8 Attachment(s)
QCTP 250-00x Jacobs Chuck Holder Plans
If you already have one QCTP tool holder for your lathe then you can make more on the mill.
In a way this method for the mill is a lot like the Lathe Duplicator or Copy Attachment for duplicating parts on the lathe.
However there is not an attachment to make. Just use your mill and vise.
1. First step is to mill a blank from the metal of your choice. Steel, Aluminum, Brass, whatever,
This blank should be as close to the pattern (Master) part width as you can make it but long enough to make multiple copies after the milling is complete. Use a vise stop so the vise can be opened and closed as needed to insert or remove the Master. (original QCTP Tool Bit Holder)
2.Using a pair of parallels support your blank and the original QCTP holder (Master, minus all fasteners) in your milling vise on the parallels. Since the blank and Master may be of slightly different widths use a shim of paper between the "narrow" part and the vise jaw. Set your end mill depth and width using the Master and then remove the Master and lock down the blank.
Note: In all of the steps below the "Pattern Part" (Master) is removed prior to any milling
and replaced in the vise prior to any measuring.
3. You now have a "guide" (Master) for your end mill and dovetail cutters. Use a straight end mill to remove most of the depth of the "slot" portion of the dovetail. Proceed to next step after the slot is to depth.
3. Insert the Dovetail Cutter in the Mill, the Master and blank in the vise then use the "Master" to align the cutter depth and width. I made my new holders from aluminum so I was able to take the dovetail cut in one pass. Don't forget to remove the "Master" prior to milling.
4. Remove the QCTP chuck from the lathe and test the fit of your new Holder. It may need a little more metal removal that you can do by taking .001 cuts in the width of the dovetail and also the height if necessary. This is a cut and test method using the QCTP chuck to sneak up on the perfect fit.
That is it, adjust for a nice close fit and you now have a strip of future holders that only need sawing apart, finishing by milling the saw cut edges, and drilling the necessary holes.
Method 2 comes to mind where you do not have to put the "template" in the vise during milling. Just put the blank and pattern in the milling vise after applying Dykem to the end of the blank.
1. Scribe the outline of the dovetail using a long thin scriber. You can mill close to these lines and then use the QCTP Chuck to adjust for fit.
THE END....
First holder I made was one for a 3/8" jacobs chuck. I had one threaded for a 1/2-20 bolt so I just cut the bolt head from the screw
and made a 1/2-20 stud for the chuck. Tapped the holder for 1/2-20 at the indicated spot per the drawing and there it is. This holder is one nice way to drill on the lathe without using the tail stock. Aligning the Jacobs chuck to the center line of the lathe can be as simple as using a 3/8 short
steel pin from the lathe chuck to the Jacobs chuck. Of course there a lot of ways to make a gage or use centers for alignment.
Cheers, JR
