Cross slide stop for threading

Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.

Moderators: Harold_V, websterz, GlennW

Post Reply
ptgord
Posts: 12
Joined: Wed Jan 13, 2010 9:20 pm
Location: AR

Cross slide stop for threading

Post by ptgord » Mon Aug 23, 2010 7:49 pm

Backlash on cross feed slide [Jet GH 1340-W] requires a lot of attention to return to original position when threading. Read somewhere about stop for cross slide. Already had bolt hole so I came up with this design. Only 1 bolt hole but it seems pretty rigid & I can repeat within a couple of thousands. There is another threaded hole under slide that I could utilize if needed more rigidity with a bracket that had a cutout for the slide to travel through.
HSM-5.jpg
HSM-6.jpg
First time for milling long slot of about 8 inches in .75 Al bar with Jet mill/drill. About halfway thru realized I would have a problem milling all the way through because the vise would squeeze the open cut. I left a small web in the middle & reclamped to finish the cut. What is the best way to handle that situation? Thought I should have made a spacer and moved it along the cut as I proceeded.
Jet GH 1340W-1, Jet JMD 18 mill/drill, Miller 175 mig, Miller Spectrum 625

EdK
Posts: 688
Joined: Tue Apr 13, 2010 6:20 am
Location: Minnesota

Re: Cross slide stop for threading

Post by EdK » Tue Aug 24, 2010 5:32 am

ptgord wrote:What is the best way to handle that situation?
Don't know if it's the best way but I probably would have attached the work piece to the table with some clamps and spacers on the ends to raise it up off of the table enough to mill the slot through.

Ed
Vectrax 14x40 lathe, Enco RF-45 clone mill, MillerMatic 180 MIG.

User avatar
Dave_C
Posts: 960
Joined: Mon Apr 21, 2008 10:34 am
Location: Springfield. MO.

Re: Cross slide stop for threading

Post by Dave_C » Tue Aug 24, 2010 7:21 am

PTGORD,

I'm having a bit of time understanding the backlash issue. My Grizzly G4003G has some backlash as well and it threads wonderfully.

What I do is set the dial on my cross slide to "0" when I have the cross slide at the position that I am going to start threading. I even put the handle in the same position each time so when I need to "flip" it back while threading to a shoulder, I will find it in the same place each time.

So upon reaching the end of the thread pass I "Flip" or turn the handle from top to bottom, move the carriage over and then just turn the dial back to zero. Backlash is not an issue anymore since I backed out a full half turn and then back in to zero. A half turn will certainly take up any backlash and put you right back where you need to be. Now it's just a mater of advancing the compound each time till I am done.

If you are not setting up this way then your mechanical stop makes sense to me.

Just sharing,

Dave C.
I learn something new every day! Problem is I forget two.

pkastagehand
Posts: 156
Joined: Thu Nov 03, 2005 9:12 am
Location: Holland MI

Re: Cross slide stop for threading

Post by pkastagehand » Tue Aug 24, 2010 11:06 am

DrDavo wrote:PTGORD,

I'm having a bit of time understanding the backlash issue. My Grizzly G4003G has some backlash as well and it threads wonderfully.

What I do is set the dial on my cross slide to "0" when I have the cross slide at the position that I am going to start threading. I even put the handle in the same position each time so when I need to "flip" it back while threading to a shoulder, I will find it in the same place each time.

So upon reaching the end of the thread pass I "Flip" or turn the handle from top to bottom, move the carriage over and then just turn the dial back to zero. Backlash is not an issue anymore since I backed out a full half turn and then back in to zero. A half turn will certainly take up any backlash and put you right back where you need to be. Now it's just a mater of advancing the compound each time till I am done.

If you are not setting up this way then your mechanical stop makes sense to me.

Just sharing,

Dave C.
I didn't understand the backlash part either. If you back out to reverse the carriage to start the next pass, and then feed in again to the same dial reading that you used to start with the backlash has been taken out.

But I can see an advantage to having the stop; quicker than watching for the "0" on the dial and not having to worry if you turned to the "right" zero or went one revolution too far if you cranked out more than you intended. I haven't made a stop yet but may eventually.

I also want to make a crank some day to put on the outboard end of the spindle for hand turning very small threads to shoulders. 60 rpm (my slowest speed) is still pretty fast for backing out at the right time on the really small stuff.

Paul

User avatar
Dave_C
Posts: 960
Joined: Mon Apr 21, 2008 10:34 am
Location: Springfield. MO.

Re: Cross slide stop for threading

Post by Dave_C » Tue Aug 24, 2010 1:05 pm

Ah yes, how many "zeros" did I back out. One more use for my DRO which I use all the time.

A mounted indicator will do this for you just as well or in this case, a mechanical stop. Now I see what it can be used for.

Thanks,

Dave C.
I learn something new every day! Problem is I forget two.

ptgord
Posts: 12
Joined: Wed Jan 13, 2010 9:20 pm
Location: AR

Re: Cross slide stop for threading

Post by ptgord » Tue Aug 24, 2010 8:10 pm

I hadn't mentioned that I am basically a newbie. Eyes don't focus on that small dial as well as they once did. Was sure I would one day go an extra round and mess up on the last pass on the thread. This seems to verify with ease.

On the milling question I can see how clamping to the table with spacer under would be a much preferable option.

Thanks to all for input.
Jet GH 1340W-1, Jet JMD 18 mill/drill, Miller 175 mig, Miller Spectrum 625

Post Reply