26 December 2009

Homemade Heated Gloves

History:
I've never been one to advocate the use of heated clothing because I always thought it to be an unnecessary expense. A good pair of gloves, enough layers, and judicious planning was all I thought I needed to make a fall/winter ride comfortable. Of course, that was thinking leftover from another life, when I was another person. Since becoming theWolfTamer, I've discovered all kinds of new truths. Most recently, theWolf doesn't like getting cold!! Now, what should I do about it?



First thing I did was research heated clothing. I've ridden with others who've used it but other than that, I hadn't been exposed to it. I was sure it would be expensive, but that was about all I knew. A little research revealed it'd be about $80-$180 for heated liners/gloves plus an additional $100 to control the heat properly. About the time I started looking into this, several people began posting on forums and other sites about making their own heated clothes. There was a seed beginning to germinate.

All I really wanted were gloves but it was quickly becoming apparent the costs were far outside my meager budget. DIY, here I go (again).

Details:
The reason. Wind Chill makes one cold. When riding a motorcycle, you generate a constant wind chill. When the temperature is as high as 50 degrees, traveling at 60 mph feels like about 39 degrees. It gets worse from there. At 45 degrees, riding at 45 mph feels like 33 degrees. Those are near freezing temps, no wonder my hands get cold.



Science. It is important you know your motorcycle before using any electronic accessories that will be using the charging system. This site has a lot of good information about calculating how much power your clothes will draw. Heated clothes work by using wires to draw resistance from a current passed through it. This resistance generates heat. The power and the length of wire determines how much heat is generated the process is explained using Ohm's Law. You will need to calculate Current/Amps (I) and Power/Watts (P) to know how much heat is generated and how it will affect the battery.

To get I, start with Resistance/Ohms (R). The R for the teflon wire is .1 R per ft, so the length of wire x R/ft = R or 30ft x .1 R/ft = 3 ohms. R = 3.

To determine how much this will draw on the electrical system, use I = Voltage (E) divided by R or 12 volts / 3 R = 4 amps. I = 4.

To figure out how much heat this will generate we can estimate how much power is needed: 4 amps x 12 volts = 48 watts. P = 48. This will put my stuff right on par with the commercially available stuff.

For gloves, I only wanted to use less than 5 ft and got numbers like 36.312 watts per glove. That's a bit high, but I decided I didn't do the math right so I'll start by wiring up some 2 for $1 knit gloves and then measure the output with my multimeter. Keep in mind, the shorter the length of wire, the more power it will make.

Supplies. To make heated clothes, the proper wire is needed for the heating element. There are several choices, the most popular seems to be teflon coated multi stranded hook up wire or nichrome resistance wire. The first wire I bought was single stranded teflon wire from ebay for about $8 for nearly 700 ft ($0.01/ft). It is the wrong wire because the single strand wire is not as flexible and has a higher max temp than the multi strand. After singeing a couple of pairs of gloves, I decided to switch to the nichrome. I was able to get 150ft for about $16 delivered ($0.11/ft).

In addition to the heat element, one must consider the type of wire to get the heat to the wire. Any 16 - 18 gauge wire will do, like lamp cord. This will be the wire to the battery or accessory jack. At first, I repurposed the wire from some old cell phone chargers which was 18 gauge. Later, I used 16 gauge auto wire.

You also need connectors for the gloves to the wiring harness and for the harness to the battery. Just about anything you can think of will do so I started out with whatever terminal connectors I had left over from building the trailer. After my proof of concept gloves (ver. 1.0), I decided to upgrade to audio connectors. I will use a 12 volt auto accessory plug instead of wiring into the battery. These come with a fuse so I won't have to worry about adding one inline.

With the wires and connectors decided, the next choice was type of gloves for the liners. For the test version, I chose the cheapest gloves I could find. I also had some gloves I'd won at a raffle I wanted to use for the final gloves. Later I upgraded to mechanics gloves.

To control the heat, you can buy a heat controller from one of the heated clothing manufacturers, use a pwm dc motor controller, a simple switch, or a pc fan controller. I chose to use a high wattage fan controller that had 45 watts per channel so that I could have variable heating like the heat controllers.

Assembly. I chose to use 2 5' sections for each glove. I ran the wire on the back of the gloves along each finger making the loop long enough to cover the back of my hand. Then I used the 30 awg teflon wire to sew the wire to the gloves.

My first attempt using teflon wire:
After I tested this, I realized I needed to extend the wiring to cover the back of the hand. This glove with the single stranded teflon wire was a fail because the wire got too hot and singed the gloves. The teflon wire used something like 6 volts per glove but put out TONS of heat. Too much actually. For version 1.2, I added heat shrink and ran 1 segment instead of two on the wires to the raffle gloves. The same thing happened with the raffle gloves forcing me to research the wire a little more. The wire actually burned through the fingers!! That is when I discovered my mistake, single strand instead of multi stranded. Due to my budget constraints, I chose bare nichrome because of the price and it has a lower temp rating. Using bare nichrome requires heat shrink tubing. The single strand teflon wire shrinks the tubing when power is applied, nichrome did not. After a little more practice, I developed version 1.3.


Version 1.3:
Still using the 2 for $1 gloves, I attached the nichrome wire with red heat shrink using the teflon wire for stitching. The PC Fan Controller arrived and I used it to control the gloves. By this time, I also tossed out the salvaged wire and used what came with the fan. Note: The 16 - 18 gauge wire adds to the output of the gloves. When I used the 16 gauge auto wire with the teflon, I constantly blew 10 a fuses in the accessory plug. The fuses did not blow with the 18 gauge wire. I hooked the gloves to an old pc power supply and let it run for an hour before I was ready to put them on.

Version 1.3 got tested on the Rejeks Christmas Party ride on 19 Dec 2009. I discovered that the knit gloves were too thin forcing the wire into the back of my hand and making them very uncomfortable. I also learned not to rely on electrical tape because the connection failed almost as soon as we left and I didn't have heat in the left glove. My right hand felt great though and I was ready for the final version.


Version 2.0:
The final outcome. Mechanics gloves with nichrome wire in black shrink wrap. Teflon wire for stitching actually matches original glove stitching material. The fan controller is in a Radio Shack Project enclosure until I can get a Pelican Case.

After trying these on a ride on Christmas Eve, I love them!! Next step? Pant Liner and maybe heated insoles.

Summary:

My heated glove liners cost approximately $25 to make. They put out roughly 27 watts or about 14 watts per glove. My heat controller cost approximately $50 to make. Total is about $75 for glove liners and temp controller vs. about $180 plus shipping for a similar manufactured setup. I have the ability to add other elements as needed so I'll start on the pant liner next using some long johns I already have.

To make the pants, I'll start with the same 5' wire sections and add until I get near 45 watts (the max capacity for my controller). That should put me near 4 segments of 5' for about 44 watts. I'll wire the segments together in series, or so that they share the same path to power, which means I add the resistance together to compute power.

On the bike:




Here are links to all of the DIY Heated Clothing posts.  


Thanks for reading,
patrice, theWolfTamer

3 comments:

  1. Very cool. I did it the easy way and bought a pair. (on my third set of those, seems they have some quality control issues. As for the article. You could use some better closeup picks of the gloves and heat controller. BTW I think you must be a genius to figure this stuff out.

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  2. Wow! these gadgets are very amazing. But, are they safe to use?

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  3. They are just as safe as the commercial stuff. I made sure the controller box stays out of the weather safely in my tank bag. I'm still looking for a better solution than the Radio Shack project box. I believe the pelican box is it after seeing an image someone had with it on their tank in the pouring rain or ice on the ADVRider forum, I think.

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