Quill slop, would this work?

[Phil Thien]

I've run into a number of drill presses that are cheap import models, and suffer from a bit of quill slop.

It is such a small (but annoying) amount, I was thinking of removing the quill and peening it, much like you would peen the bar of a miter gauge to snug it in the miter slot.

I'd peen it from top to bottom, on the back, on either side of the rack gear. Maybe every .5 or .75 inches. I'd probably stagger my dimples so they are not perfectly aligned vertically, hoping that this would slow down the wear in the bore of the cast iron head.

Any thoughts? Completely nuts?

I was going to do this without removing the splined shaft from inside the quill.

My one big concern (I would have done this already, otherwise), is that peening the quill will either break it or distort it from round.

Are cheap import drill press quills steel, or cast iron?

I suppose I could remove the splined shaft from the quill and support the blow properly. But that would be a challenge as I'd need a steel shaft w/ an O.D. closely approximating the I.D. of the quill, and I don't have one.

[Larry Edgerton]

Pistons are knurled with a cross pattern to accomplish the same thing when they are out of spec and can't be replaced, so I don't see why it would not work. I would check out the knurling thing first because of the possible problems you brought up.

I have on of those MIC drill presses and it drives me nuts. I got to get 3 phase installed in the building with the old Walker Turner because I am looking forward to introducing my sledgehammer to the piece of junk as soon as I get it hooked up.

Larry

[pat warner]

Drilling to a mil? On close centers?
In wood, metal & plastic?
Casting not split (http://patwarner.com/images/dpe.jpg) for this adjustment?
If yes, then don't start wrecking machined surfaces; it will never be as good as it is now.
You're drilling 1"+ holes with spade bits in 2 x 4's on odd centers?
Then you're already good enough.
Do not bang on this quill.

[Bruce Page]

I have to agree with Pat. Your positioning is going to be changing each time one of the dimples extends out of the quill barrel. I may looking at it as a machinist, but it isn't something I would do.

[ian maybury]

HI Phil. Dimpling is a fairly well known bodge with worn bearing housings. I've done it years gone by (although not on cast iron), but have always found that it's pretty short lived - in that the same dimples actually present only a tiny support area, and as a result either wear or get depressed very quickly...

ian

[ray hampton]

Phil , I receive a tip about this very same problem, the tip describe the drilling of a hole /center of the quill if the quill were center-punch/tap the hole/ buy a metal washer that are close to the tube inside dia./ the washer will stop the side-play, good luck and I hope that you understood my instructions

[Kevin Presutti]

I'm not sure I understand you Ray:confused:

On the otherhand I agree with Larry:D

[Phil Thien]

Phil , I receive a tip about this very same problem, the tip describe the drilling of a hole /center of the quill if the quill were center-punch/tap the hole/ buy a metal washer that are close to the tube inside dia./ the washer will stop the side-play, good luck and I hope that you understood my instructions

I came across someone else mentioning drilling/tapping a hole in the quill and using a washer, but I'm not sure I understand the mechanics. Any chance you could elaborate a little bit?

[Phil Thien]

Pistons are knurled with a cross pattern to accomplish the same thing when they are out of spec and can't be replaced, so I don't see why it would not work. I would check out the knurling thing first because of the possible problems you brought up.

I have on of those MIC drill presses and it drives me nuts. I got to get 3 phase installed in the building with the old Walker Turner because I am looking forward to introducing my sledgehammer to the piece of junk as soon as I get it hooked up.

Larry

Very interesting Larry. I will have to research this a bit. Have any idea how much knurling would increase the O.D. of a piston?

[Phil Thien]

HI Phil. Dimpling is a fairly well known bodge with worn bearing housings. I've done it years gone by (although not on cast iron), but have always found that it's pretty short lived - in that the same dimples actually present only a tiny support area, and as a result either wear or get depressed very quickly...

ian

That is absolutely a concern. OTOH, for a drill press that isn't actually used that much, and given the forces/speeds involved, I was hoping it may last for a while.

[ray hampton]

Improving Drill Press Accuracy

By Quincy Collins

Many budget-priced drill presses have a fair amount of runout, or play, especially as the quill is extended. Mine is no exception, so I headed to the internet to try to find a solution. The bulletin boards seemed to be filled with owners unhappy with the accuracy of their drill presses.
Some suggested flattening the splines with a hammer to reduce play, which seemed a little drastic to me. I then hit on this solution that has worked for me and is a little more elegant than taking a hammer to the drill press.
http://email.villagepress.com/pub/HSM/20111207/Images/1.jpgThe upper end of my quill, where it passes through the pulleys, had a countersunk center mark. I simply drilled and tapped this location and used a screw to attach a custom washer (Figure 1). The washer was sized on the lathe for a close tolerance with the bore of the pulley shaft. This served to stabilize the quill at all points in its travel.
The spindle runout of my drill press has been greatly reduced and drilling is now a much happier and less frustrating job. I have limited shop time so it was nice to have found a solution that was both quick and easy.
Thanks Quincy, your subscription has been extended by an issue!

you ask and will receive
I hope that I not breaking any rules by posting this

[Phil Thien]

Thanks for all that Ray.

I think the drill presses I'm dealing with are different, though, in that the splined shaft passes through the top of the quill, and engages with the drive pulley.

I've included a picture of someone else's gear, but it matches all of the presses I use.

[Ronald Blue]

In reference to knurling that is an effective and depending on the application even a permanent fix. You can gain probably safely .030 if necessary but keep in mind the taller the knurl becomes the more pointed the raised area. So you would begin to get the same result as using the center punch that was mentioned earlier. The sharp peaks would wear off if there was much pressure or stress placed on them. The knurling process is a shaping process that forms the metal and raises it in the process. The link I am supplying shows the process much better then I can describe it. http://www.google.com/search?q=knurling+process&hl=en&client=firefox-a&hs=k3V&rls=org.mozilla:en-US:official&channel=s&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=2L_uTq_aJoWnsQKk0PXiCQ&ved=0CHMQsAQ&biw=1440&bih=720

[Rick Lizek]

A simpler way I've used to fix this problem is to drill and tap two pairs of holes and insert brass bolts and a nut to lock it in place. The brass is soft and keeps the quill aligned securely to the back of the hole where the rack and pinion are. The bottom two screws are drilled slightly left and right of center and the higher pair of screws are drilled just high enough they still contact the upper part of the quill in it's lowest position. I've done this on a number of drill presses over the years as a service tech. Very simple and allows adjustment for wear over time.

[Phil Thien]

A simpler way I've used to fix this problem is to drill and tap two pairs of holes and insert brass bolts and a nut to lock it in place. The brass is soft and keeps the quill aligned securely to the back of the hole where the rack and pinion are. The bottom two screws are drilled slightly left and right of center and the higher pair of screws are drilled just high enough they still contact the upper part of the quill in it's lowest position. I've done this on a number of drill presses over the years as a service tech. Very simple and allows adjustment for wear over time.

I have seen some people that have done this with nylon screws. You're talking about drilling/threading through the head, into the quill bore, right?

The problem I thought of was the one Bruce (Page) mentions above. Once the quill is extended past the upper-most screws, it can now wobble in the bore. Unless you were going to drill/tap holes every 1/2" or so, then the stability of the quill would depend on how far it is extended.

[Phil Thien]

In reference to knurling that is an effective and depending on the application even a permanent fix. You can gain probably safely .030 if necessary but keep in mind the taller the knurl becomes the more pointed the raised area. So you would begin to get the same result as using the center punch that was mentioned earlier. The sharp peaks would wear off if there was much pressure or stress placed on them. The knurling process is a shaping process that forms the metal and raises it in the process. The link I am supplying shows the process much better then I can describe it. http://www.google.com/search?q=knurling+process&hl=en&client=firefox-a&hs=k3V&rls=org.mozilla:en-US:official&channel=s&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=2L_uTq_aJoWnsQKk0PXiCQ&ved=0CHMQsAQ&biw=1440&bih=720

Thanks Ronald.

I'm guessing that I only have about .002 to .005" between the quill and the bore. My fear is that even minimum knurling would increase the O.D. of the quill so much that I couldn't be able to get it back into the bore. If I had a metal lathe, I could get the quill knurled, and then use the metal lathe in the event it no longer fit the bore.

But the small difference between the quill and bore is why I was thinking about peening. My feeling is that it would provide just enough of a dimple to take up the difference.

And before anyone says I shouldn't worry about .002 to .005", when you extend the quill several inches, that wobble is amplified quite a bit.

Still in the investigational phase.

Keep the ideas coming.

[Phil Thien]

BTW, one thing I experimented with was using glues (epoxy, and super) on the quill.

The problem is, the quill is machined so smooth, the glue doesn't hold on very well, I can scrape it off with my finger. And I did clean the quill with solvents before applying the glue.

Another thought I had was splitting the casting at the bottom boss, and making my own split head. However, this would be yet another compromise as the bottom boss is rather short.

I am going to solve this problem.

[Bill Huber]

Could use use value grinding compound, I know that I have used it on some things and it works very well in getting to metal items to seat. It is not the fastest thing to use but it has done a good job for me.

[david brum]

I like Rick's idea for the brass screws. I did the same thing in order to take the slop out of the sliding tubes on my budget Grizzly horizontal boring machine. I was really surprised at how well it worked and how quick it was. The nice thing is that it's controllable, so you can adjust it to perfection. It's functions like a split housing that you'd see on older/nicer drill presses.

[John Coloccia]

You know, I've given this a lot of thought because I have a wobbly drill press too and I'm frankly terrified of buying a new drill press right now because I'm afraid it will be just as bad....AND I want a quill lock (which oddly enough exists on Delta's 17" but NOT on their new 18" :rolleyes:).

Anyhow, my current plan when I get around to it is to pickup some brass set screws and drill/tap the head right through to the quill. Two holes, 90 degree apart. Then I will snug up the set screws to take up any play.

edit: I just read the responses on the thread. Great minds think alike, Rick. Is there a reason you prefer drilling off center as opposed to 90 degrees apart?

[Brad Patch]

Great Ideas using brass or nylon screws to pre-load the guill into its bore. Evidently there are numerous folks who are dissatisfied with the accuracy of their drillpress. I'll go out on a limb and bet that the root cause of these issues stem from tools made offshore. I too had a import drill press and could never got it to drill accurate deep holes. The cheap chucks that are supplied and junk! I upgraded to a Table model Walker Turner, model 950 and the fit finish and its ability to perform accurately is light years ahead of my import. For those looking to buy a drill press hold out for an American made older model, you'll probably pay less and get a better tool in the bargain. My floor model import has been relegated to the corner of my shop and I don't moss it.

[Phil Thien]

Well before you guys get too far with your drilling/tapping holes in the head...

Many drill presses have bosses in the bore. The bosses are there so when they machine the bore, they don't have to machine a continuous 6" (or longer) hole. They only have to machine the relatively short (.5" or 1") bosses.

So the boss itself is machined, the rest of the bore may be a much larger I.D. So if you don't get your set screws into the boss itself, you may find that extending the quill causes it to cock slightly.

Before adding set screws, make sure you run your finger or a popsicle stick or something up the quill bore. If it is perfectly smooth, then drill away. If you notice that it isn't perfectly smooth, you will need to find the bosses and make sure you get your set screws into those.

[Rick Lizek]

You only need 4 tapped screw holes...at the lowest point in casting and highest point the quill goes to at lowest point of the quill drops down to...pretty simple and minimal. I typically use brass not nylon.

[Phil Thien]

I'm including a pic I found on another site that demonstrates the four-screw fix.

I had thought of doing something like this, but first conducted an experiment.

I screwed my quill lock down to the point where it was somewhat tight but still allowed the quill to move up/down. When I subsequently held the quill lock inb one hand, and moved the quill an inch up/down with the other, the quill lock was now not touching the quill again and I was able to tighten it further.

Now, my quill lock isn't perfectly perpendicular to my quill, so that doesn't help with my experiment. I just wasn't willing to drill/tap four holes without being able to perform a test beforehand to make sure I was going in the right direction. Also, I found the bosses and it may be tricky to hit the center of them.

But I am nonetheless including a pic so anyone that is interested in trying this can see the work someone else did (25 years ago, no less).

[Rick Lizek]

90 degrees apart would work. Support in the back and 2 other points from 90 to 120 degrees will give a solid three point support. This is a tried and true method, not arm chair theory. Actually that picture is pretty much what I did except for using brass bolts. Set screws would work and the brass is soft so you wear the brass and can adjust it over time. Don't know why everyone is so afraid to drill and tap a few holes. You remove the quill first of coarse. I used the technique over a few drill presses over the last 30 years.

[Phil Thien]

Don't know why everyone is so afraid to drill and tap a few holes. You remove the quill first of coarse. I used the technique over a few drill presses over the last 30 years.

Not afraid, there just aren't many people out there reporting that this technique worked for them. In fact, the pic I posted, and you, make two.

And there are other ways to skin the cat. You can split your own head.

Care to post a pic of the presses you've modded? Maybe they will provide some more inspiration.

[Myk Rian]

Are cheap import drill press quills steel, or cast iron?
Steel, and that's the problem. Get yourself a decent DP.

[Phil Thien]

Steel, and that's the problem. Get yourself a decent DP.

I'm constantly on the watch for good drill presses. The cheap imports will just continue to show up, though, and I'm not just going to throw them away.

Can you expand on why steel is inferior for the quill?

[ray hampton]

I am not Myk but I think that cast iron would be many times as thick as the steel, the extra weight will work in your favor if balance

[John Coloccia]

90 degrees apart would work. Support in the back and 2 other points from 90 to 120 degrees will give a solid three point support. This is a tried and true method, not arm chair theory. Actually that picture is pretty much what I did except for using brass bolts. Set screws would work and the brass is soft so you wear the brass and can adjust it over time. Don't know why everyone is so afraid to drill and tap a few holes. You remove the quill first of coarse. I used the technique over a few drill presses over the last 30 years.

I'm getting ready to do this with mine. I have it apart in fact. Do you think it would work if I went straight in from the front, one pair on one side of the quill and one on the other? I don't have a good way to drill at an angle (obviously because I have no drill press at the moment!). I don't see why it wouldn't work, though coming in at an angle so the screws are pushing straight is obviously better.

I suppose I could grind 45 degree flats on the corners if I really had to, and then drill straight through that. Let me know what you think.

[Jeff Nicol]

By looking at the quill in this picture, it may be possible to put a fiber or brass washer top and bottom in between the stop collar at the top and bottom between the bearing and collar. These would need to fit at a close tollerance and with both types being soft they would wear over time. Maybe some HDPE or poly would be slippery but fairly sturdy, I will have to try it on my old cheapo DP as the Powermatic I have is very nice.

Good luck,

Jeff

Thanks for all that Ray.

I think the drill presses I'm dealing with are different, though, in that the splined shaft passes through the top of the quill, and engages with the drive pulley.

I've included a picture of someone else's gear, but it matches all of the presses I use.

[Phil Thien]

John, before you start drilling, make sure you know where the machined bosses are located in the head. And make sure the screws are BETWEEN the bosses, and make sure the quill stays in contact with at least two of the bosses when fully extended.

When I was experimenting, I tried a couple of different glues to take-up the slack. It worked great, but the glue was easy to scrape off.

I never tried polyurethane, and I should have. Thinking back to my dowel jigs, the polyurethane glue does a great job sticking to the steel bushings.

If I was still trying to correct this problem, I'd put a few dots of polyurethane glue on the quill, allow them to cure, and then see how easy they are to scrape-off with your nail (I'm betting not easy). If that works, then placing dots of polyurethane glue on on the quill (like it has chicken pox) may be the trick.

[Kevin Bourque]

Peening may work, but you might have to peen the shaft in a tight spiral pattern so that there would be many points in contact simultaneously. However this could lead to a condition of overpeening.

[John Coloccia]

The glue may work, but I just don't have time for anymore experimenting. I'm actively searching out an acceptable old-iron press in the area too. I need to have this resolved tomorrow sometime as I'm dead in the water. My current press has over .030" play. That's totally ridiculous by any standard. I can literally drill better holes by hand with a cheap cordless. By tomorrow night I'll either have a working DP or I'll have fixed my piece of junk. :)

BTW, I've decided that having absolutely no way to adjust for quill wear on a drill press is an absolute deal breaker, and that any press designed like this is designed as a disposable press and should be avoided like the plague, regardless how tight it is today. I believe that includes the vast majority being made today, including the 18-900 (correct me if I'm wrong). What a shame considering how simple it is to properly build in the modification that will take me the better part of the day attempting tomorrow.

[Phil Thien]

The glue may work, but I just don't have time for anymore experimenting. I'm actively searching out an acceptable old-iron press in the area too. I need to have this resolved tomorrow sometime as I'm dead in the water. My current press has over .030" play. That's totally ridiculous by any standard. I can literally drill better holes by hand with a cheap cordless. By tomorrow night I'll either have a working DP or I'll have fixed my piece of junk. :)

BTW, I've decided that having absolutely no way to adjust for quill wear on a drill press is an absolute deal breaker, and that any press designed like this is designed as a disposable press and should be avoided like the plague, regardless how tight it is today. I believe that includes the vast majority being made today, including the 18-900 (correct me if I'm wrong). What a shame considering how simple it is to properly build in the modification that will take me the better part of the day attempting tomorrow.

I understand where you're coming from. .030" is a ton of movement.

I've run into at least one other post from an individual that indicated they had that much play. I think he had a Delta press. He said it started out fine, worked great for 1-2 years, and then the slop spontaneously appeared. It kind of made me wonder whether there was something the manufacturer had done inside the bore (like a bushing or something) that had shifted. Because going from undetectable (slop) to movement in the hundredths of an inch (overnight) is a bit suspicious.

For a hobby press, it would seem to me that a means of adjusting play (like a split head) may be overkill. It would take gobs of cycles to cause enough wear to increase play.

OTOH, how much can it add to the cost to manufacture the thing to begin with? It may even save money for the manufacturer, in that fewer heads are scrapped because the bore is too large. I think most of the problems come from the fact that the initial bore was off. A split head can fix that, too.

I agree that the price for the 18-900 is too great for a drill press with no quill slop adjustment.

I don't think the polyurethane glue would help for 0.30". Try the adjustments screws and let us know how it works out.

[John Coloccia]

Hey, anyone have any idea where to get some brass bolts of set screws locally? My local Fastenals have nothing in stock. I'd like to kill this today if I could.

[Chris Fournier]

Hey, anyone have any idea where to get some brass bolts of set screws locally? My local Fastenals have nothing in stock. I'd like to kill this today if I could.

In town we have a company called Spae Naur, they supply all sorts of fasteners. I have bought brass tipped set screws from them; the screws are steel with brass inserts at the tip. This company ships mail order world wide.

I may have some of these set screws in stock at my shop. Let me know if you require some and I'll see if I have what you're after.

[Phil Thien]

Hey, anyone have any idea where to get some brass bolts of set screws locally? My local Fastenals have nothing in stock. I'd like to kill this today if I could.

My local Ace hardware stores have isles with at least a couple thousand different fasteners. They are stocked by a Hillman rep:

http://www.hillmangroup.com/

They (the local Ace stores) carry 1/4-20 (and a few other sizes) in brass. You could check w/ your local Ace stores, or contact Hillman and ask if they have any local hardware stores to which they could refer you.

Also, check Lowes/Menards.

Finally, you could check plumbing supply stores.

[John Coloccia]

Okay, so I have a plan. I'm going to file the corners flat, at a 45, so I can come in free hand with an S drill, and then tap for 3/8-24. For now, I'm going to stick in some regular set screws, but today I'll order set screws with brass tips and replace them in a couple of days when they show up. I'll try to take some pictures as I go along. Maybe it will help someone else.

Good tip about hitting the bosses, Phil. I happen to know that they're there, but I can see how someone who has not experience with this kind of stuff could easily miss that and do an awful lot of drilling and tapping for nothing! :)

I decided against splitting the case. I think that's probably the best solution, actually, but I don't have enough material for a through bolt of any sort. It's also very inconvenient to simply clamp it because of how they mount the switch. The whole thing is just a mindbogglingly bad design. I really have a hard time figuring out how we've come to just accept this as normal.

[Phil Thien]

Okay, so I have a plan. I'm going to file the corners flat, at a 45, so I can come in free hand with an S drill, and then tap for 3/8-24. For now, I'm going to stick in some regular set screws, but today I'll order set screws with brass tips and replace them in a couple of days when they show up. I'll try to take some pictures as I go along. Maybe it will help someone else.

Good tip about hitting the bosses, Phil. I happen to know that they're there, but I can see how someone who has not experience with this kind of stuff could easily miss that and do an awful lot of drilling and tapping for nothing! :)

I decided against splitting the case. I think that's probably the best solution, actually, but I don't have enough material for a through bolt of any sort. It's also very inconvenient to simply clamp it because of how they mount the switch. The whole thing is just a mindbogglingly bad design. I really have a hard time figuring out how we've come to just accept this as normal.

3/8-24 is pretty BIG. I'd make sure the brass-tipped set screws are available in that size before you start drilling.

If you're going to order set screws, check McMaster-Carr. They carry a huge variety.

[John Coloccia]

3/8-24 is pretty BIG. I'd make sure the brass-tipped set screws are available in that size before you start drilling.

If you're going to order set screws, check McMaster-Carr. They carry a huge variety.

Ha ha...I've been around the block a few times. That's the first thing I checked :) The tips themselves are only about 1/4". I'm not very confident that I'll be able to accurately drill the holes free hand, and I want to be sure I don't end up just riding on the edge of the set screw. Remember that I have to eyeball a flat for my drill to register against first, and then I need to actually drill...all by eye. My eye's pretty good but it's not obvious to me that I'll nail it. Maybe I should fly George up here and have him do it. He can engrave it while he's at it, and maybe make me some nice, scrimshawed knobs for the spokes. :D

I figure with a tip that's 1/4" wide, I can be off a couple of degrees and still end up with a good bearing surface when everything breaks in. I don't know...maybe I'll change my mind and just do 1/4-20. I have to look at it this morning and see what I have to work with.

[Phil Thien]

Ha ha...I've been around the block a few times. That's the first thing I checked :) The tips themselves are only about 1/4". I'm not very confident that I'll be able to accurately drill the holes free hand, and I want to be sure I don't end up just riding on the edge of the set screw. Remember that I have to eyeball a flat for my drill to register against first, and then I need to actually drill...all by eye. My eye's pretty good but it's not obvious to me that I'll nail it. Maybe I should fly George up here and have him do it. He can engrave it while he's at it, and maybe make me some nice, scrimshawed knobs for the spokes. :D

I figure with a tip that's 1/4" wide, I can be off a couple of degrees and still end up with a good bearing surface when everything breaks in.

One last thought: Could you make your own drill guide by drilling a hole in some scrap, and cutting a sort of birdsmouth cut on the end that would rest on the drill press and register the drill bit properly (or at least predictably)?

This would allow you to skip grinding flats on the press. Although you may have to grind some flats or drill a countersink to get the tap started.

[John Coloccia]

One last thought: Could you make your own drill guide by drilling a hole in some scrap, and cutting a sort of birdsmouth cut on the end that would rest on the drill press and register the drill bit properly (or at least predictably)?

That's not a bad idea, actually. I'm thinking that my drilling skills are pretty good, so if I just measure the 45 degree flat on the font and make sure that's close, I think I'll be just fine. Honestly, I'm half hoping I get a major catch and crack the head. That would give me an excuse to hop in the car and drive 4 hours to Plaza Machinery in Vermont and get something nice :)

[Phil Thien]

That's not a bad idea, actually. I'm thinking that my drilling skills are pretty good, so if I just measure the 45 degree flat on the font and make sure that's close, I think I'll be just fine. Honestly, I'm half hoping I get a major catch and crack the head. That would give me an excuse to hop in the car and drive 4 hours to Plaza Machinery in Vermont and get something nice :)

My drilling skills are 2nd to none. I'd make the drill guide.

[Myk Rian]

I've run into a number of drill presses that are cheap import models, and suffer from a bit of quill slop.
Several years ago I bought a new Delta VS DP350. An import. It had quill slop.
I fixed it by getting a 1945 Delta DP220 for $125, then sold the new one. A clean-up and paint, and it works like a DP should. Nice and tight.
Trying to drill holes in the quill for shim screws will probably be an exercise in frustration, and ruin the quill.

[John Coloccia]

Done. It's silky smooth, now. I decided to go with 5/16X24 set screws. Tomorrow, I will order some brass and nylon tipped screws and see which ones I like better. I'll also post some pictures at some point. It really only took me a couple of hours once I got into it, but it did require a bit of cleverness to debur the inside of the hole (I wonder how many would have the right tool to do it?). Anyhow, it's not perfect, but it's not bad. It will be better with the nylon or brass...the hardened ones I have right now don't conform at all or have any lubricating qualities. The other ones will be even tighter and smoother.

[Phil Thien]

Done. It's silky smooth, now. I decided to go with 5/16X24 set screws. Tomorrow, I will order some brass and nylon tipped screws and see which ones I like better. I'll also post some pictures at some point. It really only took me a couple of hours once I got into it, but it did require a bit of cleverness to debur the inside of the hole (I wonder how many would have the right tool to do it?). Anyhow, it's not perfect, but it's not bad. It will be better with the nylon or brass...the hardened ones I have right now don't conform at all or have any lubricating qualities. The other ones will be even tighter and smoother.

Good job. Looking forward to the pics and an update after you've used it for a while.

Seeing as you're ordering parts anyhow, maybe you'd try a couple of nylon-tips? They're suppose to be soft enough to conform to shapes, but firm enough to hold things in place. May be just the ticket.

Did you eyeball it, or use a guide?

[John Coloccia]

Good job. Looking forward to the pics and an update after you've used it for a while.

Seeing as you're ordering parts anyhow, maybe you'd try a couple of nylon-tips? They're suppose to be soft enough to conform to shapes, but firm enough to hold things in place. May be just the ticket.

Did you eyeball it, or use a guide?

Eyeballed it. Piloted with 9/64", and finished with 9/32". I think what I may do, and what may be the best solution, is see if I can find some 9/32" UHMW rods and just stick them in there. Actually, if someone out there with a metal lathe would like to turn down some UHMW or similar plastic to 9/32" (or slightly under), and send me a 2 or 3 inches of it, I'll be happy to pay them.

Boy, I really need to get a metal lathe and a mill. Now that I don't have my day job anymore, I REALLY miss having access to nice mills and metal lathes.

[Phil Thien]

Eyeballed it. Piloted with 9/64", and finished with 9/32". I think what I may do, and what may be the best solution, is see if I can find some 9/32" UHMW rods and just stick them in there. Actually, if someone out there with a metal lathe would like to turn down some UHMW or similar plastic to 9/32" (or slightly under), and send me a 2 or 3 inches of it, I'll be happy to pay them.

Boy, I really need to get a metal lathe and a mill. Now that I don't have my day job anymore, I REALLY miss having access to nice mills and metal lathes.

That sounds like a good approach.

9/32 is going to be tough to find. I've reduced the diameter of a dowel using my table saw thusly:

Drill a 5/16" hole in a scrap of wood. Clamp this to your miter gauge. Clamp the miter gauge in the slot so the miter gauge doesn't move. The miter gauge should be positioned so the 5/16" hole in your block of wood is aligned with the blade's top dead center.

Now, just insert the 5/16" dowel (or plastic rod) into the hole and spin it as you pass it over the table saws blade.

It goes real fast and is very accurate.

[John Coloccia]

Very high level view of the mod. It's greasy and messy so I couldn't take many pictures. It's cast iron, so you generally drill and tap DRY. It drills very easily and taps very easily too, though I suspect this particular casting is of very poor quality. I definitely ran into some a number of very hard spots while tapping, which generally indicates low quality cast iron with lots of impurities....who knows what the heck I'm hitting. Sometimes you even run into completely foreign material (not in this case) but with truly garbage castings you can.

Anyhow...


This is after removing the quill. If you don't know how to remove the quill, it's generally very simple. Loosen the bolt holding the spring housing (NOT all the way...don't let the housing come off the index pin and spin....you'll get hurt!). I push the housing down with a long screwdriver to hold it down, loosen the nuts enough to allow the housing to come off, and then remove the screwdriver....It normally just comes right off the index pin and spins, releasing tension. Remove the housing, HOLD THE QUILL, and pull out the handle. The handle is the only thing holding the quill in, so once you pull out the handle the quill will generally come right out. This is looking up into the casting. You will see the two bosses Phil was talking about (one at the very bottom of the casting, and one a couple of inches above it). These are the only two points that support the quill. They save money and get more stroke by making the two bosses very close to each other, but that makes the fit all that more critical. It's a loosing proposition to increase stroke like this on a cheaply made drill press....
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After removing the switch, I took a small double cut bastard file and file 45 degree flats on the corners (centered on the boss locations). Then I center punched and eyeballed drilling a hole. First a 9/64" pilot, followed by a 9/32" drill (9/32" being the drill for a 5/16-24 (fine) thread into iron). Then I tapped it. Nothing spectacular here. If you don't think you can drill a straight hole without wobbling or enlarging it by hand, do use a guide as Phil suggested. You really only get one shot at this without having to get creative.
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Here's a better shot. The flats look curved because you have to relive on either side a bit to fit the file (it has rounded edges), but do try to get it reasonably flat at least. It makes everything easier.

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That process will leave a burr on the inside of the hole, which is remarkably difficult to get to...UNLESS you have this handy dandy right angle drilling tool left over from my aircraft building days. It's a pretty standard thread. All sorts of things will fit, including a deburring bit (or countersink if you wish to call it that). Chucked it in the drill and I had perfectly chamfered holes inside the casting in seconds. I don't know how else you'd easily do this.
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And that's it. Stick in the set screws, and voila, the piece of junk from day one Delta 17-950 is now pretty solid. The bearings on mine are actually very tight. All of the play was coming from the quill. It will still deflect if I put pressure on it, but the play is gone and I can visually see that it's now turning true (look at the tip of a brad point bit...if it looks like a blur, SOMETHING is off somewhere). My test holes were also finally clean and precise. I still don't like the DP but at least it works now.

Thanks all for suggesting this technique and giving some great advice along the way.

[John Coloccia]

So I cut the 1/4" plugs from UHMW, stuck them in, snugged it up and.....ROCK solid. As good as anything else I've ever used. Wish I had done this years ago.

[Phil Thien]

So I cut the 1/4" plugs from UHMW, stuck them in, snugged it up and.....ROCK solid. As good as anything else I've ever used. Wish I had done this years ago.

Good job!

If the need ever arrises on my current drill press, I think I will split the head.

Luckily, my "daily driver" seems very precise.