Quick Change Tool Post QCTP

[Janger]

My four position tool holder on the CX701 from busy bee has a number of problems. The main problem is it slips and rotates counter clockwise under heavy load for example when parting off. Tom's practical machining video on parting says an essential requirement for successful parting off is a very firm tool holder in a QCTP. The four position tool holder is also annoying to adjust as changes in angle require a wrench and adjusting two bolts.

Ok, I'd like something better so what to buy? At the top end are some fancy 40 position Swiss tool posts which cost more than the lathe! No matter how much money you've got you can spend a lot more with this hobby...

Busybee does not have anything they strongly suggest as anything they sell requires mod's for this particular lathe in order to mount it. KMS has a couple of options, again I think mods will be required to mount it. Both are the piston style. Research shows a wedge style post is firmer and more accurate, a little more money too. Another hobby machinist suggested one from the Canadian firm Accusizetools.com. It is $238 plus shipping.
http://www.accusizetools.com/quick-...-sets/?page_context=category&faceted_search=0

It looks pretty good. Anybody using it?

Another problem I see is the hole in the carriage where you might mount the post is actually quite far from the end of the carriage. The tools may actually be hard to get into position with the work material. I suspect a new hole needs to be drilled.

Comments... thoughts?

 

[Alexander]

The quick change tool post would be sweet but expensive. If you have the money do that. If not I would think you could take the compound rest off and put it in a milling machine. You could then drill and ream for a .25 dowel pin that connects the tool post to the compound rest. This would make tool changes slower but at least it wouldn't rotate away on you. Having a rigid setup is the most important part of any machining operation. I used to have an old manual lathe with this setup on it. My curent machine has the same style tool post but has an automatic tool changer. It has a big center bolt the tool post rotates on and a dowel pin that sticks up a bit next to it. When it needs to tool change it lifts up the tool post clear of the dowel pin and a servo motor rotates it.

 

[kylemp]

The wedge style toolposts are a lot better than piston for repeatability, as the wedge itself always drives the dovetail down into the correct height position. I just posted some pictures of the 40 position I am going to sell at What Machines Do You have? if that is the route you want to go, but its certainly going to be more than what you can get a dovetail style for. Can you take a picture and post it of what you mean for the hole in the carriage? Or do you mean compound? Just googleing the machine it looks like it shouldn't be an issue..

 

[Mphenley]

You could always try making your own...
This is the style I think I'm going to end up making(or trying to):

http://homepage3.nifty.com/amigos/qctp/qctp-e.htm

 

[Stone Wu]

My four position tool holder on the CX701 from busy bee has a number of problems. The main problem is it slips and rotates counter clockwise under heavy load for example when parting off. Tom's practical machining video on parting says an essential requirement for successful parting off is a very firm tool holder in a QCTP. The four position tool holder is also annoying to adjust as changes in angle require a wrench and adjusting two bolts.

Ok, I'd like something better so what to buy? At the top end are some fancy 40 position Swiss tool posts which cost more than the lathe! No matter how much money you've got you can spend a lot more with this hobby...

Busybee does not have anything they strongly suggest as anything they sell requires mod's for this particular lathe in order to mount it. KMS has a couple of options, again I think mods will be required to mount it. Both are the piston style. Research shows a wedge style post is firmer and more accurate, a little more money too. Another hobby machinist suggested one from the Canadian firm Accusizetools.com. It is $238 plus shipping.
http://www.accusizetools.com/quick-...-sets/?page_context=category&faceted_search=0

It looks pretty good. Anybody using it?

Another problem I see is the hole in the carriage where you might mount the post is actually quite far from the end of the carriage. The tools may actually be hard to get into position with the work material. I suspect a new hole needs to be drilled.

Comments... thoughts?

40 position quick change is better for using, but wedge style popular in USA is not too expensive.

 

[PeterT]

I have the typical piston style dovetail & have been quite happy with it. It was bought from KBC many years ago but seems to fit similar current (Chinese) 200-series tool holders very well or the 'real' (USA) brands they are cloning if you are so inclined. I've read similar comments about the wedge style being a bit more repeatable when taking tool holders on & off, so that's a consideration. That being said my piston style has been quite accurate. I tested this with a DTI in the tool holder against a ground bar in the chuck & it was within 0.001" after several on/off repeats. Maybe a lucky fit but close enough for me. If you can push your carriage or compound around +/- 0.0005" with gib slop or whatever, it kind of cancels out a super accurate tool post IMO. The thing is, unless you are banging out identical parts that requires this repeatability, its not really a big deal in my books. My requirements seem to be changing tools from facing to longitudinal to chamfering to parting to... so they are all going to be different setting to the work piece anyway. Maybe 'real' machinists have other considerations. :^

What I would say is the Chinese assemblies ones are good value & this is important as your tool holders count grows. Its nice to have various cutters & boring bars set up & centered beforehand with the height setting nut. Or maybe you want to modify a tool holder one for a special application like an odd-ball shanked tool you acquired. I don't fancy myself making these myself for 20-30$/ea. They are ground on the dovetails. But... each to their own. These would make a good project if you were so inclined.

 

[John Conroy]

I have a Chinese built BXA size wedge style QCTP and I'm happy with it. It's probably the

the same as the one Accusize sells. I have dealt with them and they seem like a good vendor.

I made up a rack for the holders for easy access.

I don't like the push style knurling tool that comes with the set so I modified it to work as a regular tool holder.

I removed the knurl wheels.

Cut off the mounting boos for the wheels.

Milled out the slot for the tool bit.

Drilled and tapped 2 more holes for the set screws.

 

[Stone Wu]

piston and wedge type are popular in America below shows,

 

[Stone Wu]

piston and wedge type are popular in America below shows,

 

[PeterT]

John Conroy, I like your tool rack idea. Your CanTek lathe looks 99% like my King. Is it a Taiwan 14x40 of mid-1990's vintage? If so, maybe I will create a new post or contact you offline & pick your brain a bit. There have been a few things on my to-do list lately & maybe you have some experience/comments.

 

[John Conroy]

Thanks Peter, I have a pdf copy of the users manual for the lathe. If you are interested I can send you a copy. You can email me at jconroy at shaw dot ca

 

[schor]

I have the axa toolpost fom accusize and it's fine for my purposes.

I had to modify my compound, didn't have a mill at the time, I really should have just filed off the small amount.

You really shouldn't use a drill press as a mill.

I made a new locknut for it.

Then I needed a tool holder holder.

 

[Janger]

Hey great videos.
In the qctp handle vid you're threading with the drill press but you don't seem to have a tapmatic or other gizmo. It flashes by pretty quick. How did you do that exactly? Under power? By hand? What kind of tap? How fast? With tapping fluid?

 

[schor]

Hey great videos.
In the qctp handle vid you're threading with the drill press but you don't seem to have a tapmatic or other gizmo. It flashes by pretty quick. How did you do that exactly? Under power? By hand? What kind of tap? How fast? With tapping fluid?

I power tapped on my milling machine, hit the power on off real quick. I only have forward so I reverse by hand. Spiral point tap since the hole is actually a through hole into the main hole.. The nut is 12l14, didn't use any tapping fluid.

 

[EricB]

Nice cleat-style tool rack, @schor!

Sent from my B15 using Tapatalk

 

[Lous Creek]

I know this post is a bit old but Janger have thought about an omni style post? I liked it so much that I spun one up over the weekend. I used to love turrets but got frustrated having to shim them up to center, also to get the tool into position sucks at times. The first holder I made for my new tool post has a 30 deg angle to it so the post stys out of the way (hopefully)

 

[schor]

I know this post is a bit old but Janger have thought about an omni style post? I liked it so much that I spun one up over the weekend. I used to love turrets but got frustrated having to shim them up to center, also to get the tool into position sucks at times. The first holder I made for my new tool post has a 30 deg angle to it so the post stys out of the way (hopefully)

I'd like to see some pics of what you made.

 

[Janger]

Me too.

 

[Lous Creek]

Sure thing here goes excuse as it's my first time. The round post itself is 38mm dia and the tool holder is made out of some 1x2 in flat bar. I also just finished my MT 4 to MT 2 adaptor so I can use an endmill holder in the lathe spindle.

 

[Janger]

Interesting pic Lous but I don't exactly follow. More pictures? More description? Where does the bit go?