Wilmac bandsaw restoration MKII

[robert the violinist]

1750 rpm sounds like a 4-pole motor on 60Hz.

Is there a brand name on the blue saw? I don't recall ever seeing one like that.

Hi Alan, Is 1750 the American speed of 2 pole motors or am i getting confused ,do they use 60HZ for domestic supply? I`ll be using whats easily available in the UK so 1400 is probably right.
yes the saw is a Walker Turner 730 driver line made in NJ. They started producing these art deco design models in the late 1920`s or early 1930`s. This one is from around 1938-39.
Ive never seen one in the UK before but quite common in the US. Im guessing it was brought over by the US military during WW11.
Heres the catalogue page and one for the motor .
Bob

[robert the violinist]

Hi,

When it comes to speed using pulleys and a motor Bob there are a number of variables so it's not straightforward at all. You mention a single phase motor at 1,750rpm? The usual speed is 1,425rpm. An 1/2hp motor is plenty big enough. Then you will need a pulley on the motor and another pulley on the main-shaft giving a further choice of speeds? The diameter of the band-wheel also plays an important part. I'll check what my Wilmac is set up with and get back to you. With saws whether band or circular there is an optimum speed for the blade; our Wilmac band-saws will not cut metal because they run much too fast but are perfect for cutting timber. Again I'll check and get back to you.

Regarding buying pulleys; firstly you need to work out pulley dimensions to match the motor and the blade speed you want to achieve. SPZ pulleys and belt are fine for the Wilmac and come in lots of different sizes having assorted taper inserts to suit the shafts. For a 20mm shaft yes you would ask for a 20mm taper insert.

For those unfamiliar with these pulleys having the taper insert; two grub screws are supplied and it will be found that two tapped holes will line up perfectly between taper and pulley allowing the grub screws to be nipped up tightly which is straightforward enough but when it comes to removing one of these pulleys this is where a novice can struggle. Remove the two grub screws and it will be seen there is a third threaded hole; insert and tighten one of the grub screws into this third hole and it will break the taper lock very easily allowing the taper and pulley to be withdraw; easy once known but if not known then removing one of these pulleys is a real pain.

Kind regards, Col.

Hi Col, Ok thanks, i`ll order some flange bearings and get a shaft mounted then i`ll worry about the motor and pulley sizes.Good tip on removing the taperlock pulleys i`d probably have got stuck if the pulley was put in the wrong place.
Does anyone know about DC motors and whether this one would be any use for anything. Its only1/4 HP (shunt wound) i bought it on ebay a few years ago but havent found a use for it yet. I know they need a speed motor control. Its a quality new brook hansen.Only cost 15 quid.
Would one of these very cheap chinese efforts work it?
http://www.ebay.co.uk/itm/190836669714?s...K:MEWAX:IT&_trksid=p3984.m1423.l2649
Thanks Bob

[Retired]

Hi,

I've just been looking at recommended narrow bandsaw speeds Bob and as expected there is a huge variation. Working in feet per minute then the lowest speed for wood cutting is about 1,000 FPM and a bandsaw at this speed with the correct blade installed will also cut aluminium. For general wood cutting I suggest around 2,500FPM.

Once you have your new motor and know the motor's speed then you can work out your pulley sizes because you already know the band-wheel diameter.

http://www.hse.gov.uk/woodworking/bandsaw.htm

http://www.hse.gov.uk/pubns/wis31.pdf

Band-saws can bite so I've added a couple of links above because many novices will read such threads as this and better forewarned than lose fingers or a hand. Never ever open a wheel guard with the saw under power otherwise you might seriously regret doing so and please do not be tempted to push small items through the saw bringing your fingers inside the danger area near the blade.

Your American Walker saw looks the business Bob and should give many years of reliable service; you seem to be collecting band-saws the way I collect lathes?

I worked at Brook Motors for 24 years Bob and you've shown me something new. I've never seen such a small DC motor made by Bull (Brook) . Bull DC motors were made in the Ipswich factory which I never visited me being based at Brooks headquarters here in Huddersfield but I've handled hundreds of huge Bull motors both by overhead crane and fork-truck; I know nothing about DC motors other than the very basics. You got a bargain though and I'm sure you'll find a good use for it.

Kind regards, Col.

[Alan Douglas]

Is 1750 the American speed of 2 pole motors or am i getting confused, do they use 60HZ for domestic supply?

Yes, 60Hz essentially everywhere in the US. Synchronous speed for a 4-pole motor is 1800 rpm, and the speed at full load is typically 1725 or 1750 rpm. The synchronous speed for a 6-pole motor is 1200 rpm and a 2-pole motor 3600 rpm.

[Alan Douglas]

Funny, I had never run across a Walker-Turner of this size before, and one showed up at the MIT Flea Market this morning (for $75). The seller said it dated around 1930. I didn't look closely at it but the blade cover appeared to be cast iron perforated with round holes. It was entirely painted silver, probably hiding rust though it looked nice enough.

[robert the violinist]

Alan are you in the US??
I think they show up regularly over the years in the US. I blieve the one that you describe is called a `snowflake` model but may be wrong. Ive just finished stripping the paint off the Walker Turner which appears to have been originally a olive grey colour.

[robert the violinist]

Hi, havent been here for a while due to work and family problems.
I finally found a  thyristor controller on ebay  which may work with the shunt motor mentioned above. See photos of the other identical capacitor that is on the board .(the blown one is the one on the left hand side of the full board photo ,nearest the incoming line .)
 Problem is i know very little of electronics and when fiddling around with a multimeter i must have shorted the circuit or something as one of the film capacitors started smoking and broke apart. I immediately removed the power but dont know if ive done any damage to the controller. Will it be a simple matter of replacing the capacitor. i cant see any damge to the rest of the control board.
The last photo is the blown part, there is also cracks in tthe other (ok?) one ,should that be replaced as well. Is there a source in the UK for this exact type (type x,i think)
Thanks for any help
Bob

[Refugee]

That is normal for those type of capacitors. Replace both immediately without question.
They are evil things.
This one was lurking in our vacuum cleaner.

[robert the violinist]

Hi Refugee, i `m all for replacing them with something betterif possible but with what ?? Also has any other damge likely to have been done?
Bob

[Refugee]

They are usually across the mains and sometimes between the mains and earth for static earthing.
All you need to do is check the thyristor with a meter between the case and the other two pins and make sure there is no short circuit and then from a good quality component supplier buy some more class X2 capacitors to replace them.
Between the pins on the thyristor will give a low reading. The thyristor could optionally be checked with a battery and bulb with reference to the data sheet but it is unlikely to be faulty if it is only the mains filter capacitor that has blown up.