QUICK CHANGE TOOL POST

My lathe came with a four-way tool post and I wanted to convert to a "quick change" system.   Quick change systems are commercially available, but I decided to make my own, modeled  after commercial designs.

Quick change system consists of a Quick Change Tool Post, QCTP and Quick Chance Tool Holders, QCTHs.  Commonly, a number of QCTHs are dedicated to hold a particular bit.  Any QCTH can be mounted on the QCTP.  

The below photographs start with a making of a variety of Quick Change Tool Holders, followed by the making of a Quick Change Tool Post. 

Design goals

    The QCTP shall easily replace the four-way tool post.

    A wide range of cutting tools shall be accommodated, including parting tools     and boring bars. 

    The design shall be robust and secure. 

    Once set up, no adjustments shall be required.

 

<< The drawing is here >>

1.  An assortment of QCTHs and holders for carbide inserts.
1. (HOLDER)
Mild steel section, 30 mm x 60 mm x 250 mm being  aligned.

As shown below, the entire length will be slotted and dovetailed, and then cut to length to make individual tool holders, QCTHs.

2. (HOLDER)
Slotting 8.5 mm deep,  using 12 mm roughing  end mill at 340 rpm.  Slotting time about 12 minutes. 

3. (HOLDER)
Checking dovetail with digital micrometer.
4.(HOLDER)

Chamfering dovetail corners   after machining.

The length is then cut into individual "holders," with allowance for milling.
5. (HOLDER)
Fly cutting a typical holder 30 mm section.
.
See Article Number 36 for making a fly cutter.

See Article Number 29 for making a  precision milling vise.
6. (HOLDER)
Cutting tool groove in holder using a roughing end mill.
7. (HOLDER)
Making a parting tool holder. 
8. (HOLDER)
This is for the boring bar.
------
8. Slitting a boring bar holder, one of many  QCTHs that were made for the QCTP.
9. (ECCENTRIC CAMj
Making the Quick Change Tool Post starts with making the  eccentric cam.

The material is free-cutting steel, 40 mm diameter.
10. (BODY)
Boring the body while held in 4-jaw chuck with protective strips.
11. (BODY)
Cutting the body's dovetails for a neat fit with the dovetails of the tool holders, QCTHs.
12. (BODY)
Chamfering body edges  with deburring  tool.

After deburring,  remove machining marks with a belt sander.
13. (SUNDRY PARTS)
Knurling brass rod to make height adjustment nuts, one for each tool holder.   Several made at one time.

 
14. (SUNDRY PARTS)
Machining ball for end of the lock lever.  Material is brass.
PTD
Parts for QCTP and  QCTHs  prior to black oxide finishing.

16. QCTH  mounted on QCTP, ready for use.  

Locking is  smooth  and easy, and overall I am very pleased .