# BB CT129 Quill Runout



## whydontu (Oct 6, 2022)

Since you all say you like photos, how about a video?

I have a Busy Bee Ct129 mill. It's had a rough-ish life. I bought it second hand, from a fellow who attempted an unsuccessful CNC conversion. It's been dropped, used to machine stuff that was way too big, and in general has not been babied.

MT2 quill.

First section is dial indicator on the female MT2 taper.

Second section is a used 1/2" end mill in a BB $200 MT2 - ER32 collet chuck. 0.001" runout

Third section is a used 5/8" end mill in the same chuck - less than 0.001" runout, so unless I managed to get the 5/8" mill in exactly the right position, or it's bent the same amount as the 1/2" mill, my guess is the chuck is pretty reasonable.

Fourth section is the same 1/2" mill in my no-name keyed drill chuck at 0.003" runout.

Perfectly reasonable for the work I do with this mill.


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## Degen (Oct 7, 2022)

whydontu said:


> Since you all say you like photos, how about a video?
> 
> I have a Busy Bee Ct129 mill. It's had a rough-ish life. I bought it second hand, from a fellow who attempted an unsuccessful CNC conversion. It's been dropped, used to machine stuff that was way too big, and in general has not been babied.
> 
> ...


I would suspect that that your about for the drill chuck is whacked, replace it.

I would also clean the interior of the MT2 spindle, dirt/oil build up.

I find my HS endmill have more variation, good quality carbide cost a little bit more and worth the money.


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## Susquatch (Oct 7, 2022)

whydontu said:


> Perfectly reasonable for the work I do with this mill.



Looks great to me @whydont!  Anytime you can get stacked tapers to run that low is a good thing if you ask me.


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## phaxtris (Oct 7, 2022)

Isn't that a .0005 indicator ? Look like half of the runout your calling, unless it's the angle in the video


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## Susquatch (Oct 7, 2022)

I tried an MT3 - R8 adapter and my Southbend keyless chuck today. There really wasn't much point. The runout on the inside of the MT3 taper was 5 thou. The chuck held that so its prolly pretty good on its own but wasted with my adapter.


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## jcdammeyer (Oct 7, 2022)

Of course I can't resist trying this too.  

Runout on the R8 surface of the spindle is less than 0.0002 based on needle movement.  In fact I can grab the spindle and pull or push and create a deflection of 0.004 to 0.006 or so.

I then installed my R8 to MT3 adaptor which I've never used nor can see having a need to use.  But it's there just in case.  Sure sticks out far too.

Anyway, also less than 0.0002 runout on the inside of the MT3 taper.


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## PeterT (Oct 7, 2022)

phaxtris said:


> Isn't that a .0005 indicator ? Look like half of the runout your calling, unless it's the angle in the video



if the dial legend is saying 0.0005" per division, looks like the needle just barely tagged 2 div's so ~ 0.001" TIR. But the face is not quite perpendicular to camera.
Another thing I watch for is if the needle displaces in a relatively localized area vs does it progress up to that level over say 1/4-1/3 rotation. A localized bump cold be result of a tooling nick or burr got squeezed when tightening. Sometimes they can be stoned out. Depending on the collet, sometimes they have pretty high min torque values spec'd by manufacturers. So lightly tightening the nut might be different than spec torqueing the nut.


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## phaxtris (Oct 7, 2022)

PeterT said:


> if the dial legend is saying 0.0005" per division, looks like the needle just barely tagged 2 div's so ~ 0.001" TIR. But the face is not quite perpendicular to camera.
> Another thing I watch for is if the needle displaces in a relatively localized area vs does it progress up to that level over say 1/4-1/3 rotation. A localized bump cold be result of a tooling nick or burr got squeezed when tightening. Sometimes they can be stoned out. Depending on the collet, sometimes they have pretty high min torque values spec'd by manufacturers. So lightly tightening the nut might be different than spec torqueing the nut.
> 
> 
> View attachment 26975


 

in two of them it looked to me like it hardly even tagged 1 div, pretty dam good, less than .0005

what i sayin, he's being modest.....pretty stellar numbers no?


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## Susquatch (Oct 8, 2022)

jcdammeyer said:


> I then installed my R8 to MT3 adaptor which I've never used nor can see having a need to use. But it's there just in case. Sure sticks out far too.



I'd offer to trade you mine for yours, but I feel like it would be a waste either way. Not that you would be interested! LOL!

I can't really see ever needing to use this R8 to MT3 adapter either! And even if I do, it's not likely that it's runout will matter. I only bought it because I have so much MT3 Tooling from my old mill/drill that I wanted to be able to use on my Hartford R8 mill. But it sticks out so much as to border on ridiculous and I've never actually used it. Knowing it's runout now only further reduces the chances that I ever will.


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## Susquatch (Oct 8, 2022)

jcdammeyer said:


> Anyway, also less than 0.0002 runout on the inside of the MT3 taper.



Love that little indicator holder you have there John! I bet that comes in really handy sometimes!


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## jcdammeyer (Oct 8, 2022)

Susquatch said:


> I'd offer to trade you mine for yours, but I feel like it would be a waste either way. Not that you would be interested! LOL!
> 
> I can't really see ever needing to use this R8 to MT3 adapter either! And even if I do, it's not likely that it's runout will matter. I only bought it because I have so much MT3 Tooling from my old mill/drill that I wanted to be able to use on my Hartford R8 mill. But it sticks out so much as to border on ridiculous and I've never actually used it. Knowing it's runout now only further reduces the chances that I ever will.


Originally I used my Sears 20" drill press with a hollowed out spindle to pass a draw bar for my milling.  So i have a few MT3 based tools too.  My Gingery Lathe was built using that with an XY vice for milling many of the parts.  

The table on the floor standing drill press can move a long way from the quill so size of tooling was never an issue.  The House of Tools versions of the G3616/3617 mills don't have that space.  There's about 2" lost because the X axis table can be pivoted.  All for the ability for the horizontal mill feature to be able to cut helical gears.  With CNC now that's kind of redundant.  But still that long MT3 extension seems kind of useless.


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## jcdammeyer (Oct 8, 2022)

Susquatch said:


> Love that little indicator holder you have there John! I bet that comes in really handy sometimes!


The magnet could be a bit stronger at times but it does fit into tight spots for testing run-out etc.





						NOGA,NOGA LC6210 MINI MAGNETIC BASE,1-457-918,KBC Tools & Machinery
					

NOGA,NOGA LC6210 MINI MAGNETIC BASE,1-457-918,KBC Tools & Machinery




					www.kbctools.ca
				



I bought it in 2017 for $112.84


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## Susquatch (Oct 8, 2022)

jcdammeyer said:


> Originally I used my Sears 20" drill press with a hollowed out spindle to pass a draw bar for my milling. So i have a few MT3 based tools too. My Gingery Lathe was built using that with an XY vice for milling many of the parts.
> 
> The table on the floor standing drill press can move a long way from the quill so size of tooling was never an issue.



That's almost exactly how I started milling! 

Mine was a floor standing Beaver drill press. It had a Jacobs 33T taper. The T in 33T means it had a threaded on collar to keep the taper engaged. 

Since I had no Morse taper or collets at the time, I used the drill chuck to hold end mills. I mounted an x-y table on the drill press table to move the part around. 

It was crappy as hell, but it did a lot of work for me for about 40 years. 

Being a floor stand drill press meant that height was NEVER a problem. That thing had a 48" Z-Axis!


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