Miter saw by DeWalt

[Robbox]

I've borrowed a mates DeWalt mitre saw. Halfway through making the raised flowerbed, I noticed this....

The back guide plate or whatever it's called is not straight. It deviates from the centre line on both sides (ignore the chewed up plastic thingy).
So if you have to cut an inch off a piece of wood, and one lines up the wood with the back guide, you get something other than a 90deg cut....
There is no visible damage, it's a piece of cast metal, no cracks, all looks kosher. Is this how it's supposed to be?

 

[rsgaz]

back guide plate or whatever it's called

The fence.

it's a piece of cast metal

You mean both sides is one single continuous piece of metal, like this?

Is so, then it's knackered. If the fence is in two halves, both sides can be adjusted so they are straight, then reset the 90 degree adjustment after.

Is this how it's supposed to be?

No.

 

[SammyInnit]

Model number?

Not much we can do to suggest a fix with the information you've given.

 

[Roger928]

A kick back will cause misalignment on that type of fence..(Post 2) And once misalignment occurs kick backs are more common.
LS1013 has a similar fence and easily rectified if its out.

 

[Robbox]

De Walt 707, discontinued. I don't see any damage to the fence and the misalignment is same both sides. That is, with a straight edge across the fence, both sides veer off to the middle.

 

[Robbox]

The fence.



You mean both sides is one single continuous piece of metal, like this?

Is so, then it's knackered. If the fence is in two halves, both sides can be adjusted so they are straight, then reset the 90 degree adjustment after.




No.

I will check that one out. Maybe it is two parts and I don't see the join.

 

[SammyInnit]

Ok so it's a single piece fence. If those two faces don't have a flat parallel line, it's damaged. Replacement new is £50ish.

Using the straight edge across the back fence (your level), check the blade against it for 90degrees. If it's out the positive stop plate needs adjusting, my understanding is there is very limited movement in the fence on that saw and other DeWalts are adjusted by the movement of the stop plate.


So presuming it's square but you still have the issue of the fence showing out, I would take a decent bit of ply just over the width and depth of the saw table and fix a piece of construction standard timber to the back then clamp it up to the fence.

 

[Roger928]

De Walt 707

Part No - 868687-00....
https://www.partshopdirect.co.uk/dewalt-dw707-type-2-mitre-saw-spare-parts-s5913/

Wouldn't recommend a new one as easily straightened when removed.
I always screw on a 3 or 4 meter auxillary fence to the left and helps reduce kickbacks, protects the alu fence and makes stop block setting for repetitive cuts easy.
The stand for my scms is wooden trestles, a small table and plywood sheeting.
Wouldn't take the gift of those horrible things the manufacturers make.

 

[Robbox]

Update guys. I found new both fence and plastic insert/sacrificial thing, for £34. Dunno why so cheap, have to wait for delivery....probably made out of pixie dust.
One weird thing I have noticed, the pan head machine screws holding it down ARE NOT ROUND! Both have a cross section something like the ****el rotor. What is that all about? The Phillips head is a bit chewed up, so was thinking to replace with a hex head screw, when I noticed the old screws had this strange cross section.
Any ideas?

 

[Robbox]

Wouldn't recommend a new one as easily straightened when removed.

I did look for damage, there is a fine crack at one stress point. I did try to bend it back without much success. Replaced with new.

 

[Deleted member 174758]

This issue of cast one-piece horseshoe fences warping or cracking with age is nothing new. I've replaced fences on three different Makita models as well as on one DW model. In the short term I did get by with adding a sacrificial front fence to the cast fences and adding shims, but I don't regard that as a long term solution as it teduces capacity in some circumstances. BTW we recently had a DW703 simple mitre saw on hire for cutting aluminium profiles (I'm hardly going to put one of my saws on that job) and that had a warped fence, too.

 

[Robbox]

Are there any tips for avoiding kickbacks?

 

[Deleted member 174758]

Are there any tips for avoiding kickbacks?

Ensure that your workpiece is always firmly held against the fence. Try to avoid cutting through dead knots (which can turn into high speed projectiles). Always make cuts on a pull-out type saw (SCMS) by pulling up and out, plunging down then pushing the blade back towards the fence. If the fence isn't straight add a fence plate onto the front. When cutting small section stock and/or stock where the offcut is smallish and will not be supported on the fence at the end of a cut (e.g. changing the direction of a mitre) at the end of the cut hold the saw down, turn off the motor and let the blade spin down to a stop before lifting the head out of the cut - it's lifting a spinning blade out of a cut where the offcut is unsupported (and can therefore fall against the blade) which can create a high speed projectile

 

[Robbox]

Ensure that your workpiece is always firmly held against the fence. Try to avoid cutting through dead knots (which can turn into high speed projectiles). Always make cuts on a pull-out type saw (SCMS) by pulling up and out, plunging down then pushing the blade back towards the fence. If the fence isn't straight add a fence plate onto the front. When cutting small section stock and/or stock where the offcut is smallish and will not be supported on the fence at the end of a cut (e.g. changing the direction of a mitre) at the end of the cut hold the saw down, turn off the motor and let the blade spin down to a stop before lifting the head out of the cut - it's lifting a spinning blade out of a cut where the offcut is unsupported (and can therefore fall against the blade) which can create a high speed projectile

Thanks for the advice. It seemed to happen random, but clearly there are ways to mitigate it.