More instrumentation

[BobL]

Been meaning to do this one for a while but only just go around to it.


The blue do-hickey is a temp gauge (I got it from an RC hobby site - thanks for the lead Martrix).
Sorry about the F readings - pics taken for an American site.
48F - so a regular cool winter morning for Perth

The temp probe is located in a small gap between two cylinder fins, just on top of the exhaust port. See red arrow.


I started the 880 and let it idle until the gauge read a constant temp - that took about . You can see 2200 rpm idle is a touch low. That took about 5 minutes but I don't think the whole saw had reached it's equilibrium temp.


Cranking the throttle immediately drops the temp indicating the cooling air is reaching the probe tip. I am reluctant to block the gap the probe sits in, any ideas of where else to place the probe?

Then I cut a slab - so it sure reached operating temp. The probe has a "hold max temp" facility which is nice - max temp reached was 182F

Then I let it idle to constant temp again - see the idle is now 2400 rpm - which is where it should be


Why did I do it - because I could and because I hope to assess thermal load on the saw when I'm cutting some big slabs.

[Burnsy]

I am sure you have invented some kind of gadget in that physics dept of yours that makes your days 8 hours longer than anyone else's

[Burnsy]

Nice work by the way - be interesting to see the difference in temp between different saws cutting the same timber.

[BobL]

Nice work by the way - be interesting to see the difference in temp between different saws cutting the same timber.

Thanks Mike - yeah plenty of scope to experiment with all these - teh ability to hold a max temp is really useful- even same saw cutting different wood will be interesting. Might have to start keeping a log book! (Har Har - )

[pjt]

Bob, always thinking or should that be tinkering
Apart from the. ooo ooo look at me temp and rev gadgets,
I would think it will be good for tuning the saw with the modified exhaust, just need to know baseline temps of the air between the fins and how hot that is gonna get

[Sigidi]

Bob you are just a legend aren't ya? That looks so cool. I once approached my dealer (who sold my husky to me) about getting a tacho fitted to Harry, but they said can't do it - too much vibration. So you've done what apparently isn't possible

[BobL]

Bob you are just a legend aren't ya? That looks so cool. I once approached my dealer (who sold my husky to me) about getting a tacho fitted to Harry, but they said can't do it - too much vibration. So you've done what apparently isn't possible

The same type of (induction) tacho has been tried by a few scooter riders and they say they lasted about 6 months before they die. No one really knows why they died but it is probably vibration although it could just be a bad batch of batteries. That's one thing I don't like about these cheap tachos is the battery is not replaceable but they are supposed to last for 5 years.

I have mounted mine on the wrap handle which has reduced vibration and so far so good. My idea was to just use it for tuning and then take it off but I find it quite useful while milling so I'm leaving it there for a while anyway. This type of Tacho counts sparks so it is very useful since it also tells you if you have spark! eg when I accidentally leave the kill switch on and flood the engine. With the tacho it shows zero rpm when there is no spark.

[Sigidi]

Yeah my Lucas has the same brand tacho, that's where I got the idea from, especially when you take into account my lack of chainsaw knowledge - I wanted a precise way to 'tune' Harry without having to take him to the shop or spend however long it needs to get my 'ear in'

[weisyboy]

where can i buy one of the tacos?

how mutch more can u get on that saw bob?

[BobL]

where can i buy one of the tacos?

If you do a search on google for "Sendec Tachometer" you will get heaps of hits. be careful the cheaper ones only go to 4k or 8k rpm. If you want to use them on a CS you need the faster ones that go to 16k rpm. I got mine from the US at "www.baileysonline.com/itemdetail.asp?item=17122&catID=" when I bought a heap of other CS parts . Many have built in hourly operation recorders which are good for servicing etc. The Sendec website show the range of instrumentation available.

how mutch more can u get on that saw bob?

Coming up - wood grain and ally dashboard