DIY Dimmer Question

L

leaftors

Well-known member
Do I have to use a 3 pin cord?

I want to buy a cheap cord from the dollar store but they only have 2 pin cords.

What is the ground for?
 
Especially in DIY equipment you should correctly connect all grounds.

Dont buy cheap cord. Work out the wattage of your dimmer and use the proper wire. Proper cord is not expensive. Last thing you want is a cable melting on you because it's only rated for 500w.
But to answer your question, ground is an emergency pathway for electricity if there is a short in your device. It will prevent your device from becoming electrically live and dangerous if there is a problem.

Never ever remove grounds from extension cords or devices
 
The ground wire is there in case any metal casing on the fixture or dimmer box becomes live. It provides a path for this current that is not through one's body.

If you have to ask what a ground pin is, and are buying your electrical supplies from the dollar store...then I'd say you should take a pass on this project and buy one of these for a deuce:

http://www.harborfreight.com/router-speed-control-43060.html
 
David W. Jones said:
I use those router controllers all the time. They work great up to 1K lights.
Click to expand...

I picked one of those up and tested it out on a couple of shoots I just completed. It worked great and I am going get a few more for sure. One bit of advice, if you go to a Harbor Freight store, bring a print out of the product page from the website. I went through three "Sales associates" who said they didn't carry any such gadget. I had to get the manager to look it up on the website before they found it. They only had one in stock. I am going to buy the rest of the ones I am going to get on line to save the hassell. Also, the router controler is fused, with a 15 amp straight automotive fuse. Harbor Freight has them at their store. I picked up a box of them (for about $9.00), just in case. You don't want to lose shooting time for lack of a spare fuse.
 
Your DIY dimmer will still work wonderfully if you don't wire in the ground.

You however, may not...

Think about how easy it would be for one of your wires to twist out of the plastic cap over time. As soon as the bare wire touches the metal frame then the whole dimmer becomes a bare wire. I've built several diy dimmers (no longer thanks to Harbor Freight!) and one of them had a hot wire that came loose and was doing just that. If not for the ground then whoever picked up the dimmer would have been shocked, injured or worse.
 
so theoretically, the only way for me to get electrocuted is if I touch the electrical box, and one of the wires becomes uncapped and touches the box?
 
I wouldn't say that's the only way. I have to agree with Pickthome that the questions you are asking make it sound as if this isn't a safe project for you to take on.
 
I'm a big fan of DIY. But not in this case. There is no advantage to make your own dimmer. If you need a small one, there are plenty of in-line dimmers at the local hardware store suitable for low wattage (300 watts or so). The Harbor Freight dimmer is dead cheap and is the next step up. It works great. It's' $20 bucks!

Please don't guess what might be safe. Your questions make it clear you should not be doing this project. Mucking with electric without a sound understanding just isn't worth it. The life you save may be one of your crew. I highly recommend you stop this project now and go buy a dimmer.
 
How about dimming 2k lights? Haven't really seen any cheaper solutions, the last time I saw a 2k variac dimmer it was $300 (used).
 
right, the scrims always do come in handy...

I do wonder however, if those cheap Harbor Freight dimmers could be wired up into a 3 channel fire-flickerbox easily. I've been looking for nice tutorial on one because I have little electrical background, I'd like to have a more realistic looking fire source than a large panel of silver reflector shaken up...
 
snipe2k5 said:
I do wonder however, if those cheap Harbor Freight dimmers could be wired up into a 3 channel fire-flickerbox easily. I've been looking for nice tutorial on one because I have little electrical background, I'd like to have a more realistic looking fire source than a large panel of silver reflector shaken up...
Click to expand...

I don't know about that. The Harbor Freight Router Controller works just fine as a dimmer, for fixtures less than 1K, but I don't think that they would hold up well with being taken apart and modified. If you want to build a flicker box, I would go DIY all the way and start with appropriately rated components for the whole job. The Harbor Freight gizmo doesn't seem to me to be built to the highest standards and any kind of load that is off spec even a little bit might stress the thing to an embarrassing end.
 
They're rated for 1,500 watts but they get awfully damn hot with just a 1k.

On a side note, there's a dirt cheap white cyc stage in town that's outfitted with a bunch of second hand cast off fresnells and cyc lights. We rented it for a music video and the owner told me the "dimmer board" was in the closet. I opened it up and there were a dozen extension cords (orange, I wouldn't even call them stingers...) hanging down the walls and each one was plugged into a Harbor Freight dimmer!
 
Nice, well if they get the job done, right??

I thought so David; it'd be more of a pain re-engineering the router controls. Most candlelight tutorials are for a non-electric method, but I'll find something that works eventually.
 
Do it right and make is safe.

Remember that one day someone else might be helping you and be using some of the DYI equipment you built.

Don't take any chances to ruin your own or someone else's day.
 
snipe2k5 said:
Nice, well if they get the job done, right??

I thought so David; it'd be more of a pain re-engineering the router controls. Most candlelight tutorials are for a non-electric method, but I'll find something that works eventually.
Click to expand...

Shane Hurlbut ASC has an interesting blog post about a DIY fire box set up. I am not going to get into anything that elaborate, unless absolutely necessary, but I thought it was pretty interesting.

http://www.hurlbutvisuals.com/blog/2012/07/building-medusa-the-perfect-diy-fire-light/
 
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