My Dumb Question #1

[CuttySnark]

I'll add something from a personal perspective. I don't know **** about modifing electric stuff, but on face value it doesn't seem as fun to me. Having a ported saw is part of the fun, but the process of building it is fun to me as well. I guess since it isn't a "perfect" process...figuring things like combustion chamber volume and shape, port timing/width/shape, ignition timing, etc.

With electrics, how do you modify them? Throw more voltage at them?

Can't really just turn up the volts to fix a lack of power, after you get a build going. Once you've established what your pack voltage will be, it pretty much sets the limit for other parts of the system. Little details like what the max voltage can be for power capacitors inside the motor controller, maximum forward gate voltage for the MOSFET's, there's a few things to do with limiting inrush current that are very difficult to solve. Back EMF can ruin your day if you don't know how to deal with it. And what about learning how to make changes in the code? - piston motors are easy, in comparison. There's generations of R&D going back to the early 1900's, though in my opinion WW2 is when things really got going

Just yesterday I got into a never ending discussion on why a Buell Blast(my personal bike) has flow reversion at idle. The other guy insisted that it's perfectly fine for the intake ports to be bigger than necessary, and that the reversion was only because the bike has a high performance race cam (it doesn't) They had no interest in discussing velocity tuning a port to achieve 80% of the flow below the speed of sound, or why that might matter. But what I really wanted to go over was how that speed of sound changes when there's a partial vacuum during the intake pulse, while it's the complete opposite for the exhaust because the peak flow happens with positive pressure involved. I've already worked out that the intake port is a perfect size for a 900cc cylinder, while it's in reality a 500cc. The size of the port wasn't really an issue. I already know it's too big, it's just that's the discussion starter I had tried to begin with

 

[CuttySnark]

https://www.mgm-controllers.com/en/sensored-lmt-308040kw motor think it needs an 800amp esc. Just the first one I could think of off the top of my head

I think I haven't done enough homework on this! 800 amps, not so sure about the backpack idea...

Oh, hold on. You're assuming 50 volts? I'd rather go with 500 volts/80 amps

I might look at that motor some more, it's actually really interesting. Just now realized how big it is

 

[sean donato]

No it's not something you would think about unless your in the hobby, and even then it's a niche of a niche.

 

[CuttySnark]

Can you reprogram your car? The complexity of options your talking about takes serious work! And you should probably patten the system when done.
Electric whatever is the hot topic for people who don't rely on their equipment for the same performance as combustion engines, hell an axe will cut a tree down!
This current topic is inherently political and what control the government is exercising is theirs to wield.
Electric chainsaws were first used in the 30s and there's a damn good reason we didn't follow through with them same as electric cars (1920s ) they are a novelty and virture signaling.

Uhm, actually I can. But that's only if I convert to something like the Megasquirt. I built one of those back when I was putting a 2.4 into a Plymouth Horizon. But then I wound up running it as ignition only and went with a set of side draft CV carbs off of a big sport bike. I think they had 40mm bores. It was really fun using a laptop to play around with a 3D timing map. The map charted RPM/MAP signal/Timing advance. I had wanted to use the TBI as a kind of ITB, by cutting it down into a single barrel. But I couldn't get any useful info on the injectors, so I welded-up a custom intake to throw the carbs at the car

Yeah, being a 'hot topic' is why I'm looking for exercise projects. I actually have some other applications that I do want to patent, should I get one of those up & running

 

[Maintenance supervisor]

Well the new programs are not megasquirt which is user friendly. The programs are actually modeled after DNA chains so that if you change something, say thremostat parameters your wipers will sporadically come on or the electric windows won't work. Thats the kind of complexity of just the simple stuff, electric Engines will require just as much if not more complexity to be competitive.

 

[CuttySnark]

Well the new programs are not megasquirt which is user friendly. The programs are actually modeled after DNA chains so that if you change something, say thremostat parameters your wipers will sporadically come on or the electric windows won't work. Thats the kind of complexity of just the simple stuff, electric Engines will require just as much if not more complexity to be competitive.

I don't know about that! But I do know that if you have to have the car inspected for emissions equipment, none of these things will pass. I live in an area where testing is not required because there's not enough cars registered per square mile. So I could 'theoretically' change out the ECU to run a Megasquirt. I think the real fun is getting the instrument cluster to play along. Or just replace that too

For custom dash panels, I use frontpanelexpress.com

That can also work for anything on a saw that's flat & requires logos or lettering, such as a something like a 'custom license plate'

For more advanced stuff, I'm learning how to draw in Fusion360, which I can then export out to files that I can run on my 3D printer. So eventually I'll be making my own custom airboxes which can allow using better filters

 

[lwmibc]

Cutty--why not just build one, go to some meets, beat everyone's pants off for cutting speed and watch the reactions? Might be a novelty show at first, but so was freestyle at the Olympics once.

Hard to get that cord snaked through the cut blocks though, so I don't know just how much it will change practical chainsaw evolution the way logger sports days have done; any faller trying to beat 300 cu meters per day watches how fast a gas saw can cut at those things, thinking of how long he stands in one place every working day making sawdust. Who knows the future.

 

[CuttySnark]

Cutty--why not just build one, go to some meets, beat everyone's pants off for cutting speed and watch the reactions? Might be a novelty show at first, but so was freestyle at the Olympics once.

Hard to get that cord snaked through the cut blocks though, so I don't know just how much it will change practical chainsaw evolution the way logger sports days have done; any faller trying to beat 300 cu meters per day watches how fast a gas saw can cut at those things, thinking of how long he stands in one place every working day making sawdust. Who knows the future.

I'd be inclined to do just that

But I'd like to know why I would be the first one to try it. If it's just something that nobody thought was worth looking into, or if it's something outright banned?

ps - only cord involved would be a 3' cable running from a battery pack to the saw, if I were to try having the battery separated from the saw itself. I'm mainly thinking about how Stihl has a backpack battery system. I would be doing the same thing as Stihl in the one respect, even if the voltage is different. Be funny if I actually used the Stihl pack, but modified with my own battery. I'd probably have to use a Warn winch connector, or something like that, instead of the Stihl connector. Melt that little thing in a second!

 

[Lightning Performance]

OP

When you mention ports and sizing them accordingly you lost 99.99% of the readers here. It's like beating a dead horse trying to discuss things most will never be able to comprehend. Almost no one has a clue about actual port configurations or how to achieve better velocity rates and not just "grind it bigger" the old copycat way. You'll find a few more might understand the concepts of voltage vs amps but the genera public still has no clue on how a brushless DC motor actually is smaller and uses less power to produce more torque with less drag. Trying to relate that to actual wet flow ports is also generally not understood very well at all. The flow bench was created for a reason and it wasn't for grinding bigger holes to get more top end volume as many would like to believe. In fact the actual inverse tends to be true because of limited quality control, longevity and some other juicy bits general not covered most times. Staying within set parameters is the preferred way to produce a broader band of useable power on an assembly line with limiting factors like packaging issues.

I'm game if you want to try some things with electric top handles but not on a public forum. It generally turns into a giant pissing match of he said he said.

 

[CuttySnark]

OP

When you mention ports and sizing them accordingly you lost 99.99% of the readers here. It's like beating a dead horse trying to discuss things most will never be able to comprehend. Almost no one has a clue about actual port configurations or how to achieve better velocity rates and not just "grind it bigger" the old copycat way. You'll find a few more might understand the concepts of voltage vs amps but the genera public still has no clue on how a brushless DC motor actually is smaller and uses less power to produce more torque with less drag. Trying to relate that to actual wet flow ports is also generally not understood very well at all. The flow bench was created for a reason and it wasn't for grinding bigger holes to get more top end volume as many would like to believe. In fact the actual inverse tends to be true because of limited quality control, longevity and some other juicy bits general not covered most times. Staying within set parameters is the preferred way to produce a broader band of useable power on an assembly line with limiting factors like packaging issues.

I'm game if you want to try some things with electric top handles but not on a public forum. It generally turns into a giant pissing match of he said he said.

I know

But I also know that not everybody is unable to think outside of the box - by choice. Every mind is equally capable of pioneering insights into any endeavor, should there be sufficient desire to give a damn

So if I were to get enough input to push this into a working prototype, then I would suggest moving this thread over to endless-sphere.com. That's where I actually get real advice on how to make this work

But here in what I had assumed was a 'hotsaw' sub-forum, I was optimistically hoping to find out if there's any reason that a battery powered saw can't compete. So far it's sounding like I have the jump on the entire planet, which isn't something that happens every day

I already know that such a saw will work just fine provided the details are worked out, so I'm not interested in hearing why it can't work. You're right, most people say the world is flat, that only birds can fly, that the people are never going to have a say in what the landlords do. Those have no history...

So this is where I'm at right now: "Seriously? Nobody's tried simply because they haven't seen someone do it 1st? Lame...."

 

[Lightning Performance]

I know

But I also know that not everybody is unable to think outside of the box - by choice. Every mind is equally capable of pioneering insights into any endeavor, should there be sufficient desire to give a damn

So if I were to get enough input to push this into a working prototype, then I would suggest moving this thread over to endless-sphere.com. That's where I actually get real advice on how to make this work

But here in what I had assumed was a 'hotsaw' sub-forum, I was optimistically hoping to find out if there's any reason that a battery powered saw can't compete. So far it's sounding like I have the jump on the entire planet, which isn't something that happens every day

I already know that such a saw will work just fine provided the details are worked out, so I'm not interested in hearing why it can't work. You're right, most people say the world is flat, that only birds can fly, that the people are never going to have a say in what the landlords do. Those have no history...

So this is where I'm at right now: "Seriously? Nobody's tried simply because they haven't seen someone do it 1st? Lame...."

Agreed, lamb.
You'll find nothing going public from the factory R&D programs regarding these new designs. Makita is at the top of the game I'd bet.

I lack a shop currently to be dickering about on electrical parts to really get into one although I do have the battery power here and a well thought out way to use it for climbing purposes. The top handle offerings would be my place to start and altering the chain speed will be your biggest hurtle if you ever expect to catch a tiny three cube hotsaw with a damn good chain on it. Start simple and try the least amount of chain, think thin and light, to get a cut finished repeatedly without breaking the chain. Torque is going to be your enemy with electric power. Tearing up sprocket noses will be next so stepping up to regular 375 will be your best bet once you have a baseline of test to follow. If you can get your chain speed high enough without shearing of the main drive then your going to need a professionally made race chain if you want to compete. The gear drive big chainsaws from the old days solved the bearing issues and pulling more drivers on extremely long bars. You may want to look at that aspect to keep your motor rpms up to avoid overloading and overheating. It will add weight and complications but I see that as must being your chain speed needs to be insanely high in feet per minute. Just my 2ct.
GL

 

[CuttySnark]

Agreed, lamb.
You'll find nothing going public from the factory R&D programs regarding these new designs. Makita is at the top of the game I'd bet.

I lack a shop currently to be dickering about on electrical parts to really get into one although I do have the battery power here and a well thought out way to use it for climbing purposes. The top handle offerings would be my place to start and altering the chain speed will be your biggest hurtle if you ever expect to catch a tiny three cube hotsaw with a damn good chain on it. Start simple and try the least amount of chain, think thin and light, to get a cut finished repeatedly without breaking the chain. Torque is going to be your enemy with electric power. Tearing up sprocket noses will be next so stepping up to regular 375 will be your best bet once you have a baseline of test to follow. If you can get your chain speed high enough without shearing of the main drive then your going to need a professionally made race chain if you want to compete. The gear drive big chainsaws from the old days solved the bearing issues and pulling more drivers on extremely long bars. You may want to look at that aspect to keep your motor rpms up to avoid overloading and overheating. It will add weight and complications but I see that as must being your chain speed needs to be insanely high in feet per minute. Just my 2ct.
GL

I'm asking about the big saws, but yeah, better to begin at the small end. Wont cost as much, for one thing, and still be able to learn a lot before going bigger

And I'm absolutely not against the idea of skipping a whole lot of scratch-building, by using an existing saw and just swapping in a custom motor. It wont look as nice, but that approach will get things going a lot faster

I bet I can find a dead saw for free, if I try

But building something from scratch allows avoiding tons of compromises when things refuse to go together because of unforseen compatibility issues

Actually, what I really should do is buy a Stihl MSA 220 C-B, then hotrod that platform. They also make a AR-1000 backpack battery that plugs directly into the MSA 220 with a short cable

 

[Lightning Performance]

I'm asking about the big saws, but yeah, better to begin at the small end. Wont cost as much, for one thing, and still be able to learn a lot before going bigger

And I'm absolutely not against the idea of skipping a whole lot of scratch-building, by using an existing saw and just swapping in a custom motor. It wont look as nice, but that approach will get things going a lot faster

I bet I can find a dead saw for free, if I try

But building something from scratch allows avoiding tons of compromises when things refuse to go together because of unforseen compatibility issues

Sure that is a given but are you willing to burn it down repeatedly?

Testing with the small stuff may just put you way above board imho vs a three cube or less.

Marrying old tech won't be very useful like a Skill 120V or 240V electric. The design and materials are inferior now days. Running that old **** off of a solar grid would be genius given parts are available to use one at the wood pile for farm chores. Getting your chain speed up is easy but producing a linear power delivery based on dual or triple rotor drives can flat out deliver more everything smoothly in a non weight limited package. I'd consider muti-motors or dual drives before singling out a single. You are thinking outside the box, yes?...

Just burn that box and maybe triple nipples are the answer or quad mods
Never seen a "stacked pack" of drive motors so get after it soon if you want to be the first.

 

[ballisticdoughnut]

Stihl released the MSA 300 in Europe. Seems like the first respectable battery saw so far, that I know of anyway. Not available in the states yet.

 

[CuttySnark]

Sure that is a given but are you willing to burn it down repeatedly?

Testing with the small stuff may just put you way above board imho vs a three cube or less.

Marrying old tech won't be very useful like a Skill 120V or 240V electric. The design and materials are inferior now days. Running that old **** off of a solar grid would be genius given parts are available to use one at the wood pile for farm chores. Getting your chain speed up is easy but producing a linear power delivery based on dual or triple rotor drives can flat out deliver more everything smoothly in a non weight limited package. I'd consider muti-motors or dual drives before singling out a single. You are thinking outside the box, yes?...

Just burn that box and maybe triple nipples are the answer or quad mods
Never seen a "stacked pack" of drive motors so get after it soon if you want to be the first.

Linear power delivery is trivial with BLDC motor drives. But is a linear torque output the best choice at all times?

I think a single motor will be the best choice for several reasons. Only two shaft bearings, motor controllers at the entry level will typically only have one output. Motor cooling is much easier when contained inside one single case. The advantage you claim by having multiple rotors is actually much easier to do in software with only a single rotor

Maybe later, when I should get to a point where having a multi rotor motor controller built to my specs makes sense, then we'll see something like that

For now, I'll limit my choices to COTS options. But there's plenty of those as it is!

Why not take the MSA 220 and re-power it with something like that 53HP RC motor mentioned earlier? Though I haven't checked it's kilowatt rating, so I don't know if it's fast enough. But there's other RC motors out there

 

[sean donato]

Modern electronic speed controllers are programmable. With a sensored version you can control motor timing, speed, braking, torque curve(we refer to this as punch.) And throttle curve. When the kids want to play with my savage, I just back the throttle and punch setting way down and let them have the remote. It's a real bugger to do this with a 2 stroke. Really gearing and cooling will be your biggest issues. Run time will be the next issue. There's nothing really ground breaking, it just adapting the tech to a suitable, reliable, platform.

 

[CuttySnark]

Stihl released the MSA 300 in Europe. Seems like the first respectable battery saw so far, that I know of anyway. Not available in the states yet.

Missed that, MSA 300. Nice! Stihl claims it's good for 2.5KW, or a little bit more than 3HP

But I have a hunch that the 220 might be a better candidate simply because 1st I do with the saw is rip the stock motor out and install something totally different. I'd use Stihls backpack adapter except it probably can't handle the power. So I don't even want the battery slot on the saw. That would be sliced out and replaced with a connector that might have been intended for a forklift, or something else

 

[CuttySnark]

Modern electronic speed controllers are programmable. With a sensored version you can control motor timing, speed, braking, torque curve(we refer to this as punch.) And throttle curve. When the kids want to play with my savage, I just back the throttle and punch setting way down and let them have the remote. It's a real bugger to do this with a 2 stroke. Really gearing and cooling will be your biggest issues. Run time will be the next issue. There's nothing really ground breaking, it just adapting the tech to a suitable, reliable, platform.

The saw only needs to make three cuts, in a log that can be as much as 30", as quickly as possible. So cooling might not be as critical as you might be accustomed to

To really push the limits, I'd be looking at BLDC motors up around 100HP, which is going to be a bit more than what a 6s lipo pack can handle

 

[sean donato]

The saw only needs to make three cuts, in a log that can be as much as 30", as quickly as possible. So cooling might not be as critical as you might be accustomed to

To really push the limits, I'd be looking at BLDC motors up around 100HP, which is going to be a bit more than what a 6s lipo pack can handle

6s would handle it fine, its getting an esc that will take the amp draw. Hence why we jump up to higher voltage in bigger motors. I was thinking more along the line of 12-16s. Helps keep the amperage down. And motors run cooler. Heat soaking is a big issue with the motors and esc, in rc application. Unfortunately there isn't room in them for extravagant cooling systems. A 100hp motor will also be quite heavy, actually at that I'd suggest twin motors just for packaging (still trying to keep it looking somewhat like a traditional saw) also would be easier on the motor(s) and esc. Making a master/slave esc is pretty common in twin motor set ups, although I haven't messed with twin motor set up. Seems to be more of a boat or custom large scale application.

 

[CuttySnark]

6s would handle it fine, its getting an esc that will take the amp draw. Hence why we jump up to higher voltage in bigger motors. I was thinking more along the line of 12-16s. Helps keep the amperage down. And motors run cooler. Heat soaking is a big issue with the motors and esc, in rc application. Unfortunately there isn't room in them for extravagant cooling systems. A 100hp motor will also be quite heavy, actually at that I'd suggest twin motors just for packaging (still trying to keep it looking somewhat like a traditional saw) also would be easier on the motor(s) and esc. Making a master/slave esc is pretty common in twin motor set ups, although I haven't messed with twin motor set up. Seems to be more of a boat or custom large scale application.

I'd be using a VESC, unless I find something better. Those come in different amp ranges. Their applications state that you can use one of their ESC's for anything from RC, skateboards, bikes, motorcycles and airplanes