I just wear gloves also. Doesnt bother me.
Heated Handles
- Thread starter Ryan Willock
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ClearH20Scott
ArboristSite Operative
I really like the heated handles on my 346XPG. I was out in
about zero degree weather yesterday, and was in a brisk
wind with that fine, powdery snow that always gets your hands
cold and damp. I can only stand to wear cotton gloves to begin
with, so the heat's a welcome feature. I wish my 357 had 'em.
about zero degree weather yesterday, and was in a brisk
wind with that fine, powdery snow that always gets your hands
cold and damp. I can only stand to wear cotton gloves to begin
with, so the heat's a welcome feature. I wish my 357 had 'em.
Gypo Logger
Timber Baron
Hi Scott, I didnt think the 346 was available as a Sno Pro (heated handles), not in Canada anyway. I hope I am wrong though.
John
John
<b>Stihltech</b>: 440 compression release has evidently been seen and purchased, http://www.arboristsite.com/showthread.php?s=&threadid=7073&highlight=440+compression+release
<b>Newfie</b>: Maybe <i>I'm</i> looking at it too simplistically. I don't think it would require any extra energy to run the generator if there were no load on it, at least not anything worth writing home to mom about. But putting a load on the generator <i>will</i> require power. The power source here is a certain amount of fuel and air being burned in a certain time frame, which is also intended for pulling the chain around the bar and through wood fiber. Both loads are vying for the same source of power via the common crankshaft, and it's first come, first serve, so you must subtract the electrical load from that available before even starting the cut. I guess I was just wondering if anyone knew what the power requirements are for the heat traces in the handles and carburetor plate.
Glen
added: John, look at http://www.mcouat.husqvarna.ca/node126.asp
<b>Newfie</b>: Maybe <i>I'm</i> looking at it too simplistically. I don't think it would require any extra energy to run the generator if there were no load on it, at least not anything worth writing home to mom about. But putting a load on the generator <i>will</i> require power. The power source here is a certain amount of fuel and air being burned in a certain time frame, which is also intended for pulling the chain around the bar and through wood fiber. Both loads are vying for the same source of power via the common crankshaft, and it's first come, first serve, so you must subtract the electrical load from that available before even starting the cut. I guess I was just wondering if anyone knew what the power requirements are for the heat traces in the handles and carburetor plate.
Glen
added: John, look at http://www.mcouat.husqvarna.ca/node126.asp
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Glen,
Interesting thought about power requirements taking away from performance. A 60 watt light bulb will fry your fingers. Since the heated handles only need to give off heat and not light (and not enough heat to burn ya), what would you guess the total power requirement to be? Out of 2.5Kw, what percentage of power loss would that be?
Interesting thought about power requirements taking away from performance. A 60 watt light bulb will fry your fingers. Since the heated handles only need to give off heat and not light (and not enough heat to burn ya), what would you guess the total power requirement to be? Out of 2.5Kw, what percentage of power loss would that be?
mryb
Resident Creep
I have an 028 with heated handles. It doesn't seem to want to burn your hands though...Rick/Creep
Crofter
Addicted to ArboristSite
power usage
The heat output of the human body at rest is just over 50 watts so I,d think the handles would not need to put out much more than a tenth of that, so would be a pretty small part of the total 3000 or so watts available. I guess the heated handle idea is partly preventative medicine; they will keep your hands from getting cold 30 years from now.
Frank
The heat output of the human body at rest is just over 50 watts so I,d think the handles would not need to put out much more than a tenth of that, so would be a pretty small part of the total 3000 or so watts available. I guess the heated handle idea is partly preventative medicine; they will keep your hands from getting cold 30 years from now.
Frank
Tony Snyder
Addicted to ArboristSite
Glens, having come from an engineering career, I know that you are correct, that is, that the power to heat must come from the engine output at the tune of 1 horsepower per 7 hundred and some watts, plus losses.
On the larger saws, they are probably not taxing to total power output, therefore, do not notice the loss. On a mid size saw that might not be the case.
Also you have the added disadvantage of a lowered power to weight ratio.
We know that because of the the mechanical laws difined by Newton we cannot get energy without a trade off.
On the larger saws, they are probably not taxing to total power output, therefore, do not notice the loss. On a mid size saw that might not be the case.
Also you have the added disadvantage of a lowered power to weight ratio.
We know that because of the the mechanical laws difined by Newton we cannot get energy without a trade off.
Tony,
If you have access to a heated handle unit and a meter it would be easy enough to figure out the power used by the heated handles.
The unit could also be tached and readings taken with the switch off and on just to see how much loss of rpm it effected.
If you have access to a heated handle unit and a meter it would be easy enough to figure out the power used by the heated handles.
The unit could also be tached and readings taken with the switch off and on just to see how much loss of rpm it effected.
Gypo Logger
Timber Baron
Not excelling in solving electrical problems, I cant see how an Arctic could rob performance. There are no moving parts, just a flywheel revolving around a stationary generator. Aside from the minimal pull that a small magnet would have, I cant see any chance of significant power loss. Could someone explain if I am missing something?
Thanks in advance.
Poindexter
Thanks in advance.
Poindexter
dbabcock
Hi Tech Redneck
First, measure the voltage that the wire coming out of the flywheel coil for the heaters produces while the heaters are hooked up and turned on and the saw is at cutting RPM. Set the meter to Volts and AC, then connect one lead to the saw motor case (ground) and the other lead to the wire that comes out of the flywheel coil . Next, disconnect the flywheel coil wire from the heaters and set the meter to read Ohms. Touch the two meter leads together and look at what the meter reads. With low value resistances, the meter leads themselves can contribute a sizeable error (something in the range of 0.1 to 0.5 Ohms). Then connect one meter lead to ground once again and the other lead to the wire that goes to the heaters. For this measurement, the saw isn't running, but make sure that the heater switch is on. After you get this reading, subtract the shorted meter leads number from above to get the heater elements' true resistance.
Use the following equation to calculate the power that the heaters require from the motor:
Power = (Voltage)^2/(Resistance)
In other words:
Power equals voltage squared divided by resistance
Figured this way, the units for power will be in Watts.
Then, converting Watts to Horsepower:
1 Horspower = 746 Watts, so the equivalent HP would be what you figure for Power above divided by 746.
Example:
Let's say your first measurement from above yields a meter reading of 10 Volts. You then measure the heater resistance and it is 5 Ohms. The equation would then be:
(10)^2/(5) =100/5= 20 Watts.
Then to convert to HP:
20/746= .03 HP.
I have no idea what your actual readings will be as the above is just an example, but I can say that 20 Watts would provide reasonable heat. A 100 Watt bulb gives up much of it's energy in heat and they're too hot to touch. If 20 Watts is taking .03 HP from your saw motor, I'd say that any power used for heating grips would likely have almost no impact on saw performance.
Use the following equation to calculate the power that the heaters require from the motor:
Power = (Voltage)^2/(Resistance)
In other words:
Power equals voltage squared divided by resistance
Figured this way, the units for power will be in Watts.
Then, converting Watts to Horsepower:
1 Horspower = 746 Watts, so the equivalent HP would be what you figure for Power above divided by 746.
Example:
Let's say your first measurement from above yields a meter reading of 10 Volts. You then measure the heater resistance and it is 5 Ohms. The equation would then be:
(10)^2/(5) =100/5= 20 Watts.
Then to convert to HP:
20/746= .03 HP.
I have no idea what your actual readings will be as the above is just an example, but I can say that 20 Watts would provide reasonable heat. A 100 Watt bulb gives up much of it's energy in heat and they're too hot to touch. If 20 Watts is taking .03 HP from your saw motor, I'd say that any power used for heating grips would likely have almost no impact on saw performance.
ClearH20Scott
ArboristSite Operative
Hi John, I bought the 346XPG down here and I sent it up to
Walker's to see how I'd like it. I like it more and more everyday.
That will probably change when my DG357 shows up. Can't wait.
Funny thing, they must not move too many of them, mine was a
brand new 1999 model. The steel tag and all the plastic was date
coded 99'. The saw had been sitting in a warehouse for some time. Walker's had never seen one, so I guess for now it's a
one of a kind.
Walker's to see how I'd like it. I like it more and more everyday.
That will probably change when my DG357 shows up. Can't wait.
Funny thing, they must not move too many of them, mine was a
brand new 1999 model. The steel tag and all the plastic was date
coded 99'. The saw had been sitting in a warehouse for some time. Walker's had never seen one, so I guess for now it's a
one of a kind.
Newfie
Addicted to ArboristSite
Glens,
My thinking was along the lines of Gypo. No additional moving parts, so no appreciable requirement to scavenge energy from elsewhere. of course the other points offered about the minimal wattage required probably makes the whole thing moot. I wish I had the G in my 372xp this morning!
My thinking was along the lines of Gypo. No additional moving parts, so no appreciable requirement to scavenge energy from elsewhere. of course the other points offered about the minimal wattage required probably makes the whole thing moot. I wish I had the G in my 372xp this morning!
After Doug went through all that I sure hope someone is interested enough to follow through and post the results. Not many heated handles around my neck of the woods. If Ryan gets one, maybe he'll let me "borrow" it.
Tony Snyder
Addicted to ArboristSite
Doug, we would not want to forget the I squared R, the eddy current, and as well as the histeresis losses in the generating mechanism. In such a small generating mechanism this may exceed the the example load. There would also be coupling losses with flux lines not 100% coupled to and collapsing back into the field coils. In other words the saw inself is obsorbing some of the flux as well as the stay flux leakage turning the saw into a magnetic wave transmitter. A field strength meter held nearby would confirm that. All this stuff adds up.
It seems like I remember something in my service info on Jonsereds that the power consumption overall is more like 150 to 200 watts on a W 2171. That is getting close to 1/4 horsepower.
I am not trying to debate with you, I just wanted to remind you of the losses. I was involved in transformer design for a few years; power, audio, pulse, and saturating mode stuff. So, at least at one time, understood this stuff qiute well.
It seems like I remember something in my service info on Jonsereds that the power consumption overall is more like 150 to 200 watts on a W 2171. That is getting close to 1/4 horsepower.
I am not trying to debate with you, I just wanted to remind you of the losses. I was involved in transformer design for a few years; power, audio, pulse, and saturating mode stuff. So, at least at one time, understood this stuff qiute well.
dbabcock
Hi Tech Redneck
Tony,
I'll take your word for this as I haven't been involved in transformer design specifically. I suspect that the hysteretic and eddy current losses would be very small given that the overall Q of the coil in this case is probably rather high because of the relatively slow risetimes and PRF the system was designed for. Given the low voltage, I would think that the series resistance of the coil would be very low (on the order of tenths of an Ohm) and because of the limited amount of turns required, that the leakage inductance would be relatively small as well. Of course, that's just the "electrical" end of things and says nothing about the magnetic coupling efficiency as you have stated, which I know very little about. This is all theory for me and is not based on any practical experience. Electrical efficiency of such a gizmo could very well be much higher than 50%, but again, I have no feel for the magnetics.
As a side note, your mention of the 2171 W is ironic in that when Zyp was down here in September, I took apart his 2171 W because he said that the heated grips had never worked. It was my first look at heaters on saws. I wasn't aware that there was an intake and carb heater in addition to the front and rear handle heaters. They were all wired in series. Very simple actually. Anyway, I found nothing immediately wrong with the anything. I just disconnected all the wires, blew it out with some air and hooked them back up. After that, it worked fine. John was extremely pleased with my supposed prowess. I played it up real big with some fancy BG wording and charged him $300 US for my efforts.
I'll take your word for this as I haven't been involved in transformer design specifically. I suspect that the hysteretic and eddy current losses would be very small given that the overall Q of the coil in this case is probably rather high because of the relatively slow risetimes and PRF the system was designed for. Given the low voltage, I would think that the series resistance of the coil would be very low (on the order of tenths of an Ohm) and because of the limited amount of turns required, that the leakage inductance would be relatively small as well. Of course, that's just the "electrical" end of things and says nothing about the magnetic coupling efficiency as you have stated, which I know very little about. This is all theory for me and is not based on any practical experience. Electrical efficiency of such a gizmo could very well be much higher than 50%, but again, I have no feel for the magnetics.
As a side note, your mention of the 2171 W is ironic in that when Zyp was down here in September, I took apart his 2171 W because he said that the heated grips had never worked. It was my first look at heaters on saws. I wasn't aware that there was an intake and carb heater in addition to the front and rear handle heaters. They were all wired in series. Very simple actually. Anyway, I found nothing immediately wrong with the anything. I just disconnected all the wires, blew it out with some air and hooked them back up. After that, it worked fine. John was extremely pleased with my supposed prowess. I played it up real big with some fancy BG wording and charged him $300 US for my efforts.
Tony Snyder
Addicted to ArboristSite
Now hot exhaust gas, that would be a way to really get some heat for free. Just figure how to get it routed where you want it.
