camel back drill press

[Joe Michaels]

Hello Todd:

I am glad you are getting a copy of "Machinery's Handbook". I've got a few copies floating around the house/shop. I've given a few used editions to young people coming into this work. It's a timeless reference, and, at the risk of blashphemy, used to be referred to as "The Bible of the Mechanical Industries". A correct analogy.

The Babbitt which Belmont recommended is a high lead babbitt. It will likely have a lower melting point than the lead/tin/antimony babbitt that Kapp recommended. Either will work for your application. Personally, I'd go with the babbitt having 10% tin. It will be a bit harder than the 90/10 babbitt, which has no tin. You are dealing with a low speed bearing seeing relatively light loading. I favor a babbitt with tin as it is just that little bit harder than the lead/antimony alloy. It will be a bit better in terms of 'scraping in' as your scraper will take off a nice thin chip (I've scraped in soft leaded babbitts vs harder tin containing babbitts). I'd use the softer alloy if your shaft journals are chewed up (scored or ridged). Better chance of it 'bedding in' to a chewed-up journal.

A few hints on babbitting a cast iron bearing:
1. Melt out ALL the old babbitt.

2. Clean the cast iron bearing shell to 'white metal'. Choices of method include:
-abrasive grit blasting (aka sandblasting)
-running an air needle scaler over the cast iron surfaces which will have the babbitt bonded to them
-taking a skim cut using coarse feed, machining off maybe 0.020" of cast iron, coarse feed leaving a rough surface finish to help with mechanical 'interlocking'
between the iron and the babbitt. On really oily or damaged cast iron bearing shells, machining to sound/virgin iron is done in some babbitting shops.

3. If the bearing has keyways (dovetail grooves in the iron) or blind holes to mechanically lock in the babbitt, tinning the bearing shell is not an absolute requirement.
If the bearing shell has a plain bore, I'd recommend tinning the surfaces of the iron the babbitt will be poured against. Tinning will insure a solid bonding akin
to 'wetting' as happens in soldering. To tin the shells, you will need tinning compound (Kapp has it), flux, and a stainless steel brush to work the tinning compound
around the surface of the bearing shell and into any nooks and crannies in the surface of the iron bearing shell. I've used "Jet Flux". This is a gel type flux used for
soldering copper piping with lead free solders. I have soft soldered steel and iron using this flux. Plumbing supply firms have it.

If you are going to tin the bearing shells prior to babbitting, aside from cleaning to white metal, you will need to wash the shells with muriatic acid. This is known as
acid pickling. You can put the acid on with a plastic spray bottle or paint brush, and then rinse with very hot water. A heat gun or weed burner works well for drying
the pickled surfaces. Keep on heating with the weed burner to get the shells hot enough for tinning. The shells will need to be hot enough to melt the tinning
compound, same as if you were sweating a copper pipe joint and had the solder hot enough to run or flow but not so hot as to bead up. The other reason for
heating the shells is to drive off any remaining moisture. Moisture + molten metal = a spit-back or explosion of sorts.

4. Once you have the bearing shells tinned, you can let them cool and do the setup of the shaft in place for the babbitting. You would install the end 'dams' on each
bearing shell at this same time. I'd use sheet metal washers cut to a snug fit on the shaft for the end dams. Put some of the babbitt damming putty on the end of
each bearing housing and bed the sheet metal washers in it, clamping them to the bearing housings. The damming is the last thing you do after you have
established the shaft on its correct centerline/level/square to the spindle. The shaft has to be smoked (soot blackened) before you position it and set the dams.

5. As I'd written previously, getting the shaft positioned and locked there will require some temporary fixturing, akin to lathe steady rests, and sometimes called
'Catheads". You are going to be pouring those bearings in place on the drill press main frame. As such, you will be working some height above the floor and
not on a work bench or similar convenience. For this reason, I'd build some kind of temporary scaffold or platform so you and your helper can stand on a solid
footing and access the bearings with the babbitt ladles without straining, over-reaching, or putting yourself in danger. Spilled babbitt on the floor is one thing.
On you or a helper, spilled molten babbitt can cause serious burns. Having a good solid place to stand and reach the bearings with the ladle is a very
important part of the job. Whether you make a platform out of a few concrete blocks and some planks or build something more elaborate is your call.

6. When working with the molten babbitt:
-positive airflow to keep you from breathing in any fumes is required. Melting the babbitt outdoors (if you are working in a home garage) is a good idea if possible.
A 'box fan' put behind you and blowing fresh air past you and towards the work is also a great idea.

-When I pour babbitt I wear a welding jacket (either flame proof fabric or rawhide), welding gloves (the heavy ones for stick welding and oxyacetylene cutting, not
the thin ones worn for TIG welding). I also wear a face shield and a welder's cap (also flameproof). Avoid wearing any synthetic fabric clothes. Hot babbitt hitting
polyester or similar will melt it and stick it to the wearer's skin, making a worse burn. Wool or cotton clothing is what's safe to wear. Long pants, no shorts, and no
flip flops, sandals or running shoes (aka 'sneakers' as my generation called 'em). Leather work shoes, preferably high-top so less chance of a spill of molten
babbitt getting into your shoe.

7. Make sure the babbitt melting arrangements, whether a plumber's stove or babbitt pot and torch (or propane weed burner and some firebrick) is solid not about to
tip over. Preheat your ladles with the weed burner or torch before dipping up molten babbitt for the pour.

8. Make a few dry runs to practice the moves of dipping up a ladle of molten babbitt and getting it up to the bearing being poured. Have a good helper who knows
the job so you are not having to explain what you want while handling a ladle of hot babbitt. Typically, one person keeps preheating the bearing shell/shaft
with a torch and rosebud, and the other person dips up the ladle of babbitt and does the pouring. The person with the torch may take a piece of stainless steel
rod (I use 1/8" diameter stainless steel TIG rod) and poke it down into the molten babbitt along the shaft. This is to help work up any air bubbles. Don't be afraid to
pour the babbitt just a little higher than the top of the bearing shell. This will provide what the foundrymen call a 'riser', a kind of reservoir of molten metal to help
reduce the possibility of shrinakge related defects in the pour.

 

[todda323]

Man! Thanks Joe. That's alot of great info. I really do appreciate all of your advice and guidance. I am looking forward to the sketches you are going to send. Once I have something to hold the shaft in place I will do some calculations and put in an order for babbitt supplies.

 

[Joe Michaels]

Todd:

It's been all quiet on this thread for the past few weeks. Any progress on your re-babbitting of the top shaft bearings ?

 

[todda323]

Apologies to everyone for letting things get stale. I promise I haven't given up on things. Hopefully I can return to working on this dinosaur shortly. Life has a way getting busy and throwing unexpected curve balls at us.

 

[todda323]

I'll spare everyone the excuses as to why summer and fall have forced things into hibernation but let me just say it has been a heck of a ride. In my limited time I have putted around with a mock up of something to hold the shaft steady from some junk around the shop. After discussing this with Joe I'm not going to use cast but use steel. The nut would be drilled and tapped at 4 points to lock the shaft in place. Of course I would duplicate the front model but to accommodate the rear of the shaft.

 

[todda323]

One question for everyone on this a I move into mock up of securing the shaft in place for a bearing pour. I'm trying to make sure alignment between the top shaft bevel gear and the crown gear are satisfactory. What would be considered the line between acceptable and unacceptable backlash between the main shaft bevel gear and the crown gear? Shimmed about as high as I can there seems to be alot. I have to put a dial on it still but if I had to guess between 15 and 30 thousandths.

 

[john.k]

Never shim up the backlash in bevel gears to 'take up' wear ......you will inevitably cause tooth breakage.

 

[Joe Michaels]

Todd:

You are facing a situation that can best be described by the word "indeterminate". Namely: the babbitted spindle bearing of the drill press is worn excessively, as are the two top shaft bearings. The result is you do not have a solid 'datum' or starting/reference surface to work off of.

Let's start with the overall mainframe of the drill. The only thing you can work off of is the table surface. Lock the table on the column of the drill. Rub the table off with an oilstone, wipe with solvent and sit your precision level on it in two directions at 90- degrees. Level the drill press mainframe using temporary shims. When the table is level in two directions, you have something to start working off of,

The spindle centerline of the drill press is what 'rules'. By levelling off the table, we can hope that the spindle is plumb (vertical). This is hoping that the builders of the drill bored fit for the quill square to the table. This centerline of the spindle must be square to the table. Let's go with what we may have to work off of with your drill press. Let's figure the fit of the spindle in the quill (most of these camelback drills ran the spindle journals in the quills in bored fits, no bronze or babbitting) is still reasonably tight and good. Let's also figure that there is a set of pinch screws to allow for adjusting the fit of the quill in the mainframe of the drill press. If you make up on the pinch screws to the point the quill is tight in the mainframe, that eliminates one source of slop. If you can remove the spindle and mike the journals that run in the quill, and mike the bored fits in the quill, you have the clearance between the spindle journals and the quill. By adding shim stock around the journals to take up this clearance, you can hopefully center the spindle in the quill. Tighten the pinch screws (if your drill has them) and the quill is locked tight in the mainframe. With the shim stock in place around the spindle journals and the pinch bolts made up tight, you have 'staked' the spindle as best you can and established its centerline. You also have hopefully gotten a plumb spindle.

Now we move up to the top spindle bearing in the mainframe. As you've posted, the babbitt in this bearing is badly worn. This is why I suggest using the quill as a means of establishing the spindle centerline. Once you have done this, you are already ahead of the game with the catheads to establish and hold the top shaft in position. This is where the game gets interesting. What 'rules' with the top shaft is its centerline relative to the split-lines of the top shaft bearings. The top shaft centerline has to be at the same elevation as the split joints of the two top shaft bearings. What may be a bit confusing is the fact the top shaft bearing 'housings', being part of the mainframe casting, are 'as cast' and rough. As such, there are no surfaces other than the surfaces of the split joints on the bearing housings to work off of. Using the vee groove on the base of your precision level, level the top shaft by adjusting the screws on the catheads.

To set your top shaft in the catheads so its centerline is coincident with the split line of the bearings, we have another exercise in measurement. I'd lay some 1-2-3 bolts on the split joint of each bearing and span them with a heavy parallel. A piece of 1" square cold rolled steel is accurate enough for this purpose. This makes a bridge running over and across the top shaft, supported on the split joint of the lower half of each top shaft bearing. Using a depth mike or a dial (or digital) caliper, or a good combination square, get the depth from the top of the 'bridge' to the 12:00 position on the top shaft. Subtract the depth reading from the height of the bridge off the bearing split joint. This will give you how high the top shaft sits above the split line of the bearings. Adjust the catheads until you have the top shaft centered vertically in the bearings. Using your eye, as well as a machinist rule or combination square blade, check where the top shaft would intersect the spindle. The straightedge on the top shaft is held so it touches the side of the top shaft and the spindle. You adjust the catheads horizontally so the top shaft centerline intersects the vertical centerline of the spindle. You may find that using your eye much as you might sight a rifle will work as well as anything else .

What we are working towards is centering the shaft top-to-bottom in the bearing housings, as well as having it levelled and centered with the spindle. As noted, the spindle has to be 'staked' on center. We take it on blind faith that if the drill press is levelled, and the spindle staked in place, its centerline will be plumb.

In an ideal world, given the condition of your drill press, the sequence of repair work would be:
1. Melt the old babbitt out of the upper spindle bearing in the mainframe.


2. Make a dummy spindle with no keyway (known as a mandrel). Machine this dummy to a very close fit in the quill bores.


3. Smoke the mandrel with soot (lampblack) and install it in the quill and mainframe of the drill.

4. Dam the bottom of the mainframe top spindle bearing housing and preheat, then pour the babbitt.

5. Leave the mandrel in place and setup as per above for establishing the top shaft position relative to the spindle. This gives you a starting point to work off of
for positioning the top shaft relative to the spindle.

As long as the centerlines of the spindle and top shaft intersect and are square to each other, I would call it 'good' for babbitting. Once the babbitting is done with, you can then set the clearances on the top shaft bearings with shim stock. To set the gear engagement, replace the dummy (mandrel) with the spindle and install the crown gear. With the top shaft and bevel pinion in place in the bearings, you then place trial shims under the hub of the crown gear to bring it up to where the gear teeth mesh with about (2) thicknesses of printer paper (about 0.008-0.010") of clearance. You can use a thin coating of grease or Prussian Blue paste on the teeth of the bevel pinion and turn the top shaft thru a couple of revolutions. This will transfer some of the grease or bluing to the teeth of the crown gear. Adjust your shims under the crown gear hub to improve contact, but you must be able to have at least 0.004-0.005" of gear lash (one sheet of printer paper). Using a trip of soft aluminum cut from a beverage can between the gear teeth will 'roll in' . Add shims under the crown gear hub until you can roll the shaft easily but have a slight drag on the soft aluminum when you go to pull it out from between the teeth. It's a backwoods method, but for old and worn open gearing, will be fine. We have to go with the belief that the top shaft and spindle may not be dead square to each other, so we set the gearing up on the looser side.

 

[todda323]

Ill give it a try Joe. Thanks for the great guidance. For some reason I feel like I should be paying tuition here. It's like taking a Vo Tech class. Thank you to everyone who has the patience to put up with this long thread and offer advice. Its exciting to learn and try something new...when I don't ruin anything. I think many folks here would be surprised how many machinists, antique car owners, self proclaimed black smiths and engineers I have met that have heard of babbitt but never poured it. Especially in an area that was founded and supported by factories and mills, some dating back to the late 1800s. The closest I have come was an old machinists mate from the navy (WWII era) who worked in their boring shop on the ship. He never poured but bored a whole lot of babbitt. Even he didn't know a whole lot about the process.

Since a torch is still in my future I have a bud who has a set and is going to help. Ill probably drag my son in on this as well. He's easily persuaded with a higher quality beer and working with fire. Beer after fire being the correct sequence here. Joe I will order up some of the babbitt grade you recommended in either an earlier post or PM and build a cat walk so we can work down instead of over our heads. The method you described for centering the spindle and crown gear using the spindle mainframe is very close to what I had in mind. I don't think I explained it as it appeared in my head. My hope was that I could insert the crown gear from the bottom with the spindle running through the crown gear there by centering the crown gear in the head but I can have a machinist acquaintance of mine make a slug. That should not be much of an issue. Since the spindle mainframe is removable if there is any error in the spindle being 90 degrees to the table I would imagine the mainframe could be shimmed, to some degree, to correct for the spindle being out of perpendicular with the table if that ends up being the case. It seems I checked early on and things were looking very true. That was before I had the spindle hard chromed and things disassembled to this degree though.

How can I determine what taper this uses? It didn't come with a chuck or a MT. At the bottom of the spindle where the taper is inserted where the knock out slot is I have a rough measurement of 1.04". At the bottom I have 1.24 (rough). Unfortunately I only have cheap Chinese snap gauges. Looking at the charts it looks like an mt4 would be close at 1.231 on the bottom end and 1.020 on the top/ small end

 

[Joe Michaels]

Hello Todd:

Thanks for the kind words. I've been called "the Professor" by kinder people at the powerplant (pre retirement), and plenty worse, and asked if I was 'injected with a phonograph needle" by one 'board member. Our communications has been an interesting process- both of us trying to explain a complex job with words and your posting pictures (something a dinosaur like me has yet to master).

Babbitting is one of those skills that is not too common nowadays. Bearings are sent out to babbitting shops which specialize in that work. Very few machine shops pour babbitt (nor do they have any need to). The move to 'antifriction bearings' (i.e., ball, roller, needle) has greatly reduced the number of smaller babbitted bearings. Larger machinery such as turbines, generators and some larger low speed diesel engines and low speed large compressors will still have babbitted bearings. Not sure when the big shift in auto engine bearings occurred, but the move to 'insert type' bearings for automotive engines came inro being maybe post WWII and by the early 50's, was pretty much 'across the board'. The 'antique car' community is aging out, with people wanting to restore and drive 'brass era' or cars from the 20's and 30's becoming less common. The muscle cars of the 1960's and 1970's are what seems to be the antique cars. For ages, the most common automotive and motorcycle wheel bearings were tapered roller bearings. Mechanics and owners doing their own maintenance on their vehicles had to know how to repack a roller bearing and set the preload. Even that is vanishing as the move now is to sealed/factory lubed bearings.

As for your drill press's spindle taper, it is almost a sure bet it is a Morse Taper. Number 3 MT spindles were quite common on the majority of camelback drills. Number 4 was used in heavier camelback drills. A purchaser of a drill press could sometimes order a different spindle taper than the standard spec'd by the manufacturer. My Cincinnati- Bickford camelback drill is about a 25" machine, and it has a number 3 MT spindle taper. My suggestion is to get hold of some Morse Taper shanked drills and try them in the drill press's spindle. It is difficult to determine what taper a female taper bore is. Adding to the mix is the fact that the drill press spindle has a socket for the tangs on the drill shanks. If your first choice of a number 3 MT shanked drill is too small for the spindle, reducing sleeves work quite well. I have a mess of drill chucks from 1/2" to 1" Jacobs "Superchuck", on number 2 & 3 MT arbors, along with a number of small diameter drills on number 1 MT tapered shanks and loads of taper shanked drills with number 2 & 3 MT shanks. Having some reducing sleeves as well as drift keys (for removing a taper shanked drill from a spindle with a female taper) is a necessity. This lets me use tapered shank drills and drill chuck arbors in different machine tools in my shop.

 

[todda323]

Looking for an opinion here. As I prepare to proceed forward with the bearings I was wondering what opinions are on leaving the top shaft journals "as is" or having them turned down slightly to clean things up a bit. What is seen is better than when I disassembled things as I used some emery cloth to soften the ridges. I don't have a lathe but have access to folks who do have one. It is an inconvenience but quite doable if suggestions lead that direction.

 

[Joe Michaels]

Hello Todd:

Regarding the top shaft journals: I would NOT turn the journals down. From the pictures you posted there is some light scoring but nothing too deep. I'd give the shaft a bit more polishing with emery cloth. I buy emery cloth in 'shop rolls', narrow strip rather than sheets. For polishing the shaft without a lathe, use the emery cloth in a longer strip, working it like you were shining a pair of shoes. Some light oil on the shaft will improve the polishing action. Finish with a "Scotchbrite" pad. When the shaft journals are smoked up for the babbiting, things will come out OK.

On the matter of positioning and aligning of the shaft with the spindle, it is kind of like building a house. Consider the table of the drill press as the 'plates' of a house foundation. Get that levelled in two directions as you do not have too much else to work off of. Stake the spindle on center as per my earlier post. If the moon is in the right house and the planets align, this should put the top portion (the keyed shafting) of the spindle plumb and squared to the table.

That then gives you the next reference line or surface to work off. Kind of like getting a column or studwall plumb when framing a house.

Once you have the spindle centered and plumb/squared to the table, the top shaft is located and aligned. There are several points to work on with the top shaft:

-what 'rules' is that the top shaft centerline intersects the centerline of the spindle.

- the depth to which the top shaft sits down in the lower bearing housings (part of the mainframe) needs to be established so the top shaft's horizontal centerline is coincident with the split line of the bearing housings.

The catheads let you move the shaft in two axis as well as levelling it. Regarding centering the top shaft in the bearing housings, I'd say the vertical centering is more critical than lateral (horizontally). You may find the top shaft is not centered in the bearing housings when it is properly intersecting the centerline of the spindle. The bearing housings are not machined in their bores, but are 'as cast'.

-Before you start adjusting and aligning the top shaft to the spindle, I'd suggest you place the crown gear on the spindle. It will have some 'drop' to it and likely not fully mesh with the bevel pinion.

-after getting the top shaft centered with the split lines of the bearing housings, and centerlines of the top shaft and spindle intersecting, raise the crown gear on
temporary "C" shims to mesh with the bevel pinion. If the cathead screws are just snugged, you may be able to turn the top shaft and see how the bevel pinion &
crown gear mesh and run together.

-You may have to tweak the catheads a little bit to get good running between these two gears. When you have good running, lock the screws on the catheads to
stake the top shaft in position for babbitting. The temporary shims under the crown gear will hold the gears in mesh, and may be setup with little to no gear lash.
Running gear lash and depth of engagement will be set with the permanent thrust shim under the crown gear after babbitting the top shaft.

-Using Prussian Blue is a bit tricky. It is easy to use too much and get a 'false positive'. A few light dabs on the pinion's teeth, wiped with a tissue paper to make a thin
film is what's needed. Hold off on doing any blue checks of tooth contact until after the top shaft bearings are babbitted.

 

[todda323]

I will take your advice and hold off on checking tooth contact until after the bearings are poured. I just want to make sure I understand how best to check engagement properly. I would assume I am looking for a consistent wear pattern in blue or marking paste ford to aft and bottom to top on the side of the crown gear teeth being driven when bluing/pasting the crown gear gear. I would also assume I would want the wear pattern in the paste to be centered similar to how I have seen differential gears adjusted or shimmed. I would not necessarily be looking for blue transfer to the face width/apex of the bevel gear teeth from the valley of the crown gear correct?

 

[Joe Michaels]

Todd:

These are bevel gears, and have seen plenty of use and resulting wear. Let's say you applied the blue to the bevel pinion's teeth and rolled it against the teeth of the crown gear. If the gears were meshing properly, you'd be looking for a light blue contact mark on the flanks of the crown gear teeth, with the blue at its thinnest (or a bright metal area) at the pitch line of the teeth. Reading blue contact checks is a bit counterintuitive. When two surfaces make contact, and that contact is in the form of a line or point rather than a wider area, the blue tends to be squeezed away from that contact line. This is due to a high localized contact pressure. I call this "leopard spots" as the blue will sometimes form a kind of ring or halo around a bright metal spot (as happens when scraping in babbitted bearings). With the gear teeth, you should see a very light haze of bluing at the pitch line and a slightly darker patch of bluing on the tooth flank. As the gear teeth mesh, there is a rolling action and the bluing will be carried upwards towards the crests of the teeth for a short distance, but should not make it to the crests of the teeth.

Crests of teeth and the roots of the teeth should never contact each other if teeth are in reasonably good shape and at proper depth of engagement. If teeth are badly worn and depth of engagement is set too deep, this would cause the crests or tips of the teeth to contact the roots of the mating teeth. If that happened with teeth having anything like a good profile, chances are there would be some heavy wear if not broken teeth.

For now, get the top shaft aligned relative to the spindle and depth set in the top shaft bearing housings. After the babbitt is poured, the top shaft will be in its running position. This will give you something solid to work off of to set the gear engagement and lash.

 

[todda323]

Following Joe's lead I found when I lock the quill down in the quill housing only the upper bolt seems to tighten enough to hold the quill and spindle. The bottom bolt tightens but does not seem to have any purchase on the quill. This leaves some play that can be shimmed until the crown gear bearing can be poured. I noticed the housing has a piece cast in the middle of the split. I was wondering if there were any reasons I should not grind this out so the entire length of the split in the housing can be adjusted.

 

[Joe Michaels]

Hello Todd:

There is a reason the designers of the drill press did not make the split continuous on the quill housing. The reason (at least to my thinking) was to leave one portion of the housing as a 'full circle'. The idea might have been to leave that un-slit section as a guide for the quill, concentric with the spindle centerline. The split sections, when the pinch bolts are tightened, would deform 'out of round' and would take the quill/spindle off its centerline. At least that would seem the likely theory.

I'd leave that un-slit section. As far as the top bolt being able to pinch/lock the quill vs the lower bolt being unable to, there is more wear in the bottom portion of the quill housing. Any number of things can cause the spindle of a drill press to want to orbit about its centerline. These include: drills ground with unequal cutting lips; bent drills; excessive side-load (radial load) on the spindle (running end mill cutters in a drill press being an example of this). The pinch bolts are there to takeup wear in the bore of that housing, to maintain a close sliding fit with the quill. Running the drill press with the pinch bolts slacked off and subjecting the spindle to conditions that cause it to orbit about its centerline will result in wear in the bored fit that the quill slides in. During the earlier life of the drill press, as a matter of operating practice, the pinch bolts should have been made up so side play between the quill and the housing bore is taken up.

Cutting out that remaining web of iron between the upper and lower split cuts should not be done.

 

[todda323]

Hello Todd:

There is a reason the designers of the drill press did not make the split continuous on the quill housing. The reason (at least to my thinking) was to leave one portion of the housing as a 'full circle'. The idea might have been to leave that un-slit section as a guide for the quill, concentric with the spindle centerline. The split sections, when the pinch bolts are tightened, would deform 'out of round' and would take the quill/spindle off its centerline. At least that would seem the likely theory.

I'd leave that un-slit section. As far as the top bolt being able to pinch/lock the quill vs the lower bolt being unable to, there is more wear in the bottom portion of the quill housing. Any number of things can cause the spindle of a drill press to want to orbit about its centerline. These include: drills ground with unequal cutting lips; bent drills; excessive side-load (radial load) on the spindle (running end mill cutters in a drill press being an example of this). The pinch bolts are there to takeup wear in the bore of that housing, to maintain a close sliding fit with the quill. Running the drill press with the pinch bolts slacked off and subjecting the spindle to conditions that cause it to orbit about its centerline will result in wear in the bored fit that the quill slides in. During the earlier life of the drill press, as a matter of operating practice, the pinch bolts should have been made up so side play between the quill and the housing bore is taken up.

Cutting out that remaining web of iron between the upper and lower split cuts should not be done.

Much thanks Joe. And I'm glad I asked before I thought I had things figured out. I would imagine since thie quill main frame is easily removable it would be a candidate for a bushing in the future to bring in this slack. If you haven't noticed one thing I'm good at is asking questions, intelligent or not. As you noted in our conversation yesterday this thing has more wear than I originally thought. It was caked in 100 years or so of suit, coal dust etc impregnated oil and grease making tolerances tighter than when cleaned. Not that my objective of restoration and use is any more significant than the simple need for use and the method by which that was achieved by the original owners but I do see that, practically, their method of keeping and maintaining had it's value. Restoration is not necessarily better than checking for harmful grit, wiping things down a little and re oiling things and maybe packing a little grease where required and if appropriate. If I had done that then this thing would probably be in use now, not that any projects are waiting on it. If I had done that I would not have had the opportunity to learn everything I am learning from the generous and friendly folks here on the forum.

As we were discussing the matter of the table being out of true yesterday I decided to give in to my OCD a little. I took a grinder and file to the table's reference surface on the table arm. I got the majority of the reference surface on the arm down to within about .003 give or take. Much closer than .050 I was getting before touching it up. I found that when I put the table back in the arm it was still equally out in the same directions being 9:00 to 3:00. You hit on something in our conversation referencing the hole in the table arm being the victim of poor alignment between the top and bottom rings inside the hole. I will investigate this a little further and see if some light touching with a die grinder burr has any effect. If so then I will proceed cautiously and slowly.

 

[Joe Michaels]

Hello Todd:

It was great to have a 'phone conversation with you yesterday. As for our discussion of the table being square (or out of square) with the spindle, bores in the table support arm are the likely culprits. As you told me, by dial indicator, the table is within a few thousandths of flat. Also by dial indicator, the table is about +/- 0.003"
from square to the spindle in the 12:00 (closest the column) to 6:00 (180 degrees opposite). The 3:00-9:00 locations are something like +/- 0.025 to 0.030" out of square.

Dressing the top of the table arm (where the shoulder of the spud on the table contacts the arm) won't do a whole lot towards bringing the table into square with the spindle. Squareness of the table to spindle is determined by the two (2) bored fits in the table arm. The bored fir for the column as well as the bored fit for the spud on the table have to be parallel in two directions with the centerline of the column (presuming the spindle centerline is also parallel in two directions with the CL of column).

Plainly, there is a lot of wear in your old drill press. Using an inside micrometer, I'd satisfy my own curiosity as to whether the bore that the column runs thru within the table support arm is still round or has worn out of round. The amount the table is out of square to the spindle from 3:00 to 9:00 sounds way out there, more than I would expect even in a well worn and ancient drill press. I would not suspect the bored fit for the spud on the table of having much wear. The fit of the table support arm, riding up and down the column, seems the more likely culprit. Use of the drill with the table swung to one side, and not locking the support arm clamp over many years, along with particles of grit and soot getting onto the column could cause some wear in the support arm bore.

I am reminded of an old friend of mine and a story he told me. My friend had an early 1950's Dodge "Jobmaster" pickup truck. He worked as a fireman (the kind that shovelled coal) on the ore boats on the Great Lakes, so we are going back to the 1970's. My friend was working on the oreboats, and left his pickup truck with his father. His father was using the pickup truck to get in firewood. The father, knowing his son would be coming home at the end of the season on the Lakes, decided to do an oil change on his son's pickup. By the time my buddy got home, his pickup would not start. It would crank over like crazy, had spark, had fuel up to the carburetor. My buddy and his dad were not auto mechanics, so could not figure what caused a previously good running engine to suddenly stop running following an oil change. The problem was simple: the oil change was done using detergent engine oil. That old truck had nothing but non detergent straight-weight oil used in its engine for its entire life prior to the oil change. As my buddy put it, "all the compression went into the oil pan". The carbon deposits and varnish from years of running non-detergent oil had maintained the fits and sealing of the piston rings and probably the valve stems in the guides. Sometimes, when we get into old machinery, we discover that parts have 'worn into' each other and a combination of that kind of wear and sludge or similar kept things running. Once we get the idea to do some repair or rebuild, we open the proverbial can of worms and wind up with a much bigger job that we first planned to do. As for my buddy and the Dodge Jobmaster pickup, I think he got hold of some heavy steam cylinder oil and poured it into each sparkplug hole (this being a flathead 6 engine). The heavy oil sealed the pistons and rings enough to get the engine started. It took a few iterations of starting with steam cylinder oil spritzed into the sparkplug holes to reseal the engine. Not a truck you'd take cross country, but fine for getting firewood or groceries with. Your old drill press sounds like a similar situation. A combination of wear and a buildup of sludge or gunk and no one needing a particularly precise machine tool meant the old drill kept it in use until it got put into storage awaiting your purchase.

 

[todda323]

Thanks for the advice Joe. It was a great conversation. The stories of the past, along with your advice are great. If you don't mind going back to an earlier issue noted a few posts above referencing the play in the quill housing. I would imagine I am left with two options being having the pinch surfaces, upper and lower, inside the quill housing sleeved or going back to hard chroming the quill itself. If sleeves were to be used they would have to be split to make allowance for the piece on the back of the quill that engages the arm that raises/lowers the quill. Is there a way that this could be done securely so the sleeves will not slip if they are split as such?

On another note I found a broken tooth on a gear on the main shaft pulley. This gear drives the back gears. Any opinions on having this repaired or having the entire gear re made? This is not in sequence with the bearing pour, but is a question I would have down the road so why not get it out of the way now.

 

[just Dave]

You can likely get a stock gear that pitch at a bearing house but it will need to be bored to match.