Clarke power hacksaw not cutting true

[Shedendman]

I have an old clarke power hacksaw,i say old as its build date is 1987.
Anyway dragged it out today to cut some 50x50x2mm box only to find its cutting offline for the life of me i dont know why
here it is all set up ready to cut,the stock is clamped up tight as and is flat on the bed


the cutting starts fine but as its going down you can see the blade starting to bow/twist away,not easy to capture this as it was moving while taking the photos camera angles etc


bit blurry this one as the saw was cutting at the time,but you can see the blade slightly twisting away from the line

Resulting in this

Now as i look at this the box dont seem to be flat going by the angle of the clamp(make sense?)but it is a steel rule shows me the beds ok,the blade is tightened up as far as it goes,the vice/clamp is holding the box firm ie no movement while it cuts but its still not cutting true,also blade is not that much used,say its had about 20-30 cuts,can anyone throw some light to whats wrong please,its driving me nuts

 

[aametalmaster]

Don't loose to much sleep over it as it just needs a simple adjustment. There should be adjustable bolts on the ends of the blade guides. Where you loosen a bolt and turn another bolt with a wrench, it will take two of them . Just turn the adjuster the opposite way that the blade is cutting off...Bob

 

[bigegg]

dunno about hacksaws, but bandsaws do this sometimes when a new blade is required.

 

[stef1]

We often find this happens on some of our saws (not power hacksaws) when the blade has lost it's set - causes the blade to twist and cuts squint

 

[smpw]

I had a similar experience with my Q&S hacksaw and it turned out the vice was slightly off square, having addressed this it now cuts fine. Also I have always used coolant when doing a lot of cuts, assuming that this would keep the blade from expending when hot.

 

[John_Duffy]

Is the blade properly tensioned?

 

[julianthegypsy]

Is there any adjustment for cutting pressure? I found my old wicksteed, which was huge, would go off line if I let it cut too fast. It was so powerful that it would slice away happily with loads of pressure on the blade, just not in a straight line!

 

[octo0072000]

I have an old clarke power hacksaw,i say old as its build date is 1987.
Anyway dragged it out today to cut some 50x50x2mm box only to find its cutting offline for the life of me i dont know why
here it is all set up ready to cut,the stock is clamped up tight as and is flat on the bed
View attachment 39312
View attachment 39313
the cutting starts fine but as its going down you can see the blade starting to bow/twist away,not easy to capture this as it was moving while taking the photos camera angles etc
View attachment 39314
View attachment 39315
bit blurry this one as the saw was cutting at the time,but you can see the blade slightly twisting away from the line
View attachment 39316
Resulting in this
View attachment 39317
Now as i look at this the box dont seem to be flat going by the angle of the clamp(make sense?)but it is a steel rule shows me the beds ok,the blade is tightened up as far as it goes,the vice/clamp is holding the box firm ie no movement while it cuts but its still not cutting true,also blade is not that much used,say its had about 20-30 cuts,can anyone throw some light to whats wrong please,its driving me nuts

try a spirit level on the bed then on the box see if you get the same level
also change the blade as well

 

[wheresmejumper]

does the blade drop perpendicular to the piece when under no load,not running?

 

[Shedendman]

Right guys,bit of an update and some answers to your questions.
First of all i changed the blade,which is an Eclipse 14TPI 350-25-1.25,which i think for what i'm cutting might be a bit to course,i'll explain this later.
I took apart the blade holder/tensioners check them over for wear etc all was fine(as i see)
this is the front

and the back

Now before i go on,after i fitted the new blade and tried its 1st cut,as it broke through the box there was a lot of vibration then it jammed whole thing came to a halt,it did this twice after,i think either the blade is to course or it needed bedding in so to speak???
Ok 3rd go it was cutting fine,but as you can see,it still wandered over abit


Now it starts to wander over,not a lot but it does,blade thickness

now heres it finished see the bow in the blade?


Now when i pull the arm up you can feel the blade rubbing against the box,once its cleared you see it spring straight again,very slightly though

To sum up,new blade fitted,tensioned up even and tight to the best i know(does the set up on this look right?),the bed is flat,but i've just two things that bothers me,cutting thin walled box(2mm) with a course blade cant be right(?) the other thing as its cutting the vibration must be moving the box down from the clamp,which i might add if i tighten that up anymore i'll be squashing the box
Theres no speed adjustment on this as such,you can change the stroke length its on short stroke for this atm,the pressure the blade is the weight of the whole arm itself,nothing i can change there.
So there you have it,its doing my head in,hope this answers everything, as i'm lost now

 

[Shedendman]

i was meant to add i'll try and do a video of this but its not easy using the phones camera

 

[mike 109444]

been years since I've been near one of these but looking at your first post, pic number 3 surely the teeth should be pointing the other way ie towards the fixed vice jaw and thus cutting on the return stroke not the forward stroke (like a coping saw and not a HAND hack saw)

 

[Shedendman]

No,this cuts on the forward stroke,on the back stroke the blade arm is lifted up then goes back down as its pushed forward,when i do a video you'll see what i mean

 

[MattF]

That looks like you have some slop somewhere.