# Trying to Machine a Threaded Backplate on my G0602 Lathe



## NightWing (Jul 17, 2014)

FRUSTRATION!  I recently bought an ER40 flat back collet chuck and an unmachined backplate. I threaded the backplate on the spindle nose and was setting up to turn the OD and machine a registry diameter on the face.

I can't get close enough to the plate to machine it.  The carriage hits the backsplash.  If I remove the backsplash, I still can't get in close enough because the carriage will hit the headstock.  I might be able to do it if I hang the tool out as far as I can and wind the compound rest all the way out, which leaves it unsupported.

I need a hockey stick tool!

I am going to buy a quick change tool post to replace the turret that came with the machine.  It is too limited and shims have to be used to center the tools.  That's another story.

OK, how have any of you machined a backplate on a Grizzly 0602?


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## JimDawson (Jul 17, 2014)

I guess in this case I would remove the back splash, and hang the tool out as far as needed.  Just take light cuts and you should be fine.  If you have a boring bar you could use that for facing.  Just set the tool at an angle that it will reach the work with a cutting edge.

Half of machining is figuring out how to do the impossible, while having nothing to work with.


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## Andre (Jul 17, 2014)

Can you set the compound to the left and reach it out far enough? That, an overhung tool, and light cuts should do the trick.


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## chips&more (Jul 17, 2014)

I would also suggest a boring bar. The biggest one you have that will fit in the turret tool post. And you might want to cover the exposed gibs and ways from cast iron swarf, it’s not really machine friendly material. Also, if you experience any chatter, like from the extended boring bar, put some Duct Seal on the areas that sound off. Duct Seal is the stuff that HVAC folks use, but also works great for deadening vibrations…Good Luck.


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## NightWing (Jul 17, 2014)

I snapped a compound rest in half years ago hanging it out too far.  My boring bars are only a couple of inches long.  

I am going to indicate the OD and the face to see how much runout exists, if any, and mark accordingly.

I will remove the backplate and put the 3-jaw chuck back on, probably with jaws reversed.  Then I will chuck the backplate up on the hub, tapping it home as the scroll is tightened.  Then, I will indicate the OD and face again, tweaking, rotating and shimming as needed to at least duplicate the original runout.  If that isn't possible, I will try the 4-jaw.  Then, I will take light cuts on the OD, face and registry...and buy a lottery ticket after.


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