Chainsaw help

[patrick_g]

Not sure where this should be posted. Suggestions considered.

I have a collection of gasoline chainsaws ranging from a couple 16 inch Macs and some 18 inch Huskies to a 32 inch Husky and they all have the spark plug and spark plug wire sort of toward the top and or near the hand grips.

As a recipient of an ICD (Implanted Cardiac Device, AKA pacemaker/defibrillator) whose manufacturer instructs us to use chainsaws that don't have the spark plug and/or spark plug wire near the hand grips or positioned toward the user I am asking for your help.

Anyone out there in TBN land have or know of such a configured chainsaw? I will probably want to get one of those.

I bought a Harbor Freight electric chainsaw that said on the box, "Not for use by people with pacemakers" and gifted it to my wife but that isn't a satisfactory long term solution.

Thanks in advance for any leads.

Patrick

 

[ArlyA]

Patrick, there is a chainsaw section here. http://www.tractorbynet.com/forums/chainsaws/

 

[arrow]

Don't know how much you need to cut. Am wondering if the proliferation of the battery saws could be applicable. They have come a long way over the years.
I have owned a ton of chainsaws. Unless somebody made a gas powered saw with its piston moving sideways, It would be difficult if not impossible to find a saw w/o its spark plug at the top of the saw.Best Battery Powered Chainsaw | Chainsaw Journal

 

[Clint S]

Have had 2 uncle's use Saws for years with pacers and no issues, most Saws are insulated through the handle and plug is covered. Old Saws they were not covered and the handle was steel connected directly to saw. As always use your MDs advice and they will direct you towards the manufacturer

 

[Liquidsilver]

And good thick leather gloves should reduce the chance of getting a spark plug zap. In years of operating piston-powered everything, I've only gotten zapped once, and it was with one of those metal clips that snapped down to ground the plug... I was bare handed.

Best to you.

 

[Egon]

There are special insulated gloves electricians use at times.
[video]http://www.minecableservices.ca/portals/0/images/products/Cable%20Handling/Electrical%20Hot%20Gloves%20sample%20set.jpg[/video]

 

[dfkrug]

And good thick leather gloves should reduce the chance of getting a spark
plug zap.

The implanted device maker may be concerned more about the stray electric field than actually getting
zapped. If shocked, the current is thru your hand, both in and out. The stray electric field is large and
radiates outward from the spark. There may be an induced current in any diodes nearby, as with
old spark-gap transmitters in the Nicola Tesla era.

BTW, I work on a lot of engines and I use a wireless tachometer that can receive these "signals"
from several feet away.

 

[patrick_g]

There are special insulated gloves electricians use at times.
[video]http://www.minecableservices.ca/portals/0/images/products/Cable%20Handling/Electrical%20Hot%20Gloves%20sample%20set.jpg[/video]

Egon, et al, It is the ICD's manufacturer's information that I was going by. While a shock hazard is a legitimate concern, that is not the issue I want to raise. For example they say to keep the ICD at least 2 ft from an electric fence. Clearly not a conducted current issue but one of electromagnetic field strength. The issue is magnetics and RFI (Radio Frequency Interference.) The spark plug wire radiates electromagnetic energy which can potentially upset the functionality of the ICD. The manufacturer lists devices that are generally considered safe, items that should be kept 6 or more inches away from the ICD, items to keep a foot away, 2 feet away, etc.

The manufacturer specifically mentions chain saws should have the spark plug and its wire located away from "the user side of the unit" and away from the handles. I can't say that part of the warning (away from handles) isn't a shock hazard issue rather than RFI.

They just don't make it perfectly clear in their writings. They do list maximum field strengths in specified frequency domains that the unit is expected to operate normally within. Not having a well instrumented lab at my disposal I can't test various saws for their potential to cause RFI in the various frequency bands of interest. So, instead I was trying to ID a saw that met the conditions of their advisory comments.

Again, thanks to everyone who responded.

Patrick

 

[TemporaryKubotaOwnerMark]

The implanted device maker may be concerned more about the stray electric field than actually getting
zapped.

Bingo. A firing spark plug generates a lot of electrical noise, and insulated gloves or handles don't have anything to do with it.


If you can find a ham club near you, you might find someone willing to make a spark plug wire out of coaxial cable, with the shield grounded. That should kill most of the radiated energy. Probably enough to give you a reasonable safety margin.

 

[patrick_g]

Bingo. A firing spark plug generates a lot of electrical noise, and insulated gloves or handles don't have anything to do with it.


If you can find a ham club near you, you might find someone willing to make a spark plug wire out of coaxial cable, with the shield grounded. That should kill most of the radiated energy. Probably enough to give you a reasonable safety margin.

Uh yup... I am an extra class ham and intend shielding the spark plug wire as we used to do on cars back in the day... I really don't want to get defibbed. I will be shielding the spark wire of a saw that has the spark plug and wire where the mfg recommends. Yup, belt and suspenders.

Patrick

 

[TemporaryKubotaOwnerMark]

There ya go. Something with a nice double braid and a silicone dielectric should do you very nicely. :drink:

 

[patrick_g]

There ya go. Something with a nice double braid and a silicone dielectric should do you very nicely. :drink:

I was thinking of using a scrap of Heliax to get as close to 100% shielding as is practical. Alternatively as a pilot I could befriend and buy a local A&P a beer and ask for a used aircraft engine spark plug wire. They are good for high power magnetos and are well shielded to avoid RFI issues.

Patrick

 

[Egon]

Not gloves, an electron sheild is what is required.

No proper knowledge but there should be some kind of vest available from X-Ray, laboratory, military/law enforcement or maybe even dental suppliers.

 

[CobyRupert]

Not gloves, an electron sheild is what is required.

No proper knowledge but there should be some kind of vest available from X-Ray, laboratory, military/law enforcement or maybe even dental suppliers.

:thumbsup:

Look up "taser proof shirt", the principle is it shields the wearer.

Also look up "resistor plug" for the saw.

The comment about having shielding on the spark plug wire is good too. What I don't know is if the shield itself would become a "choke" (impedance) to the pulse being sent to the plug. But there's a lot of information (in the automotive world) about spark plug wires that limit radio interference. Edit: Oops, like you're knowledgeable & on the case looking for airplane plug wires.

-And that's what we're really talking about, limiting (through shielding/grounding) radio frequency interference (RFI), or more broadly electromagnetic forces (EMF's)

 

[CobyRupert]

Some suggest using carbon tape on their clothing as a shield.

A few DIY projects: Google

 

[patrick_g]

Not gloves, an electron sheild is what is required.

No proper knowledge but there should be some kind of vest available from X-Ray, laboratory, military/law enforcement or maybe even dental suppliers.

Egon, et al, When I was first told to stop welding because of the ICD (well, after the air was less blue around me) I did a little searching. On the welding sites of all the big names in welding like Hobart, Lincoln, etc. there are guys whose jobs are modified or lost due to prohibition against welding. As you might imagine there are a lot of off the wall ill conceived attempted remedies right up there with the solid scientific measures where folks put aluminum foil on their heads to stop extraterrestrial influences or whatever. Guys trying lead filled vests ala dental X-rays and on and on. The MFG of my ICD says none of the aprons or vests will work.

I was an electronics guy and a physicist before I was a computer scientist. In the olden days of CRT's in oscilloscopes the CRT was often surrounded by a metal shield to prevent stray fields from deflecting the electron beam and causing error in the data presented. These shields were made of mu metal (Greek letter mu pronounced mew) The mu metal alloy makes a good magnetic shield. So I went surfing the web for a source of mu metal to make some sort of suit of armor like maybe a breast plate like Coronado's troops might have worn. SHAZAM and GOLLY GEE you can now buy mu metal that has been made into thread and woven into cloth. Really serious cloth for costuming the freezer wrap on the head crowd.

I did not follow through with my plan to enlist the help of someone who could weld to weld with and without a mu metal vest under their leathers while I made various field strength measurements. I can't do the experiment myself without risking setting off the defibrillator which is like simultaneously getting kicked in the chest by a mule and hit with A 10kv hot wire electric fence. It can do a little damage to your heart when it defibs you. Better than not having a heart beat but not something to intentionally induce if it can be helped. If my ICD was only a pacemaker and was not also a defib I would take several precautions and weld knowing if I felt dizzy or faint I could stop welding and recover just fine. Ditto with a chain saw.

But I do have a defib so I want to reduce the risk of setting it off by following the MFGs recommendations re spark plug wires and spark plug. I can go the extra mile and shield the plug wire. But right now I don't know what brand/model chain saw has the desired configuration. Hence the reason I started this thread.

Patrick

Patrick

 

[Egon]

Wow, Patrick. It would seem your knowledge is well above most of us here. I'll stop my irrelavent unimformed chatter.

The nickel dropped! For some reason I was under the impression there was a different name in other times. Signs of an aging memory fed an insufficient nutrient supply.

 

[Coyote machine]

How about NOT operating a chainsaw anymore? Seems like the wisest move....

 

[TemporaryKubotaOwnerMark]

Not gloves, an electron sheild is what is required.

No, there are no stray electrons running around. It's an electromagnetic field.

The comment about having shielding on the spark plug wire is good too. What I don't know is if the shield itself would become a "choke" (impedance) to the pulse being sent to the plug.

It won't.

I was thinking of using a scrap of Heliax to get as close to 100% shielding as is practical.

Hmmmm. Not sure I like the Heliax. Too rigid, I suspect. I think you need some flex to allow for the vibrations of the saw.

Alternatively as a pilot I could befriend and buy a local A&P a beer and ask for a used aircraft engine spark plug wire. They are good for high power magnetos and are well shielded to avoid RFI issues.

Oh, now you're cheating! That would be the stuff! Not being a pilot, I didn't know about that. Makes sense. In fact, I just learned about aircraft shielded wire a few weeks ago talking to a friend of mine who is building a plane. Since he's a signal processing engineer, and I'm in communications, we talk shop a lot. He was telling me about the shielded wire that runs to his clearance lights. Noisy beasts, those clearance lights. Xenon, I think?

Something like that should do you fine.

 

[Egon]

[QUOTENo, there are no stray electrons running around. It's an electromagnetic field.][/QUOTE]

But don't those electro magnetic fields get started by electrons ?