Should I buy this?

[BaronJ]

Hi Guys,

I've seen many posts, where people have had to machine or grind material off the bottom of the tool post in order to get the tool at centre hight.

 

[goldstar31]

Hi Guys,

I've seen many posts, where people have had to machine or grind material off the bottom of the tool post in order to get the tool at centre hight.

John

Trouble is that some of the QCTP's are tempered and I have a bad temper.

Kind regards

N

 

[ignator]

My experience is when the tool post height controls the height of the square cutting bits, or a boring bar holder. This is the only time I had to machine material from the bottom of these holders. In this case it was a turret tool post with 4 positions, and a boring bar holder that holds different bar diameters, that is split in half, along the bar axis.
I changed over to a QCTP on both lathes (size A and CA) and never had to do anything but make a custom "T" nut to fit the compound, for the post hold down bolt.
If this is required on a QCTP to get within the adjusting range of the tool holders, then the post is probably too large for the mini lathe. I just recently have seen very small QCTP's available for this issue.
The problem with the turret tool post is that only one size of square tool bit could be used without shimming. As well not all tool bit manufactures had the brazed carbide at the exact same height, as well ground HSS tool bits having the cutting edge move, from resharpening.

 

[BaronJ]

Hi Ignator,

I don't have this problem with the Norman Patent toolpost that I made. It will take a 1/2" inch tool blank at least 5 mm below centre hight and the bottom of a 1/2" tool blank 1/2" above centre.

The QCTP that I got rid of couldn't do that even though they were designed for 1/2" tool blanks. Whilst I am not knocking them, for production work they are great, they aren’t really useful to a hobbyist. Anyway I would rather spend my money on more useful things.

Re: your comment about the mini lathe, I've seen the Norman Toolpost used on a 15" inch DSG using 1" tool bits. Enormous thing !

 

[limeyguru]

On my Grizzly G0702 The tool height was limited by the height of the compound. I opted to skim about 0.06" from the bottom of the compound -- that was enough to allow setting tools on center.

 

[ignator]

they aren’t really useful to a hobbyist

I was replying to the comment about tool post being too tall to put the cutter on center.

I would never go back to the rocker style lantern tool post. A QCTP was the best add on to my home shop (10x24) lathe. 1/8" to 1/2" square and round bits (boring bar) can be used in the A series QCTP. Changing from facing to turning is quick (assuming multiple pre loaded holders), makes accurate machining.
I also have a turret style post, but have not used that in years.
And I would have to dig for the rocker post that came with my lathe, as I consider that useless.
I have had one failure of a CA series QCTP, on my 18x40 (450x1000mm) lathe. I was trepanning, with a 1/2" square shank cutter hanging out 1.5 inches. It grabbed, bent the cutter shank, the wedge clamp of the QCTP slipped and bent the 8mm holder stop stud (the tool holder height adjust screw with thumb wheel and lock nut). So the limits of this friction clamp can be exceeded.

 

[velocette]

I get cross but am too old for this pollination thing.

Gung Hey Fat Chow

Norm

Cross Pollination extends to my workshop I made a couple of tool holders for my "Home Brewed" tool post then the little buggers started to breed ended up with 26 of them. Now with a strict birth control regime in place so no more offspring.

 

[ignator]

ended up with 26 of them

That seems about the right number of tool bit holders. I assume you're using a home spun QCTP of some sort.
Just the standard brazed carbide tool bits have 7 different types (A thru E, with A&B haveing left right), so for turning and facing setup, you need 14 holders. Add in some cutoff, and form tools and 26 seems perfect.

 

[goldstar31]

Cross Pollination extends to my workshop I made a couple of tool holders for my "Home Brewed" tool post then the little buggers started to breed ended up with 26 of them. Now with a strict birth control regime in place so no more offspring.

I'm not far off you in numbers of holders but my worse fault is collecting Myford accessories .

Thinks!!!!!!! Better return than the present UK bank interest which is - after allowing for tax and then inflation is not worth the thoughts.

Cheers- Have fun instead

Norm

 

[Shopgeezer]

So the A0 size tool post is too small, designed for mini lathe, and the A1 size is too big for my cutting height. After a lot of digging I found a new size, Ab, that is halfway in between. The specs seem perfect so I ordered it. The vendor was really good about answering emails. He even dug out one of these Ab tool posts and mounted it on his lathe in China to send me pictures of it. Of course couriers do not deliver to rural properties so too bad if you live on a farm. I have to send it to a friend in town who has a street address. He just bought a nice 12” gear head lathe so I will be suspicious if he claims my toolpost never showed up.