startrite bandsaw help please.

[9fingers]

Hi Mark,

One check to do when you have time is to run the motor with the blade removed. Firstly when you switch off, you should hear a clunk of the centrifugal switch closing as the motor slows and after that perhaps increased rubbing noise. This is normal and to be expected.

Next run the motor for a long period - longer than you normally would before the thermal cut out opens.

With the motor unloaded, does it trigger the thermal switch and/or get nearly as hot as when it is running the saw?

These test are to try and check if the starter capacitor is being switched out properly. If you suspect the switch, unplug the power, take off the cowl covering the fan and remove the fan blades. Under there should be a dished cover held on by a few screws. Remove this. and you should find the switch.

Keeping hands/kids/pets well away, run the motor and watch the switch. It should open when the motor gets up to speed, possibly with a little spark from the contacts and then re-close as the motor slows down. it is quite safe to run the motor without a fan for a few minutes but NOT long term.

Try that lot and see how you get on.

Bob

 

[dickm]

a quick update on the saw.

i took the back cover off the saw today and dismantled the tensioning system to get access to the motor and pulleys, after reading the manual i have discovered that the quick release tensioning lever has been broken and rendered un-useable.

my intension was to put the saw on to the lower speed, however i discovered that as the motor`s rpm is twice as fast as the original motor, the previous owner had put a larger pulley on the motor end to compensate for this. but as the motor pulley is larger, the belt wont stretch over the lower speed pulley even with the motor adjusted as close to the pulley as possible. if that makes sense :?

Er... am I being thick, or is there something wrong there? If the replacement motor was faster, surely the pulley on the motor should be smaller to compensate????
It sounds as if there could be a more-than doubling of the blade speed, with corresponding loss of torque. So maybe just getting the right two step pulley would solve the problem? I can measure my pulley if it helps - also pics of the tensioning mechanism if that would help.

 

[sparkymarky]

hi dick m, that makes sense regarding the pulley size, if you could get a measurement on the motor pulley size that would great.

i`ll try to take some pictures of the tensioning system tomorrow.

cheers, mark.

 

[sparkymarky]

i`ve spoken to a machinery repair engineer today who has informed me that the original speed of the motor would of definitely been 2850rpm not 1425rpm which is good news as that means i have the correct speed motor.

the bad news however is that the motor pulley is a two step pulley not a single step pulley as shown in the pictures, to replace the pulley would be £85+vat=p&p, i would then need to get a engineering firm to bore the pulley and key it, to get it to fit the axminster motor, he wasn`t keen to give me the sizes on the replacement pulley needed. the current pulley measures 107mm to the furtherest out size diameter. so if anyone could get a measurement i would be very grateful.

the broken belt tensioning system i have overcome by using a pair of water pump pliers on the teardrop shaped nut, and adjusting by lifting / pressing on the motor assembly. so that is no longer an issue.

i have also dug up this post from 2002 (startrite-352-bandsaw-pulley-size-t49531.html) but been left confused as two different measurements have been given but i`m not sure which one suits which speed of motor, 6" & 4" or 4" & 2"

i have included a few pictures on the bandsaw for reference.

cheers, mark.

 

[dickm]

Had a quick check on the pulleys on my machine, and their outside diameters are 4" and 3". So assuming your m/c has the right pulley on the bandwheel, the 107mm one should be spot on for the "normal" higher speed.
If you are looking to get a new step pulley, Picador used to supply them for much less than the figure you quoted. Don't know if they still exist, but it might be worth just asking your local bearing/power transmission suppliers, numbers from Yellow Pages. Bee-line bearings in Milton Keynes used to be quite helpful, and there is probably an equivalent near you.

 

[sparkymarky]

hi all i know i`m digging up a oldish post here, i`ve now today sorted the problem with a 2 step 3" - 4" pulley. i bought a 19mm 4 step pulley from rdgtools and had the local engineering firm mill the down to 2 step`s and add a keyway for the motor shaft, total cost for the pully £35. had a quick test session on some 4" thick green hart with no problems and no scorching as before on the higher speed so all is looking good.

thanks for the help everyone.

cheers, mark.

 

[9fingers]

It always good the hear of a happy ending!

Bob