Official Luthiers Forum!

I am a newbie setting up shop and have been making the jigs for my first build. I built this Doolin style side bender based on many posts in the archive.


I elected to use an Omega 6"x36" blanket and 2 stainless steel slats from LMII. My problem is, that keeping these blankets within a certain temperature range, can be a little tricky. It is very easy to overshoot a specific temperature, so I decided to build a controller for the blanket. This also has the added advantage as it includes a digital readout of the temperature.

A new controller from Omega was around $200 which was out of my price range, so I went to my old friend ebay and found the following controller for $40. The nice thing about this model is that it has a auto tune function where once the temperature is set, it will auto tune itself to stay as close to the set temperature as possible.

My next step is to add a timer so that once it reaches the core temp it will remain at that temp for a period of time and then shut the blanket off.





Thanks for looking

when i converted over to blankets i also blinked real hard at the cost of the omega controlers and i have been using a power stat to control my blankets for a while now. but i have often seen such controllers on ebay and wondered about their applicability to our usage.

if one is an electical/electronics ignoramus, as i am, how do you determine that a particular unit will work controlling a blanket?

and the "how to" would be useful.

I agree that a schematic would be very useful - but if the arrangement is original and not a duplicate of a pre-existing design you may want to patent the circuit, and make some for sale and reap the profits of your electronic savvy!
Selling the controller alone may be a real boon for people that already own blankets and use thermometer methods of heat regulation,,,
This may not appeal to you - but it just might - a couple nights of sucking solder fumes a week just might keep you in all the wood you need to build your guitars!

   If you are interested in marketing your circuit:
I would check the article in one of the guitar building magazines - {I forget which one} in order to see if the electronics are the same as the temp regulator printed there -
and also Mandomaniac Tom Durr has a patent on a circuit that does the same thing... may be quite different though.
Cheers
Charliewood

It is really not that complicated. It is just a programmable temperature controller hooked to a solid state relay. I added a couple of illuminated switched to the front. The left one is main power, and the right one is to manually switch off the power to the blanket.

I am going to try it out this weekend as soon as I have time I will post a wiring diagram and a parts list. Not looking to make anything off of it. It would be nice to give back to the OLF community after everything that it has given me.

[QUOTE=DarinMcC] It is really not that complicated. It is just a programmable temperature controller hooked to a solid state relay. I added a couple of illuminated switched to the front. The left one is main power, and the right one is to manually switch off the power to the blanket.

I am going to try it out this weekend as soon as I have time I will post a wiring diagram and a parts list. Not looking to make anything off of it. It would be nice to give back to the OLF community after everything that it has given me.[/QUOTE]

Very kind of you Darin

I am looking forward to seeing your diagram as I think it may be very useful for me. I have an Omron controller, a solid state relay , a blanket with "J" type thermo coupling and appropriate male plug and female panel mount to wire up the thermo wire so it plugs into the back of the a housing box. I even have a extra bit of "j" type wire to go from the panel mount to the controller however, I am an electonumbskull.

I have hesitated to put things together so far as I am not to sure what goes where on the back of the controller. Some of the wires seem to have a logical home which appears to be confirmed by the schematics that came with the controller. But others like connection to the relay are not so clear. Maybe your drawings will help, fingers crossed Welcome to the OLF

Cheers

Kim

When I first started using my bending set up I noticed the same issue with the temp. It seemed it was easy to over shoot the temp or under heat things. I envisioned building something similar to what you have build. I am sure I will have more questions if I start building this but now I know who to ask! Nice job!

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Brad
Avon, OH

Hey man, where did you get those black handle/nut type bolts, that tighten down the cauls for the bender?

I made a bender and a mold and just got a new blanket from john hall, but my benderis rather simple like yours without the whole guillotine looking fox bender piece. I bought similar bolts, but could only find regular wing screws. When I tried to put that into practice with a hot blanket it was impossible. If I could find some of those handle/nut things, mine i think mine would work too.

the knobs are avaiable from most woodworking houses and industrial suppliers, e.g., graingers, msc, reid, etc.

were you wearint heavy gloves?

Nice Job!!! Did you make the enclosure? I'm putting one together that has three programmable cnotrollers but lack the skills and tools to make a nice enclosure like yours. Can you point me in the right direction? Thanks, Don

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Don Sharp
Got Brazilian?
http://www.sharpguitars.com

I've also found those knobs at Busy Bee (the Canadian analog to Grizzly, so I'd say Grizz must have them, too). I think I'm going to move to a spring system like I've seen someone else on here using, though, it seemed a lot smoother...

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I bought them at woodcraft, I believe that they were a couple of dollars a piece. But I used it for the first time this weekend and I could not imagine not having them.    Well worth the money. IMO

Darin

Sharp,
I bought the enclosure from Jameco. The first one that I bought actually ended up being to small for the big heat sync. The SSR is rated at 10amp so I was concerned with heat building up in an unventilated enclosure. SO I decided to go with the big heat sync and a larger enclosure.

I used it for the first time yesterday and heat does not appear to be a problem.

Hartville Tool has a large variety of plastic jig knobs priced as low as 79 cents.
http://www.hartvilletool.com/category/541?view=&category_id= 541&start=20&like=&exact=

Ray

Thanks,

I found them last night at the Home Depot. They were listed as for use on the handlebars of lawn mowers and were in the lawn mower section. They fit perfect on some 5/16" by 8" bolts. I am itching for a day off to go at it again. 

Micahel, yes I was wearing heavy gloves.

Thanks Darin. I appreciate it!

_________________
Don Sharp
Got Brazilian?
http://www.sharpguitars.com