Anyone here got a cooksley (or another old) morticer?

[jpor4180]

I have an old Cooklsey morticer

To attach the drill bit, instead of a chuck there is a set screw. This appears to be a bolt cut in half and then a phillips slot hacksawn into the end. I have no reason to believe that it once had a chuck from looking at it, but I do think the particular bolt in question is not OEM. This wouldn't surprise me, as every time I go to change the morticer size, I lose it for a few days.

The slot is worn, and the thing refuses to hold small size bits. I never do small mortices with it but if I ever wanted to the drill bit would chatter free as soon as it was switched on.

I've used the vernier callipers to measure the thread, and the diameter comes to 9.34mm. A 3/8" bolt doesn't fit. Does anyone know what bolt might fit here?

Longer term, has anyone successfully converted an old morticer to using a chuck? at present, the drill is direct drive from the motor sitting vertically above it, with basically a 3" long or so female-female connector linking the output shaft and the bit. This connector houses the aforementioned set screw and is connected to the output shaft via a allen head set screw. I can't take the allen head fixing out because it's either 4.5mm or imperial (4mm way too lose, 5mm doesn't fit)

I think the other fasteners on the machine are a mixture of metric and imperial heads and threads.

Bonus question: the hollow chisel is held in place with a kind of rudimentary collet inside a housing with a split down one side and a bolt for tightening. This housing was broken at some point in its history and badly (well messily, I don't know how to really tell what the strength is without breaking it) braised back together. Does anyone know a guy in Kent that'll fix this and if so for how much?

TIA Jacob

 

[wallace]

On one of my wadkins, the LP recessor the chuck is fixed into a crude collet similar to the one you describe. It has a slit running the length and when you tighten a grub screw it secures the spindle of a chuck, I think the spindle is 1/2". I might have one buried somewhere if your not in a rush.

 

[merlin]

Hello Jacob,
On my Wadkin it uses a Allen head grub screw to hold the auger bit in place, I always file a flat onto the round shaft of the bit so it has something to grip onto plus it wont deform the round part making it difficult to remove.
It uses different size collets for the auger bits as well as the chisels, these have a slot in for the chisels and a hole in the side for the auger.
It also has a normal drill chuck if you want to use it as a pillar drill, it fits the same way but spins in the chisel bush.

Merlin

 

[jpor4180]

Thanks guys, I take it the grub screw method is conventional then? My augers happen to have a flat edge for accepting the screw anyway.

Merlin, my set up looks very similar to yours, is it possible that the Cooksley model I have was some kind of relation to yours?

Wallace, I'm not really in a rush, so yes that'd be great! I rarely use the morticer anyway - not as much as I'd like to because jobs in the last 6 months or so have just required housings, biscuits or pocket screws.

Serious question: what kind of place should I take my bolt cut off to find out what size thread it is? I've offered the thread as many trial sizes as I can think of. It would of course be easier for me to just tap a larger thread but I just have to find out now!

 

[AndyT]

The best way is to buy a thread gauge - they are only a few quid on eBay etc - to find out the tpi/pitch by direct comparison. The other key measurement is the outside diameter, for which you just need a micrometer or digital caliper.
Post the measurements on here and someone will find the thread for you.

Alternatively, put the screw on a white background next to a nice clear ruler and take a well-focused macro photo. BugBear is good at counting pixels to get accurate measurements.

 

[jpor4180]

Hi andy,

with the vernier calliper, it's 9.34mm

I can take a separate reading with Imperial micrometer if required?

 

[AndyT]

That's a bit skinny but could be 3/8".
The threads per inch is the crucial thing - there are standard threads at 16, 20, 24, 26 and 32 and probably others.
BSF might be right on a grub screw - that's 20 tpi.

 

[jpor4180]

I've read the photo posting thread but I'm not having much luck. But I do have a picture

The 3/8" bolt I tried doesn't even fit in the hole. As a sanity check, this 3/8" bolt was measured on the micrometer - weirdly it measured 0.385". Maybe it's not 3/8 after all.