Hi everyone, this is officially my first instructable!

In this instructable i will show you how to turn a useless piece of junk, with rotten batteries into a handy tool.

If you happen to still own a "roto-matic" then this is made just for you

Ok what is a "roto-matic"?

a roto-matic is a piece of junk, plain and simple, beyond that its a dremel wanna be, that was sold on infomercials in the early 2000's

it touted special features like

--10,000 RPM !!!!

while visiting my aunt and uncle in Lake Mary, Florida, I took my niece to the mall (a few times), and they had an "AS SEEN ON TV" store. I ended up with a assortment of stuff, some awesome and some not so much, the roto-matic with its "featuers" and 40 bits for a sale price of 15 bucks seemed like a steal

And it was a steal! From my wallet!

A little back history

growing up i lived (basically) in a fully functional wood shop, dad had everything, including a old 1970's dremel and all the attachments, which he still owns today and is in perfect working order

and let me tell you, that is a man's tool, if you don't plug it into the vintage speed control (steel box with a knob) when you flip it on, it will jerk your wrist 25% clockwise!

steel meh! just like butta!

so when i moved away, i wanted a tool that i had become dependent on, and when i saw the roto-matic i jumped on it, got it home and tried to cut a rivet head off and learned my awful mistake

heres the crap factor of the roto-matic

10,000RPM, 0 Torque, i could equip this thing with a cutting disk and touch my finger on it and stop the motor

battery's, 3.6v, and after spending nearly 30 min i had barley made a dent in the rivet, and the battery's were dead, 1/16th of an inch in and i needed an 8 hour recharge

Bits, while most (like 3/5ths) were the same size of a dremel, the rest were not, which you were required to keep track of 5! collars, wanted to grind and buff? Well you had to remove the chuck screw, replace the collar, refit the chuck, fit the bit and go on. Im sorry, thats stupid

I think it lasted a week before i threw away all the non "standard" size bits and collars, it maybe lasted about 2 months before i just threw it in a box to forget, since at the time i only lived 10min away from my parents house, and access to real tools

fast forward 6-7 years, and i live across town, im married (which sometimes prevents me from just up and leaving the house) and i want a dremel darnit!

i looked at the 26$ battery operated one at walmart, with 0 bits, and remembering my dislike for a "dremel on a cell".

Also the "engraving" model which is 120v powered, down at Lowes, again with no bits, and the real dremels, which, honestly the 20$ model + bits is not really in my budget atm, let alone a 60-100$ kit.

Darn, all i want to do is cut, sand, and drill some pcb's or abs project enclosures ...

enter mom, who was cleaning out the garage and presented me with a box of "my crap", that i had forgotten i was storing there. Digging tru the box of crap, i found a hot knife (sweet) a glue gun (sweeeeet) and my roto-matic (ugh, well maybe not?)

Welcome to my instructable! (gah finally, you friggin windbag!!!)

Step 1: Basic Plan & Stuff Needed

The Plan:
Turn this useless dead hunk of junk into a usable tool by removing the dead / useless battery pack and hooking it up to a wall wart

Phillips head screwdriver with a narrow / small tip

Soldering iron, mines a 15/30 watt radio shack, and i have not used the 15 watt setting in the nearly 20 years I have owned it

Damp "yellow" sponge

Solder sucker or wick, i just use the red bulb from radio shack in this case

jewelers file, fine grit sandpaper, or any other similar abrasive to clean off the corrosion from the solder points


Solder, 60/40 rosen core in this case (ill switch to silver when this spool is used up)

Zip Lock style baggie (for the nasty battery to go in)

Wall wart

the wall wart i choose is a 5v switching model with a 2.5 amp load rating, ... why?

well theres no way this motor is speced for exactly 3.6v, thats what the old battery pack took to charge

The motor itself, probably can take 12 or more volts, but theres no markings on it, so i choose 5v @ 2.5 amps because its what i found in my "box of warts" with a similar voltage, and a nasty amp rating.

Which allows an increase in torque, and ensures me that if I really really push the tool I probably would burn out the motor well before even warming up the supply, remember were not trying to machine tool grade steel here, just cut, drill, and sand pcb's and project boxes

Switching, cause its what I happen to lay my hands on, and it has the bonus of being tiny, which is nice

after reading some other instructables, I thought I should test the load of this thing to ensure safe operation, with no load the motor is drawing less than a half amp, but with the motor stopped, it quickly jumps to a little over 3 amps
Thanx for the info!
<p>Pretty cool.</p><p>Thanks for this :)</p>
<p>Pretty cool.</p><p>Thanks for this :)</p>
<p>I just want to use the accessories that came with the Roto Matic with a small tool in jewelry making (drilling holes in beads etc) Any suggestions? I bought a SE 9V Cordless Rotary Tool but I haven't been able to figure out how to use the much smaller accessories of the Roto Matic with it as the chuck seems to be one size only (there was no manual with the Rotory Tool). Am I just being dense? Thanks. </p>
has any one found out the MIN / MAX, Volt &amp; Amp this little motor can handle ? <br>I just got given one without a charger , would an old cell ph charger (5v 800mA) be any good ? <br>any advice appreciated
hi i found my roto matic along with the recharging cable! you said you used a 5v switching model with a 2.5 amp the charging cable says OUT: 6v DC 0.3A<br><br>so my question is can i use the charging cable to do the same thing as you did to the roto matinc?
That's confusing, I have a Roto-matic, but, it's not a screwdriver, it's a Eureka vacuum power nozzle,a completely different tool and purpose altogether... :P<br>
Can you post a picture of the Radio Shack Resistor Cheat Card? I haven't seen anything like that anywhere!
This roto-matic looks like a sex toy that is trying to get a second job!
it doesn't have enough torque
Here is a picture of some of my Roto-Matics (I have more). The silver one in the lower right, a CP-860, is one horsepower. A regular wrist wrapper if one is not too careful!
Do we get an example of it throwing sparks now?
heh, thats funny i was just reading your drill on a wall wart instructable and probally no sparks, but i guess i could show some sawdust or melty plastic
How well is the collet holder centered on the motor? I had one of these-possibly even cheaper-and the bits were just enough off center to mess things up.
its pretty close to center, your not going to be able to do any fine engraving, but sanding and cutting function fine (course i cant really tell if its the motor or just wobbly bits, i probably will get a dremel bit just to see)
Can any rotary action tool do fine engraving? I have an engraver and it vibrates. I've also done some engraving with among other things a Swiss ultra high speed rotary tool and well it just isn't as nice. What I am trying to say here is the quality of the rotary tools I use is not an issue. The die grinders I have are like what Dremels dream of being. CP, ITC, Foredom. I've had lots of Dremels too, so I know what they're like. Usually dead and smoking by the time I'm done with one of them.
short answer no
Not with a hand piece that vibrates (sounds like you threw a bearing).<br/><br/>Not with a heavy hand (if you are blowing Dremels, you are pushing way to hard).<br/><br/>Most engravers using power use some form of hammer handpiece, air or rotary driven. Some use a rotary to do the roughing in, then use gravers to final details and burnishing.<br/><br/>But, since you don't believe me, do your own search.<br/><br/><a rel="nofollow" href="http://handengravingforum.com/">http://handengravingforum.com/</a> (requires registering to see more than a page or two, tends to be product specific)<br/><a rel="nofollow" href="http://www.igraver.com">http://www.igraver.com</a> <br/>www.thecarvingpath.net (more than engraving)<br/>
I bought EXACTLY that same thing for 2,50 Euro (about 3 Bucks). And you are absolutely right about the quality. It's rubbish. I use it from time to time though. btw. I bought FOUR of them. Two for me, two as gifts... Nonetheless, three bucks is about exactly the price I would recommend paying for this thing.
I bought a pile of hobby stuff yesterday and this was one of the things thrown in. What a POC. I will check what surplus wall warts I have around the house or maybe go to the thrift store and see what I can find. Or simply convert it to 12V with a lighter plug and carry it in my camper. Either way, the thing has led to to the instructables site so it can't be a complete waste! Thanks for posting this osgeld!
yea this thing is a real piece of , ... um work 12v might work with the motor (again i dont know its specs) it seems quite happy on 5v and im glad you found this site, its a really cool place to hang, welcome
This would be sweet to do to the cheapy 20$ walmart battery dremel too
maybe, but i would use a much stronger power supply, because the dremel probably has a much stronger motor even this cheap thing can send the wall wart into overload protection if you stop the motor (another bonus of the switching model vs an iron core one) which is around 3.2 amps, or enough where I am thinking about adding a fuse before going crazy with it (ill update the instructable if I do)

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