

Don

 

That's OK, Don - I made a huge mess the first time I tried doing something like that myself!

Better wait a bit though, I haven't finished double-checking everything.

[eta]
Hold the presses! I found an error...

 

OK, it took a good bit of fiddling around but I discovered that I had a couple of errors in a library. Hope you didn't waste any of that press & peel stuff; it isn't cheap.

The new board (Rev1) looks about the same; but I had to move a few things around. It's now exactly 1-3/4" square. I didn't bother to put mounting holes on there; I figured you'll drill a couple of holes or maybe just use some velcro on the back in case you want to pull it out easily.

You'd said before that the RX-18 outputs 7.2v, so I didn't put in a + connection for your RX-18.

[eta] Found another error - arrrgh! fixed, re-uploaded all files

 

Thanks Sarge,

No Problem. I've not done a thing yet. You are the best!

Don

 

Hey Don,
Check out the 1/5 scale tank Robb is building in this thread:
http://forum.allaboutcircuits.com/showthread.php?t=31638

 

Now that is some building! Wow

Sarge one of the items in that post got me to thinking,
(thats dangerous.)

The 1/16 scale tanks I build use 7.2 volt motors (2) Is there a Circuit that could read the voltage going to the motors, and match that to a sound module. End result being that when the tank is sitting still all you hear is the engine idle. When the tank moves forward the sound of the engine and track nosies increases with speed. I have sounds of a KING TIGER and a Panther. For the KING TIGER I have not only the engine sounds but the two methods of startigthe Engine, electric and crank. Just an idea.

Best

Don

 

One thing at a time, Don - one thing at a time

Let's get this project wrapped up and working, otherwise we'll get way sidetracked. I just thought you'd get a kick out of it. I have a feeling that a big tank might be in your future, down the road a piece

As far as the sound goes; something like Roman Black's BTc PIC implementation might be pressed into service:
http://www.romanblack.com/
it would require looping a short sample at various rates, depending on an ADC input. I just stumbled across that application & hardware yesterday, but I don't see offhand why it couldn't be adapted to your needs. Since the tank's sounds will be low frequency anyway, that'll be relatively easy to reproduce.

 

Oh I know, that project will be in the future. However I find if I don't write it down somewhere I get lost. And speaking of big tanks. Here is the dream. 1/4 Scale Tiger 1. These use 12 Ga. Blanks, can tow small cars, and weigh in at about 300 lb or more. Cost? Oh with everything about $11,000 not including shipping from the UK.

http://www.mark-1-tank.co.uk/tiger-1.html

Cool Huh?

Don

 

It's already reversed - actually, I'm uploading a newer version right now...

I like this layout better; traces are wider, MOT+ and MOT- are closer together, mounting holes marked

 

OK, what are you saying? The relay doesn't fit the holes?

Maybe I read the datasheet backwards.... let me know.

It makes it more difficult when I don't have the part in my hand.

 

Duh!

I was drilliing the holes with the printout facing up, which is not the way it will be when I place it on the board for etching. Boy am I a big dummy!

Sorry

Don

 

Don't do that, You get me exited about something else and I will get sidetracked. Sound, WOW. If you guys get on that subject, be sure and get me in the loop.

 

I'm gonna nominate you for the first Homer Simpson award for the new year!

dOH!

Actually, I beat you to the big dummy thing... when I was laying out the board, the transistor orientation didn't look right (emitter base collector); the emitter and collector were swapped, so I went into the Eagle transistor.lbr library to figure out what was going on... and then I "realized" that the package layouts for all the TO92 packages had their leads swapped around, so I swapped them how they were "supposed" to be; and then I went to look at the device connections to the symbols, and realized that THOSE were all backwards too.... then I realized that I goofed up with my first realization and had to swap them all back over again.... it was like a Chinese fire drill.

 

I deserve it. Oh hey those reed switches operate with a pretty strong magnet. Just in case you ever need them. They work great though.

What is your opinion on "Liquid Tin?" I was reading that if you do not use it on the PCB it will corrode fast. Any thoughts?

Don

 

I've never used it. However, it would probably be a good idea.

You could always just spray clear lacquer over the bottom of the board to seal it, after you're done with all of the soldering and cleaned it off really well. Lacquer thinner will get it right off if you need to fix/change things later.

Are you going to try Rev2? I'd like to know if it's going to work.

 

That makes more sense. Gosh knows I have a lot of that around. The average 1/16 Tiger 1 uses about a can and a halfto getthe weathering right.

Another good idea from the Sarge.

Thanks

Don

Oh yes I am working up Rev.1 as we speak. In between the "Honey Do" list

Thanks again!

Don

 

Well Sarge the Fire Ball was not too big. Don't know what went wrong. Used the multi-meter to make sure all the traces were good. Board was etched perfectly. I used my opti-visor to inspect the traces after soldering.

You should see how reed switches look when they glow. Hummmm I think I'll etch another board and get some more bits and try again. Can you think of anything?

Best

Don

 

Ouch!
You made the Rev1 board, right? Which switch got toasted?

If D1 or D4 were backwards or shorted, that could easily toast S2.
If D3 were backwards or shorted, it could toast your RX-18 output.

You might want to put small fuses in those lines (say, 1A) just in case those diodes fail shorted.

I didn't like that layout much; that's why I went to the Rev2 board. Please don't try making another Rev1 board. I don't know why your reed switch got fried, but I'm going to double-check the Rev2 board to see if there is a problem.

But before you make a Rev2 board, let me go over it with a fine-tooth comb.

 

Okay Sarge will do,

I checked with electronic goldmine and it seems they are out of the relays, what other type could we use. Do you think I damaged the relay?

Thanks

Don