Is a QCTP less rigid than the standard one supplied

Being a newbie at this machining hobby I don't have the experience to comment on the rigidity of different tool holders. But I can comment on ease of use. The lantern tool post is a royal PITA to use. I use mine to get into tight places where the bulkier 4 way or my shop made QCTP don't fit. Shimming the 4 way to get to center takes a little time to set up and you need a lot of different thickness shims to dial it in. My QCTP is the easiest to use. I made a Norman style QCTP like what Martik777 posted above. Here's mine.

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With any QCTP you will need lots of tool holders which can quickly get very expensive. I made seven to start with and recently got the material to make 4 or 5 more. The whole idea for using a QCTP is to have a tool holder for each type of tool that you need. Having to change out the different tools defeats the purpose of a QCTP.

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Making my QCTP was a very good learning experience. I learned a lot making mine that I would not have learned if I just bought a QCTP.
 
I agree on the rigidity issues, however on many lathes the compound and cross slide is a bigger problem. The tool post isn’t as big contributor. I love my QCTP. However I’ve taken great pains to keep the tooling close to the post. That’s one of the benefits of direct mount tooling like I modified.


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The 4 way holds the tool closer to the pivot point so it gives the tool less leverage to pull the tool down. So it is slightly more rigid. The mini lathe is not very rigid to begin with. It helps to keep all the gibs on the tight side and lock the ones not in use. But if you do a lot of operations on each work piece it can be tireing to change and shim the tools. I used a cheap set of feeler gauges to shim the different tools when I first purchased my mini. I quickly purchased the QTCP from LMS and every couple of months purchased more holders. The QTCP is very quick and easy to center the tools and is a joy to use. The LMS QTCP is a quality tool and is highly recommended. I did not realize how many tool changes are required for many small projects when I first started my learning curve. So if you don't mind shimming every tool the 4 way is very good. Also the 4 way is made for 5/16" or 8mm tools. 3/8" or 10mm tools will be too high to use. The QTCP lets you use the larger toosl up to 1/2" or 12mm. The worst part is the expense. I think Mikey summed it up nicely. I am not a machinist, just a hobbyist so your mileage may vary.

Roy
 
I don't think the 4-way is as onerous as claimed. Basically you set up two commonly-used tools (or the ones that are difficult to set up, like a parting tool) more or less permanently, then use the other two slots for per-job tooling. Given how cheap 4-way posts are compared to QCTPs, it might not hurt to have a "standard" one with four permanent tools and an extra one to swap in when the job requires form tools, knurling, etc.

Really, once you have made a lathe center height gauge, shimming is less of a problem, and you can always rubber-band a shim to its tool when removed from the toolpost.
 
I used a four way I'd built for years, it was made for the lathe it was on, made to hold 3/4" insert tooling, any tool I put in was right on center. I eventually made some adaptors, (3/4 square with a 3/8 cut out on top) for 3/8 tooling.
 
rouesses - I have never shimmed a tool in a 4 way tool post in my life. I'm trying to say that for insert tools, you modify your tool holder once only, and then never need to set the height again. Shims are never required! I just can't stress this enough.

- I am in the process of moving all my old tools from my old lathe to my new one: they only require .002 grinding off to get to the same height. (I could mill the .002, but why not use the SG?) Fix the 8 or so tools once, and they are all at centre height automatically!
 
Thank you all for your comments.

I am going to stick with the 4 way toolpost as it seems to be the most rigid option as I can have minimum overhang.

I am not bothered with the extra time it takes to get the tool height right and will have some sets of feeler gauges for shims.
 
Dabbler I understand that. But being a newby I tried 1/4" tools that were available at the time. They were carbide inserts and needed 1/8" shims to come to center.. I also tried some hand made HSS 5/16 that were ground a little shy of center and used feeler gauge shims for those. Remember this is on a mini lathe . I don't think any 2 mini lathes would have the same center height out of the factory. Now that I use mostly Warner hss insert tools with the QTCP I no longer need to shim. I realize that you as a pro know much much more than I ever will and would take your advice without question.

I appreciate the members here who are pro's or advanced hobbyist's who are so willing to help out those of us who are just hobbyists learning a new craft for personal enjoyment. Not many machinists are willing to help or even have the time to. I have learned a lot from this forum. I usually give likes when I learn something but don't always give feedback on how your tips and tricks have helped me with a project. I just want to thank you all for the great help and attitudes that make it so much fun to be on the forum.

Roy
 
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All good. I just thought you didn't know about making the toolholders fit. Apparently it seems rare to do so.
 
What do they use in machine shops ? ;) The Aloris wedges are expensive but possibly for a good reason . If you plan on using the machine for a long period of time , the cost should be of no issue , plus it has a high resale value if you ever have the need to resell it .
 
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