The Square Head Thread.

[L.S.Barker1970]

What an informative thread this has been!!!!!
I have a Macson/Barker 12" Jointer that has a round cutter block with knives that are about 5 mm thick, while my 12" Thicknesser, a Jeffwood, has a square cutting head sporting knives that are 12 mm thick.
I watched Norm mill some architraves using a "lunch box" type thicky with custom ground knives. I figured that the Jeffwood could do the same job and probably a bit better due to the bulk of heavy cast iron.
I asked one tool sharpening crowd in Sydney about cutting some knives for it and they told me to go back to the manufacturer and source them from there. I wish!!
Do you know of a crowd that could make some profiled knives in Aus?
Its a fancy full notion, I have, to get cutters to run a particular moulding for a job as being retired I don't really have a project in mind that would warrant the expenditure
Its been great reading about what these "old" machines were capable in their day and really they are still capable even with the authorities doing their best to get them out of the picture.

Hi Rod,
Jeffwood thicknessers were designed to also run small mouldings, it actually mentions this in the users manual.
Cutters can also be ordered from Jalor Tools PTY Ltd. - About - Google+

Here is a page from the manual showing an example...


Melbourne Matty.

[L.S.Barker1970]

Some pics as requested ...

I have last used it while making a front pergola-type thing out of some pretty solid 2" 2ndhand hardwood
... planing completed ... pergola, not so much.

So I cleaned up one side, they both had some melted paint build-up on the blade.

Nice looking cutter head Paul, the middle slot is to run moulding cutters also.
The blades are on their last sharpen, any good saw doctors in Perth ?

Melbourne Matty.

[jgforsberg]

I also had never heard of EDM and I agree that the heat build-up might be an issue. Weinig rough out their pre-made profile knives with water-jet cutters to get around that problem.

I was told by my machinist (tool and Die ) friend that EDM is the only safe way to cut brazed tooling with out damage to the braze weld from heat. the cutting is done under water and its said to be

better than grinding i am told. I asked because i am having some old square head tooling that is carbide brazed to mild steel 1/2" cut to make cutters for the trenching Heads




great thread

jack
English machines

[L.S.Barker1970]

2) adequate support for the cutter , cont..


Thought I would push on with this thread, I have a bit of interesting stuff to show and felt the need to start with some talk on Bolt condition.
The Bolts that hold the cutter in place are probably the most crucial aspect to the function of a square head cutter.
I know, I have gone on a bit about "bolt condition' but for me it can be the start of most square head cutter accidents.
Over tightening can be a big oversight upon setting up, yes, there is the need to have cutters well attached to the head, but putting a length of water pipe over a spanner for leverage is a big no, it puts way too much pressure on bolts.
For tightening up bolts a 300mm long spanner with enough physical force is plenty, any more is over kill.
If needed, this can be checked with a torque wrench set at around 100 to 110 lbs, but I will always prefer to hand tighten, its a feel thing.
New bolts are the best, its like putting on a freshly washed and ironed shirt, I guess what I am trying to say is that its like most things, all bolts will basically have a shelf life, how they are cared for will extend the life of the bolt, over tighting and abuse will only bind and stretch the thread leading to a shorter amount of use.
Never oil the threads nor soak bolts in oil, keep dry and rust free, if a lubricant must be used then graphite is acceptable.
A good test for threads is to remove the nut from the bolt and turn it over/upside down and if it threads back on to the bolt the condition is good, if not then the thread has been compromised.
Below are some great examples of over tightening and wear on threads.



These are dovetail bolts from a larger square head, the top bolt is stretched enough to angle the thread away from the bolt, where as the bottom bolt is still in reasonable condition.



These are bolts from a square head thicknesser, and again the top bolt is stretched and shows visible signs of distortion, where as the bottom bolt is still quite usable.



And the last example, these are from a Jeffwood thicknesser, very small bolts and easily over tightened. the top example is unusable, the bottom is still in reasonable condition.

Melbourne Matty.

[jayeson]

Sorry bump and old thread, but wanted to share some second hand experience.

Someone visiting my shop in 2004 saw my old jointer and held up his hand. It looked just like the pic from the Oliver catalogue Matty posted earlier in the thread, only with just slightly more of each finger left. My jointer had a round head which was hidden from view and I was able to confirm that his accident was with a square head.

I have seen one square head jointer in person - was in an old line shafted shop that had not be used in a long time - many babbitt bearing machines. The jointer was an 16" and I'm pretty sure from mainland Europe. Funny thing, there was also a very early 12" Barker jointer there - round head of course - and was the newest machine in the shop. It appeared that even the shop owner thought exposed belting everywhere at below waist level was OK (the belting ran under and across the floor), he was sufficiently afraid of the square head jointer to buy something safer.

- Jayeson