Machine Mortice Chisel

[Hemsby]

Hi

Sorry these may seem strange questions but I have never used a mortising machine and am slightly confused, not that that’s unusual :?

Obviously there will be different quality chisels in both materials and manufacturing available that I understand but the apparent possible difference with machine mortise chisels and their mounting size is a mystery. The machines I have been looking at seem to have bushes.

Why bushes, does this mean that there is not a standard size mounting , or are there other reasons for choosing different size chisels with different bushes.

Also for any given cutting size of chisel do they vary in overhaul length between manufacturers.

Help and advice would be appreciated.

Thanks

 

[carlb40]

The cheaper end of the market use the 3/4 inch chisels and the better ones use the next size up. I think it is to make sure people don't get a cheap morticer and then use the larger bits ie the actual bigger chisels ( not the larger shank) as the motors are smaller . If that makes sense?

 

[John15]

Hi Hemsby,
Just to try to explain the system, the mortice bit is held in a chuck similar to a drill chuck. The bit has two components - an auger
which removes the waste set inside a hollow square section chisel which forms the sides of the mortice. A number of woodworking machine suppliers have them, ranging from the hobby models to trade and industrial machines. I have the hobby machine from Axminster and find it suitable for my needs.
Hope this helps,
John

 

[Hemsby]

Thanks for the information it was a great help.

I am only considering a Hobby type machine presumably with 3/4 diameter socket.

Regarding my question as to whether the lengths of the chisels are standard. my reasoning is, if for example a machine has a maximum work piece height of 110 mm presumable the manufacturers have based this on using a certain length chisel :?: . Therefore would my assumption be correct that all chisels are the same length :?: . Or are you restricted to chisels specifically for that machine :?: .

Regards

Keith

 

[John15]

I think they are all a standard length.
John

 

[custard]

The augers (the drills) come in different lengths but they're all longer than your machine actually needs. You have to cut them down to the appropriate length for your particular machine. Not difficult, a normal hacksaw will do it in a jiffy. The other thing is to file a flat on the chisel where the grub screw engages. Otherwise the grub screw will raise a burr which can make removing the chisel a struggle.

It all sounds complicated but it's really not, when you stand there with the machine in front of you it all makes perfect sense.

 

[custard]

One other thing, learn how to sharpen the auger and chisel and do it regularly. Again, not hard, but it makes a huge difference.

I've worked in a communal workshop where no one bothered to keep the mortice machine tooling sharp...and it was hard going, noisy, and the quality suffered. In my own workshop I make sure all the tooling is kept in tip top condition and, even though my machine is just a bog standard Sedgwick 571, it goes through oak like a knife through butter, where the previous workshop's giant Wadkin would smoke and screech when faced with a bit of poplar.

 

[Hemsby]

The augers (the drills) come in different lengths but they're all longer than your machine actually needs. You have to cut them down to the appropriate length for your particular machine. Not difficult, a normal hacksaw will do it in a jiffy. The other thing is to file a flat on the chisel where the grub screw engages. Otherwise the grub screw will raise a burr which can make removing the chisel a struggle.

It all sounds complicated but it's really not, when you stand there with the machine in front of you it all makes perfect sense.

Thanks for that,

Thats me sorted, machine ordered

regards,
Keith