Tapping tool for the mill

[firebird]

Hi

I have thought for some time that when I drill a hole that needs to be tapped in the mill it would be handy if I could tap the hole while the chuck is still in position. This is what I came up with. This set has been made to suit all the taps in my model engineering thread sizes, additional holders for metric and imperial will be made as I need them. The set consists of a 3" length of 5/8" steel tube with a bore of 7/16". 6 x 4" lengths of 7/16" steel rod. (there are 6 shank sizes in my set of taps).

Each rod is faced in the lathe then centre drilled then drilled to a depth of 5/8" the 6 different shank sizes.

Each rod is then cross drilled and tapped to take a 3mm cap head to lock the tap in place and cross drilled 3/16" to take a 4" length of stainless steel rod.

Thats it. Job done.

At this years Harrogate model engineering exhibition I bought a metal blacking kit so decided this was an ideal candidate. It gives the tool some protection against the dreaded corrosion and makes it look better.

All the parts were degreased with thinners first. The parts are attached to short lengths of wire. Plastic coated is best. That way none of the solution is wasted blacking the wire. The wire is the sort gardeners use for tying plants.

Here are the 4 stages.

First the parts are are immersed in the de0greaser for 10 minutes.

The parts have to washed in clean water in between each stage. It reccomends running water if you have it.

Next is the conditioner for 1 minute, then rinse again.

Then the Blak for 2 minutes, then rinse again.

Finally the oil for 10minutes then leave to air dry.

The finished parts.

To use the tool simply put the tube in the chuck. Select the appropriate tap and holder and insert into the tube. Fit the handle and tap the hole.

About 2 hours in total to make the tool.

The tool in use, before I blacked it.

cheers

rich

 

[bentprop]

Great idea,Rich.I can see myself making a set!
How do you find the blacking stuff?It's a bit hard to see,is it really black,or a sort of dirty brown?I can get the stuff locally(at a price ),but don't want to spend a small fortune if it doesn't work good.Regards.Hans.

 

[CrewCab]

Simple, effective ........... and nicely finished 8) ........... works for me .....

Nice one Rich ......... yet another job on mi' list :

CC .......... aka .......... Dave

 

[firebird]

Hi Hans

Yes it is a good black. After it has dried just give the parts a quick wipe with an oily rag to give the shiny black finish. I have scanned and uploaded the leaflet that comes with the kit, I hope its readable. I paid £20.00 for the kit at the model engineering exhibition at Harrogate. The price included the 4 plastic pots.

Cheers

Rich

 

[georgeseal]

Rich,
You might consider a second set screw on the flat of the tap. This will prevent rotation of the tap
What you have now is a hardened setscrew against a hardened tap

Just my $0.02 worth and well worth what you paid :big:

PS By the way nice work :bow:

 

[firebird]

Hi George

Yes I might have to do that thinking about it. I'll see how they perform first.

Cheers

Rich

 

[HS93]

Just a point about the metalblack I spoke to the chap at Harrogate as I wanted there product for brass, I wanted to use it to blacken brass fittings I make for model boats as I did not want to paint them as I would loose some of the sharpness and fine detail, but unfortunately it does not stop them tarnishing, he said you have to protect then with lacquer or similar , same goes for steel it does not stop rust you have to coat protect it , but for tools oil or wd would do I think he said

peter

Hs93