MikePepler

7 hours ago, spandit said:

Didn't realise you were a member on here - been reading your blog for a while. Just seen you've posted a video of some coppicing you did with an electric saw

Thanks for reading, I don't get much time to post on it at the moment... Yes, used the battery husky for 99% of the coppicing last winter. Slower than the petrol but quieter and no exhaust fumes to inhale! ?

Just now, openspaceman said:

Great

 

Perhaps one day we can have a separate discussion about personal renewable energy on another thread?

Certainly, feel free to start one and tag me in it. ?

23 minutes ago, dumper said:

Digital motors have no windings they use magnets so removing the heating element, they are generators in reverse if they are spun without power they create electricity, the best are single phase running as three phase. They do however require a board to run simply wiring up to the current won’t work they just stay still.

Sorry, all motors have windings (or coils). It's the flow of current through these that generates the fluctuating magnetic fields that 'push' against the fixed fields of the permanent magnets in a brushless motor. The electronics are to sense the rotor position, back emf, etc. and switch the current in the windings to make the rotor spin. 

If you're sure you've found something different, please post a link to some technical details. Just saying it exists isn't enough I'm afraid. 

8 hours ago, openspaceman said:

What's the difference between a brushless and a digital brushless motor?

As far as I'm aware, 'digital motor' is a marketing term invented by Dyson. All brushless motors are electronically controlled. There's a good explanation here https://en.wikipedia.org/wiki/Brushless_DC_electric_motor

On the other points, unless a motor uses superconducters (which require liquid nitrogen cooling) then they will never be 100% efficient, and the losses will be through heat due to resistance in the windings. When I'm not in the woods my day job is in renewable energy, and I previously worked in electronic engineering, so I do have some experience in this. 

1 minute ago, dumper said:

The new motors do not generate heat I picked up a motor that had been running hard for an hour wasn’t even warm. It’s money and politics stopping improvements

OK, but even if that's the case, 100% efficient is still only 10% more than with current motors. Then after that you need more juice from the battery to get more power. 

1 minute ago, dumper said:

The new generation are digital brushless a whole different motor

Sure, but if efficiency is already 90%, there's not much room left for improvement - you can never quite get to 100%, as some of power is always lost as heat in the motor windings. I'd expect the main improvements to be around making the motors smaller and lighter. 

I think we'll be waiting a while anyway, husqvarna have updated their saw already but it doesn't look much different... 

5 minutes ago, dumper said:

No you need to use the power in the batteries better the lithium iron batteries are good

Well, brushless DC motors are already 80-90% efficient, so while there's some room for improvement you're still going to need better batteries (in terms of kWh capacity, discharge current, weight, and volume) to get more kW of power delivered to the chain. But there's improvements every year, and I assume the manufacturers could put better cells into the existing battery casings so they'd be compatible with existing chainsaws. 

13 minutes ago, dumper said:

It’s not batteries but motors that are the problem various companies have tied up ultra efficient motors with patients and are sitting on these until the completion and the Chinese try to catch up,  saw a video last week of a motor moving a 800kg load with only one moving part.no brushes, no bearings.

 

 

 

 

You need a better battery too, to provide the capacity for a more powerful motor.

20 minutes ago, peatff said:

So you can look at the battery as a very expensive fuel can that takes a long time to fill with fuel which is cheap but not available everywhere. Depending on the charger it can take between 45 minutes and 3 hours to charge to 100% so you need the AL300 charger at £60 as well so for 2 batteries and a charger you are in for about £300 plus the saw which is "equivalent to a 30cc saw" it's not sounding very tempting yet.

Depends on the value you put on not breathing in carbon monoxide, particulates and unburned petrol ? But I agree, there is still some way to go before battery saws can do all the jobs required.

11 hours ago, peatff said:

 

So you could be looking at chainsaws with pedal assist  Brilliant idea. When battery prices come down and technology gets good enough they will be a better proposition, storage needs to go up and charging times need to come down before they can replace just slopping another pint of fuel in and away you go again. I know the price of fuel is high compared to electricity to charge a battery but you don't need to buy £120 of fuel at one go and it's there straight away not in 30 or 40 minutes or whatever time an AP200 takes to charge.

My view is that charging time isn't too important, it's the cost. I can't charge a battery in the woods anyway, so have two, then charge them at my leisure at home. But you then end up spending quite a bit on batteries. Maybe if there's ever a reasonably priced electric 4x4 then charging from it in the woods might be feasible. Charging from an inverter on a petrol/diesel engine would be very inefficient.

1 minute ago, scbk said:

I've no doubt that in 20 years time we'll all be running about with battery chainsaws, hedge cutters, etc, and we'll be trying to explain to youngsters what 2 stroke was.

 

Ps just fitted an ebike kit to my bicycle, wow, great fun! 

Yes, I think so. Tesla cars are already faster than any petrol car for the same money, and are coming down in price. I've driven a BMW i3, and the experience is great. E-bikes are potentially even better though, you feel like you have bionic legs! I had an early model 10 years ago, would like to buy one again soon... All these developments should fed through to the chainsaws - e-bikes are quite similar in terms of batteries and motors. I guess the chainsaw manufacturers might take a while to do new models though, I guess they'll want to earn some cash from the existing designs first.

For the chainsaw, the only points that annoy me are the lower power (I'd rate it equivalent to a 30cc saw) and the low-profile chain/bar they sell it with. But for me these are outweighed by the plus sides most of the time.

I realise this thread has gone quite some way off the original topic! ?

2 minutes ago, openspaceman said:

Understood and they are already handy things for higgling about or just kept by the chipper to sort the odd awkward bit to feed plus they're getting better all the time.

I coppiced about 40m3 (stacked volume) using the battery saw this winter, and it stood up to that OK. I do look forward to the day when they can get a bit more power out of them though. I think the limitation at the moment is the battery - there are plenty of compact electric motors that can deliver several kW, but they'd drain the battery too fast and reduce its cycle life too. Maybe the battery tech will move on over the next few years, seeing as the electric car sector is growing so fast.

16 minutes ago, woody paul said:

From you video I can not see the point of not cutting lower to start with. You will run out of battery power soon cutting that way. 

Yeah, you can't see the curvature in the tree there, and there wasn't much in this one. Anyway, I made the video to show a battery saw felling a tree, rather than as a tree felling demo. 

Battery life has been very good actually, I've got two 9Ah batteries, and not yet managed to empty them both while coppicing, though that's allowing for time spent splitting and stacking wood, moving brash, etc. Logging is probably a better test, and I've found filling a 1m3 trailer uses about 3/4 of a battery - sometimes more, sometimes less, depending on log length and how hard the wood is.

12 minutes ago, openspaceman said:

I expect you wear green welly boots too, sloppy workmanship but I'll not have a hissy fit like TCD  even though I agreed with him.?

 

Chestnut coppice is a relative newcomer but the  niche created by coppicing was largely one of artificially removing nutrients available at the surface to the herbaceous layer [1]. Underwood was the province of the poor people and they made use of everything they had bought. As such on the heavier soils that had remained in woodland had an impoverished surface layer, it is this and the regular baring of the ground to let sunlight in that gives plants like bluebells a competitive edge over grasses and brambles.

 

The minerals for the woody species get replaced by mycorrhizal associations with the deeper tree roots and return to the surface as leaves drop in the autumn.

 

[1] this also meant little bonfires didn't happen in coppice cants

I know it's best to cut as low as possible, but I find the curvature and thickening at the base of chestnut stems annoying when I'm processing them later for firewood (which is what most of the wood is used for, and I use a Truncator for processing), so I tend to cut a little bit higher and leave the chog behind. Is there any reason not to? Happy to improve my knowledge if so.

I stopped having fires about 10 years ago, saves time and avoids breathing in lots of smoke and killing the seeds in the ground where the fire would have been. I've seen wrens, robins and mice making good use of the brash piles I've left instead.

20 minutes ago, openspaceman said:

and why you have a chogs left over too.

You mean the lump off the bottom of the stem? I leave them in the woods to rot for biodiversity benefits.

8 hours ago, scbk said:

Mike Pepler, the celebrity!

 

Recognise the name from years ago on youtube!

Hardly! ?

But as you mention it, here's a video to show why I ended up with a spare 346xp in first place. Battery saws won't be for everyone or every situation, and I still have a working 346xp and 570 as well, but the electric one has done well enough over this winter that I felt I no longer needed two 346xp's:

4 minutes ago, billpierce said:

Worth a good look at this pot as if this is salvageable the OEM one is the best quality one you'll get. There is a meteor stockist in Greece who is reliable, although cant see it listed from him on Ebay.

 

There are 2 sizes one for the older 40somethings cc 346s and one for the new silver side cover 50cc ones. Cant remember exact bore diameters but easy enough to Google.

 

You'll save 80quid atleast if your pot is reusable. 

 

 

Thanks Bill, and @Stubby, I've emailed @spudulike to ask for some details. I've got the newer model, with the silver side. I guess if I decide to send it to Spud for porting he may be able to advise on the pot.

5 minutes ago, Stubby said:

Send it to Spud for a rebuild and port job then sell the other as a working saw . They are saught after , being non AT and the last of the 3 series saws .

Yeah, I gathered they are popular saws, and I've certainly enjoyed using them over the years. Roughly what does a port and rebuild cost, and what are the benefits in use?

3 minutes ago, billpierce said:

I'd probably give it a real thorough clean out ( all those shreds of metal out of crank bearings ) slap a meteor p and p on ( assuming the current pot is goosed?) Vac test and keep it as a working spare ( inevitably more useful) or sell it as working.

Dont know how much it's worth in that state. If given the option I wouldnt want to pay more than 50 quid. New p and p required and possibly big end bearings/crank issues
 

Thanks Bill, that's very helpful! A thorough clean is certainly needed, or it would be trashed again the first time I fired it up. The pot is visually OK, but it would make sense to replace it at the same time as the piston. Is there a good place in the UK to buy the Meteor kit if I go down that route? Most of the stuff on ebay is other brands, with the Meteor stuff coming from the USA. There also seems to be a range of cylinder bores available...

Done! I've been using a battery chainsaw (536LiXP) for nearly a year now, alongside a couple of petrol ones, and it's been doing a great job.

Hi All,

I've been lurking here for a long time, reading interesting discussions. However, I've got a question I'd be interested in people's views on.

I've got a couple of 346XP (newer version) chainsaws, one bought in 2007 and the other in 2009. Having recently bought a 536LiXP, I decided to sell the older 346XP to a friend who was just starting in forestry. But, 6 weeks later it stopped dead while he was cleaning up a tree stump, and the engine wouldn't turn over. My assumption was not enough mixing oil, but we took it apart last night and found the piston had broken (see attached images), with no sign of overheating damage to piston or cylinder.

So... I'm refunding him his money, as I sold it thinking it was working but promised that if it died in the near future I'd pay him back. And now I'm not sure what to do from the following options:

1. Have a go at repairing it myself. Problem here is I don't really need it (which is why I'd sold it) - I have a working 346XP, a larger petrol saw too and am trying to use the electric one as much as possible.

2. Keep it for spares for my other 346XP. But then I may not use any of the parts for years...

3. Sell it as it is for someone to repair or use for parts. It was in working order in all other respects.

4. Sell parts from it on ebay. (more money that option 3, but a lot more work)

Any thoughts greatly appreciated!

Thanks, Mike