Any tips for creating an arbor?

[vigsgb]

I am about to actually try and make something I am going to use rather than throw out

What I want to make is an arbor for my 3/8" drill chuck so I can use it in my mini lathe. I think the taper I need is a 3MT short to fit my tail stock with a threaded portion for the chuck to screw onto.

First off I was wondering if this project is deceivingly simple looking as I understand the taper has to be spot on to fit and function properly.

This seems like a simple project but I am new to all this so what end do I start with? The threaded end or the taper? Keep in mind I don't have a dog or plate so I can't turn on centers and have to use my chuck.

Any advise or tips would be appreciated.

Thanks

 

[lensman57]

Hi,

Is the 3Mt the Tailstock or the Headstock taper?

Regards,

A.G

 

[Tin Falcon]

Tapers are not the easiest things to make but with patience and proper measuring procedures can certainly be done. The South bend project book for students has taper gauges as student projects.
there are three way of cutting a taper
compound rest
taper attachment
tail stock offset.
you can just buy a machininable arbor for less than ten bucks and just machine the one end!!
http://www.victornet.com/report/Arbors-Morse-Taper-to-Blank-End/1370.html


Tin

 

[vigsgb]

Hi,

Is the 3Mt the Tailstock or the Headstock taper?

Regards,

A.G

I am going to build one for the tailstock and I think it is 3MT but have to measure to confirm. The book says that is the size.

 

[vigsgb]

Tapers are not the easiest things to make but with patience and proper measuring procedures can certainly be done. The South bend project book for students has taper gauges as student projects.
there are three way of cutting a taper
compound rest
taper attachment
tail stock offset.
you can just buy a machininable arbor for less than ten bucks and just machine the one end!!
http://www.victornet.com/report/Arbors-Morse-Taper-to-Blank-End/1370.html


Tin

I plan on using the compound rest method just have to figure out what angle to set the cross slide at. I am sure there is a formula somewhere for that.

Thanks for the link to the site. If I happen to fail at making this I will buy a blank and turn that down and thread it. Ether way it will be good practice.

 

[Art K]

I think you could still turn it between centers assuming you have a tail stock center. You can make a dog with two pieces of flat stock drilled and tapped so they can tighten together and a hole drilled perpendicular for a screw to stick out the back and be driven by the chuck jaws. You then put a piece of stock in the chuck (chucked OD smaller than that outside the chuck), and turn the portion sticking out by setting the compound rest to 30 degrees. Voila you have a chuck center. I have done this when I needed to turn something between centers at work and there was no center.

Art

 

[names]

According to Wikipedia's article on Machine Taper, a MT3 tapers has an angle of 1° 26' 16", or 1.421°. Obviously you can't set an angle that precise using the scale on the compound. However, you can refine an angle to get it an precise as you need.

Rough out the arbor, set the compound as accurately as you can, and cut a taper. Then remove the arbor from the chuck and apply layout bluing to the arbor. (Layout bluing is just a thin solvent-based dye. Permanent marker might also work.) Place it in your tailstock and rotate it. Places where the dye is rubbed off are where the taper is making contact. From this, you can tell if your compound angle is too small or too large. Clean the inside of the tailstock, adjust your compound, re-chuck the arbor, and make a light cut. Repeat the process until the bluing is rubbed off from most of the surface and you can feel the arbor sticking in the socket.

If you only have a three-jaw chuck, you're going to have problems with re-chucking the arbor. Fiddling around with it while looking at the runout on a dial indicator may help a bit.

Turning the taper between centers using an offset tailstock is easier. You don't need a faceplace to turn between centers; just a lathe dog. Chuck a piece of stock in your three-jaw chuck and turn a 60° point on the end. Now you can use the three-jaw as a faceplate by using one of the jaws to drive the dog.

 

[tomol409]

I typed Morse Taper into Google search and Wikipedia gave a complete table of the information required. Place a suitable length and dia. of steel in the 3-jaw, and turn as near as you can. Careful measurements at the correct distance apart will yield a fairly accurate blank. Remove the tailstock barrel from the tailstock and use it a a gauge. Smear the roughed out taper lightly with engineers blue, and test. If taper is too shallow, it will rub at the small end, and vice versa. Readjust, take tiny skims and keep testing until blue rubs uniformly. The taper will be turned true in the chuck. When correctly fitted, reverse and place in headstock taper if it is the same. If not use an adapter sleeve, then turn and thread the end. Chucks are commonly 3/8 inch UNF thread. The chuck will bed against the shoulder and run true.

 

[Tin Falcon]

I plan on using the compound rest method

BUUUZZZ!!! wrong answer bro . Most compounds will not travel that far.
you will Likly have to use tail stock offset method.

I made a few on my SB with a raper attachments IIRC like 0 mt for the Craftsman Dunlap 109. you just do not see them for sale that size atleaste not often.
Tin

 

[abby]

A blank 3MT is very cheap to buy so I wouldn't bother to make one , I collect old 3MT and 2 MT drills , these are butt welded to the HSS and can easily cut off .
The tapers can be used for all sorts of tooling , especially small faceplates and fixtures for holding difficult jobs whilst turning.
Use an adapter sleeve to fit the smaller tapers into larger and I always drill and tap the ends to fit my drawbars , you don't want the taper coming loose halfway through a machining operation.

 

[Springbok]

posted twice:hDe:

 

[Springbok]

There are many traders both in the UK and USA who sell blank arbours already ground. UK Arc Eurotrade USA Grizzly, Have a small stock of them in my workshop and
use them on my rotary table, mill and lathe.
Do not usualy post reply's on this forum but noticed this thread.

Tin facinated by your use of Latin and grammer.
Regards

 

[vigsgb]

I found out something pretty interesting this evening.....

• 
  For the mini mill I need a short arbor without a tang so it I will be able to use the compound method otherwise Tin is correct the mini mill cross slide would never make it.

• 
  I measured the diameter of the tailstock with plug gauges and found that the arbor size I need is a 2MT.

• 
  I also found that I had a 2MT arbor for the mini mill so I chucked that up zeroed it out in the four jaw chuck mounted a dial indicator on my tool post and while trying to zero out the indicator I noticed that every time I advanced the compound feed screw the indicator would jump two to three thousands of an inch and the feed screw felt sticky. I disassembled and found that the piece that held the compound feed was loose so when I tightened up the cap screws the lead screw would only go in half way and bind tight. I took out the lead screw and found that it is bent and thus the sticking and jumping. I also expected when I took apart the compound that the lead screw would be riding on some sort of bearing but there are none and the lead screw bearing surfaces are all chewed up.

I am going to look for an upgraded compound slide for this machine or get a new one so I can start out with something that works properly.

Once I get this lathe working smoothly and not jumping all over the place I will make this taper.

Without every ones replies to all the different threads out there I would not even known to check that ever thing was tight.

I am off to order some items and hopefully by end of week I will be turning this taper.

Thanks for all the great info.

 

[Tin Falcon]

you should not need to replace the cross slide. but you will likely want to/ need to replace the gib and gib adjusting screws . you will probably also need to smooth out the rough edges and possibly even lap the mating surfaces. Caution with lapping. grit left behind can cause damage rather than good.
Tin

 

[vigsgb]

I bought a new gib as Tin suggested with new set screws a new compound slide screw.

Now I am off to read about how to lap in the slide and new gib when I get it.

 

[vigsgb]

I lapped the slides today and created a post with pictures about it in the Finished projects section.

This made a 110% difference in the performance of the slides and the gibs can be adjusted so that the travel is smooth during the entire length of travel with no unwanted movement in the slides.

So much better that if I had know about this when I got the lathe this is the first thing I would have done...

Tomorrow I will be making this arbor and will posts some pics of the finished product when I get it complete.

Thanks for all the tips..

 

[vigsgb]

I created the Arbor for my Jacobs 3/8" chuck and it turned out great. I used a piece of 1018 steel and set the compound as close as I could and made some cuts. Then placed blue sharpie marker all over the piece and slide into the tail stock adjusted the compound attached my new compound tool grinder and took very light passes across the part measuring and repeating until I got what seems to be a darn near perfect fit. I used the micrometer at each end of the taper and the final measurement was dead on.

It did take me three tries but with each mistake I made I learned.

I covered all the newly lapped ways of the lathe with shop rags dampened in oil as the grinder makes perfect lapping grit lol

The worst part of the entire job was changing the gears for threading.

I did take a series of photos during the process but when I went to unload them from my phone I found that when I applied an emergency phone patch provided by my carrier that it erased all the contents of the phone.

 

[MachineTom]

You have made the taper already, so store this trick for furture use. You have a taper part, to copy that taper with the compound, mount the already tapered part between centers, or at least supported at the tailstock end with a center. Mount a DI on the compound, estimate a place to start with the angle on the compound. lock the carriage with the point of the DI centered on the OD of the taper, turn the feed screw of the compound. Adjust the compound angle until movement of the compound screw causes NO movement to to the DI reading. The compound is now parellel with the taper.

To set up to cut a taper without a piece to copy. first turn the work to the Major D of the taper, next measure off a know diamension on the work, 2" is a good choice, next look up or figure the taper per inch of the angle. Say its an MT 2 with a .5994 taper per foot, divide by 2 = .300, then divide by 6 (2''=1/6 foot)=.050" taper over a 2" travel.
Now adjust the compound so that over the movement of 2" (or 2.001" on the compound dial) the DI shows movement of .050". When it set you now will cut a taper of .600 per foot, MT-2.

It took longer to type this than it does to do it.

 

[tomol409]

I would question the tailstock taper being 3MT on a Mini Lathe. All the ones I have checked up up on are 2MT. The taper does not necessarily have to be full length. It will still locate accurately even if slightly shorter. The topslide travel on my Boxford is just too short to turn a 2MT arbor, but I have many where I just turn the small end parallel to allow ejection. do not know the exact travel of the slide on a mini lathe, so it may be a lttle short.

 

[vigsgb]

I would question the tailstock taper being 3MT on a Mini Lathe. All the ones I have checked up up on are 2MT. The taper does not necessarily have to be full length. It will still locate accurately even if slightly shorter. The topslide travel on my Boxford is just too short to turn a 2MT arbor, but I have many where I just turn the small end parallel to allow ejection. do not know the exact travel of the slide on a mini lathe, so it may be a lttle short.

Yes it was a 2MT taper not a 3MT as I had thought at the original post.