Quick question for Sedgwick 571 owners - 1.3/16" chisels.

[YorkshireMartin]

Hi all.

I'm getting a bit of scalloping on the innermost mortice side (the edge furthest away when facing the machine). I've narrowed the problem down to chisel alignment. I'm using a 1.3/16" chisel so no bushing is installed. 20mm chisel is Japanese made and Japanese pattern from axminster and as far as I can tell, is straight and true. The machine has a jacobs chuck.

When installing the chisel, I encounter a problem when I nip up the retaining screw. Essentially, there is a slight clearance between the chisel and it's mount, so tightening it is bringing the tip of the chisel forward ever so slightly, approx 1mm, exposing the auger on the far side, thus creating the scalloping which is about 0.5mm deep.

I just wondered if there was a bushing of any sort for the 1.3/16" chisels? If not, has anyone else experienced this problem and overcome it? I thought of perhaps using a shim made from a coke can if it will fit.

I'd leave it except that it causes the bit to chatter against the chisel from time to time (this may be normal?) and also for through mortising, the finish will be affected.

I'd appreciate any input.

Many thanks.

 

[custard]

You'll really struggle to remove this completely (I use the same 571 morticer by the way). I've seen this with a wide range of morticers in different workshops with different tooling. It's almost impossible to reliably get rid of it as the chisel and the auger are almost never absolutely concentric plus the auger will run out a little in contrary grain.

It doesn't really matter for most mortices because the scalloping is hidden underneath the shoulders (which is why manufacturers have never tried to engineer it out). The problem is with through mortices where it looks a bit naff. You can sometimes get away with a very small auger projection which often fixes it, but then you have to just use this for a very shallow mortice on the face side before flipping the workpiece over and resetting the auger for a deeper mortice from the opposite face.

Two other fixes I have occasionally used in through mortices are to take advantage of the tiny size differences between metric and imperial, for example cut a through mortice with a 6mm chisel then replace the 6mm chisel and auger with just a 1/4" chisel (no auger) and pare out a few tenths of a mill of extra waste in the hope that this removes the scalloping. Alternatively run a 6mm auger in a 1/4" chisel and accept slower cuts (with frequent waste unblocking) and frequent chisel sharpening. The other solution is if the scalloping is at the end of the mortice. I was trained at The Edward Barnsley Workshops and use their method of wedged through tenons, the face side mortice ends get cut away at a slight angle to allow the wedging to expand the sides of the tenon. So the scalloping gets removed as part of this process.

To be honest I generally accept scalloping in traditional mortices but often cut through mortices with a router.

Good luck!

 

[YorkshireMartin]

You'll really struggle to remove this completely (I use the same 571 morticer by the way). I've seen this with a wide range of morticers in different workshops with different tooling. It's almost impossible to reliably get rid of it as the chisel and the auger are almost never absolutely concentric plus the auger will run out a little in contrary grain.

It doesn't really matter for most mortices because the scalloping is hidden underneath the shoulders (which is why manufacturers have never tried to engineer it out). The problem is with through mortices where it looks a bit naff. You can sometimes get away with a very small auger projection which often fixes it, but then you have to just use this for a very shallow mortice on the face side before flipping the workpiece over and resetting the auger for a deeper mortice from the opposite face.

Two other fixes I have occasionally used in through mortices are to take advantage of the tiny size differences between metric and imperial, for example cut a through mortice with a 6mm chisel then replace the 6mm chisel and auger with just a 1/4" chisel (no auger) and pare out a few tenths of a mill of extra waste in the hope that this removes the scalloping. Alternatively run a 6mm auger in a 1/4" chisel and accept slower cuts (with frequent waste unblocking) and frequent chisel sharpening. The other solution is if the scalloping is at the end of the mortice. I was trained at The Edward Barnsley Workshops and use their method of wedged through tenons, the face side mortice ends get cut away at a slight angle to allow the wedging to expand the sides of the tenon. So the scalloping gets removed as part of this process.

To be honest I generally accept scalloping in traditional mortices but often cut through mortices with a router.

Good luck!

Cheers custard, I wont worry too much about it then.

It's been a bugger to align this thing. The motor was out of alignment, caused in transit. I checked the bit for anything unsual in rotation and spun it without power, no probs. Next thing I know, it's gone nuts and overheated the auger. Luckily it's not too bad and now I've realigned it all, it's still chattering, but at least it works.

I just wonder if it's chattering a little bit too much. Does yours chatter also? I've never used one of these before so unsure what to look out for.

I'm mainly concerned with it overheating again as the bit does seem to get really hot but not smoking anymore at least...lol

 

[Steve Maskery]

If it is overheating, I'd look at the clearance you have between the auger and the chisel. Heat only appears where you have friction, and that is the prime suspect for that. If there is insufficient clearance, then it's not so much metal on metal as trapped sawdust. Both will produce heat.

 

[PAC1]

We used to cut a piece of aluminium from your favourite drinks can and wrap this around the chisel to create a small bushing. Heath Robinson but it worked

 

[custard]

I'm not sure what you mean by chattering? A morticer is a fairly noisy machine but there shouldn't be any real vibration or pronounced metal on metal rubbing (although sometimes you'll get the odd squeal or two which isn't anything serious as long as it's brief).

I wonder if your auger and chisel are sharp enough? They generally don't come supplied with anything like a good enough edge. The other thing is I always take the outside flats of the chisel up to a polished finish on an 8000 water stone, that really helps it cut smoothly and minimises binding. And if you're in any doubt give more auger clearance not less.

The chisel and auger will feel pretty warm after use, much like any drill bit, but heavy and continuous smoking (beyond a few little wisps) is a sign that's it's either time to re-sharpen or give a tad more clearance to the auger.

The 571 is a great machine by the way, along with the similarly sized Multico it's an absolute staple machine in thousands of furniture workshops. I've never met the 571 that can't be brought into tip top operational order with a bit of care and practise.

Good luck!

 

[YorkshireMartin]

I'm not sure what you mean by chattering? A morticer is a fairly noisy machine but there shouldn't be any real vibration or pronounced metal on metal rubbing (although sometimes you'll get the odd squeal or two which isn't anything serious as long as it's brief).

I wonder if your auger and chisel are sharp enough? They generally don't come supplied with anything like a good enough edge. The other thing is I always take the outside flats of the chisel up to a polished finish on an 8000 water stone, that really helps it cut smoothly and minimises binding. And if you're in any doubt give more auger clearance not less.

The chisel and auger will feel pretty warm after use, much like any drill bit, but heavy and continuous smoking (beyond a few little wisps) is a sign that's it's either time to re-sharpen or give a tad more clearance to the auger.

The 571 is a great machine by the way, along with the similarly sized Multico it's an absolute staple machine in thousands of furniture workshops. I've never met the 571 that can't be brought into tip top operational order with a bit of care and practise.

Good luck!

It makes a metallic chatter on occasion. It's defintely the auger hitting the chisel. Although when I remove it from wood, it's mostly silent. Quite odd really, must be clearance related. I'll have a play with the clearances and see what happens but this is the best I've got it to work so far.

I will give the bit and chisel some tlc. I've got some 15k grit on my strop a the moment which should polish it a treat, its actually fairly rough ground so this is definitely worth a look.

I'll post back with progress made in due course.

Thank you all.