The Most Useless Machine EVER!

Step 4 Parts

The Ultimate Useless Machine V2 :  pre-soldered machines and Kits are available here: http://frivolousengineering.com/?page_id=1568


Or you can order parts from Digi-key:

Battery Holder 4-AA Cells BH24AAW-ND (Note: 3 AA's or even 2 AA's should work, your mileage may vary)
DPDT Toggle Switch 450-1533-ND
SPDT Micro-Switch EG4544-ND (Just about any with 3 pins and a lever should work.)
Parallax Continuous Rotation Servo 900-00008-ND (No need to modify the gears on this servo, you just have to do the wiring to the motor)

NOTES:

The servo I'm using is a JR Sport ST47. It's a standard size servo with a torque of 55.0 oz-in.

Stay away from any of the micro-sized servo’s. A standard size servo with at least 4-5Kg/Cm torque will work in most cases. Keep in mind that the toggle switch and arm length are some of the things that will determine how strong a servo you’ll need. Most of the standard servos should do the job.

mrrigsby reports that a toggle switch from Radio Shack, catalog # 275-636 works.

He also pointed out that it's better to use "4 fresh alkaline batteries--with 4 rechargeables, I couldn't depend on having enough power to always throw the switch."

Comments

[icelandinthesun]

This is the most amazing thing i have ever seen. Thank you so much!

[Frivolous Engineering]

thanks!

[Meuryn]

It isn't the parallax servo, can't find them anywhere in the UK (apart from DigiKeyUK which charges £12 delivery!), but this looks like a continuous rotation servo, will this work?

http://www.oomlout.co.uk/index.php?main_page=product_info&products_id=235

[Frivolous Engineering]

That one should work fine. And you won't need to mod the gears, just the wiring.

I've found that the JR Sport ST47 is a good servo to mod to.

[Meuryn]

Ok, thanks!

[JasonJAYWatson]

Would an illuminated toggle switch work? Like this one...?

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=360-1939-ND

[Frivolous Engineering]

That should work.

[mara0192]

would this work for the toggle switch?

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=360-1015-ND

[Frivolous Engineering]

Also called a panel mount

[Frivolous Engineering]

Electrically this will work, but this switch is meant to be mounted on a circuit board. The kind of toggle you want is a chassis mount, that comes with a little washer and nut for mounting through the lid of the box.

[6black6knight6]

hello , im working on this item ive buy your listed toggle switch , and says on- off -on so i have a momentary toggle switch in this project is useless right ?

[Pierce 93]

I was going to ask the same thing, the switch listed online is on-off-on, not on-on. I don't think there would be a difference with continuity, but I personally believe it would be annoying to click the switch twice to turn it on.

[6black6knight6]

sorry i still dont understand what kind of toggle switch use , on-on , on-off - on-off-mom ? im very confused

[janzak]

I don't think an on-off-mom switch would do you much good in this project but I'd love one for when I don't feel like doing my laundry or making breakfast

[6black6knight6]

so what kind of switch i must use on this ? i still dont understand

[Pierce 93]

Try to find a 5 amp on-on switch. You only want the thing to click into two positions. Using the on-off-on would be annoying because of that extra click in the middle. Now I say "try" because I've had difficulty finding one, but it doesn't have to be 5 amps. Anything rated higher will work, and SaskView has said that 3 amps would work, although I personally wouldn't recommend it. Janzak- nice joke.

[janzak]

Haha sorry. I had to.

[Pierce 93]

This would be perfect. I'm a little annoyed that it's so hard to find a DPDT switch without a middle setting. PLEASE correct me if I'm wrong but this thing should only click into two positions. http://www.galesburgelectric.com/McGill-1121-0003-DPDT-ON-ON-6-Amp-Toggle-Switch.html

[Pierce 93]

Hey guys I know for sure now that anything 3 amps and up is good. Also, as long as the switch is DPDT and only has two settings, it's exactly what you want. I went out and bought a 3 amp dpdt switch at Radioshack for 3 bucks and it looks like it's going to work fine. It actually has a faceplate that says on|off, but don't let that deter you, it should work anyway if you wire it right. Plus, if you don't want to see the faceplate, you can remove it!

[Bad2Grim]

You sir are my hero. THANK YOU!!!!

[mara0192]

does the main toggle switch have to be a 5A switch? digikey is out of stock on them and all i can find elsewhere is 3A

[Frivolous Engineering]

3A should be fine. There's not too much current to worry about.

[tniemuth95]

 the micro switch from digi-key isnt there anymore, or atleast the part number changed.  Could u find another one from digi-key? I'd rather not have to make separate trips/ buy from other places and pay addition shipping and handling

[tniemuth95]

 that or find a motor that will work from radioshack, I would prefer to buy from radioshack but if they dont have one I will buy from digi-keys.

[Frivolous Engineering]

Can't find any servos listed at Ratshack.

EG4544-ND comes up on DigiKey, but it may be just on the Canadian Site.  Can you confirm that this is the one you are searching for.

[jeff-o]

There's no difference between the US and Canadian Digikey sites, they have the same stock.  They just list prices in Canadian dollars instead of USD.

[tniemuth95]

 hmm, i got it to work.  for some reason it wasnt working last night. Thanks!

[TheReaper]

Can i use an Ne555n timer instead if the NE555P one?

[Frivolous Engineering]

Yep, shouldn't be a problem!

[TheReaper]

If it wouldnt be too much trouble, could u post what it would like on a breadboard

[Frivolous Engineering]

Sure, check back in a day or two!

[TheReaper]

Thanks alot man, you seriously rule :D

[Frivolous Engineering]

I've added step 7 showing it breadboard.

[TheReaper]

Thanks alot! i cant thank you enough :D

[Toggleme]

What would be the effect of using a 0.15 uF capacitor? My local shop only had these...

[Frivolous Engineering]

It might work, but you may not get as much rotation as you need.
It won't hurt anything to try it out.

But I would recommend going with a modified servo.  No need for the control circuitry, much easier.

[zapedy]

 What gauge of wire is being used

[Frivolous Engineering]

I used some wire from a piece of telephone extension cord.  It's quite thin, around 24 gauge, I would think.

There isn't a lot of current so just about any wire will do.  Stranded wire is best, but solid will do in a pinch.

[Jorgassimo]

Is it possible to use servo with thease specs:
Servo 4.8-6.0V, output torque 4.0kg/cm/4.8V, Speed 0.25s/60degree

I havent done electronics so much but I can solder quite well. Is it too difficult for beginner to mod the servo to be continous?

[Frivolous Engineering]

That servo should work.  Modding it for continuous rotation looks to be fairly easy, if the servo is like the one in this 'ible:

www.instructables.com/id/How-to-modify-a-servo-motor-for-continuous-rotatio/

Probably easier doing the mod, instead of using the 555 circuit.