Morse Taper Turning

[jvdv]

Hi,
I am trying to machine my first no 3 morse taper arbor that will carry a slitting saw. I am using the top (compound) slide method as described by Harold Hall in his book “Lathework A complete course”

I have finished the taper/drawbar end of the arbor but was wondering how one decide if the taper was good enough or not?

I resorted to drawing a line on the taper with a blue marker pen and then used my lathes No5 to No3 adapter to test the fit by turning the adapter a few times and then studying the ink smear. Is this the correct method or is there a better way?

I am a bit afraid to just use this arbor in my milling machine/lathe because it may damage the surface area of the morse taper in my spindles.


Regards,
Jan

[glock40sw]

G'day.
I turned a 5mt to suit the head stock taper of my lathe by offsetting the tailstock.
It worked great.
It is a bit fiddly to setup but once set, the job was easy.
Getting the tailstock back to centre was a bit of a pain, but not too hard.

[jvdv]

Hi glock40sw,
Thanks, I have read about that method but was a bit reluctant to tamper with my tailstock. The method that I have used is also fiddly and requires that you make a test piece first that is used to set the angle on the top slide. The test piece can be re-used to make subsequent tapers.

Anyway, how did you test your taper? Is it a case of just putting it in the headstock of the lathe and making sure that it locks with light pressure?

What was the finish like on the taper before you used it? Did you polish it up with some wet and dry sandpaper? The book that I have suggests a finishing tool that you need to grind out of a HSS tool bit. I did not attempt making this finishing tool yet and is using carbide inserts at the moment.

Sorry about all the questions, but I can’t seem to find this type of info in the books that I have.

[forge]

Sorry about all the questions, but I can’t seem to find this type of info in the books that I have.

Hi ,jvdv .Try joining a machining list http://groups.yahoo.com/group/7x12minilathe
or another link from G-http://www.users.bigpond.com/pjifl/taper_turning_gauge.html
Dont know what sort of lathe you have but there is a lot of info available ,they are helpfull people.Good luck, you are further along then me .
Regards ,forge

[cub3]

Hi jvdv,

You should use Bearing Blue sometimes called engineers blue. Available from Repco, engineers suppliers, Auto One. Use very sparingly. or the results will fool you.

Definitely use the finishing tool, it is the total amount of contact that increases the locking force of the tapers. In production these surfaces should ideally be ground.

If you have a spare 3/4 or 3/5 adaptor you may be able to lap surfaces, though use the finest lapping paste sparingly.

Keep the concentricity of taper and blade journal the same or the blade will only cut on a few teeth.

Regards
cub3

[jvdv]

Hi forge,
Thanks for the link. I have read the material and it looks like a great idea if you need to do a lot of taper turning. I printed the article and made it part of my reference library.

Hi cub3,
On the Bearing Blue: Thanks for the tip. I have just picked up a tube at repco.

I will try and grind the finishing tool and redo the taper. I am not very happy with the surface after my first attempt.

With regard to the concentricity of taper and blade journal: I was thinking of boring a hole into the arbor while the new arbor is mounted in the lathe’s headstock. The slitting saw will then be mounted on a plug that locates into the bored hole. What do you think about this design? Something similar to the drawing in the attachment.

[Ashore]

The compound slide method you are using is fine it's just harder to get a good finish and the finish on the morse taper is all important , you need a mirror finish if possable as any blemish on either face will transfer to the other and cause damage & eventually slippage , the best bet in my opinion is when you get the male unit finished using a finishing tool then emery paper or wet and dry as smooth as possable use the back of the paper and some very fine grinding paste while still in the lathe to give that final finish

What is the shape of the finishing tool they suggest ?

Can you remove the winder handle from the end of the slide and use a cordless drill to move the slide , as this usually gives a better finish as you do the entire length without stopping, but be carefull at the chuck end , can be better to start at that end and wind towards the tailstock

Rgds

[cub3]

HI jvdv,
checked out attachments. before i can reply a number of questions.

What is you,re application. What are you trying to achieve / slitting / overhang / bore of slitting saw, OD, depth of cut, to be taken on each pass / material you are slitting (metal/type ,wood ?)

Indeed as Ashmore asked what is the shape of the finishing tool?

Please Caution if you use any lapping compound, please after use, before any further checking/fitting, totaqlly remove from all surfaces. Scrub internal surfaces and external surfaces to remove all traces of lapping compound, Followed by light lap unto each with kero.

[jvdv]

Hi,

The dimensions on the slitting saw are: 4"x1/16"x1" HSS SLITTING SAW.

The application will basically be general slitting saw work around the workshop.

In the near future, I have two jobs for it. The one is slitting a locking collar that will go onto the back axle of a go-kart that I am building for my son. The other is a small little clamp that I want to use for mounting a DTI on my mill. Please see the attached pictures for more detail.

If the overhang describes how far the slitting saw will be sticking out once mounted in the spindle, I was thinking in the region of 50mm to 70mm.

Due to my lack of mechanical “gut feel” for a lack of a better term I am very timid with regard to depth of cut. I will likely start at 0.1mm and work my way up from there. With that said, I see that things change quickly and I am already a lot bolder on the lathe.

I will be slitting metal and from memory I think the steel/metal merchant said it was 1030 or 1020. I originally asked for free machining steel (1214? or 1214L?) but the merchant said that it was specialized and he was not prepared to source it for me. So I just went with what they had.

I also include a picture of the finishing tool that I will attempt to grind, if you think it is the correct tool for the job?

I still need to study the drawings, but it should be possible to remove the winder handle on the top slide.

Regards,
Jan

[cub3]

Hi Jan,

Sorry for all the questions earlier, gives me a better picture.

Your earlier picture shows a slitting saw with no internal keyway, and mini lathe link shows 1/4" screw securing hole saw.

Mandrel design not bad will allow you to use different thickness slitting saws or side and face cutters.

Your slitting saw has no internal key so you have to rely on torque of bolt to secure slitting saw, suggest min. 1/2" to 5/8". Though at your 0.1mm depth of cut the former. Grease thread and under head of bolt/cap screw to increase clamping effort.

Have a look at this page http://www.homestead.com/tool20895/arbacc.html (Thank Forge for original post to different page)

The first one is basically where you are, though note the thickness of flange securing slitting saw (+ key way) the second, a more simple way to do it. The step is less than the thickness of saw blade, note the thickness of retainer and securing cap screw, this will only accomodate this particular thickness saw.

This cut can be taken in a single pass, if you can supply full flow coolant. It is not so much the depth of cut as feed rate.

Dont spend, too much time worrying about your finishing tool, by the time you grind this shape in you will have wasted good HSS hopefully with cobalt!) All you need is the radius/ surface speed/ a good coolant flow( it helps prolong tool life)

It can be done by hand with compound slide alone.

Apologies, was going to bring camera to work today and take pic of mandrel for Bridgeport Mill. R8 instead of M3, one pass full depth. Clamping effort/ collant flow/ feed rate.

You have it very well covered, but you cannot rub (multiple light cuts) HSS. The material needs to be used, if possible supply coolant.

In a nutshell. Clamping pressure on saw/feed rate over depth of cut.

Will try and remember to take camera and show R8 1" mandrel

Regards
Dennis

[vern thorn]

Mick carries alot of that morse taper stuff. Try www.moyles.com.au

[cub3]

Hi, Jan,

Pic's as promised. the saw position can be changed on mandrel by swapping around spacers.

Diameter of thread 1", Key is 1/4" wide.

Regards
Dennis

[jvdv]

That’s great, thanks for all the help and info. I can’t wait to get some shed time and give this a go. Hopefully I should be able to get a few hours behind the machines over the weekend.
PS..
I just hope my mill will grow up to be a Bridgeport one day!

[Metal Head]

Hi,
I am trying to machine my first no 3 morse taper arbor that will carry a slitting saw. I am using the top (compound) slide method as described by Harold Hall in his book “Lathework A complete course”

I have finished the taper/drawbar end of the arbor but was wondering how one decide if the taper was good enough or not?

I resorted to drawing a line on the taper with a blue marker pen and then used my lathes No5 to No3 adapter to test the fit by turning the adapter a few times and then studying the ink smear. Is this the correct method or is there a better way?

I am a bit afraid to just use this arbor in my milling machine/lathe because it may damage the surface area of the morse taper in my spindles.

Regards,
Jan

Hi Jan,

As you have already done the taper end this advice will be no good to you but maybe for others who read this thread in the future. Personally i have never read the book in question so I may end up having egg on my face as this is how he explained it should be done.

I would set up the appropriate morse taper sleeve in between centres and have "clocked" the taper using a DTI (Dial Test Indicator) mounted in the toolpost and then zero'd the compound slide movement to suit the taper. That way it should be extremely close to the "angle" required.

I think something overlooked on the machining of the slot is that the "workpiece" should always be feed onto the cutting edge of the cutter. Otherwise you will get what is known (in the trade) as "climb milling" that is highly likely to stuff up both your job but the cutter as well. I think the arbor that Dennis has show you is left hand threaded this is to prevent the cutter coming loose.

I hope this helps.

Regards
David

[dazzler]

Gotta ask

What does a slitting saw slit:confused: