Well Well Well never Thought!

J

jmbfestool

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Joined
Jan 9, 2009
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6,646
Well I never thought the Kapex wouldnt run on a Generator really made me angry! I turned up at the job to day fitting skirting and architrave but I couldnt cut it!!! Its a 3 quarter driver  so I didnt want to drive home and pick up my Makita shops saw.

1. I plugged the Kapex in and turned the laser on and it worked I pulled the trigger the laser turned off!!! I was like  [scared]

2. I thought not enough power so I plugged the kapex straight into the generator with out a extension lead  [crying] no still doest work

3. I replaced fuse  [big grin] Yes laser turns on saw starts up!!!!!

4. Get architrave mark and cut  [eek] no kapex wont turn on! Check fuse with other tool fuse is okay!!!

5. okay kapex wont work!

6. Work mate turns up from other job! YES [smile] borrow his 12inch Dewalt (110v running from transformer of 240V generator)! Few! Works fine on    Generator

7. Im  [crying] all day thinking Kapex is broken! Get home Plug Kapex in and works fine!!  ( Its a 240v version)

Why wont the Kapex work on a normal size (takes two blokes to carry) generator. What size is a minimum generator to run a kapex

JMB
 
JMB,

It's probably nothing to do with the size of the generator, it could be the quality of the generator output.

Mains electricity is a sine wave at 50Hz (in the UK at least). The output from the generator might not be a sine wave, it could be square, plus the frequency could be off. That might affect the electronics. I don't know though, that's just a guess.

The Kapex is rated at 1600W - if the generator is rated above that, then it's not a problem with the power output.
 
jonny round boy said:
JMB,

It's probably nothing to do with the size of the generator, it could be the quality of the generator output.

Mains electricity is a sine wave at 50Hz (in the UK at least). The output from the generator might not be a sine wave, it could be square, plus the frequency could be off. That might affect the electronics. I don't know though, that's just a guess.

The Kapex is rated at 1600W - if the generator is rated above that, then it's not a problem with the power output.
Click to expand...

I had a thought its something to do with the electronics more so than the watts cus Dewalt is high watt and my makita but still I will have a look at the generator 2 moro and see what the output is. Just strange it did start once but it could just had enough to go. All the other times it wouldnt even make a noise like as if their was no power at all.

Cheers

JMB
 
This was discussed before. Rick Christopherson posted an explanation about why the Kapex's electronics don't like generators.  I tried tracking down the thread but I couldn't find it.
 
jmbfestool said:
Well I never thought the Kapex wouldnt run on a Generator really made me angry! I turned up at the job to day fitting skirting and architrave but I couldnt cut it!!! Its a 3 quarter driver  so I didnt want to drive home and pick up my Makita shops saw.

1. I plugged the Kapex in and turned the laser on and it worked I pulled the trigger the laser turned off!!! I was like  [scared]

2. I thought not enough power so I plugged the kapex straight into the generator with out a extension lead  [crying] no still doest work

3. I replaced fuse  [big grin] Yes laser turns on saw starts up!!!!!

4. Get architrave mark and cut  [eek] no kapex wont turn on! Check fuse with other tool fuse is okay!!!

5. okay kapex wont work!

6. Work mate turns up from other job! YES [smile] borrow his 12inch Dewalt (110v running from transformer of 240V generator)! Few! Works fine on     Generator

7. Im  [crying] all day thinking Kapex is broken! Get home Plug Kapex in and works fine!!  ( Its a 240v version)

Why wont the Kapex work on a normal size (takes two blokes to carry) generator. What size is a minimum generator to run a kapex

JMB
Click to expand...

Its due to the variable speed module on the Kapex I had it with a router once it went haywire ona generator
 
Joiner, etal.

Novice woodworker that I am, and knowing nothing about electronics, I have a question, not necessarily regarding this situation specifically.

If in fact there is incompatibility between a tool and the generator, is it possible for the tool's electronics to suffer repairable or irreparable damage?

Thanks.

Neill
 
If it had been a properly sized Honda generator, I'll be you it would have worked fine. Those things are amazing.
 
Neill said:
Joiner, etal.

Novice woodworker that I am, and knowing nothing about electronics, I have a question, not necessarily regarding this situation specifically.

If in fact there is incompatibility between a tool and the generator, is it possible for the tool's electronics to suffer repairable or irreparable damage?

Thanks.

Neill
Click to expand...

Thats what worried me as well really but when I tried it at home it seems fine nothing wrong with it.
 
Brice Burrell said:
This was discussed before. Rick Christopherson posted an explanation about why the Kapex's electronics don't like generators.  I tried tracking down the thread but I couldn't find it.
Click to expand...

I did have a quick search and found nothing thats why I posted my topic ofcorse.
 
Brice Burrell said:
This was discussed before. Rick Christopherson posted an explanation about why the Kapex's electronics don't like generators.  I tried tracking down the thread but I couldn't find it.
Click to expand...

I had a search around and found  Christopherson but on a different topic do you think it might be this forum u might of read just they are on about inverters.

http://www.talkfestool.com/vb/festool-tools/527-kapex-wont-start.html

JMB
 
Brice Burrell said:
This was discussed before. Rick Christopherson posted an explanation about why the Kapex's electronics don't like generators.  I tried tracking down the thread but I couldn't find it.
Click to expand...

I don't recall making such a posting, nor have I found anything on this topic I have written anywhere. So I suppose that is why it is not listed. (Oh, I was reminded a moment ago that I did make a similar posting, however, it was related to running an MMC controlled tool from a power inverter. That is not the same as a generator.)

First off, the power output from an electromechanical generator will be a true sine wave. It is after all the mathematical definition of a sine wave. (A power inverter will not produce a sine wave, and that was the basis of a previous discussion.)

The only thing myself and a member of the service department could surmise is that when the saw is first started, the MMC electronics package will see a sudden droop in frequency as the generator is loaded. Or similarly, the governor on these small generators is not holding frequency steady in the first place. I am only speculating about this, but the MMC might be using the incoming AC frequency to synchronize the Pulse Width Modulation to provide a smoother variable speed output signal to the motor. If they were out of sync, the motor would be receiving spikes of power every few cycles, so this does stand to reason. If this is true, then it also stands to reason that the MMC would shut itself down if it was unable to lock on to the incoming fixed frequency it is expecting to find.

My guess is that the problem is not related to the size of the generator (which is a huge issue with induction motors) but instead to the quality of the generator's governor. Granted, the smaller the generator, the more susceptible the engine rpm will be to sudden changes in load. Larger generators will have enough rotational mass to hold rpm (frequency) for the instantaneous changes it sees.
 
jmbfestool said:
Brice Burrell said:
This was discussed before. Rick Christopherson posted an explanation about why the Kapex's electronics don't like generators.  I tried tracking down the thread but I couldn't find it.
Click to expand...

I had a search around and found  Christopherson but on a different topic do you think it might be this forum u might of read just they are on about inverters.

http://www.talkfestool.com/vb/festool-tools/527-kapex-wont-start.html

JMB
Click to expand...

Yes, that was the discussion my friend at Festool reminded me about while I was typing up my previous response.
 
Soooo I have to make a decision then I take it.

But......  my kapex is 240v  if I was to buy 110v would I still have the same problem?!  both being plugged in directly into the generator?

Would I have the same problem with 110v plugged into a 110v transformer which is plugged into a generator running 240v???

Just saying now but I dont know!!! If a 110v kapex will still have the same problem!

Would buying a good HONDA generator solve the 240v kapex problem?!?!I can tell my self I might need a generator in the future any way!

If I was to go to another job I will now always ask if they are running on a generator and leave the kapex and take my makita instead because I dont want this to happen again it really slowed me down to day I didnt do as much work as I wanted feel really bad being on a day rate.

JMB
 
I had issues where a Fein multimaster would not operate unless some other device was putting a load on the generator. We used a 250 watt shoplight. It would appear that there was just not enough load with the Fein to kick the generator off of idle.
 
Rick Christopherson said:
Brice Burrell said:
This was discussed before. Rick Christopherson posted an explanation about why the Kapex's electronics don't like generators.  I tried tracking down the thread but I couldn't find it.
Click to expand...

I don't recall making such a posting, nor have I found anything on this topic I have written anywhere....
Click to expand...

I stand corrected, sorry about that Rick.
 
As I understand it, there are three types of generator.

The least expensive are 'site' generators, such as Honda's EC range.  They output a truly horrible waveform and are suitable really only for lighting.

Next up are smoothed generators, such as (most of) Honda's EM range.  They output close to a sine wave and should work with most power tools.

Both of the above types of generator need to run at full speed to give the correct frequency.

The final type are inverter generators, such as Honda's EU range.  They take DC from the alternator and electronically turn this into AC.  It is very a very pure sine wave (usually better than mains electricity).  Furthermore these generators only run as fast as they need to to fulfil the power demanded; reduce the draw and they go back to tick-over.

I have no connection with Honda, other than I really like their EU20i!

Andrew
 
I was working in a client's house the other day and lugged the kapex (unwillingly) up the external staircase to cut skirting.  I'd been using a Festool vac and various sanders and the TS 55 all week.  The Kapex wouldn't work.  At first I nearly had heart failure thinking it was broken, but eventually decided it might have been the very dodgy 1960's French wiring (with no earth)
The client kindly hooked up and extension cord from his garage and all was well.  I am stilled puzzled.

Carting the Kapex around for just a few lengths of skirting has had me eyeing up the Metabo KS 216 - its about ?75 here, weighs 9kg and looks reasonable.  Any suggestions anyone. (I have the small Symetric Festool saw but it will only do architrave)

Richard
 
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