Quick Change Tool Post

[gus]

Now building a QCPT from the latest Model Engineers Workshop.I am upgrading from a very primitive version built 12 months ago.
Some expert tips appreciated from the Gurus. Milling the dovetail slots can be scary.

 

[gus]

Sure need a Mechanical Saw to cut this 1 1/2 M.S.Square Bar.
Took 15 mins to hacksaw thru .End cut turned to be quite square.Seen the old hands cutting same in no time and quite effortless too.Gus was wheezing away.

 

[dman]

one of my favorite cutoff tools is a portable band saw. a friend of mine even has one with a stand that can be a chopsaw style or can be put vertical to make contour cuts. it looks to be about 40years old an i dont know who made that particular type but in general portable band saws are great for garages and small shops.

 

[n4zou]

I also use a portable band saw. I had a band saw that could be used vertically or horizontally but it's use was regulated to the shop. Being a hobbyist ready to take advantage of scrap metal the portable band saw is indispensable. It also takes no floor space when it's in it's carrying case on the shelf. I have an inverter that will power my portable band saw from the truck's battery so it's easy to take advantage of cheap or even free scrap metal.

 

[gus]

Clearing shop clutter to put a small band saw.
Please advise on the Proxxon Band Saw.Is it worth the money spent?
May consider a Taiwanese Band Saw.Bought an industrial version for factory use long ago.Gave me satisfaction.
Will also consider "Made In China".
Manual hacksaw is good exercise but I don't to waste my valuable time and energy. 69 now and not too much time left.

 

[gus]

Milling male or female dovetails is tedious as the end mill cannot take deeper cuts and manual cannot be heavy to avoid breakage. There must an easier way to remove bulk cuts and finish up with dovetail mill.
See attached foto. Took just one hour to rough cut two male dovetails.Will finish up with dovetail end mill.

 

[dman]

i never really had to cut dovetails but maybe a vertical band saw would be the best way to rough it in similar to what you did if the dovetail cutter has problems. also it would be best to work with hot-rolled steel or have your metal annealed or normalized then hardened when complete. i'm not sure what the hardness requirements would be or what alloy you are working with though. but maybe you are just not using a dovetail cutter that meets the requirements.

for example this:

instead of this:

or:

would get the job done without issues.

 

[Tin Falcon]

I too am in the process have been for a while of making four sets of QC tool posts. I have a aloris and a A2Z. But need more.
the normal way on a verticle mill is use a dovtail cutter.
I would not use a saw. a fly cutter would work.
I did mine on a shaper did all four blocks in one shot then cut apart.
As far as a saw. if I was in a cramped I would get a portaband. the milwaukee brand ones are nice and will last a long time the Harbor freight Chinese are cheap.
If you have a strong bench a saws all will also work. They do shake things up abit if you let the blade bind.
Also with a saws all easy to change blades and have a blade assortment.

Tin

 

[gus]

Sorry Guys. Sorry for the messed up.This foto shows one side male dovetail done using slitting saw.
With dovetail rough cut and finished up with dovetail angular mill cutter.Will post next foto tomorrow. Lots of good ideas coming.

Next task would be cutting both male dovetail to same height/depth and width.That uniform dimension. Please advise best method.

 

[petertha]

I'll be very interested to watch your progress. Is the Model Engineer design a piston type locking mechanism? (I think thats what they are called, as opposed to 'wedge').

 

[gus]

I'll be very interested to watch your progress. Is the Model Engineer design a piston type locking mechanism? (I think thats what they are called, as opposed to 'wedge').

Yes.Its piston & cam lock and dovetail wedged.
Tool post was suppose to be 2" x 2".I goofed using 1 1/2 x 1 1/2 from scrap bin. Should be fine as my existing QCTP used 1 1/2" sq.
Thanks for the flyer.


Gus

 

[gus]

OK Guys. Tool Post Block done.
One Dovetail Cutter busted with too heavy cuts. Fortunately I had a spare to backup. Have to take light cuts to finish up.Both dovetail within +&-0.001". Will make Tool Holders interchangeable.
See attached.
Next to work on the tool holders which have female dovetails. Now beating my brains for best labour saving and yet procedure to get good dovetail sliding fit.Some manual fitting required.Taking my sweet time.

 

[scruffy]

Looks good Gus I dont even have a machine yet but Ill put this in the memory bankI can see how it could be helpful

 

[gus]

Looks good Gus I dont even have a machine yet but Ill put this in the memory bankI can see how it could be helpful

Thanks for the encouragement.
Where about are you located in Melbourne? My daughter lives in Glenhuntly.

Does't take a big chunk to buy a small lathe and drill press. I did it bit by bit.

 

[scruffy]

Im in Dandenong not too far from Glenhuntly

 

[Antman]

Myself, I think a shaper is the bee's knees for making dovetails. When I made my (not so )QCTP I decided against dovetails and made a cylindrical toolpost with toolholders clamping around it with a cotter pin, gives a great clamping action. I wish I could post pix.
Ant

 

[petertha]

...Dovetail Cutter busted with too heavy cuts...

I have yet to do dovetails, but its coming one day. When you say 'too heavy', about how much were you advancing the dovetail cutter when bad things happened?

 

[gus]

Im in Dandenong not too far from Glenhuntly

Was in Ingersoll-Rand ,Dandenong plant for a short while in the 80s.
Plant is gone.
Took a ride on the Puffing Billy in October 2012. Very educational.So much history.

 

[gus]

Fruits of today's labour.
1. Tool holder. Female dovetail milled.
As dovetail cutter is too slender.Slotting thru with same cutter will incurr rapid wear. Mill "key-way" slot.Followed by dovetail cutter.Ran cutter at medium speed to cut dovetail slot.Depth of cut must not be too shallow to avoid rubbbing with no real cutting.
Trial mating of dovetails. Achieved light drive fit. Light push fit achieved with one light cut.
2. Both male dovetails fit tool holder. Manual fitting eventually to slide fit.

Total machine time 3 1/2 hours. See fotos.

 

[gus]

With 6 tool holders to make. Blanks best to skim off with four jaw chuck on the lathe.End Milling takes too
long with the small vertical mill.By using the lathe to face tool holder blank,mill will be solely used for key
way slots and dovetail slots.This is best work flow. Oh!!! Going back to manufacturing again.
Four more tool holders to manual hacksaw!!!! No worries.My saw skill has improved. Takes only ten minutes now with practice.