Mt2 ==> Mt3 Adapter (step Up, Not Down)

tfleming said:
Interesting thought. So, can someone answer this. These are HSS and no doubt heat treated. Wouldn't the MT3 taper have to be ground vs. machined? I would also think that so that the finish is appropriately smooth as well. I have a Dumore tool post grinder, so I could certainly consider that. I have already purchased the MT3==>MT2 adaptor, so that part is complete. Obviously, there are options. I think at this juncture, I'll kick the tires on the adaptor. If it mis-behaves, I'll look into possibly grinding the MT3 to MT2. That is definitely a cold winter project......
Click to expand...
The shanks on all drills including one's with Morse tapers on them are somewhat soft. They are not hard. You can cut on them with most cutting tools. Just don't get carried away. You could work harden them in the process of cutting on them. Grinding on one of them would take all winter to do just one. Ken
 
Ok, I just learned something, which is always a good thing. Thanks Ken. So, the shank end on these has been center drilled where the tang is. 3 jaw on the headstock, and live center on the tail stock to hold these puppies? I also have the taper attachment for the lathe, so getting the MT2 taper should be straight forward. I am thinking that the approach might be to turn them down, and get them close, then take a finish pass with the Dumore with a fine stone. Should give a nice finish on them. I could also turn them, and use fine emery paper as well for the final polish.
 
When you chuck up on the drill, try to bit on it right there past the flutes next to the tapered shank. That's the only place you can grip the drill bit and get it running true in the chuck. And yes, the center in the end of shank will help in alignment too. Word of caution, the tang on some drill bits are slightly hard but you can still cut on them. No need to grind a nice finish on the taper shank, just use some emery to polish it a little. What you are going to be doing at first is getting the taper attachment set to cut the proper taper. No matter how close you get it, it's almost impossible to get it perfect. Just shoot for the larger end of the taper grabbing in the socket and get it as close as you can get it. If you have a spare No. 2 Mores taper socket, cut the tang end of the socket off, debur, and use this for a gage. Also use it for blueing the shank and making impressions with. Have fun! Ken.
 
Here's a picture of some that I turned down from no. 4 MT to no. 3 MT. One thing to keep in mind, these bigger drills don't stay locked in on the taper and tend to spin. I've had to use certain wrenches to hold them in place to keep the drill from spinning. Ken

DSCN3536.JPG

DSCN3537.JPG
 
@4gsr : Hi Ken,

For an MT-2 taper you'd likely not have enough compound/top-slide travel to allow this, and would need the taper attachment.......but just trying to understand the process of copying an existing "sample" taper in general.

I have never done it, but from thinking about it can you set the top-slide or taper attachment to the proper sample taper angle like this:
  1. mount your sample taper (an MT-2 shank drill bit, in this case) and chuck it up as stated above using the tailstock centre in the shank end hole
  2. put a dial indicator in the lathe tool holder adjusted so the tip is at the lathe centre line height
  3. with no taper attachment: adjust the compound/top slide angle until the indicator sweeps the length of the sample taper with near zero offset (using top slide feed)
  4. with taper attachment: adjust the taper attachment angle until the indicator sweeps the length of the sample taper with near zero offset (using carriage feed)
  5. chuck up one of the "oversize" drill bits and take cutting passes until the minor and/or major diameter equals that of the the target MT-2 shank
Thanks for any feedback.

-brino
 
brino said:
@4gsr : Hi Ken,

For an MT-2 taper you'd likely not have enough compound/top-slide travel to allow this, and would need the taper attachment.......but just trying to understand the process of copying an existing "sample" taper in general.

I have never done it, but from thinking about it can you set the top-slide or taper attachment to the proper sample taper angle like this:
  1. mount your sample taper (an MT-2 shank drill bit, in this case) and chuck it up as stated above using the tailstock centre in the shank end hole
  2. put a dial indicator in the lathe tool holder adjusted so the tip is at the lathe centre line height
  3. with no taper attachment: adjust the compound/top slide angle until the indicator sweeps the length of the sample taper with near zero offset (using top slide feed)
  4. with taper attachment: adjust the taper attachment angle until the indicator sweeps the length of the sample taper with near zero offset (using carriage feed)
  5. chuck up one of the "oversize" drill bits and take cutting passes until the minor and/or major diameter equals that of the the target MT-2 shank
Thanks for any feedback.

-brino
Click to expand...
Brino,
That is exactly the way I did mine.
Ken

Sent from my SAMSUNG-SM-G920A using Tapatalk
 
Hi tfleming, very good score on a set of larger drills. I suggest caution with using good sized drills in the tailstock. As other have pointed out, this can be hard on the tailstock (many tailstocks do not have a slot for the tang and rely on the taper - not good if it spins, also hard on the little drive key or the slot). You could certainly add a torque arm. I believe a better option is to hold the drill in the tool post. Many tool post systems (i.e. Phase II) will offer a MT holder. You can also make a block, bored for MT, that you can hold in the tool post.

Drilling from the carriage is very nice, you can rapidly clear chips, you get power feed and the length is reduced. The MT2 ->3 adapter will work fine in the drill press.
 
my frejoth lathe came with a number 2 mt. but when I went to grizzly in Washington I found a number 3 mt spindle that fit my tailstock so I upgraded to a larger spindle in my tailstock. the only problem I had with the upgrade is that the anti rotation pin in the tailstock bore would not take the increased load so I had to remove the pin and broach a keyway in place of the pin this worked to handle the increased rotational load. bill
 
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