What toolposts are these?

[Paul MercerParticipant @paulmercer13838]

A question for those with more lathe experience.

I’ve had my Amadeal 250×750 for quite a few years and made a lot of stuff on it, but I’m just working on the lathe itself to make things better.

It appears to be the same as the Grizzly G0602, but does seem to have a slightly different carriage.

Onto the current topic – the carriage lock – which I’ve never used before. I’ve just tried to use it mid machining hence the mess, and it doesn’t lock anything!
I’ve removed it from the machine to see what’s going on with it. There are 3 machine bolts, 2 M6, and 1 M8. It is the M8 that is shown in the instructions to be the carriage lock.

My guess on how it works is that the 2 M6 bolts should be tight and these prevent the carriage from lifting, but give enough clearance not to lock the carriage. The M8 bolt can tighten and should flex upwards and lock the carriage – flexing at the ‘cut’.

Am I correct in thinking that this is how it should work?

In my mind, there isn’t enough flex in the carriage lock block (aside from the tolerances not being correct).  If I left the 2 M6 bolts slightly loose, the carriage lock block would be able to rotate upwards and lock.

Does the lathe need the 2 M6 bolts to be tight to prevent the carriage lifting?

 

lots of questions, and unsure how to word it all. Thanks

 

In the photos, the carriage lock block has been removed and placed on top of the carriage in the same orientation.

[JourneymanParticipant @journeyman]

Sounds similar to my old WM250, I modified the clamp and added a lever to solve the problem. See – Saddle Clamp – on my website for more info.

From this:

To this.

If you rummage around the website there is also some stuff on QCTP as per the original post.

John

[Paul MercerParticipant @paulmercer13838]

Hi John

Thanks for your reply. I was supposed to have started a new thread for the carriage lock question – but messed up somehow.

Your solution is the perfect one to my problem. That’ll be my job for the afternoon.

I’ve had a root around your website – lots of Interesting reading.

Thankyou!

[old martParticipant @oldmart]

I agree with S O D about QCTP being less stiff than four way posts which do not have the joint. I have avoided QCTPs at the museum simply because we hardly ever use HSS and we have a huge quantity of indexable tools which have been milled down from 20mm square to 17.53mm height which means no shims, except for boring tools which are boxed with custom milled shims. The quantity of tools would cost thousands if QCTPs were used and take up a much larger space. The Atlas 12 x 24 has had the new cross slide made to give a tool height exactly the same as the Smart & Brown model A and the new toolpost that I made is two way rather than four way as the tools are much too long for four to fit in any tool post anyway.

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