# Wiring a circuit for DC



## JR Custom Calls

I'm hoping this is the right place for this... Since it's related to woodworking in the sense that I'm wiring a dedicated DC circuit.

I'm confident in my wiring ability... Wired quite a bit. I have no concerns about running the wiring for my DC. I'm going to take the easy road and use some flexible metal conduit I have and go from the breaker box, halfway across the garage to a switch, then on over to the DC. 

My only apprehension is wiring the circuit in to the panel. I have a 200a box with one open space. I'm going to use 12 g wire and a 20a breaker. There's just something scary about reaching in to a breaker box. I'm obviously going to kill the main breaker, and test a few random breakers for juice... But is there anything else I should do as a precaution? Really just looking for reassurance and tips on anything I haven't thought about.




I should add that my DC is a 2hp and draws 16a. Currently, my garage is on one 15a circuit. With the lathe, lights, and radio going, I'm just asking for trouble running the DC as well. 

Is also be curious as to whether or not I should add a plug to this new circuit for a filter (ie whether it would be better on that one or the existing 15a). The one I'm getting has a 1/4hp motor, but I can't find how many ps it draws. It's the big rikon from woodcraft.


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## Kevin

I never kill my main breaker when adding a circuit, but that's just me. Just make sure to do all your wiring and work your way to your box, then when you tie into the main box make sure your breaker is off when you clip it into your panel. Then make sure all your loads are off before flipping the breaker on. If you aren't comfortabl;e working in a live box don't do it. I've done it all my adult life.

If I understand you correctly, you're running your lathe and lights on one 15A circuit but are adding the dedicated 20A DC circuit right? I don't see a problem.

Reactions: Thank You! 1 | Agree 3


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## JR Custom Calls

Thanks man. Yes, that's the plan. I'm going to be purchasing an air filter next week as well and am wondering if I should run it on the existing 15a circuit, or add a plug upstream of the switch on the new 20a circuit.

I may have my uncle come over and wire in to the box if I get started and still don't feel good about it. He's an electrical genius.


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## Tclem

I'm assuming whatever you are hooking up is 120 VAC as you stated you have one empty space. I'm with Kevin. All I ever do is switch the breaker off and hook her up. What are you hooking up

Reactions: Agree 2


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## woodtickgreg

JR Custom Calls said:


> Thanks man. Yes, that's the plan. I'm going to be purchasing an air filter next week as well and am wondering if I should run it on the existing 15a circuit, or add a plug upstream of the switch on the new 20a circuit.
> 
> I may have my uncle come over and wire in to the box if I get started and still don't feel good about it. He's an electrical genius.


If you have someone that is good with electrical and you are not real confident, then let them do it, it's just not worth the risk if you are uncertain. Like Kevin I have been doing it for many years and I wouldn't think twice about it, my friends call me for help, no shame in that.

Reactions: Thank You! 1 | Agree 1


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## Tclem

woodtickgreg said:


> If you have someone that is good with electrical and you are not real confident, then let them do it, it's just not worth the risk if you are uncertain. Like Kevin I have been doing it for many years and I wouldn't think twice about it, my friends call me for help, no shame in that.


Except when they call you to redo 150' of service to their shop. Lol. That's my next weekend project

Reactions: Like 1


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## JR Custom Calls

@Tclem I'm wiring a dedicated circuit for my dust collector. It draws 16a and my garage only has one 15a circuit. 

@woodtickgreg I asked my uncle if he could come over... he's game. I'm going to go ahead and get everything wired to the box, then let him hook it up. I'm going to run an extra plug on the ceiling for my air filter. If I don't use it, it's not going to hurt anything. And.. I'll be able to pull all the wiring when we sell the house if the buyer for some reason wants to use the garage to park a car or two in. 

I'm fairly confident I could do this with no issues.. I've wired in to breaker boxes before, but it was always before service had been connected. There's just something about making that wrong move that I'm not very comfortable with.... especially with 3 kids and a wife to support (although, I am worth more dead than I am alive... shhhh)

Reactions: Like 1


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## Tclem

Brother if you are uncomfortable let someone else do it. Don't go into it nervous or something will happen. I've wired for a long time and have people all the time ask for help because they know what electricity can do to you. Get someone to help. No shame in that bud.

Reactions: Thank You! 1 | Agree 3


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## Kevin

JR Custom Calls said:


> There's just something about making that wrong move that I'm not very comfortable with.... especially with 3 kids and a wife to support (although, I am worth more dead than I am alive... shhhh)



I agree with Tony 100%. Don't do it Jonathan. Even if you get bit odds the worst that will happen is you'll . . . . get bit. But it ain't worth it man it's obvious you don't have the confidence you should have going into this. NO SHAME AT ALL not to do it yourself. If you put me in front of a huge lathe with a 36" round log and said _"happy turning!"_ I'd probably wet my panties. Certain things you just got to work up to man. . . . . . . . . and wearing panties is one of them.

Reactions: Agree 1 | Funny 5


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## JR Custom Calls

Haha. You in panties just made me LOL. 

No shame here. The more I thought about it, the less I liked the idea. I'll watch my uncle do it, and probably feel more comfortable next time... Although my box will be maxed out so I won't be doing it on my own any time soon.

Reactions: Like 1


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## Mike1950

Kevin said:


> I agree with Tony 100%. Don't do it Jonathan. Even if you get bit odds the worst that will happen is you'll . . . . get bit. But it ain't worth it man it's obvious you don't have the confidence you should have going into this. NO SHAME AT ALL not to do it yourself. If you put me in front of a huge lathe with a 36" round log and said _"happy turning!"_ I'd probably wet my panties. Certain things you just got to work up to man. . . . . . . . . and wearing panties is one of them.




 I think a lot of this on a need to know basis and this is one helluva lot more then I need to know!!!!

I agree with don't do it if it don't feel right...........

Reactions: Agree 1


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## Kevin

JR Custom Calls said:


> Although my box will be maxed out so I won't be doing it on my own any time soon.



Unles you have an old Zinsco box or some fire starter like that, you can always use a certain amount of piggybacks. At some point too many p'backs cause a clustereff and also the cheaper boxes should not have too many if any because as indicated there is such a thing as a cheap main box like some older Sylvania and Zinsco's aren't designed for the extra amps piggyback allow. Hopefully you have a SquareD or some such better quality. Your uncle will know what I mean.

Reactions: Thank You! 1


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## Tclem

@Kevin it's all good brother just don't post a picture if it and we will keep it a secret

Reactions: Agree 1


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## JR Custom Calls

It's a 200a Siemens box. Takes type qp breakers if that tells you anything. 30 slots and I'll be adding the 30th circuit. Our split hvac (separate heat pump/air handler for upstairs and downstairs) used up 2 extra slots that wouldn't be used if we had a typical single unit system. 

House was built in 07, so everything is pretty new tech, I think.


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## Schroedc

Always good to have some extra power! And I second, or third, or fifth the advice that if you aren't totally cool with it, have someone else do the final hookup. Might want to consider having an electrician add a sub panel with several circuits for the garage in the future if you suddenly have an overabundance of cash so you can add lots of new equipment or even some 220 stuff........

Reactions: Thank You! 1


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## JR Custom Calls

Can I add a subpanel? I thought a subpanel was wired in to the existing box, which is now maxed out?

I seriously think that if I had an over abundance of cash, we'd probably sell our house and build the house we've been designing (read drooling over) with a dedicated workshop and 3 car garage that we could actually use.


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## Schroedc

JR Custom Calls said:


> Can I add a subpanel? I thought a subpanel was wired in to the existing box, which is now maxed out?
> 
> I seriously think that if I had an over abundance of cash, we'd probably sell our house and build the house we've been designing (read drooling over) with a dedicated workshop and 3 car garage that we could actually use.




What we did in grandma's house was move two of the circuits that were in the main box down to a sub box to open up the spot for the big breaker and then had all the other spots in the sub box to use too.

Reactions: Thank You! 1


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## Kevin

JR Custom Calls said:


> It's a 200a Siemens box.



It's a high quality box.

Reactions: Thank You! 1


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## Mike1950

JR Custom Calls said:


> Can I add a subpanel? I thought a subpanel was wired in to the existing box, which is now maxed out?
> 
> I seriously think that if I had an over abundance of cash, we'd probably sell our house and build the house we've been designing (read drooling over) with a dedicated workshop and 3 car garage that we could actually use.




Sub panel is the way to go. we had the same problem- had a sub panel installed to free up space.

Reactions: Thank You! 1


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## JR Custom Calls

Well, I've got this new circuit wired up... all that's left to do is wait on my uncle to come over and run it in to the breaker box. 

I'll ask him about adding a sub-panel when he comes over. Not something I see as necessary at the moment, but if I were to get something requiring 220, I think that would be my only option.


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## JR Custom Calls

Ok... that was easier than I had thought it would be. @Kevin, I now understand why you don't worry with killing the main breaker. I don't think I'd have any worries doing this in the future. Now I can run my DC without worrying about melting the poor little 14 gauge wire that my garage is wired with.

Reactions: Like 2


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## Tclem

That 14 gauge is good for lights


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## Schroedc

I use 14GA to make hanging hooks when I paint......


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## Kevin

I use 20 ga for dove and quail but 12 ga for ducks.

Reactions: Funny 3


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## JR Custom Calls

I just learned about tandem breakers.. I gotta do some research on them, but this might be the key to opening up a couple slots for a 220 circuit in my shop. Was talking with an electrical engineer and he was telling me about them. Sounds like the perfect solution to my full panel.


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## woodtickgreg

Yes you could use the tandems for a couple of 15 amp circuits to free up space for a full size 220 breaker. But if it was me I would either change the panel to a bigger one with more spaces or add a sub panel. If you are not comfortable doing it hire an electrician to install a sub panel. jmo


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## JR Custom Calls

So, pardon my ignorance here... but what would be the difference in moving two existing circuits on to tandem breakers (15a circuits), and adding a 30a 220 circuit, and installing a subpanel, re-routing at least two existing circuits to it, and spending several hundred, when my panel is rated to carry quite a bit more than it currently is? Perhaps that will be answered once I get a chance to read up on those breakers a bit. Just seems like it would be such a dramatic cost increase to do a subpanel just to add one circuit. If it weren't for my dual heat pump setup, I'd have 4 empty breaker slots. 

Hope that didn't come across as argumentative or anything. Genuinely curious.


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## woodtickgreg

My main point was that if you added a sub panel you would have many more circuits, not just one. Every time you think you are done you will need more. Don't think you'll add any more machines? I'm just saying that if your panel is full it might be time to expand and add some more circuits with a sub panel or at least the possibility of them if and when they are needed. jmo
Plus I have never really been a fan of those dual breakers, but that's just me.


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## JR Custom Calls

I gotcha. I may just hold off on that thought then, since I'll be building a workshop at some point in the nearish future, and I'll have to run a subpanel and upgrade to 400a service when that happens.


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## brown down

be careful as to how many twins you add in a panel most older panels are only rated for a maximum of 3. some of the newer ones are rated for up to 10.


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## TimR

brown down said:


> be careful as to how many twins you add in a panel most older panels are only rated for a maximum of 3. some of the newer ones are rated for up to 10.


Jeff, I'm not an electrician, but have done a fair amount of wiring that got inspected to the NEC. I'm not familiar with why the number of twins is a factor even for older boxes. Personally, for someone trying to add a couple circuits, and with room getting into/out of the box for new cable, I'd be all over the consolidation of a few lighting or outlet circuits into twins to provide open slots. Do you know why the use of twin breakers is an issue?


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## eaglea1

Well, I guess it's time for me to chime in. As a licensed electrician for the state of Wisconsin, I will offer this.
1st Just about everybody on here is correct in one way or another, especially everyone that said, "if you don't
feel comfortable doing it, then don't".
2nd This is my advice  when you do decide to call a licensed electrician, the following items must be followed
to a tee.
Have a chilled bottle of Pouilly Fuisse wine ready to go, and make sure you put on your best tie and blazer, normally
reserved for British Royalty and American workmen.
Now as soon as he comes in, take him into the living room and make him feel comfortable. Put pictures of the children out on all the tables. You want him to know you believe in the family just in case he’s a Republican (Most us are). Now, above all, do not discuss politics with him. You don’t want to lose an electrician over the prayer-in-school issue.
What do you discuss with an electrician?
Benjamin Franklin. After all, he was the father of electricity. Then there is Thomas Edison. Electricians think Edison is the cat’s meow.
You could talk to him about the stock market. Anyone who is a licensed electrician automatically becomes a member of the Fortune 500. (At least thats what I'm told).
Be your natural self, an electrician puts his pants on one leg at a time, just like a plumber.

Reactions: Funny 3


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## JR Custom Calls

My house was built in 07, so my panel is fairly new. 

With that said, I've all but decided against doing any further wiring until I build my shop. The ONLY way that will change is if I somehow come in to enough money to buy the Rikon 18" pro, which will require a 220v circuit. 

And with that said, I'm more than curious as to some discussion on these breakers. Not necessarily because I want to use them, but more so because I like knowing about stuff.


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## Schroedc

eaglea1 said:


> Well, I guess it's time for me to chime in. As a licensed electrician for the state of Wisconsin, I will offer this.
> 1st Just about everybody on here is correct in one way or another, especially everyone that said, "if you don't
> feel comfortable doing it, then don't".
> 2nd This is my advice  when you do decide to call a licensed electrician, the following items must be followed
> to a tee.
> Have a chilled bottle of Pouilly Fuisse wine ready to go, and make sure you put on your best tie and blazer, normally
> reserved for British Royalty and American workmen.
> Now as soon as he comes in, take him into the living room and make him feel comfortable. Put pictures of the children out on all the tables. You want him to know you believe in the family just in case he’s a Republican (Most us are). Now, above all, do not discuss politics with him. You don’t want to lose an electrician over the prayer-in-school issue.
> What do you discuss with an electrician?
> Benjamin Franklin. After all, he was the father of electricity. Then there is Thomas Edison. Electricians think Edison is the cat’s meow.
> You could talk to him about the stock market. Anyone who is a licensed electrician automatically becomes a member of the Fortune 500. (At least thats what I'm told).
> Be your natural self, an electrician puts his pants on one leg at a time, just like a plumber.



Personally I refuse to hire an electrician that doesn't worship Tesla....

Reactions: Agree 2 | Funny 1


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## Kevin

Jon when I mentioned "piggybacks" in my posts last year I was referring to tandem breakers. I live in Texas and everything has a food connotation even breakers. A piggyback is not a child's game where they carry each other it's pork meat. Or an electrical breaker with two in the space of one normal one. As a once-licensed journeyman electrician myself (I finally just stopped doing the CE and let it lapse) I can vouch for everything Randy said.

Colin I first read about Tesla back in the early 80s while reading a book about some esoteric subject matter. I remember not liking the book very well but the half chapter dedicated to Tesla piqued my interest and I started loking for books about him. Back then, there were no modern books written about him that I could find. I found his autobiography written early 1900's but couldn't wrap my mind around it too well at that time (I reread it again after I read the book I'm about to mention). There were a few books written in the 90s but finally a lady came along who could actually write and did the requisite research n him, and published "Man Out Of Time".

I'm not aware of a better book on him that hers. It's a small book and leaves you wanting more, but unfortunately most of Tesla's work mysteriously vanished and since his life was his work, I guess there isn't much else to be found about the reclusive genius. If you haven't read her book - you must.

Reactions: Thank You! 1


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## robert flynt

I don't know if this has been said, but as a general rule all motors should be on their own dedicated circuit. In some places, such as here where I live, it is code. Also if your going to put the DC on an outlet make sure you use an outlet and plug in that you can't plug AC equipment in to and vice versa.


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## woodintyuuu

I am not trying to confuse this tread but i will present a different point of view: where i live there are tons of left over (as in free THREE PHASE motors in any flavor you desire) Years ago i hatched a scheme to pay less for my power. I run a rotary 10 hp phase converter, to and through a buckboost transformer, which creates true 440 volt three phase power. I have a magnetic dropout box in case i lose a leg . That makes sure i do not burn out a motor or wire. The magnetic dropout feeds a subpanel where i can take of any configuation of three phase 440 or 220 i desire. I use this power to run all sorts of silly inventions i dream up . I have a 6 inch hyraulic driven blade that looks like a arbortech
to hollow the life size hollow forms. (there were a cupla guys named vinny and pendolino that had intrest in that one)  I generate enough power through it i get excess and can run cheaper. I belive it can be done on a little smalller scale also. Hope that made you guys ponder for a millisecond @woodtickgreg i figure if i dangle enough cool stuff in front of you mabey you will come up soon .

Reactions: Like 1 | Informative 1


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## brown down

TimR said:


> Jeff, I'm not an electrician, but have done a fair amount of wiring that got inspected to the NEC. I'm not familiar with why the number of twins is a factor even for older boxes. Personally, for someone trying to add a couple circuits, and with room getting into/out of the box for new cable, I'd be all over the consolidation of a few lighting or outlet circuits into twins to provide open slots. Do you know why the use of twin breakers is an issue?



adding twins allows you to put two circuits in one breaker spot on the buss bar.. most 200 amp panels have 42 slots for breakers. putting twins in can potentially overload your panel and or cause a very unbalanced load. In a single phase 120/240 v home its impossible to have a true balanced system, I haven't even run into a true balanced load in commercial systems either! but if you keep adding twins into the panel the potential is there. I rewired a chevy dealership a few years ago and in one panel alone there were 18 twin breakers  and a way under rated transformer running the system. needless to say we had to add another large transformer and add 2 more 200 amp panels so that would never happen again. its easy for people who either A aren't qualified to perform the work or B are too lazy to do the work correctly to overload a panel.. I have a feeling their in house guys were the ones who did the work!! even tho your panel may be newer you should check with the manufacturer or supply house and make sure its (rated) for more then 3 twins! only some of the panels are rated for up to 10 but thats the max!

Reactions: Thank You! 1


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## JR Custom Calls

I guess I don't see how it can be an issue. As long as I'm not exceeding 200a, I don't see how it can cause a problem. But, I'm not an electrician... so there must be something I'm missing.


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## brown down

here is a fairly new article explaining why up until 2008 NEC code! the panels aren't rated for more than the allowable circuits they are designed for! http://www.startribune.com/local/yourvoices/140688183.html I have been trained not to cheat regardless of what a customer wants! At the end of the day I look at it like this, if I wouldn't do it at my home or at a loved ones home I won't put any other person at risk to save a few bucks!! when it comes to electricity it is very unforgiving! I've seen first hand what overloaded panels can do and its scary! I've seen buss bars melted away! I work with much higher voltages than that of a home but the theory and codes are the same.. 277/480v all the way up to 4160v primary feeds.

Reactions: Like 1 | Thank You! 1 | Great Post 1


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## TimR

Good info Jeff, very handy having such a diverse crowd of folks go glean info from. It does seem, in the end as I read that article, that if the panel board will accept the breaker as designed, without cheating, that it's ok within reason, based on total number of circuits allowed in the panel and some balancing thoughts on each pole. I needed to have my 40 yr old panel replaced on the house a few years ago when finishing up some siding work (outside mounted panel) and decided it was best to wine and dine a local electrician to do the work. I think it had it's share of half-breakers but don't think any required cheating. I don't think I'll ever use all the breakers on my shop fortunately. I built it in 1996 and had a separate service run and installed a 200 amp panel with only about 1/3 being used.


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## brown down

don't get me wrong I have used twins on job sites before and will continue to do so if the panel has room for them and is rated for them! they changed the code how the panels are to be built some years back so people can't just add as many breakers in until they fill it up with nothing but twins like that dealership I did! but the older panels you can add away and thats where people can get into problems! to give an idea of how scary electrical work can be, I did a school up in the poconos a couple of years ago. All 120/208v lighting and heat and receptacles, no 277/480v panels until we added them for the HVAC. now they shared the neutral on almost everything. and used 3 phase branches, when one of the guys shut off one of the circuits lol it lit the receptacles on fire in the adjacent rooms and had almost 30 amps on the neutral wire. we had to swap out every breaker and install 3 pole breakers so that could never happen either, they were too cheap to pull out the wire and add a neutral for each circuit which in my eyes is wrong  considering kids were going to be there!!!!!!

Reactions: Agree 1


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## robert flynt

woodintyuuu said:


> I am not trying to confuse this tread but i will present a different point of view: where i live there are tons of left over (as in free THREE PHASE motors in any flavor you desire) Years ago i hatched a scheme to pay less for my power. I run a rotary 10 hp phase converter, to and through a buckboost transformer, which creates true 440 volt three phase power. I have a magnetic dropout box in case i lose a leg . That makes sure i do not burn out a motor or wire. The magnetic dropout feeds a subpanel where i can take of any configuation of three phase 440 or 220 i desire. I use this power to run all sorts of silly inventions i dream up . I have a 6 inch hyraulic driven blade that looks like a arbortech
> to hollow the life size hollow forms. (there were a cupla guys named vinny and pendolino that had intrest in that one)  I generate enough power through it i get excess and can run cheaper. I belive it can be done on a little smalller scale also. Hope that made you guys ponder for a millisecond @woodtickgreg i figure if i dangle enough cool stuff in front of you mabey you will come up soon .


Sounds like a mad scientist to me. I'd have to run that by my wood turning retired electrical engineer friend, to explain it to me.

Reactions: Funny 1 | +Karma 1


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