Centrifugal clutch on the 542iXP

DHansen · January 13, 2025, 06:36:02 PM

I asked on another thread but will start a new thread on the topic. I have a 540iXP and like it for what it is, rear handled, easy and convenient. Wish it had a low bar oil level indicator warning light. But the 542iXP has two updates that the 540iXP does not. One it has a centrifugal clutch and second it has a low bar oil warning light. Just looking for information on why or what is the benefit of the clutch on an electric motor? I can understand the clutch adding additional rotational mass that would add in cutting force when things get tight or heavy handed. I understand the motor spinning before the chain engages, but I thought electric motor develop max torque instantly. I did also pick up a T542iXP (top handle) but have not cut with it yet. Any input on these saws is welcomed.

Thank you, David

rusticretreater · January 13, 2025, 07:46:58 PM

Electric motors have more torque overall, but do not develop max torque at startup rpms. There are electronics that boost current during the start cycle to get the motor turning and ease off when higher rpms are reached. The centrifugal clutch will keep the load off the motor when it is not at usable torque rpms plus perform all the other actions of a clutch as well.

Dave Shepard · January 14, 2025, 01:17:25 AM

I have also wondered why it had a clutch. I have the M18 top handle. No clutch, and I'm not sure why I'd why one. Most Milwaukee OPE boasts 0 to full speed in under a second.

Al_Smith · January 14, 2025, 07:56:54 AM

I'd guess that saw uses a brushless DC servo motor but I've never seen the saw in question . DC motors are not to be confused with standard AC motors you might see on your furnace blower .Some DC motors will effectively be full power at any speed some are not .DC horse power rating is not the same as a say an internal combustion engine .Many will argue that fact but effectively electric to gas will be about a factor of three .In other words one HP rating on electric will be about three gasoline .
I'll give you an example .Of my many interests I have a 36 volt DC golf cart the motor rating is only 2 HP but the same cart in gasoline is around 8 HP .On a full charge my cart will out run the same machine were it gasoline powered .Now of course after a period of time the batteries will drain and it won't run as fast .That cart uses a series wound DC motor .The advantage is it doesn't need oil,gasoline and it always starts no matter how cold it gets .Plus it only costs pennys per hour to operate .
My only battery saw is a micro about the size of a small battery drill .While it's as handy as a pocket in a shirt it's not an oak slayer just a handy little tool for small jobs .That one does not have a clutch .

DHansen · January 14, 2025, 08:57:11 AM

Appreciate the added comments and information. The owners' manuals on both models list 24m/s or 78.7 fps as top chain speed. Both list the same 36 volt DC brushless motor. The 542iXP is more than a pound heavier than the 540iXP.

I have never thought there was any delay when hitting the trigger to start cutting. Compared to the RPM increase (throttle response) when throttling up a gas saw. I have cut with the Ryobi, Milwaukee and Husqvarna electric saws. All performed very well. They will not cut as fast or produce more work output as a gas 40cc saw can but are useful for the tool they are. They work nice when starting and stopping often or setting the saw down often. Cutting larger stuff is not efficient and is like just saying you could do it. At a point it is just more efficient to grab the correct tool for the job.

DHansen · January 19, 2025, 12:10:22 PM

DHansen · January 19, 2025, 12:17:11 PM

Comparing the 540iXP and 542iXP, it was 6°F and first thing I noted it the low bar oil warning light does not like the cold weather. Light was on most of the time even with oil in the bar oil tank. Will need to cut with it more to determine the oil warning lights usefulness. What good it if I have to look anyway. At this temperature I was getting 45 minutes cut time with each battery cutting 12" to 6" red oak. Might be my imagination, but the 542iXP seems to deplete the battery faster. I am also not convinced the clutch make much of a difference in what I have been cutting. But I do like both saws.

DHansen · January 19, 2025, 05:12:26 PM

Cutting today on diameters that I would normally grab a gas powered saw to do. I wanted to push the battery chainsaws further and see if the centrifugal clutch made a difference. And it does if you are pushing the limits. The 540iXP without the clutch will stop cutting and you have to release the trigger and reapply the trigger to start cutting. If you didn't let up on bar pressure in the wood it will just stop again before even spinning the chain. And you have to repeat the process of letting off the trigger. On the 542iXP, you can just keep the trigger pulled and just let up on bar pressure, the saw will just keep cutting. The bar oil level warning light worked well today. Photos to show diameters.

DHansen · January 19, 2025, 05:18:29 PM

DHansen · February 16, 2025, 07:05:41 AM

The low bar oil warning light has been unreliable is cold weather. Temps at 5°F or colder and it will indicate low bar oil level when it is not low. I have only been using Husqvarna Cold climate bar oil in this saw. I will switch to a synthetic bar oil and see is the warning system operation improves. When the saw is warmer the low bar oil warning system works fine. This was a feature that I thought I wanted and thought would be a benefit. Not so sure now.

rusticretreater · February 16, 2025, 09:18:13 AM

Better warned than not.

Old Greenhorn · February 16, 2025, 09:50:15 AM

We have been finding that in the cold weather these battery saws do not use much bar oil because even the thinnest mix will still not flow properly when cold. So we switched over to canola oil and thinner stuff like that. The battery saws generate almost no heat at all and the oil never warms or thins out.
I predict that at some point there will be a different bar oil mix for electric saws.

DHansen · February 16, 2025, 12:27:48 PM

I have been using Husqvarna cold temp bar oil, but just today switched to Amsoil bar oil. It does pour better at the same temps comparing how the product is poring from the one gallon container. Very noticeable difference. 8° F current temp at noon.

arojay · February 17, 2025, 10:41:08 AM

Just curious; as the battery draws down, do you lose the power/rpm required to engage the clutch, before the battery is completely discharged?

DHansen · February 17, 2025, 10:48:44 AM

I see no decrease in performance until the red light comes on and it shuts down. There is a bar graph of 4 leds showing battery level. Cuts the same at one bar or four bars. Very happy with performance.

Old Greenhorn · February 17, 2025, 12:16:35 PM

There are a few things on these battery saws that we all have to adjust to, some of which are easier than others and the cutting habits are one. It either cuts at full power or none, at least on the Milwaukee saws. There is some fancy monitoring stuff built into these saws so that when you reach that minimum charge, it just won't run the saw at all. This prolongs battery life. Another difference is if they draw too much current for too long they will also shut down. When that happens, the saw needs about a 10 minute rest depending on ambient temps. This prevents burning up the battery or motor. It's the main reason I use a gas saw if I have to buck the butt off a large saw log, so I avoid that. Remembering to put bar oil in is also a learning curve. These saws like to run WOT and running slower isn't really good for them, but you can do it.

DHansen · February 17, 2025, 01:32:36 PM

Both of my Husqvarna battery saws have an eco button for lower consumption, slower chain speed and longer run time. I never have used it. 78 or 79 FPS on regular run mode. I have not experienced any over working that required the saw to cool down. But I have not cut heavily in high temps with either of theses saws.

DHansen · February 17, 2025, 02:53:55 PM

With the Amsoil bar oil and at -11°F the low bar oil warning light is functioning correctly. Will try a few oil bar tank refills. Then switch back to the Husqvarna bar oil and see if the warning light issue returns. I know this is below Husqvarnas recommend low temp operating range. But I have work to do.

Big_eddy · February 19, 2025, 02:22:51 PM

Back to the clutch question. What advantage does it give?

I have a 535i (no clutch) and so far have been very impressed with it. We started with a full battery cutting dead ash as a test (up to 12" dia) and found that we were able to cut almost a half a cord on a charge. I buried the 14" bar in a 16" oak log, and it cut straight through without slowing down or stopping / overloading 5x in a row. You need to have the chain off the wood when you first pull the trigger, but once the chain is moving, it powers through regardless of load or pressure on the bar.

So why the clutch? Husqvarna doesn't help us. They give no reason or explanation as to how it's better, although they do like to advertise it has one

Btw - I've found I often grab the electric chainsaw inside the shop to quickly trim a 2x to length or make some other quick non-precise cut ..... One of the unexpected use cases I've found since I bought it. Quick, easy, no noise or fumes, and way faster then a handsaw, skilsaw or reciprocating.

DHansen · February 19, 2025, 02:52:23 PM

This is the best way I can describe the difference between the two saws that I have. The one with out the clutch, if I bury the bar in red oak and use the dogs to apply too much pressure, the chain will stop. And the motor will also stop. As I let up on bar pressure the chain will not restart. You must release the trigger and reapply the trigger for the motor and chain to start spinning. The one with the clutch you can just release bar pressure from the cut and the chain with take off again. No need to release and reapply the trigger.

DHansen · February 19, 2025, 02:53:21 PM

I do not see a big advantage to the clutch or the bar oil warning light.

Big_eddy · February 19, 2025, 03:34:02 PM

Quote from: DHansen on February 19, 2025, 02:53:21 PMI don't not see a big advantage to the clutch or the bar oil warning light.

The first time I swapped out a dead battery, I didn't even think about refilling the chain oil. We were well into the second battery and it was pretty low by the time I even thought about it. And this was AFTER I had read your thread commenting about oil. So I also thought a chain oil warning light would be a good thing. Now I make sure to top off the oil every time I swap batteries and it's no longer a thing.

DHansen · February 19, 2025, 04:50:47 PM

When I was walking out of the store with my first battery operated saws the selling dealer said to me, "keep and eye on the bar oil". I thought yeah like I would ever let that happen. Yep, first day using it I ran it out of bar oil. Live and learn.

hedgerow · February 20, 2025, 11:49:04 AM

Back when I would cut wood in the cold of winter I would always cut the bar oil with some Hyd to get it to flow a little better. I haven't needed any of my M18 saws in the winter. If I do I will cut some bar oil with Hyd oil. So far I have ran my M18 saws out of bar oil.