Measuring Drill Press Feed Handle for Knobs

HMF

Site Founder
Administrator
Joined
Sep 22, 2010
Messages
7,223
Very stupid question- I apologize in advance.

My drill press that I bought 35 years ago (Enco, made in Taiwan) needs new feed handle knobs.

http://www.use-enco.com/1/1/34994-pulley-driven-geared-head-floor-bench-drill-presses-308-0056.html

Here is the manual:

http://www.use-enco.com/Machinery/125-1142.pdf

I need to know the size hole of the knob and the thread to replace them. I have already sadly bought the wrong sizes once... :rofl:

I have a prospective supplier:

Essentra (formerly Reid Supply):

http://www.reidsupply.com/products/knobs-handles-hand-wheels/knobs/ball-knobs/


But I need to measure the pull-down feed handle's thread diameter and thickness to know if I need 3/8-16, 10-32, 5/-18.
I tried using a digital caliper, but I was off, and bought the wrong size.

What do I need to measure the thread accurately?

Thanks in advance.
 
My guess is that it is a metric thread. You can measure the diameter and the pitch with a metric thread gauge. The other thing would be to get a selection of metric nuts from the hardware store and see if you can get a match.

David
 
Nels, you know better!! There is no such thing as a stupid question!!

I have a similar drill press, 20 years old or so, made in Taiwan. Does this one look like yours?? 13 inch, 16 speed, 1/2 HP

The threads on the spindle feed levers are definitely 3/8"-16 on mine.

Don't know if it helps, but maybe we'll get lucky on this one? What sizes have you tried?? The knobs on mine do fit a little tight, but I believe that they are meant to so that they do not vibrate off when it's running.

Please excuse the photo quality. That corner of the garage has a fluorescent fixture in it that refuses to work most of the winter, so I had to use some improvised lighting.

2014-01-14 21.51.18.jpg

ON EDIT: I followed your link to the Enco machine, and it is exactly like my machine, except that mine is a floor model. Otherwise everything else is the same according to the specs on the Enco site. The only thing that is different is that I only paid $140 for mine brand new, about 20 years ago.

UPDATE: I just went out and threaded a 3/8"-16 nut onto mine - perfect fit.

To answer your question about measuring, I measured the rod diameter first, it was .327" then measured the OD of the threads, which was .368" (formed or rolled threads, explains the thread OD being larger than the parent stock) then checked with a thread gauge, 16 TPI fit perfectly.

2014-01-14 21.51.18.jpg
 
Last edited by a moderator:
Nels, you know better!! There is no such thing as a stupid question!!

I have a similar drill press, 20 years old or so, made in Taiwan. Does this one look like yours?? 13 inch, 16 speed, 1/2 HP

The threads on the spindle feed levers are definitely 3/8"-16 on mine.

Don't know if it helps, but maybe we'll get lucky on this one? What sizes have you tried?? The knobs on mine do fit a little tight, but I believe that they are meant to so that they do not vibrate off when it's running.

Please excuse the photo quality. That corner of the garage has a fluorescent fixture in it that refuses to work most of the winter, so I had to use some improvised lighting.

View attachment 67791

ON EDIT: I followed your link to the Enco machine, and it is exactly like my machine, except that mine is a floor model. Otherwise everything else is the same according to the specs on the Enco site. The only thing that is different is that I only paid $140 for mine brand new, about 20 years ago.

UPDATE: I just went out and threaded a 3/8"-16 nut onto mine - perfect fit.

To answer your question about measuring, I measured the rod diameter first, it was .327" then measured the OD of the threads, which was .368" (formed or rolled threads, explains the thread OD being larger than the parent stock) then checked with a thread gauge, 16 TPI fit perfectly.


Terry:

Thank you so much for checking, just for reference, Essentra Components (formerly Reid Supply Co.) has the ball knobs in several diameters- I ordered item No. B-6 1-3/8 inch diameter, 3/8-16 thread, brass insert, phenolic in black, ($1.76 each), and item DM-85 1-1/4 inch diameter, 3/8-16 thread, brass insert, phenolic in red (the originals were red) $3.38 each. They have other types- it's almost ridiculous how many choices you have there, including soft grip plastic and steel inserts. My originals were very cheap plastic with the threads molded in, no insert, and they cracked from years of use.

For measuring, I assume you used a caliper? And an imperial thread gauge like the sets Starrett sells?
 
Every machinist should have a pitch gage. Then all you need is a way to measure the major diameter, and you can identify the thread.

0625435-23.jpg


There is a variety of these, some are UN only, some are Metric only, some are both, some are Whitworth, etc. Should be able to turn up something on ebay pretty easily.
 
Yup, I just used a dial caliper as dead on accuracy was not critical. Being off a couple of thou would not make a difference. For checking the thread pitch, I just used a thread pitch gauge, similar to the one shown in Tony's reply.

I know what you mean about the original knobs cracking, as mine have done that also. I plan to replace them once I get my new shop space in the basement done and get the DP moved down there, but I was thinking of building a ball turning attachment for my lathe, then make my own knobs out of something exotic like teak, ebony or maybe bloodwood. Make them with brass inserts pressed into the blank, then I could simply thread the blank onto a self made 3/8"-16 mandrel in the lathe and turn the balls. Once sanded and varnished, they should look pretty sharp!
 
The saga of my stupidity continues.... :banghead:


I tried the 3/8-16 knob I got from Reid and it doesn't work- apparently the made the rods thicker back when I bought mine.

The measurements with a digital (Mitutoyo) caliper I got is:

.4345 for the unthreaded portion of the lever (rod)
.4860 for the top of the threaded portion
.4360 for the indentations in the threads

I used the #472 Starrett thread gauge that I have as per Tony's post, and 11-1/2 was the best fit for the threads on the threaded portion of the lever.


I tried a metric nut, and it goes on a bit.

So... What size knob is it? Is it 5/8-18 or 20? Some metric size? I need to match it to one of the ones that Reid sells.

Thanks for bearing with me, guys.
 
Nelson,

With the sizes you are quoting I would be inclined to go 7/16-20. Or one of these:

Reid Knobs

But, try a nut on it be for you buy.

Your number is even oversize for 12mm.
 
Last edited:
Back
Top