Tournament Bodycord Tester

**Emfuser** · 09-25-2009 09:48 AM

Originally Posted by SJCFU#2

Or even just one meter if you use a 2-pole/6-position rotary switch (also available at Radio Shack).

Just be certain that the multimeter has a 1-ohm range (many inexpensive analog meters only go down to 1k, or 1,000 ohms).

The cheap 5 ohm ones from Radio Shack are about $17 apiece. They work great.

I'm not as big a fan of using the 2-pole rotary switch, even though that's nice for portability and space reduction. I would go for alternate means of detecting shorts.

**brtech** · 09-25-2009 10:16 AM

Originally Posted by Emfuser

The cheap 5 ohm ones from Radio Shack are about $17 apiece. They work great.

I'm not as big a fan of using the 2-pole rotary switch, even though that's nice for portability and space reduction. I would go for alternate means of detecting shorts.

What you want is 5 ohms or 10 ohms center scale. 10 ohms is enough: you can easily read the difference between 1, 2, 3,4 ohms. Another source is:
http://www.multimeterwarehouse.com/YX360TRnf.htm.

A single meter box with rotary switch is the least expensive way to build a test box, a consideration many have to deal with. Most armorers I know started with one of those. If you need to test in volume, then you should consider a 3 meter setup, but only if you have a shorts test of some kind.

One way to do a 3 meter setup that does check shorts is to have 3 buttons or switches that interrupt the lead to one side of the cord. You press the button, and the meter should go to infinite ohms. If it doesn't, you have a short. Joe Byrnes has a box like this.

If you build your own ohmmeter circuit instead of using an external multimeter, you can use an LED and a trick I describe in:
TournaTest 3 meter test box

**fencerbill** · 10-02-2009 03:28 PM

It is relatively easy to grow a one meter box into a 3 meter box. You just have to add dedicated meter jacks for the A and C lines. I use the original switched meter jacks set on B to test all 3 leads at once. You can set the switch for AB short to test Epees and set it to BC short to test Foils.

My personal preference for a switched box is from a schematic that Ted LI drew for me. It has short test positions between continuity settings. The tests, in order of switch position starting from full clockwise and moving counter clockwise are:

AA Continuity
AB short (Epee)
BB continuity
BC short (Foil)
CC continuity
AC short

I have recommended Sperry analog meters which I have been able to get at Home Depot for under $20 each. They are 5 ohms midscale. Instead of the original test leads from the Sperrys, I use a stub of #14 solid electrical building wire soldered to stranded wire to the test box jacks.

**Nolano** · 10-03-2009 01:15 PM

I forget where, but I've gotten those same Sperry meters for about $5 plus shipping somewhere on the internet, I think.

**Mergs** · 10-06-2009 10:06 AM

Originally Posted by SJCFU#2

Or even just one meter if you use a 2-pole/6-position rotary switch (also available at Radio Shack).

The issue with the Radio Shack rotary switch is that it an open cage design and has issues with corrosion on the contacts after a while. There is a closed body one that Dan recommends (and I use on my boxes) that is a tad bit pricier, but worth it. PM me for details.

**jdavies** · 10-07-2009 06:57 PM

Well, this looks like a learning opportunity for me.

I am currently building my own test box for body cords only. I'm basically testing for continuity, so my setup is extremely simple with 2 AA batteries, 3 resistors, 3 green LEDs, plastic housing for it all and of course the required parts that the body cord plugs into. Total cost is about $50 and I can cut $12.00 off of that if I skip using a grid board and just solder everything together.

Is there more to body cord testing than continuity? Should I be looking at specific resistance readings also?

**Purple Fencer** · 10-07-2009 08:11 PM

Originally Posted by jdavies

Well, this looks like a learning opportunity for me.

I am currently building my own test box for body cords only. I'm basically testing for continuity, so my setup is extremely simple with 2 AA batteries, 3 resistors, 3 green LEDs, plastic housing for it all and of course the required parts that the body cord plugs into. Total cost is about $50 and I can cut $12.00 off of that if I skip using a grid board and just solder everything together.

Is there more to body cord testing than continuity? Should I be looking at specific resistance readings also?

Yes....you're allowed 1 ohm per line. Keep in mind that a scoring box will fire even up to 250 ohms....so while the cord may work wonderfully in club at 50 ohms, it certainly won't pass at control.

Also, with a hookup to an analog meter, you'll be able to see the needle flicker when you wiggle/pull the cord, thus showing a wire break....something that may not show on a digital.

Also, if you're going to test cords, you might as well test weapons, as well...a B/C short in epee will keep the weapon from registering, even if the A/B connection is good when the tip is depressed.

Part of the art of armory is finding those irritating little things that cause a weapon system to not function properly.

**SJCFU#2** · 10-07-2009 11:51 PM

Originally Posted by Purple Fencer

...a B/C short in epee will keep the weapon from registering, even if the A/B connection is good when the tip is depressed.

Part of the art of armory is finding those irritating little things that cause a weapon system to not function properly.

And just to add to the confusion, some scoring machines (SG's, Eigerteks, possibly others) will still work even when there is an A/B short.

**Natureboy** · 10-08-2009 09:55 AM

I'll give SJCFU#2 and PurpleFencer a bump on that and add that a lot of the little weapons testers don't register the B/C fault. So someone who shall remain nameless can assemble some newly wired blades, check them out with the cheapy tester instead of breaking out the real tool only to find at the tournament that the screws had gone through the plastic on the tip. Result: B/C short, weapons no workie, fence with borrowed weapons.... :P

Seriously, if you build the box you will find yourself using it for everything and wondering how you lived without it.

**jdavies** · 10-09-2009 06:46 PM

Well, I'm working on a circuit that will test the body cord to 1 ohm now. Learning a fair bit about electronics along the way, so that is a good thing.

I haven't given any though to weapon testing because I fence sabre, so I don't have any experience (or access to) the "point" problems that seem to plague foil and epee fencers. However, once I get the body cord problem solved, I'll be looking for a new problem to solve.

**Purple Fencer** · 10-09-2009 09:42 PM

Originally Posted by jdavies

Well, I'm working on a circuit that will test the body cord to 1 ohm now. Learning a fair bit about electronics along the way, so that is a good thing.

I haven't given any though to weapon testing because I fence sabre, so I don't have any experience (or access to) the "point" problems that seem to plague foil and epee fencers. However, once I get the body cord problem solved, I'll be looking for a new problem to solve.

Lame resistance, 5 ohms point to point. Weapon is 2 ohms, if I remember right.

Best to learn about foil and epee, because once word gets out that you know how to check it, you'll be asked, trust me!

**Emfuser** · 10-14-2009 05:07 AM

Originally Posted by fencerbill

It is relatively easy to grow a one meter box into a 3 meter box. You just have to add dedicated meter jacks for the A and C lines. I use the original switched meter jacks set on B to test all 3 leads at once. You can set the switch for AB short to test Epees and set it to BC short to test Foils.

My personal preference for a switched box is from a schematic that Ted LI drew for me. It has short test positions between continuity settings. The tests, in order of switch position starting from full clockwise and moving counter clockwise are:

AA Continuity
AB short (Epee)
BB continuity
BC short (Foil)
CC continuity
AC short

I have recommended Sperry analog meters which I have been able to get at Home Depot for under $20 each. They are 5 ohms midscale. Instead of the original test leads from the Sperrys, I use a stub of #14 solid electrical building wire soldered to stranded wire to the test box jacks.

Rudy is my coach, so I have had an earful of this very idea and have played with a box of this type of design in his armory.

I just have different ideas that I've been too overwhelmed to mess around with.

**SenorEquis** · 10-30-2009 04:32 PM

Ok, to go back to the OP, we decided to buy the one available from SwordMasters. I've since received it in the mail, but without the promised explanitory DVD (out-of-stock, apparently). So now I have a cool tester, but no real understanding of how it works. Does anyone have first-hand experience with this tester? What is its power source? Batteries? If so, what kind and where do I put them? Oh, and how do I turn the darn thing on? Help!

**Purple Fencer** · 10-31-2009 12:20 AM