Monday, December 2, 2013

A Shopmate Model 748B 3/8" Portable Drill Teardown

This is an old-timer. It predates variable speed, and it's not reversible. It's either off, or it's on full-bore clockwise -- that's it.

The drill was made by PET U.S.A. for sale in Canada via Portable Electric Tools (Canada) Ltd. Here's a view of the drill's I.D. plate that's on top.

Portable Electric Tools is no more. There are some brief notes about the firm here.

This drill runs, but it's probably about time it got some TLC, and fresh grease in its gearbox. I'll tear it down completely and tend to it.

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1) Chuck

The chuck is a Supreme H13A. The chucks on non-reversible small drills typically just thread onto a 38"-24 spindle in the conventional manner. To remove one, insert the chuck key's pilot into one of the holes, and give the chuck key's shank a sharp, forceful rap with a hammer in the rotation direction. The chuck will loosen, and can then be fully unscrewed.

I'll set that chuck to soak in the parts washer; it has a bit of a grungy feel to its action.

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2) The Right Side Casing Half

- Two 8-32 x 1 1/4" screws at the front.
- Three 8-32 x 3/4" screws at the rear.
- The casing half just lifts away, bringing you to here.

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3) The Switch w/Line Cord

NOTE: The wiring in any motor can be a real headache come reassembly time. There's seldom much space to accommodate it, and it often must be run/lain in a very particular way. It's a good practice to sketch or photograph the wiring before dismantling any motor.

This machine is not too bad for wiring difficulty; some are much worse -- beware.

This switch employs 'poke home' type wiring connections. Inserting the shank of a 1/16" twist drill in the opening alongside a wire will back off the wire's retention tang and free it.

This switch's wiring is about as simple as it ever gets. Reversible drills' switch connections can be bewildering -- a sketch made before disconnecting anything is strongly advised.

I'll give the switch a good shot of WD-40 -- switches like that stuff. That incoming line cord wiring is in dreadful condition; I'll deal with that later.

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4) The Brushes

The brush caps unscrew for brush removal.

It's not essential, but it's a good practice to scribe brushes with their position and orientation as you're removing them. I've scribed these brushes 'UR' (Upper Right) and 'LR' (Lower Right). Maintaining brush position and orientation minimizes brush wear -- the brushes go back into service seated exactly as they were.

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5) The Motor's Field And Armature

- Four 4-40 x 5/16" pan head screws to free the bronze bearing retainers.
- The item just lifts out. NOTE that there is a semicircular oil wick tucked away under the rear bearing. Remove it.
- As with brushes, it's a good practice to scribe bearings so they can go back in place after cleaning exactly as they were.
- NOTE the presence of thrust washers. You'll want to be certain of getting any and all thrust washers back in place exactly as they were. Here's a view of the field and armature out of the drill.

And that's as far as I'm going. Here's a closer view of the gear-train that I'm not going to attempt to dismantle.

I'm unsure of how that comes apart, and I can't risk damaging anything with ignorant tinkering.

I'll dig out the sludgy old grease, and flush the gearbox as well as I can. I'll give any bronze bearings plenty of oil afterward to replenish what the parts washer solvent might deplete. Then I can pack in fresh grease.

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The Gear-Train As Good As It's Gonna Get

Here's the gear-train after much flushing and digging and brushing and compressed-air blowing.

I'll start giving the bronze bearings plenty of oil, well before I repack the gearbox with grease.[1]

Next up is to clean all the remaining components, and burnish the commutator. I'll deal with the shabby input wiring, repack the gearbox and reassemble the tool.

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Nearly Done

Here's a view of the machine about to have its right side cover reinstalled.

The commutator is marginal. I suspect it's been turned down at least once in the past. It's very nearly at the point where its mica ought to be undercut.

I couldn't save the original line cord strain relief, so I went with a conventional grommet with a ty-wrap to take tugging forces.

- - -

All Done, Almost

Here's the finished drill.

It has a leashed chuck key, per my usual method, and it runs beautifully.

The only thing missing is a screw-in side handle. The drill has 14"-20 provision for a handle at either side, but the original handle is long gone. I'll have to fabricate one.

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A Screw-In Side Handle

A pleasant bit of wood turning got me a handle. Here's what I started with.

And here's what I ended up with.

And here's a view of the handle installed on the drill.

Just the thing for drilling holes in concrete when the drill has no 'hammer' feature -- you can really lean on the thing.

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[1] The grease I use for gearboxes like this one is Canadian Tire's No. 28-0422-2 Wheel bearing & Chassis Lubricant. Similar products are no doubt available everywhere.

For all that I really know about grease lubricants, there may well be a better grease for the purpose. A local warranty repair shop for any of the major toolmakers might be a good place to ask.

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Sunday, November 24, 2013

A Cummins Fixmaster 1/4" Drill Teardown

[NOTE: This post got truncated by a Blogger mishap, and I didn't have it in me to try to recreate the lost material. The information here is sound as far as it goes.]

I brought this over from the garage. I thought I'd tear it down and clean it up and pack the gearbox with fresh grease. When I'm done, I'll make a place for it in the workshop where it can be at-the-ready. If nothing else, I'll have a very nice drill handy for light work. Here goes.

1) The Brushes

A neat feature of this drill is the externally accessible brushes. And they don't look too far gone at all.

2) The Handle Left Side Cover

- Remove the two small screws that secure the slide switch. NOTE that these screws are an uncommon size; I think they're 3-48 -- not a likely hardware store item. Should they ever be lost, you'd probably have to drill and tap the switch frame to accept 4-40 screws.
- Two 8-32 x 5/8" oval head threading screws.
- There's a little triangular projection near the top front of the handle cover that makes removing the cover a bit of a 'wiggle-and-jiggle' exercise.

3) Gearbox

- Two 10-24 x 3" plain slot filister head screws.
- NOTE the thrust washer that's loose on the motor's output shaft at this point.
- NOTE that the circular I.D. plate can come away now.

This is a drill gearbox architecture I've not seen before -- there's a plate enclosing the reduction gearing chamber that carries the front motor bearing

4) The Chuck

The chuck is a wonder. It's tightened by means of a cam that you turn with a 5/32" hex key. Here's a view of the chuck taken apart.

The cam is that shouldered pin affair at the lower left of the photo. Note the barely visible dot on its end, and the red dot on the base of the chuck. On the base of the chuck it says, "ALIGN DOTS. ADJUST SLEEVE. LOCK WITH KEY."

Aligning the dots sets the cam to where it least extends that round plunger to the right of the chuck's base. At that point, you  snug up the chuck's sleeve by hand, then you turn the key in the cam to force the plunger up against the ends of the chuck's jaws. That's the action that securely tightens the chuck.

* * *


 I'm not even going to try to re-create it. 'Sorry, but I'm going to truncate this post and call it a loss.

- - -

Anyway, I did carry on and complete the cleanup and re-lubrication of the drill, plus I replaced its shabby power plug. It runs beautifully.

I also modified the chuck key for better comfort and leverage, and added a chuck key leash per my usual method. Here's a view of the drill with its chuck key leash.

Now I have a portable drill that's about the same age as I am. (From what I can find, these date from the early 1950s; I was born in '51.)

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Thursday, November 21, 2013

A Pants Hanger Gone South

Nothing is really 'broken', it's just that the prongs of the hook/clamp affair came out of one of the hardwood jaws.

I'll put it back together with CA adhesive, but I'll add a little touch that will make the glue-join even more secure. I'll file a few shallow notches in the prongs, to give the adhesive some 'tooth', like so.

Here's the hanger reassembled with CA adhesive.

That should stay together approximately forever.

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P205/75R14 Spare Tire -- 1999 Ford Ranger

Back when I bought my '99 Ford Ranger new, I got the base offering -- no optional extras whatsoever aside from the long box. I thought, "There. I've got one of the commonest, easiest-to-maintain vehicles on earth. What can go wrong?"

Well, what went wrong is that 14" wheel rims became obsolete. You may as well go shopping for new wheels for your Roman chariot as try to obtain a replacement for a 14" rim on a Ranger; 14" rims cannot be had, except for the odd one on Ebay.

"Why do you need a wheel rim?", you may be wondering. I need a wheel rim because the spare tire's rim is a rusted ruin. The Ranger's spare tire lives outside beneath the box. After a decade of that treatment, the rim looks like something that's spent a decade under a pickup truck's box, in a climate that features salty slush on the roads for a good part of each year. Here's a view of what I'm left with.

Air-tightness at the tire's beads is not on; the thing had multiple bead leaks on both sides.

The least costly solution I can think of is to install an inner tube -- those can still be had; my son is getting me one from an internet outlet in the U.S.A.. We'll see how this goes.

I'll update this post as I go along.

- - -

It's Here -- MONDAY, DECEMBER 9, 2013

The inner tube finally arrived -- standard parcel mail service across the border takes its own sweet time

Anyway, the tube came folded up in a USPS 'PRIORITY MAIL' box -- there was no manufacturer's packaging. On the tube is printed,


The tube looks to be quite substantial; it looks like it ought to hold air.

I take it that the "GR-13/14/15" indicates that the tube will fit 13, 14 or 15 inch tires -- it's quite the versatile item.

Later today I'll take it to Dan's garage, along with the tire and rim, for them to install the tube. We'll see how this goes.

- - -

All Done

The tube fits and works. Yeehah!

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Saturday, October 19, 2013

A Broken Wing Screw

I went to take a photograph of something on my workbench with the aid of my mini-tripod, and something didn't feel quite right as I tightened the little wing screw that secures the head of the tripod. It turns out there was a good reason for that.

The plastic wing affair broke. Here's a view of the screw removed and on its own.

Piece of junk.

I'll have to get the remnants of the wing off the screw however I can, and see if I have a wing nut that will fit that I can glue on for a replacement wing.

- - -

Here's a method for clamping a screw thread in a vise without marring the thread.

Cut through one side of a hex nut, and use that as a primitive 'collet' to grip the thread in a vise, like so.

Now I can get pliers onto that wing remnant and crank it off the screw.

- - -

That worked fine, but my 'collet' didn't want to unscrew easily after having been clamped onto the screw in the vise. I hammered a chisel tip into its saw cut gently to persuade it to open up a bit, and it unscrewed. The chisel's tip never reached the screw's thread, so no harm was done.

- - -

I happen to have exactly one M5 wing nut in my stash of M5 stuff. Here, I've attached it to the screw using CA adhesive as a threadlocker.

Back in business.

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Recapping Tubes Of Sealants

Don't let this happen to you.

That's what happens when you over tighten a tube's cap. It's not helpful.

The temptation to over tighten is great; after all, you don't want the material to harden in the tube. Resist the temptation, though. Just snug down the cap and leave it at that. Further tightening past the point of closure only leads to the pictured result.

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Tuesday, October 8, 2013

Ryobi 10" Table Saw (BTS12S) -- Tilt ('Bevel') Mechanism

I was given a broken down old BTS12S that I've been restoring to working order. I've got the saw running, but there's a curious problem with the 'bevel'/tilt[1] mechanism. Permit me to back up a little, and describe the whole elevation/tilt operation of the machine.

On the BTS12S, a single handwheel operates both blade elevation and blade tilt. The default position of the handwheel is for it to engage the elevation screw. Pushing the handwheel in against a spring disengages it from the elevation screw, and engages a rack-and-pinion gear set that operates the tilt function. The problem I have with the machine is that the rack-and-pinion gear teeth barely engage one another deeply enough to work -- the teeth mostly just skip to no effect. I can see no adjustment to improve the gear teeth engagement. Here's a view of what I've just been on about.

Everything about the mechanism appears to be factory-issue, which says that the tilt function on this saw has never worked, right from day one. That likely wouldn't have mattered to the guy who gave me the saw, because he was only using the saw to cut up shipping pallets into firewood. Regardless, whether I keep this saw or give it to someone, I'd like for the tilt function to work as it ought to.

From what I can see so far, it looks to me like the elevation screw emerges at the front of the saw too low down for the rack-and-pinion gear set to ever engage properly. I need to see if there's a way I can alter that, without fouling up the elevation function.

- - -

Here's a view of the front of the saw upside down with the handwheel and elevation screw removed.

Note the position of the large washer just inside the tilt slot where the elevation screw emerges -- it's not centred, it's almost as far away as possible from the rack. It's beginning to look to me like Ryobi got a dimension wrong, and may have made many of these saws with this same defect.

I've removed the washers and spring that are immediately behind the tilt slot, to get a direct view of the hole in the tilt carriage that the elevation screw emerges from. Here's a shot of that.

The photograph shows it poorly because of a shadow, but that hole is way too far from the rack for the elevation handwheel's pinion to ever engage the rack fully.

I'll try elongating that hole in the direction of the rack, so that the elevation screw can be manually forced toward the rack when the tilt function is engaged.

- - -

Well, the job I did of elongating the hole with a hand grinder is not pretty, but it did yield the outcome I was after; it's now possible to force the rack-and-pinion to engage fully. The tilt function is operable throughout its entire range.


I'm normally disinclined to condemn a piece of engineering, I know that there are many compromises that must be made, but for this tilt mechanism I'll go right ahead and condemn. The tilt mechanism is, in a word, shabby. It never should have left the factory. What respect I ever may have had for Ryobi has taken a nosedive with this little exercise. I consider such marginality in a mass-produced, low tech piece of gear to be inexcusable.

If you're shopping for a legitimate woodworking machine for cabinet making and the like, steer clear. If you're looking for a firewood cutter, the Ryobi will serve. That's the class it's in, after all.

- - -


[1] Ryobi insists on referring to 'tilt' as 'bevel'. Tilt and bevel are not the same thing; bevel is an effect, tilt is a cause. Setting the blade's angle to something other than ninety degrees via the tilt mechanism bevels nothing -- it merely tilts the blade. Cutting wood with the blade tilted results in a bevel.

It appears that Ryobi's grasp of English is as marginal as its tilt mechanism.

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Friday, October 4, 2013

A Light Switch Failure -- Or -- Some Things Just Aren't Repairable

I had a light bulb socket with a built-in push-button switch become troublesome, so I took the thing apart to see what the problem was. Here's a view of the switch's innards in the 'off' position.

The spring-loaded contact-closure bar is flipped over to the right, well away from the two curved springy contacts; the switch is 'open'.

And here's a view of the 'on' position.

The contact-closure bar is flipped over to the left, where it's firmly shorting the two springy contacts together; the switch is 'closed'.

The mechanism is working as it should, but there's a problem that the above two photos don't reveal. The lower one of the two springy contacts is quite worn out, like so.

(My camera is barely capable of getting a grip on an object so tiny. The above is the best I could do.)

The contact has been impacted by the closure bar so often that a notch has been worn clear through it. The switch is finished.

So, it's off to the landfill for this switch. Some things just aren't repairable.

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Thursday, October 3, 2013

A Wooden Frame For A Small Parts Carousel

* * *

[Note: Rouge River Workshop's author is and has been having a spot of mid-life crisis. Between a prolonged illness, and lay-off from employment back in May of this year, life has left a bit to be desired lately.

Anyway, I'm on the mend now, and have a great deal of catching up to do on many fronts. My blogging here is going to suffer for awhile because of that. This post is much abbreviated from what I would normally present. 'Abbreviation' is likely to be a feature of much of what little I'm able to post for the near future.]

* * *

I brought this item over from the garage.

If you read the linked post, you'll have gotten the introduction to this brief post. What it boils down to is that I have to fabricate a wooden frame for the carousel, to substitute for the original steel frame that's gone missing. Here goes.

- - -

The Frame

Here's a view of what I've come up with for a frame.

The carousel fits easily between the two side frame members, which raises the problem of bearings that can 'reach in' to support the carousel. Here are the bits and pieces I came up with to deal with that issue.

The threaded rod pieces are 1/2"-13, with a 5/8" deep, 5/16" diameter bore at one end -- those are my adjustable bearings that do the 'reaching in'. The rest of the stuff is to assure secure bearing retention in the frame -- the bearings mustn't be free to 'walk' out.

Here's a view of a completed bearing assembly from the outside.

Inboard, the bearing relates to the carousel like so.

So far, so good. Now I have to find a place to install the thing.

My workshop's wall space, and overhead space, are pretty much taken up with stuff already. When I find a place for the carousel, I'll be back with a photo of it. Meanwhile, at least I've got a satisfactory replacement frame to take the place of the missing one. This carousel is something I rememeber from early boyhood, so I couldn't just let it languish in the attic. It pleases me greatly to have the use of it.

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Installed -- FRIDAY, OCTOBER 4, 2013

As promised, here's a view of the installed carousel.

That's the headstock end of my metal lathe's bench that the carousel is now attached to. All things considered, that's not a bad place for it.

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Saturday, September 21, 2013

Why One Can Never Be Too Careful

I'm restoring an elderly 6" bench grinder, and I wanted to confirm the rotation direction of the 1/3 hp motor I have for it. When I switched on the motor, it started up, let out a huge CRACK!! and flash of light and tripped the breaker. Hmmm.

The motor had been checked out long ago by someone of my acquaintance, and should have been ok. I opened up the motor to inspect the internal wiring and found this.

Note the red wire at the centre of the photograph. Its insulation is gone in a spot right down to bare copper. The wire had been getting whacked by the nearby fins of the rotor until its insulation had worn through. I think I know how this came about, and what caused it.

First off, there is no such thing as a limp copper wire -- they all have some 'springiness' to them. When the motor was last opened up and reassembled, the red wire had not been absolutely, positively tucked away where it couldn't possibly come in contact with the rotor's fins. The red wire had been tucked away alright, but not away enough. On first testing the motor, all had seemed well but, in time, the wire's springiness caused the wire to move toward the rotor, eventually contacting it and resulting in the incident I experienced.

Anyway, I cut and spliced and insulated the damaged wire. Here's a view of that.

When I reassemble the motor, I'll make good and sure that that wire is tucked away safely and 'tamed' -- I don't need any repeat performances of the arcing, breaker-tripping incident.

- - -

I ended up adding a ty-wrap, just to be safe. The other wires all lie away from the rotor nicely, but the red wire wants to travel. The ty-wrap takes care of that tendency.

And here's a view of the motor completed and running, happily turning in the direction I need it to.

That was a great illustration of how a tiny oversight can have dire consequences. It pays to pay attention, and leave nothing to chance.

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Spray Paint Can Nozzle Maintenance

On a can of Tremclad yellow in my possession, it says, "Clean valve immediately after use by inverting can and pressing valve until free of material."

I've never had much faith in that procedure. For some weeks now, I've been using a different method to keep nozzles clear, and it's been working reliably. Here's what I do:

  • Immediately upon completion of spray painting, take off the can's nozzle and immerse it in lacquer thinner. Leave it there awhile while other things are attended to.
  • On returning to the immersed nozzle, take it out and blow compressed air in its face, so the nozzle gets a backwards burst of air through it.
Doing the above has put an end to clogged nozzles around here.

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I save known-good nozzles, so as to have spares right at hand.

I've occasionally had the experience of having a good nozzle clog on me while painting something, and it's a real nuisance. (I imagine that paint cans sometimes have particulate contaminants in them that can clog a nozzle.) With a good, spare nozzle handy, such an incident is easily gotten past.

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Tuesday, September 17, 2013

A Furnace Chain Chuck Key Leash

I have an old Craftsman portable drill whose plastic chuck key leash took retirement long ago. The leash had been retaining the style of chuck key shown below.

Ever since, I've been carefully keeping track of the loose chuck key. I got tired of doing that, and decided it was high time that the drill and the chuck key were reattached to one another; hence, this post.

- - -

While casting about for a way to fabricate a chuck key leash, it dawned on me that furnace chain might be a good thing to make a 'leash' from. Here's the method of making a chuck key leash I came up with:

- - -

First off, the key's T-bar is an interference fit in the key's shank; hammer it out.

Next up is to fashion a short sleeve that will fit over the key's shank, and provide an anchoring point for one end of a short length of furnace chain.

I happened to have on hand some 3/8" O.D. steel tubing with a 5/16" I.D. A 13/16" length of that is what I needed.

The tubing was a little too snug-fitting on the key's shank, so I bored out the tube to 21/64" diameter for a depth of 7/16" at one end. Six millimetres from the bored end of the tube, I drilled the tube through 11/64" diameter. That hole is for the T-bar to go through to retain the tube.

Five millimetres from the other end of the tube, I drilled through No. 43, then drilled through one side only 7/64".[1] I tapped the remaining No. 43 hole 4-40. Here's what I have so far, along with what's needed for completion.

The ty-wrap is 3 3/4" long. The furnace chain is longer than it needs to be; I'll shorten it to about 4 1/4". The 4-40 screw is just over 3/8" long.

And here it all is fully assembled and installed.

I installed the 4-40 screw using CA adhesive as a threadlocker. This should be a durable chuck key leash.

Anyway, I have a leashed chuck key again. Chuck keys, I discovered, like to wander and play hide 'n' seek. It gets annoying. That's why chuck keys are kept leashed.

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A Fly In The Ointment -- WEDNESDAY, SEPTEMBER 18, 2013

I noticed something that I didn't care for about the behaviour of the chain. (I should have seen it coming.)

One twists the chuck key in order to tighten a chuck. That, in turn, twists the chain. Furnace chain has very little twist in it before it does this.

It;s no big deal. It really doesn't detract from the chain's fitness for its job, but it irritates me. (Note that the same effect is operative for a plastic or rubber leash, but a plastic or rubber leash will untwist itself -- a chain won't.)

So, here's a little refinement to eliminate the problem.

I've added a snap swivel right at the cord. That lets me use a more substantial ty-wrap, and it should do away with the twisty/kinky nonsense

I'll see how this works out as I continue to.use the drill.

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Addendum -- WEDNESDAY, SEPTEMBER 25, 2013

The snap swivel works nicely; it renders the leash completely nuisance-free, so I ended up liking that leash for the Craftsman drill so much that I made one for my Bosch hammer drill.

Fastening the chain to the chuck key was much easier here. I filed a flat on the end of the T-bar, and drilled and tapped it M3 .

With CA adhesive applied as a threadlocker, I ran in an m3x8mm screw until it would just allow the chain link to pivot freely.[2]

The snap swivel makes the key easily detachable, and that could be a good thing at times

Years ago, while building some furniture, I noticed that a dangling, swinging chuck key can strike a work's surface and leave a tiny dent. Were one to be working on something that oughtn't be struck, one could detach the key until the delicate work was over with.

Anyway, I'm back to having conveniently leashed chuck keys, on leashes that will never stiffen and crack with age.


[1] 7/64" is not quite clearance diameter for a No. 4 screw -- it's sort of an Interference/clearance diameter. 1/8" is clearance diameter. I went with 7/64'" to obtain the strongest possible screw/clearance-hole interface.

[2] M3 is a little too large to fit freely through the eye of a furnace chain link. Use a taper punch to widen the eye's opening, and an M3 screw then fits fine.

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