Thread: Electric Chainsaw

Hi Hoover,

power means a lot for chainsaws. Electric ones can be very puny, with tiny chains and bars and motors with little power reserves. If so, they are plasticcy and little fun to work with. Budget machines often have budget solutions for nearly every component. Which means a flimsy oil pump, flimsy bearings, flimsy bar attchments, flimsy housing parts and sparingly built motors, since they contain expensive raw materials like copper. Chainsaws are typical tools for which investment pays off. In the long run you will be glad to have spent the extra money to obtain a machine that stays with you for many more years and doesn't let you down when you need it.

The Makita types are value for money. They already were so some 30 years ago, but they still are, thanks to the cooperation with Dolmar from Germany. Dolmar from Hamburg was the true pioneer, with Stihl in close pursuit, whereas many people think that Stihl was the originator. Dolmar brought petrol motor knowledge into the Makita organisation, which spawned a whole array of petrol driven chainsaws. Dolmar also yields bar, pump and drive technology, whereas Makita in return makes the electric motors for the electric Dolmar range. Thus there are several electric chainsaws models in either red Dolmar and blue Makita styling, which are in fact identical constructions.

My personal favourite is the Stihl E220C (presently evolved into the MSE 220 CQ).
It is a sturdy 3/8"chain model with a 2200 Watts motor. It started off as the E20 some 20 years ago, with a 2000 Watts motor. From the range of E10 (1000 Watts), E14 (1400 Watts) and E20, the latter was the most powerful. Some years later the motor was souped up to 2200 Watts and the model was remaned E220. There also was a soft-start version (fitted with a starting current limiter) named E220C. This limiter is an electronic module containing a triac (full wave AC control), with a fixed setting of approx. 70% of the full sine wave. This is enough to ensure that the startup current peak is reduced to 50-60%. The switch has a built-in time lag element with a second set of contacts, which close after one to two seconds. At first switch-on, the limiter module is connected in series with the motor, dampening the startup current peak and the typical startup jolt through the machine, giving the motor and the drive train a longer life. The second set of contacts bridges the module when the set time lag has passed. In that time the motor is supposed to have accelerated to 80% of full idle rpm, after which it is directly connected to the mains by the bridging contacts.

This two-step acceleration is often used in heavy industrial angle grinders as well, many times in combination with an oldfashioned wire wound ceramic resistor instead of electronics. The resistor is considered to be more robust and reliable than electronics, even today. The famous "MSfa" grinder range by Fein was the best known example from a few decades ago, but more modern machines by Flex (L2106VC/L3206C/L3208C) and Hitachi (G23MRU) are still fitted with resistors instead of electronics.

Around 2004 Stihl introduced "MS" (for "Motorsäge") as a prefix for every chainsaw model in its range, be it petrol or electricity driven. Thus the E220C became the MSE220C , but at the same time the obligatory quick brake system was added ("Q"). The electronic module inside the MSE220C-Q was also used to provide the braking function. This is done by very briefly reversing the motor armature's polarity, meaning that is fed a power burst in reverse, making it brake and stop very abrupt indeed. This reverse burst makes for some violent brush sparking and quicker wear of the brushes, which is even mentioned in the manual. I'm not very keen on electric braking through reversing, since it is also heavy on the copper commutator strips, which are not exactly cheap consumable parts. There was no MSE220C without the Q to be had, so i still stick with my older E220C, which has current limiting but no electric brake (and no mechanical brake as well, or that matter). In principal it would be illegal to resell it or to let others use it in Europe, but owners are allowed to use non-quickbrake chainsaws for themselves, since they are accountable for their own safety anyway.

The 220 is a workhorse. It has plenty of power and speed and its progresss is superb for an electric. The 3/8" pitch RSC (Rapid Super Comfort) type chain by Stihl is a pleasure to work with. Good performance combined with adequate safety and reduced kickback risk. Stihl's "Oilomatic" chains (with grooves in the drive notches for lapping up and transporting the oil to the joints) are brilliant anyway. No load idle speed of the 7-teeth sprocket is slightly above 7500 rpm and for nominal load intake (2200 Watts) you get 1400 Watts at the sprocket in return (1.9 true hp), with nominal load speeed of 6300 rpm. Those are nice statistics, so i can recommend this machine to you.

When having taking this machine apart or overhaul and maintenance, i was initially shocked by the large and course metal 10-teeth pinion on the motor arbour, engaging an even coarser ringshaped 35-teeth fibre reinforced plastic secundary gear (teeth arranged on the inside of the ring). A round 10-to-35 ratio is odd since it means that the same teeth often meet each other again and again, whereas comon gear practice dictates that the ratio should be deliberately odd (i.e. 9 or 11 to 35), to spread the effects of one tooth having been damaged or worn slighter more than the others. But i was also surprised at the small amount of wear for such a simple choice of gear layout. Prior to dissasembling the E220, i thought it was a typical solution for the homeuser types MSE140, 160, 180 and 200, but it seems sound enough for the 220 as well, which is targeted at professional users. When the 220's price is too stiff and the amount of use is not so intense, you could have a look at the MSE 180 or 200 as well. I find the 140 and 160 too light for more than seasonal cleanup tasks.

Lovely picture of the enthusiast's collection, including 400 Volt saws! I noticed a Stihl E30 on the top shelf and as it happens, i bought and restored a second such machine for my own collection a few months ago. There are two pics added below of the finished result and i can add more if you want. There is a story around three phase induction motor saws, which i would like to mention some details from.

Stihl's first chain saw was electric. In Germany, three phase power was made available to factories, workshops and yards as early as 1900-1910. Three phase power could shift Wattages that DC or single phase AC couldn't and selling it provided stable bread and butter for electricity companies.Money earned through companies was reinvested to spread out networks to consumers and their large prospect markets of lighting and household appliances. So many timber yards were fitted with three phase AC and one- or two man operated cutoff saws were lugged around for milling timber prior to treating it with thicknessers and circular saws. The E 30 was the last in the line of three phase one-man saws (attachments for two-man operation were available and bars as long as 150 cms were part of the E30's program). The final version of the E 30 features 3300 Watts intake for 2700 Watts output, spinning the 7-teeth sprocket at around 2780 rpm. So this is a slow saw but with plenty of torque. 2700 Watts outputs means that you carry around 3.7 real horsepower , which is fairly unique for an electric portable tool. There is no soft start and no brake system whatsoever, so you need to keep concentrated while using it. Between my 070 AV and this Stihl model, i'm equally fond of both.

Greetings

gerhard