To drill the spindle or the chuck? That is the question..

P

PhatNOB

Plastic

Joined

Jul 10, 2017

• Jul 10, 2017

• #1

Hello all,

I hope this is the right area for a noob post like this but here goes..

I have a HQ400/3b lathe/mill and the spindle has a flush mount setup for mounting chucks.
This has a 72mm step/register which the chuck locates, and three bolt holes to pull the chuck snug. The bolt holes are 84mm PCD.

I bought a four Jaw chuck which has the same register (72mm) and the same PCD (84mm) but has four bolt holes instead of three.

The question I have is:

A, do I drill and tap two new holes in the chuck (can use one of the existing holes this way)
Or
B, drill two new holes in the spindle face (again utilising one of the existing holes)
Or
C, make a backplate which permanently mounts to the four Jaw chuck?

If anyone could offer some advise that would be great cheers

 

Last edited: Jul 10, 2017

D

Danny VanVoorn

Titanium

Joined

Nov 3, 2002

Location

St.Louis, Missouri, USA

• Jul 10, 2017

• #2

I don't recommend changing the spindle for any reason especially if all you need to do is fix the back plate. Seriously, it's your machine so do what you want but I would drill and tap the back plate.
Dan

 

P

PhatNOB

Plastic

Joined

Jul 10, 2017

• Jul 10, 2017

• #3

Thanks Dan, I didn't really want to modify the spindle either.
Do you mean drill and tap the back of the chuck or make a backplate to adapt?
The chuck has no backplate currently.

 

G

GoceKu

Plastic

Joined

Jun 28, 2017

• Jul 10, 2017

• #4

Drill and countersink the bolts on the back plate, is the best solution it you don't want to make a new back plate.

 

M

Monarchist

Diamond

Joined

Oct 2, 2012

Location

Sol, Terra

• Jul 10, 2017

• #5

PhatNOB said:

Thanks Dan, I didn't really want to modify the spindle either.
Do you mean drill and tap the back of the chuck or make a backplate to adapt?
The chuck has no backplate currently.

Click to expand...

Better to TRADE that four-hole backplate, unaltered, for the three-hole backplate the spindle wants.

They are built to a 'standard' of some sort, even if proprietary. Which it may not be. Check the DIN pubs for the Metrif**kated counterpart of a bolt-attached American(ish) "A" standard short-taper, perhaps?

And/or show us photos with decent dimensions, etc.

Holes may not be the only difference.

And nooooo do not f**k with the spindle!

AFTER.. you get a proper fit, backplate to spindle, THEN you turn it in situ, on the spindle it will run with, to a good fit to the shallow recess in the back of the chuck. Presuming it has such.

Bolts for that come last, but you DO want to insure they will be spaced where there is "meat' enough, AND NOT aligned with any of the backplate-to-spindle fasteners. Nor block access to them.

A photo or three of spindle for-sure, chuck back as well, really would help others to help you.

 

I

Illinoyance

Stainless

Joined

Aug 24, 2015

• Jul 10, 2017

• #6

A general rule is to modify the less costly part so if you screw up......

 

G

gadget73

Hot Rolled

Joined

Mar 8, 2016

• Jul 10, 2017

• #7

definitely don't want to meddle with the spindle. If you dink the backplate, you haven't ruined the machine.

 

D

DDoug

Diamond

Joined

Oct 18, 2005

Location

NW Pa

• Jul 10, 2017

• #8

PhatNOB said:

I have a HQ400/3b lathe/mill

Click to expand...

Machine in question:
HQ4/3b lathe/mill - Bing images

 

T

traditional-tools

Diamond

Joined

Aug 10, 2007

Location

West Coast

• Jul 10, 2017

• #9

Try the Hobby-Horse-Machining-Forums - "The friendly machining forum, run by @$$#O!E$".

 

M

Monarchist

Diamond

Joined

Oct 2, 2012

Location

Sol, Terra

• Jul 10, 2017

• #10

digger doug said:

Machine in question:
HQ4/3b lathe/mill - Bing images

Click to expand...

Meahhh.. I rather suspect the best match in MY "arsenal" for accuracy is this one:

15. Amp Super Sawzall(R) Recip Saw | Milwaukee Tool

Corded, not battery, so probably FASTER than that HDR-LSO, too!

 

M

Monarchist

Diamond

Joined

Oct 2, 2012

Location

Sol, Terra

• Jul 10, 2017

• #11

gadget73 said:

.. you haven't ruined the machine.

Click to expand...

No need. Factory ruins those in advance to lighten the workload on purchasers....

 

M

mike 44

Hot Rolled

Joined

Apr 19, 2007

Location

mays landing NJ

• Jul 10, 2017

• #12

Make a back plate. After making sure the chuck is registered correctly to the back plate , then remove the chuck and take a light facing cut across the back plate. Re-install chuck and your done.

 

B

basalt

Aluminum

Joined

Jun 22, 2013

Location

Vancouver BC Canada

• Jul 10, 2017

• #13

Don't mess with the spindle. Drill and Tap the Chuck - no back plate. That way the chuck is closer to the spindle - less over hang.

 

plastikdreams

Diamond

Joined

May 31, 2011

Location

upstate nj

• Jul 10, 2017

• #14

At .55kw will it even drill the Chuck?

 

P

PhatNOB

Plastic

Joined

Jul 10, 2017

• Jul 19, 2017

• #15

Thank you for all the great replies. I have plenty of info to work with now cheers guys.

Digger Doug: the image you found is a similar machine. Mine though, has the compound slide which doubles as the vice for the mill.

 

D

DDoug

Diamond

Joined

Oct 18, 2005

Location

NW Pa

• Jul 19, 2017

• #16

PhatNOB said:

Thank you for all the great replies. I have plenty of info to work with now cheers guys.

Digger Doug: the image you found is a similar machine. Mine though, has the compound slide which doubles as the vice for the mill.

Click to expand...

No matter, please read the sticky up above about which types of machines are not to be discussed.

 

P

PhatNOB

Plastic

Joined

Jul 10, 2017

• Jul 20, 2017

• #17

Read, understood. Apologies.