i just finished making my first micro coil winder

it runs on one rechargeable AA cell and a solar calculator. i used bits and pieces i had in all my junk items. it uses a micro gear box that is geared 50:1 here
it has a 3mm output "D" shaft so i used an aluminum tube with a small crimp to mate it to the gearbox. the tube is 4mm o.d. which is the same as some old burnt inrunners i had, i used the magnet spacers from the inrunner shaft as the forms for the coil. collets hold it all on the tube and press the = button on the calculator to count the winds.

heres the steps to wind a coil:

1. put vasoline on the tube and the 2 forms
2. put a 3 or 4mm wide length of heat shrink on the tube and shrink it down, add vasoline to the outside
3. install the other form, an o-ring and tighten to the heatshrink with the first collet
4. insert the calculator and install the second collet so its screw head presses the = button
5. tape the wire to the first form so it will rotate on the tube, run a few times to secure it
6. press "1+" on the calculator and turn on the motor, let it count to at least 300 winds for the first coil
7. put a drop of CA or epoxy on the outside of the coil, be sure its thin so it wicks into it some
8. remove the calculator, first and second collet. carefully slide the forms and coil off the tube as one item. if one form comes off easily, leave the coil on the other side. put another drop of glue on the side of the coil. now slowly take it off the other form watching for any loose winds that might stick to the form.
9. once its off the forms, put another drop of glue on the other side. now take a #11 blade and remove the heat shrink, it shouldn't stick to the coil. after thats out, use a small applicator to add a little more glue to the inside.

now check your resistance and repeat to refine until its right!

hope this and the pictures help others to make one themselves

This is brilliant derk!! Thanks for sharing your creation with us! I've been wanting to make my own acts. But my past attempts were ummm... less than notable... I absolutely love that you don't have to count your winds!! I'd lose count after 30 or so..

VERY cool!!

+Rep!!

Reset

good work derk - will we be able to purchase nice double arm actuators from your site real soon?

able to make your own stronger acts is nice, very nice

I'm a hand winder and sometimes find the counting to be a problem too. Generally, if the cats start fighting or someone calls at the door. Tend to find I wind coils last thing at night when there's noone (or cats) around.
This looks to be a very neat solution

thanks for the compliments guys! i went out today to look for a cheap battery powered clock but couldn't find any under $6
they used to sell them at the dollar store all the time but i couldn't find any there. i also went to the thrift store but they only had one again for 5.99!
tonight i will pull apart some AC/DC supplies and see if i can get any in one of them. if nothing else, i will find some and order it online.

I love the simplicity of it nice one derk! i had the same idea originally but decided to go with contact points instead... i normally count how many ohms per 40 winds... than estimate the rest based on increasing thickness... takes some guesstimating... but once you got your numbers for a certain AWG and mandrel size.. your set.

As for wire.. try a cheap plug in timer... usually has some fine wire... toaster timers also have some... ac-dc transformers usually have thicker wire... 40 AWG is the thinnest ive found... but the transformers were quite large...

yeah the converters did have large wire, i forgot most modern ones use many stages in them instead of the old ones with just 2. actually, i may have an older style one in a failed power supply i built
it only had 4 wires so it should be a simple transformer, gotta take a look in that one.
i have a relay or something from a car computer that has 2 large coils in it, but the wire is a bit too thick for plane actuators. i did make a little speaker out of it though lol

Originally Posted by derk

yeah the converters did have large wire, i forgot most modern ones use many stages in them instead of the old ones with just 2. actually, i may have an older style one in a failed power supply i built
it only had 4 wires so it should be a simple transformer, gotta take a look in that one.
i have a relay or something from a car computer that has 2 large coils in it, but the wire is a bit too thick for plane actuators. i did make a little speaker out of it though lol

try 5v relays. they're cheap and have the same gauge wire as those battery clocks. hope this can help...
by the way, great job on the coil winder!

good luck, SS

Hey guys I pulled this out today to make some smaller coils than what I had been winding. This time I am using a modified servo so I can have a smaller axle to wind on. The axle was a long screw with a .75 inch blank near the head, I cut off the head and some of the threads. This screws into the output from the servo geartrain, the forms are a bellcrank bushing and some bits of silicone. I use vasoline as release agent, and this time I tried thinned wbpu to hold it together and it worked great but takes longer to dry.
The downside is I couldn't find the control horn to use the counter so I just eyeball it.
Also pictured is the coil I got out of a mechanical wall timer switch, it was $6 at walgreens and will make somewhere near 35-40 coils I'd guess. It's much thinner than I've used before but well worth the effort.

Oh and the 2 coils pictured are 50 and 60 ohms resistance not sure of the weight but it is tiny, they have an id of 3mm

Oh and a tip for any wanting to try this, the center of this form is soft wire insulation. When pushed onto the axle, it expands from 2mm to 3mm and makes removal easy. Also having a hard rear former helps pushing the assembly off the axle.

Thats exactly how i make my mandrels for my motors and coils.. but i use a coarse thread screw... glued and wrapped in string.. funny when i made my winder i used an odd tail servo of an old heli and couldnt find the horn for it either... found one that was slightly smaller.. and split it... still grips the output shaft and is enough to activate the contact points.

For the mandrel it self.. i prefer to make the sides from a yellow lemon scented dish soap bottle.. waxy type of plastic that ca doesnt stick to... the mandrel itself gets a wax paper sheet, i make my own by dipping strips of paper in a wax solution... i use50/50 mix of hard candle wax and that soft red wax that comes on the babydel cheese wheels.

Congrats Derk, and you other boys ------------ always good to see fine DIY workmanship!!!!

Bill

Thanks billy

I just placed an order with k&j magnetics last night, $6.00 for 100 1/16th by 1/32nd magnets! Also they are rated as n52 grade, they should be good for the new tiny acts I'm making.
I have heard others had good experiences with them so I'm not worried.
The one thing they didn't carry was small ring magnets for single phase motors

Now that I received my magnet order, I will see how well these new acts perform with the butterfly rx. I have heard of folks using 50 ohm coils with it so I will try the 60 first. Turns out that 2 of the 1/16*1/32 magnets are just about perfect size as well.

Me and a few others have used coils as low as 20 ohms with the bf rx with no apparent problems.