Grizzly drill press depth stop adjustment nut

[Chris Barnett]

Have the G7948 Grizzly drill press which uses the threaded rod and stop nuts for drill depth control. The dual lock nuts must each traverse the full length of intended depth before locking down. A few other DPs use a spring loaded quick-release type depth stop nut (Delta and Steel City) which is much quicker, and Grizzly offers these nuts but not sized for the G7948, which is M12-1.5 thread.

Trying a shot in the dark, I bought the Delta quick nut without knowing the thread size but luck was not with me, and it (1/2 inch NC) did not fit. Before trying a shot at the Steel City, has anyone found a source for the M12-1.5 quick release nut? Had considered drilling out and tapping the existing hole but I don't think there is adequate difference between the 12mm and 1/2 inch for the new thread depth. I also considered welding the hole closed and then drilling and tapping, but the quill clamp (collar) having the hole, seems to be CI which I don't weld, plus any significant distortion will have me purchasing a new clamp.

Yeah, I could have bought the Delta or Steel City, but....
Any other ideas or source for a M12-1.5 quick release nut? Or anyone know the stop nut/rod thread size on the Steel City?

Thanks, Chris

[Ken Deckelman]

I re-did mine last year...I bought a piece of 1/2"x20tpi rod and a couple jam nuts(they are thinner) to fit from McMaster Carr. I also welded up a new stop that does not bend like the flimsy sheet metal one that came with it did.

Here is the stop I used from Enco:

Quill Stop (http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=945606&PMAKA=209-9003)

[Rod Sheridan]

Have the G7948 Grizzly drill press which uses the threaded rod and stop nuts for drill depth control. The dual lock nuts must each traverse the full length of intended depth before locking down. A few other DPs use a spring loaded quick-release type depth stop nut (Delta and Steel City) which is much quicker, and Grizzly offers these nuts but not sized for the G7948, which is M12-1.5 thread.

Trying a shot in the dark, I bought the Delta quick nut without knowing the thread size but luck was not with me, and it (1/2 inch NC) did not fit. Before trying a shot at the Steel City, has anyone found a source for the M12-1.5 quick release nut? Had considered drilling out and tapping the existing hole but I don't think there is adequate difference between the 12mm and 1/2 inch for the new thread depth. I also considered welding the hole closed and then drilling and tapping, but the quill clamp (collar) having the hole, seems to be CI which I don't weld, plus any significant distortion will have me purchasing a new clamp.

Yeah, I could have bought the Delta or Steel City, but....
Any other ideas or source for a M12-1.5 quick release nut? Or anyone know the stop nut/rod thread size on the Steel City?

Thanks, Chris




Chris, why not replaced the threaded rod with a piece of 12 X 1.5mm rod and use the quick acting nut you purchased?

Regards, Rod.

[John Callahan]

Other than the depth stop have you been happy with the G7948?

[Chris Barnett]

Have been very satisfied with the G7948, particularly the long stroke, but have used it very little. The larger table will be handy when needing to drill large parts.

The depth stud is already M12-1.5; it is a matching M12-1.5 quick nut that I need. The quick nut I have is 1/2-13.

Ken, that stop would work fine, but they do not say the size, or it eludes me so far. I will look into this further since that is the only solution I see so far. And, good point on the stop....I have some heavy angle that will work just fine. Thanks.

[Chris Barnett]

Have added photos of the Delta quill stop. Appears it is machined from stainless, and outside is knurled. For less than $4, a great deal, if I can make it work. Have to make it work...too nice to leave in a drawer.

[Michael Wildt]

I have the Steel City drill press. I measured the diameter of the rod to be 11.60mm, so that would be a M12 and the thread rise is 2.00 mm.

You can find the parts in the user manual:

http://www.steelcitytoolworks.com/products/20520/20520_manual.pdf

page 30, drawing (item 61 & 58)
page 31 has the part numbers:

58 OR92353 STOP NUT ASSY, INCL REF 59, 60
59 OR92354 SPRING
60 OR92355 QUICK RELEASE NUT
61 OR71515 DEPTH ROD, INCL REF 62
62 OR92409 DEPTH SCALE

[Jim Finn]

I have a grizzly table top model and I replaced the whole threaded rod with a 1/4X20 rod and installed a nut and a wing nut. Now I can adjust and secure it using no tools at all.

[Chris Barnett]

Michael
That is the size I need..thanks. Will call and hope they will sell that part although I did not buy the SC.
Can do the 1/4 threaded rod, and a wing nut would be faster, but would need to still move the nut down all the way which takes time.
I would not worry with this except that I did see the much faster way to set depth with the quick nut.
Will also check the size for an insert that will accept a 1/2-13 thread. That would solve the size issue of drilling out a 12 mm hole (.48-inches) to the tap drill size (.42-inches), ...it doesn't work, or you're already done, depending on your point of view :D!
Of course I could just sell the Grizzly and buy the SC. If the table had not been so small, might have done that. The SC is functionally very smooth.
It really sucks to have to go to a competetor to your machine to get a part that should have already been provided. It sucks worse when they don't even have the size needed for their own machine as a part.

[Maurice Ungaro]

Chris, why don't you just buy the threaded rod from Delta?

[Chris Barnett]

Maurice, the rod is screwed into the quill clamp which has a M12-1.5 thread. I would need to drill out the tapped hole and retap, but there is not sufficient material remaining since the major diameter of the M12 thread is larger than the tap size for 1/2-13 thread.

[Maurice Ungaro]

Ah...well....sorry.

[Chris Barnett]

Many thanks Maurice...I had the problem and was asking for help and appreciate any and all inputs. It was a bit confusing so I wanted to make sure you understood the problem and that I didn't ignore your comments, which I did not do.
I did order the part from SC; hope it fits. If it doesn't, I might just take the pretty stainless quick nut I bought, wheel another drill press under it, and ditch the Grizzly :D.

[Maurice Ungaro]

Now Chris...don't go throwing away a perfectly good machine! :rolleyes:
Hope the SC part works for you. If so, you may have hit upon a cool retrofit. You say that Delta part is stainless, huh? Man, my 5 year old Delta 17-968 came with a blued steel one. If it does not work for you, I'll buy it from you in order to dress mine up!

[Alan Schaffter]

Maurice, the rod is screwed into the quill clamp which has a M12-1.5 thread. I would need to drill out the tapped hole and retap, but there is not sufficient material remaining since the major diameter of the M12 thread is larger than the tap size for 1/2-13 thread.

Not familiar with the quill clamp on your drill, but couldn't you drill it out so you can slide (not thread) in a Delta rod as suggested by Maurice. Use stop nuts on the new rod above and below the quill clamp to hold it in position and forget about re-tapping it.

[Kevin Groenke]

Perhaps a clamp-on style quill stop would mesh threads enough to stay where you put it. Since it clamps on, the threads wouldn't have to match perfectly.

We actually just got a Delta 20-950 and were not particularly impressed with the fit of the stop nut: it seems a bit sloppy and lacks a real POSITIVE stopping feel.

http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1656720&PMT4NO=58876283

http://www1.mscdirect.com/ProductImages/0023303-11.jpg

[Maurice Ungaro]

Kevin,
The thing I've found about the Delta stop nut is that when you depress the button to make fast changes, you need to turn the stop nut until it engages the threads securely. Found this out by making some counter bores that went a bit deep when the stop nut slipped. I started rotating the stop nut until it engaged fully, and haven't had a problem since using that procedure.

[Ken Deckelman]

I thought I would get you a picture of my set-up (it's a G7947 (http://www.grizzly.com/products/g7947)). The stop threads are 1/2x20 LH threads, So the all-thread and nuts are 1/2x20 LH also.

[Chris Barnett]

Ken, that's what I might want to do. I could drill and tap for 1/2-13 (I had mistakenly thought the hole was 1/2 thread for the post) or just drill a clearance hole and use lock nuts like you have done. I received the quick nut from Steel City but the threads are so shallow that they don't engage well, and slips every time on the threaded post. I checked and recheck thread size and confirmed they do match, but the thread on the quick nut looks like the top half or maybe more is gone! I am really curious now to know if other Steel City quick nuts have the same problem. If not, I could have it replaced. If the same would just return if they would accept it back and replace the threaded rod and use the quick nut I have from Delta. I might want to go look at the Delta DP to see if the slippage issue is the nature of the beast since there is a lot of force on the interface. If so, would duplicate your setup since it seems the pressure can be changed.
Anyway, thanks much for the comments and the photo. Maybe Griz will take the hint and do it better ;)! (wouldn't it be nice if a tool manufacturer sent out retrofit kits! Now that would be customer service above and beyond...gee, must be dreaming.... but I'm already up :D.)
I just reread the above posts and realized what was said about the Delta...must have missed that statement before. So, seems the best action is to stop messing with the quick nuts and drill it out, install rod and buy an adjustible quill stop. But still curious about one item...left hand thread rod and lock nuts! Does the adjustible quill stop also have left hand threads that mate with the rod threads? Thought I had a clear plan, then...whammo! Left hand huh! Thats gonna be fun to find.

[Ken Deckelman]

Chris,
Sorry for mis-leading you! I don't know why I wrote LH instead of RH, but the quill stop's are indeed 1/2x20 Right Hand threads.

Also, you can do a Google of "Bridgeport quill stop for more info.

[Chris Barnett]

Whew...Ken....thought I was in for another hard search. The logic on needing a LH was....well...I was obviously not tuned in.

I then realized though that I had had a 1/2-13 heavy duty die that was left hand that I got many, many years ago and used it as a paper weight on my desk. I have no earthly idea where it is now....probably threw it out since I argued that it would never, never be used. Anyway, great work on your DP. Hope mine turns out as well!
And thanks so much for posting and clearing up the LH issue. Would have still been scratching my head and wondering.
Chris

[Rich Bygness]

I don't know if anyone is still following this thread, but I have been reading posts here and on another one on the topic of Grizzly depth stop adjustments and thought you might be interested in the highlights of a conversation I had with a Grizzly Tech Support person. The name of the other thread is: Drill press depth adjustment (http://www.sawmillcreek.org/showthread.php?105338-Drill-press-depth-adjustment/page3)