Acceptable Jacobs taper visibility with drill chuck?

[avoperator]

Hi All, I was wondering if there is an acceptable tolerance between the visibility of the arbor taper and socket when mounting a drill chuck. I'm using a 1/2" straight shank arbor to JT3 which is going to a new Shars JT3 keyless drill chuck. The visibility of the taper is about 1/8" or 3mm when fully seated. The taper itself when test fitting feels snug and concentric, no wiggle to suggest that fitment is off. (the first picture showing the silver shaft of the taper, the second picture where you can only see the chamfered edge of the taper)

On another part for another project, I'm also using a 1/2" straight shank arbor to JT3 taper to an er32 collet holder. Yet when test fitting, the taper sits more flush where it comes together. And again on this one, feels snug, concentric no wiggle, and more so looks fully seated.

Is this kind of visibility acceptable for a drill chuck? or should I be looking to make sure it sits like how the other one fits? I don't mind the visibility of the taper as it is minimal, but would rather make the correction if it SHOULD be done as so.

Thanks on any insight you guys might be able to share.

 

[extropic]

Welcome to H-M.

I think you are WAY over thinking this. The direct answer to your question is no. No specific stick-out dimension is defined.

Assuming both the chuck and arbor are new (with no apparent damage), if the chuck remains attached during use, everything is fine.

Whenever either the chuck or arbor are used (or don't stay mated), I'll remove any high spots on the arbor taper, then lap the two together to my satisfaction.

 

[avoperator]

Welcome to H-M.

I think you are WAY over thinking this. The direct answer to your question is no. No specific stick-out dimension is defined.

Assuming both the chuck and arbor are new (with no apparent damage), if the chuck remains attached during use, everything is fine.

Whenever either the chuck or arbor are used (or don't stay mated), I'll remove any high spots on the arbor taper, then lap the two together to my satisfaction.

Appreciate the insight. Yes all parts are new, no damage, and all fit together well. I'm always just of the nature to make sure whatever I'm doing is at the very least headed in the correct direction. I'm usually pretty good about putting things together, but with the nature of where this connection sits, just wanted to have peace of mind, rather than the chuck flying off somewhere down the line and at worse getting injured.

Thank you.

 

[machPete99]

Relax, things are just fine.
It is a good idea to drill the chuck out for a drift to help remove the taper in the future, if it does not already have that feature.
You can also warm up the chuck before quickly mounting the taper in a vise (jaws pulled in); it won't be falling off!

 

[extropic]

I don't recommend drilling a hole in a keyless chuck because they have a centrally located Spindle that will be compromised.

 

[avoperator]

I don't recommend drilling a hole in a keyless chuck because they have a centrally located Spindle that will be compromised.

I have read on this from other posts and threads and thought about this as well, but i decided I won't be going this way as I think I'd probably mess the chuck up somehow and getting it correct. But good to know for the future.