www.ultimatehandyman.co.uk

Hi folks,

I have a number of end caps to make up for a prototype kit. At this stage we do not know the viability so trying to make do with existing tools where possible, that said if needed can upgrade blades as required.

Currently using an Evolution mitre saw with the below blade, two problems - firstly the finish is very rough, takes an age to file down by hand which can reduce overall size. The channel is firmly clamped from both sides, tried coming down on the piece (chop saw style) or the sliding option - both more or less the same.

Other problem appears to be a wavy cut, I can only assume the piece is somehow moving during the cut - again, lots of filing leading to irregular edges.

Contacted the folks at Evolution relating to similar problem with plastic channel, their recommendation in below.

Any suggestions greatly appreciated.





https://www.evolutionstore.co.uk/furyblade255multi.php

heeelllooo and welcome Alloy ally

cross hatching on a table or pull saw tends to be caused by the blade cutting at the back as well suggesting the rest off the blade is not exactly in line

Thanks for the welcome and info.

Yup, that was my first thought regarding blade, although it is a wavy cut dipping in the middle.

There's a fair amount of lift with the blade, it could be this as difficult to get clamp right up to cutting area. On the first run when clamped at just one side it bent 2mm box section upwards, perhaps the blade has lost its edge?

Cut it by hand ? what's the dimensions of the channel ? you may get better results with a cut off saw or band saw, the evo saw will not give a clean cut with metal due the tooth count on the blade (I have cut plenty of alloy v-slot and t-slot channel over the years)


evo do there pro blades but in 180, 230 and 355mm

https://evolutionpowertools.com/uk/grou ... blades.php

Edit. 250mm 80t metal blade should give you a better cut (adjust the vertical stop on the saw)

eg. https://www.saxtonblades.co.uk/tct-circ ... -80t-metal

Imho the evo blades are a ripping blade what always give a rougher cut

Cheers, channel is 40mm x 20mm cutting by hand would be okay but unable to scale up.

The cut off saw is a good idea, is it not possible to use maybe a smaller version of those blade in my own mitre saw, perhaps upgrade later to a dedicated machine.

Nice jig to hold work.

https://www.machinemart.co.uk/p/raptor- ... -off-saw-/

The other thing I forgot to mention (this is big problem) is not being able to do multiple pieces with one cut, the blade pulls to hard on upward cut.

I had envisaged lining up day four channels side by side then making one cut across the batch, currently doing one at a time which leads to inconsistencies.

i really dont understand metal and saws
but with wood its few teeth quick easy crude cuts
many teeth smooth most large cuts heavy loading on motor so careful progress
where most will be happy with a say 24-40tooth blade on a 8-10" blade i will always go for a 60-100tooth blade
with wood you would have a sacraficial say 6mm bit off mdf on the base to save splintering
i wonder if it may be any good in preventing burring also possibly wood within the "U" section

Yup, i would tend to agree, the more teeth the finer the cut.

I came across this blade (80T) which fits the bill being aluminium specific even extrusions mentioned, price wise its worth trying.

Reductions rings = to fit different spindle sizes ?

https://www.amazon.co.uk/gp/product/B00 ... 1OLE&psc=1

as i say no metalworking with chop saw experience so dont know if an 80 tooth would overload your saw

It has a fairly hefty motor, used it to cut oak railway sleepers which it did with ease.

Any signs of slowing of blade can back off, also start with one piece at a time. Going to make a small jig to hold the work better in situ, only hope the blade is not bending mid cut causing that dip halfway along the cut - perhaps it's just lifting ever so slightly, not always easy to see with so much swarf flying everywhere.

The dedicated cut-off saw looks good with such a large blade, only draw back is mitre cuts are achieved swiveling the jig which would probably mean one piece at a time.

Cheers,

if the blade is deflecting though load [slack in the mechanism] then slower progress may reduce it a bit
now a new blade with more teeth could exacerbate [make worse]the situation but it could also cut better as it has new clean teeth
have you tried dry lub ptfa spray i use this stuff all the time on wood
https://www.toolstation.com/ptfe-spray/p63929
i would also get the new blade and try it even iff it doesnt solve the problem

A horizontal bandsaw would be the ideal tool

looking at the 60/80 T blades they have a wider kerf, so are thicker than the standard evo blade ?

You could use the evo saw as is and use a linisher / disc sander to finish

eg. https://www.axminster.co.uk/axminster-h ... der-501255 cheaper end of the market - axminster machines are usually good value for money

Cheers for replies, had another go today as needed six more for small run. Mindful of above paying particular attention to any movement securing piece from both sides.

Checked alignment of table which turned out to be a full 1 degree off from 0, surprised at this as previously reset using square angle. This should help some although only 40mm wide object may not be too visible.

I also tried turning the channel other way up (flat side on top), this improved the cut in terms of wavy dip - need to repeat as some ends were mixed up during stacking, it does look to be the case though.

My overriding impression is that either a) the blade is blunt, or b) it's far too course teeth wise, big chunks of swarf flying off leaving torn edge (see photo below).

big-all, thanks - see above re blade deflection.

Bob225, going to try the cheapy Silverline blade as this feels most suited, I could't see the kerf on that one but Evo blade is 2mm but feels a lot thicker. Bandsaw would be good, perhaps one of those upside down jigsaws with a wheel on-top to keep blade straight.





(and yes, I did chop a lump out of the back stop - not this time though )

as its only 44mm have you tried both strait chop and a slide
and just checking although its called a pull saw you are using it properly
you pull the head towards you clear off the work
start the motor drop the blade and push back

big-all wrote:as its only 44mm have you tried both strait chop and a slide
and just checking although its called a pull saw you are using it properly
you pull the head towards you clear off the work
start the motor drop the blade and push back

Yup, have tried various approaches (see above for chop v slide)

Finished filing down the last batch, big difference on wavy cut requiring lot less filing. It does feel like the blade is fighting or kicking back, perhaps too course or just plain blunt, ordered two Silverline blades today - will report back once arrived.

Cheers,