Clarke CBS45MD 6x4 Metal Cutting Bandsaw Modifications

[penfold]

Perhaps the Happy Dragon Electric Motor Factory Number 1 had an order for 500w motors fall through, or fail QC for the original customer and get rejected, and they got sold to the Swooping Dragonfly Bandsaw Factory Number 3 because they were cheaper than ordering the 375w unit. More prosaically they're just mislabelled and are actually 375w.

 

[Laszlo]

Yeah, that's pretty much what I'm suspecting too.

Regarding RPM I did a calculation based on the size of the wheels, the worm gear and the step pulleys. The result was 1525 RPM for the motor spindle. Does that sound like a probable RPM for one of these? I'm afraid I don't know much about motors...

 

[WorkshopChris]

Standard UK single phase induction motor's are usually 4 pole 3000 rpm 2 pole 2500 or thereabouts.
So your calculated 1525 is in within spec for a 2 pole motor.

 

[Richard.]

My 6x4 is a 1400rpm 1/2hp. Common motor to buy as they are used a lot on single phase little saws, drills, baby lathes etc. You should have no issues getting hold of one for it.

 

[WorkshopChris]

Standard UK single phase induction motor's are usually 4 pole 3000 rpm 2 pole 2500 or thereabouts.
So your calculated 1525 is in within spec for a 2 pole motor.

To late to edit but have just seen this should say.>
Standard UK single phase induction motor's are usually 4 pole 3000 rpm 2 pole 1500 or thereabouts.
So your calculated 1525 is in within spec for a 2 pole motor

 

[whm_fab]

@Richard. can you post some pics of your damper setup Richard please? i've been thinking about doing this for quite a while, just haven't found the time !


My 2c - for the crappy table that should be tossed over the nearest hedge, ive put a permanent 8mm milled flat mini table thats permanently bolted to the saw that sill allows full horizontal functionality. so for hand feeding small pieces for making brackets etc its perfect. Then on the underside of it, i have nuts welded to it so i can fit my slotted table for cutting tube in its vertical position very quickly. it then has a support bar going vertically down to the main saw bed.
Ive attached the only crappy photo i can find of it at the moment with the slotted table fitted.
i dont have any of the mini table, but its very similar to the second pic, just a decent bit bigger but still doesn't affect the horizontal cutting in any way.

one of the main troubles ive had with my saw is the adjuster pulley, (not the one on the motor, the other one) the stock bush/bearing arrangement has seized on me twice. has anyone replaced this with a roller bearing ?

 

[Richard.]

Of course mate.
Like every thing I try to design improve, simplicity is the no 1 goal. My damper is cheap universal adjustable motor bike steering damper. It has a wide number of adjustment positions giving me full control over the downwards pressure applied to the cut. Be careful when selecting one as it must have enough stroke length to allow the saw to go up to its max cutting thickness (in my case 100mm

 

[Fintray]

To late to edit but have just seen this should say.>
Standard UK single phase induction motor's are usually 4 pole 3000 rpm 2 pole 1500 or thereabouts.
So your calculated 1525 is in within spec for a 2 pole motor

I think you will find it is the opposite way about, 4 pole = 1500 rpm and 2 pole = 3000rpm.

 

[kcchan]

Of course mate.
Like every thing I try to design improve, simplicity is the no 1 goal. My damper is cheap universal adjustable motor bike steering damper. It has a wide number of adjustment positions giving me full control over the downwards pressure applied to the cut. Be careful when selecting one as it must have enough stroke length to allow the saw to go up to its max cutting thickness (in my case 100mm

Was there a thread about your modifications? I remembered seeing it somewhere but couldn't find it when I searched. I'm picking up an SIP swivel head bandsaw this weekend.

 

[whm_fab]

thanks richard, nice setup!

im wondering what to do with my upper blade wheel bearing situation

 

[Richard.]

Was there a thread about your modifications? I remembered seeing it somewhere but couldn't find it when I searched. I'm picking up an SIP swivel head bandsaw this weekend.

Yeah there was a thread on the entire build of it as I got it as a big box of rusty scrap all in bits and built it up over time. This is how she started life with me.

 

[WorkshopChris]

I think you will find it is the opposite way about, 2 4 pole = 1500 rpm and 2 pole = 3000rpm.

Yes you are indeed correct, i think the morphine patches are winning this week i will stop posting anything technical for a while again.

 

[kcchan]

Yeah there was a thread on the entire build of it as I got it as a big box of rusty scrap all in bits and built it up over time. This is how she started life with me.

I tried to loom for it but couldn't find it. Any ideas?

 

[Wallace]

I tried to loom for it but couldn't find it. Any ideas?

http://www.mig-welding.co.uk/forum/threads/freebee-in-need-of-tlc.55416/

 

[kcchan]

http://www.mig-welding.co.uk/forum/threads/freebee-in-need-of-tlc.55416/

Brilliant, Thanks

 

[DAPPH]

I think you will do better with a taper roller bearing if you do try to put a bearing in as it will give you a bigger surface pressure bearing area . However where can you get such a small taper roller bearing ) ( I'd love to know that in any case ) Plus there is not much meat to put one into .

When I stripped my saw down I too saw it was a bit wobbly but realised that when the blade is under tension & the drive belt correctly set ( adjusted in that order ) it will always pull to the bottom of the hole so no new bearing is needed . The roller bearing blade guides are what are important .. they took me a while to set correctly ... till I started thinking things through logically ( see below )

Putting a damper on the frame .. do you really need one ?
I ask because my saw is fairly old , on the left ( standing at the switch end of the saw ) there is a screw in or out silver tube that pulls a spring tension which adjust the pressure of the blade on the metal being cut in the vice .. put too much pressure on pusing into the metal in the vice or not enough & the blade wanders no matter how much tension in the blade that you have at the top head pulley .

I've also cut a grove in the hand knob adjuster for the head pulley so that when the blade is correctly tensioned the groove is always facing vertical . When I've finished cutting & brushed off the bits & lightly oil the bearings , blade & bed I then slacken of the head adjuster three full turns to take all tension off the blade & saw frame .

If you don't have one , these Clarke saw benches have a short manual that's available on the internet . I can't remember where my copy of it is or I'd put up the details of where to get it .

 

[Richard.]

Putting a damper on the frame .. do you really need one ?
I ask because my saw is fairly old , on the left ( standing at the switch end of the saw ) there is a screw in or out silver tube that pulls a spring tension which adjust the pressure of the blade on the metal being cut in the vice .. put too much pressure on pusing into the metal in the vice or not enough & the blade wanders no matter how much tension in the blade that you have at the top head pulley .

Probably the best mod on my saw by a mile.
Mine has a spring tension on the back and it's rubbish.
No real way of properly setting down pressure and not enough tension even fully wound up to gently feed through thin walled tube and box.
I've never had a blade wonder from setting different feed pressure. I have it set as a very slow trickle feed for thin walled box tube etc and a back it right off and let the bow weight do its thing on the thicker stuff.
Coupled up with my coolant system and m42 blades it's a bleeding awesome tool that's paid for itself dozens of times since I built it. Motorcycle steering damper is a mod I highly recommend for those basic saws.

 

[DAPPH]

Richard , the spring tensioner you have , is it like the screw in out tube at the LH side of the bed as I've mentioned ?

I've cut quite a few 1.5 mm to 3 mm walled tubes & box sections , 30 to 50 mm across on mine .
Had to do a couple of test cuts first to get the tension & weight right after changing to the fine toothed , most of the cuts were within 0.5 to 1 mm square .
Once I'd set the band running it's just been a case of letting it feed through on it's own till it cut right through & aauto switch off .

Before I'd reached this stage of adjusting it , it tended to wander , making the cut curve to the bed in a lot of cases , I'd taken to holding the weight of the arm a tad to reduce the pressure before I discovered that the silver tube was indeed an adjuster simply seized solid with rust particles etc . .

What you've said ... sounds interesting .
What belt pulley speeds were /are you using ?

 

[Richard.]

Richard , the spring tensioner you have , is it like the screw in out tube at the LH side of the bed as I've mentioned ?

I've cut quite a few 1.5 mm to 3 mm walled tubes & box sections , 30 to 50 mm across on mine .
Had to do a couple of test cuts first to get the tension & weight right after changing to the fine toothed , most of the cuts were within 0.5 to 1 mm square .
Once I'd set the band running it's just been a case of letting it feed through on it's own till it cut right through & aauto switch off .

Before I'd reached this stage of adjusting it , it tended to wander , making the cut curve to the bed in a lot of cases , I'd taken to holding the weight of the arm a tad to reduce the pressure before I discovered that the silver tube was indeed an adjuster simply seized solid with rust particles etc . .

What you've said ... sounds interesting .
What belt pulley speeds were /are you using ?

Yeah that's exactly what it is.
I know they will do the job but I find it very crude compared to now where I can set it a couple of clicks on the adjustment and know it's the same amount of pressure applied every time.

 

[Bill Edwards]

After fitting a new razor sharp Starret blade twenty minutes earlier the works machine has stripped the worm and gear

Not great timing as tomorrow (Wednesday) there's about 50 lengths of 50mm box coming and a lot of 80mm to make into things fairly quickly. Anybody know where to get the bits? I've sent a parts enquiry to Clarke as they'll probably be the same as this 1987 machine but otherwise I'm struggling. Any suggestions?