Tuesday, August 31, 2010

My attempt in making tool holders for A2Z QCTP - Milling the dovetail

This session was about 4 hours long last Saturday started around 10pm.

I spread a layer of blue acrylic paint over the surface so as to mark the slot to be milled. As this is my first attempt in milling the slot and the dovetail, I play it safe by cutting off a small chunk of stock sufficient to make 2 holders. The layout lines were scribed on using my newly acquired digital height gauge. The height gauge was Taiwanese made that is within my budget. It cost me SGD260 from Nanyang Instrument & Machinery Pte Ltd located in Jalan Besar Plaza. The Mitutoyo gauge which I initially wanted is priced at around SGD900. I trust Mitutoyo more as my vernier caliper and micrometer always return to zero when the jaws are closed. Not true for this Taiwanese gauge. It always go back to either 0.1mm or -0.1mm.

I use the Proxxon centre finder bought from Mike of sgTooling to locate the bottom left corner and "dial" in from there using Mach3 MDI (I do not have handwheels on my mill and have been using XBox360 controller to move the axes). One side of the slot was milled first to full depth and I side mill from there till I reached the opposite edge.

The dovetail was done next. This is much easier than I thought. Now that the dovetail is done, I'll do the cleaning up and drilling / tapping of the set screw holes and the slot for holding the tool in the next session.  I'm hoping that next session will be SOON...

Some pics below on what was done so far:

After cleaning up the sides


Milling the slot for dovetailing later


Love the look of this

One side of the dovetail done  

Dovetail completed


Test fitting on the A2ZCNC QCTP

Comparing with the original  

Slicing it up to size 

The gap looks kinda big when the lever is locked

When I measure the gap after locking the holder down, it seems to be almost the same as the original piece from A2Z.  Could it be the colour playing tricks to my eyes?
I'll be cleaning up the rough cut edge, drill, and tap the holes for the set screws.  Don't know if I should turn my own brass nut to use as the stop or try to find something similar.  Maybe I should try different options since I've sufficient blanks to create many pieces to fool around with.


cjellmoney said...

Hey wongster, i found your posts on cutting dovetails for a QCTP after a short search. looks pretty pro. would you consider cutting some for anyone else? i have a few tools that i would love to mount directly to the tool post. any interest?

Wongster said...

Hi cjellmoney,

Sorry for the late reply. I've moved my blog to www.wongstersproduction.com and so didn't check back here often.

Do let me know what you've in mind. We can explore.