Have I buggered my Kity? *** Update & motor help***

[dedee]

I've been ripping 2x2 douglas fir down to 2x1. 9 pieces 2.4m long. 2" is about the limit on the 419 and from the very first cut it seemed to be hard work, the blade would slow down even with little feed pressure and once or twice even stopped.

Initially I thought this could be a set up/adjustment problem with the riving knife or fence so I stopped a number of times to make adjustments but still the blade stalled. I do not think the blade was blunt as the cut, when done, was clean and smooth with no burning. The blade is a Stihl TCT and has not had much use beforehand and was not caked in resin.

At least twice the motor cut out after getting very hot, I let it cool right down and started again but after a while the motor started to make quite a loud screeching noise.
There is no wobble on the arbour and the blade still runs true.

Have I knackered the motor bushes or bearings? Can they be user repaired replaced? Or will I have to replace the whole motor?

TIA

Andy

 

[BradNaylor]

'Have I buggered my Kity?'


I sincerely hope not...

...getting my thumb caught in a table saw was bad enough!!

:lol: :lol: :lol:

 

[woodshavings]

Andy, the screeching could be the belt slipping.
The Kity should be able to cope with 2 inch stock, I would of thought the blade is suspect but you seem to have eliminated that. Does the motor screech with the blade disconnected?
John

 

[lugo35]

hi i would agree with john. tct tips may feel sharp to the touch but does not mean they are.
a new or sharp blade would cut DF easy

 

[CHJ]

dedee, that does not sound right from the word go.

My cheap and chearfull buget charnwood happily cut 4X2's and bigger (cuting from both sides) and you had to be very careless to slow it down so I would have thought the Kity would normally have laughed at 2X2, sounds to me that the motor may have been on the way out with shorted turns or something.

If you run it without load does the motor casing still get hot?

 

[woodbloke]

andy- I've got the K419 and it ought to deal comfortably with that timber and the quantity of material that you're ripping. I suspect like Chas has said that the motor may be on the way out - Rob

 

[dedee]

Oh Dear,

The motor does screech even without the blade. When I turn the arbour by hand I can hear the screech/rattle as well.
The belt does not appear worn nor is it slipping

Do I have to go to Kity for a new motor?


Andy

 

[CHJ]

Andy, check that the cooling fan has not moved and is binding on the shield.

Next step would be to split motor and see if rotor is binding or if bearings failed. If the former and bearings are good bin motor.

If it's bearings, should be no problem to replace, they may have got filled with fine dust, depends on motor construction and bearing shields.

 

[paulm]

How many teeth does the blade have ?

Ought to be no more than 24 or so ideally I believe if you are ripping any depth or quantity.

More than that will be good for crosscutting but will mean you have to feed the timber much more slowly when ripping, if indeed it will rip at all, and in any event will likely strain the motor.

Hopefully the timber is dry also and not wet as if wet the saw will struggle also........

Apologies in advance if grannies and eggs and all that

Cheers, Paul.

 

[woodshavings]

Andy, that does not sound good at all.....how old is the Kity?
If its over 3 years, then you will not have any recourse to the dealer.
I bet a replacment from Kity service agent will be expensive... get a quote!
Check out the cost of a replacment motor from the likes of Clarke etc, providing the fixing centres and spindle length & diameter are the same, this could be more economical. Alternatively, a motor rebuilder (from Yellowpages) may be the answer.
John

 

[dedee]

Thanks guys.

I guess I need to take out the motor for a closer look. I'm in mid-project at the moment (wood shelter) and should not need the saw again but I hate to leave this kind of problem unresolved.

The main Kity agent over here is in Rouen not to far away from the SIL so I looks like I'll have to give them a call as well.

Thanks

Andy

ps the Kity is about 10 years old I think.

 

[jasonB]

The pully on the end of the motor can come loose, I've had it on the saw and planer of my combi which has a lot of the same parts as the stand alone machines, If it gets too loose the key on the motor shaft will wear the metal shaft more than the plastic pulley.

As has been said you don't want more than 24T and make sure the riving knife is a couple of tenths of a mm less than the saw kerf. The plate thickness of the blade can also affect how it aligns with the riving knife.

Jason

 

[dedee]

Thanks Jason,
the blade was a 24t. As far as I can see the riving knife is a whisker thinner than the kerf.
I will see what the motor/shaft/pullley/fan look like later in the week when I take it apart.

Cheers

Andy

 

[TheTiddles]

I'm not sure of the laws in France but although buggering your kity is legal here it is highly frowned upon. :lol:

On a more mechanical note, take it apart piece by piece, checking everything, greasing what might need it etc... you'll normally come accross the problem before too long

Aidan

 

[dedee]

Full marks to Chas. The screeching noise was in fact the fan rubbing on the guard you can see the marks on the fins here. Why would the fan shift to such an extent to start rubbing on the guard?

I decided to take the motor off anyway but having never done this sort of thing before so I do not know what I am looking at.

This image either shows a washer which has been bent or is a spring to hold everything tight
I'd welcome advise.

This is the shaft bit all looks very clean.

A view of the inside from the fan end, again very clean.

A view of the other end with the shaft bit in place. There does not appear to be any play in those bearings

I am going to have to put the motor back before I forget how to and I'll buy a new blade and see how things are. I contacted a Kity agent over hear who quoted €200 for a new motor, it is an Italian GEM series from EL.PROM.

Is it possible that with no visible signs of wear or deterioration that the motor is no longer running as fast as before?

Edit, should the inside of the motor be oiled or greased in any way?

Cheers

Andy

 

[Racers]

Hi,
Does it smell burnt? if one of the windings has gone it might smell burnt.
Is the motor running slow? if it is the capacitor could be on the way out that might explain the apparent lack of power.

The only greese should be in the bearings at each end of the shaft.

PEte

 

[dedee]

Pete,
there is no sign or smell of burning inside the motor, but it is 2 days since I used it.
The capacitor? Would that the the white cylindrical thingy like this?

Is there any way I can tell if the motor is running slow other than my own feel and memory of how it sounded before.
Could the capacitor have burned out as a result of overloading the motor due to a blunt blade?

Andy

 

[CHJ]

The spring washer is just there to take up the free movement of the shaft, it allows for some expansion with heat.

If bearings are free running and no obvious rattles then they are good to go.

No grease or oil should be used inside the motor casing.

Field wires look in good condition, if there were shorted turns then you would expect to see dark patches and a distinct smell of hot varnish.

It looks like it is a two pole motor and if it is, should run at 2850rpm without any load.

As Pete mentions if it has a Run Capacitor in circuit, same as starter capacitor but a bit more robust to maintain torque under load then check it is not leaking fluid or short circuit with ohm meter.

 

[Racers]

Hi, Dedee

Thats the one, it can cause the motor to run slowly and lack power if its on its way out look for leaking like CHJ says but the best way to test it is replace it with another just get one of the same value looks like 16uF (16 micro Farads) 450 Volts#

Pete

 

[dedee]

Pete/Chas thanks again.

There is no leaking oil around the capacitor, all looks very clean.
The label states 2850 RPM so you are spot on there.

I do not have a meter of any kind so I may try and find/borrow one to test.
I've no idea where to buy a capacitor over here so that could be an interesting learning experience

I have just put the motor back in the saw and fired it up. It is running sweetly and sounds normal. I ripped a short piece of 2x2 ( not the same stuff as I did at the weekend unfortunately) with the same blade and it cut through it without problem.

I'll give it another sterner test at the weekend and see what happens.

I'm relieved that at the moment it does not seem that the motor is the problem.

Cheers

Andy