startrite bandsaw help please.

[sparkymarky]

Hi all, i have a startrite 352 bandsaw which i bought used around 6 months ago. the bandsaw originally had a 750w single phase motor however at some point in its life the previous owner replaced the motor with a axminster 240v 1100w 4 pole motor (http://www.axminster.co.uk/axminster-ax ... -prod29787).

At the moment the bandsaw is set to run at its fastest speed, the problem i have is when cutting thick stock it overheats the motor. it seems there is not enough torque to drive the band sufficiently.

I have bought a new bandsaw blade (tuff M42 3 tpi / 3/4") and have set it to track perfectly, anything over 4" though and the bandsaw starts to struggle.

should i switch to the lower speed?? if so how would i go about it? are there any on-line instructions?

cheers, mark.

 

[Mike Wingate]

On mine, I remove the metal motor casing. Use the cam lever to untension the belt and swop pulleys, retension the belt and replace the cover. You may not have enough power with that motor.

 

[9fingers]

If the original design used 1hp, then the 1.5hp axminster motor should produce as much if not more power.

Does the Axi motor have two capacitors inside the black box? If so, it is possibly a capacitor start, capacitor run type.

If the run capacitor, usually the electrically smaller of the two, has failed then the power output would be affected. I'm not saying that this is the problem but as you have a quality blade, then the motor does look to be at fault.

Incidentally how do you define 'Overheating' ? Modern motors can safely run at 60 degrees above ambient which will be too hot to touch.

Also make sure the cooling fan is clear of dust.

hth

Bob

According to the startrite manual, the 352 is fitted with a 2 pole motor and so it is possibly running too slow and it does not appear to be fitted with the ability to change speed,

 

[dickm]

If the original design used 1hp, then the 1.5hp axminster motor should produce as much if not more power.

According to the startrite manual, the 352 is fitted with a 2 pole motor and so it is possibly running too slow and it does not appear to be fitted with the ability to change speed,

My 352 did have a 1hp 3-phase motor, replaced with a 1hp single phase. Following a comment by Alan Holtham, it's run on the slower of the two speeds (two step pulleys) and just chomps its way through anything it's offered. With a decent blade, that is .

 

[9fingers]

Was it 2 pole or 4pole Dick?

Bob

 

[Mike Wingate]

2 speed, 750 watt motor, single phase. Cuts all wood, plastic, aluminium, bone really well. Axminster blades.

 

[9fingers]

2 pole or 4 pole motor Mike? Or are you saying you have a two speed motor?

Cheers

Bob

 

[sparkymarky]

thanks for the quick comments.

as far as the over heating goes when cutting through some 5" thick idgobo type stuff the motor will get very hot on the casing and then the bandsaw will shut down, the wood however does have a lot of resin in it which bungs up the blade (then taking ages to clean off). it`s kept free of any dust in and around the fan casing to help keep the motor cool.

i can only then restart the bandsaw after about half an hour of so, once the saw`s motor has cooled down.

my only thought was that as the saw originally had a 750 watt motor in it and now it has a 1100 watt motor, the rpm`s could be too high and that could be why its struggling. probably the original startrite motor was a better quality as well.

 

[9fingers]

Mark, what i am trying to get to the bottom of on your behalf is the number of poles of the original motor.

A manual I found online shows a 2 pole motor and only one pulley so single speed.
However other folk are saying it has two speeds but neither have responded on the power.

You ave not responded to my question on capacitors.

The speed of motors has nothing to do with the power. It is simply governed by the number of poles as you can read in my induction motor paper - see the footer of this message.

Bob

 

[sparkymarky]

ah ha bob i see know, sometimes it has to be spelled out to me

this bandsaw has two pulleys and had a 750w motor but after looking on the data plate and an extensive googleing i cant find any information on the original motors poles. perhaps someone might have a manual. [-o<

i think i understand how induction motors work now, i was working on the assumption that with increased speed the torque would be lower.

i will check the caps tomorrow i`ll have to clear the sawdust first though.

 

[9fingers]

My favourite old manuals site http://www.daltonsmachines.com/downloads-old.html
has let me down. It refers to a 352s single speed (which shows a 2 pole motor) and a 352 dual speed but the file is empty.

Bob

 

[misterfish]

Looking at my 352 (dual speed) handbook it decribes the motor as
0.75 kW, 1 h. p.,1425 r.p.m.

When I get a spare half an hour (hopefully later today) I'll scan all the stuff I've got on the 352 and make it available.

Misterfish

 

[Benchwayze]

My 20 year old Startrite 351 has an overheating cut-out on the motor .

A couple of weeks ago, because my rip saw was down, I used the bandsaw to rip six, 12" planks of 2" Southern Yellow Pine, into 3.5" x 2" boards. I had a new, Axminster blade fitted. The motor cut out after I had made around 15 cuts. I waited a minute and then the motor started again, no problem, so I could make the remaining cuts. So yes, the motor will cut out if it gets too hot; but that's what it is supposed to do, yes Bob?

I have 'Tuff' blades now BTW. They have given the machine a new lease of life! And a thoroughly nice guy to deal with at the other end of the phone.

HTH

John

 

[misterfish]

As promised earlier here is a scan of my '352' dual speed manual and other stuff - http://www.drosera.f2s.com/Startrite_35 ... eed%29.pdf

- maybe it will be of help.

Misterfish

 

[Racers]

Hi, Misterfish

Thanks for that I have a mahual for mine but that has a lot better exploded diagrams.

Pete

 

[sparkymarky]

thanks for the manual upload misterfish. thats a great help.

if the original motor`s rpm was 1400 and my current motor is a 2800 rpm motor i think i will put it on to the lower speed cam belt, out of a matter of course.

cheers, mark.

 

[dickm]

Was it 2 pole or 4pole Dick?

(Sorry Bob, only just logged in - the sun shone today for the first time in ages, so it was outside jobs only).
'fraid I don't know the motor speed - will have to take the base piece off and have a look. But it has a two step pulley. Thought this was standard on all 352s, but obviously not.
I've actually still got the original foot mounting 3-phase motor sitting in a cupboard; was intending to fit it on my Avon with an inverter, but the Avon has now gone and the Mystro needs a flange mount motor. So if anyone wants a really nice 1hp 3phase motor, let me know

 

[9fingers]

Don't worry Dick, Misterfish has scanned his 352 dual speed manual and confirmed 1hp 1425rpm on the two speed model.
the 352S (single speed uses a 2850 rpm motor)
SO we are making progress. The OP has the correct speed motor, we just need to find out why it is running hot.

Bob

 

[dickm]

352 dual speed manual and confirmed 1hp 1425rpm on the two speed model.
the 352S (single speed uses a 2850 rpm motor)
Bob

Just to confuse things, I checked my current motor, which is single phase 2850rpm. So checked the original, 3-phase, and that is 2850 also :?

But mine is definitely two speed. It's quite elderly, with fully mechanical iinterlocks, not lots of microswitches, which may account for the differences.

 

[sparkymarky]

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 :?

so thinking now that i will have to buy a 2nd vee belt which is slightly larger to enable me to use the lower speed.

bob- i checked the capacitors today one`s a 150uf and the other a 20uf they seemed to be intact with now signs of blowout, i wasn`t able to check the capacitance though, however my firm will soon be upgrading our multimeters, so i will check then.

cheers, mark.