Introduction: Replacement Machinist Chest Drawer Pull
In a previous instructable, I described a number of common repairs needed on used Kennedy machinist chests. I was asked on another forum about the drawer pulls, so this covers the installation of user-made pulls.
The details will change for a different make or model chest, and the models I used may not fit, but the principle is the same. The demonstration is replacing a stock pull with a longer one on the drawer above the one already repaired so they match. The prior repair used an odd hole pattern to match the existing extra holes. This time, as the only holes at the start are the factory holes, so they are all aligned.
It turned out that the longer pull is a lot nicer to use on the wide drawers, and this will let me decide whether to do the same on some other chests.
The pull was modeled in Fusion, as was the drill and tap jig. Before starting the install, the jig and as many pulls as needed should be produced via whatever method desired. Mine are 3-D printed using PLA. They pulls can wait to be finished (smoothed and painted) until the other work is done if you are worried about scratching them up.
As these are long, and they are subject to a fair bit of pull, the screws are spread out, and the ones at the end are as close to the end as practical so when the end gets tugged on, there isn't a tendency to separate from the drawer face.
3-D printed pull(s) (STL attached for Kennedy top chests)
3-D printed drill and tap jig (STL attached to match pull)
(4) #6 machine screws/pull
(2) #6 nuts for fitup
(2) #6 screws long enough to fit the template- these are longer than the mounting screws, but may be cut to use for mounting
#6 plug and bottoming taps
Tap and clearance drill bits (US gauge size #36 and #28 respectively-- 2.7mm and 3.6mm)
Drill motor, tap wrench, screwdriver, etc, as needed
Step 1: Setting Up to Drill the New Holes
The drawer lining should be carefully peeled back where the work will be done if it is being preserved, and if the original pull is still present, it should be removed. The Kennedy pulls can be removed by drilling the rivet head.
Once the area is prepared, the jig needs to be mounted. The inner holes match the existing holes on the drawer face, and #6 screws will hold it in place to mark the new, outer, holes.
The jig should be produced on the same device, and in the same orientation, as the pull(s) so the holes are the best match. Check to be sure the existing holes in the drawer match the jig, and adjust and reprint if they do not.
Jiggle the jig around as the screws are snugged to get it lined up on center vertically and horizontally. After the screws are snugged, check for level. I used a small square, but any number of other means can be used (dividers, hermaphrodite caliper, vernier or dial caliper, depth micrometer, CMM, or a carefully calibrated eyeball).
Step 2: Marking and Drilling
The clearance drill is the same size as the jig holes, give or take tolerance of the 3-D printer. It is used to mark the drawer face for drilling. No need to drill through with the jig, and it will make a mess if you try. Just leave a center mark with moderate pressure and a few revolutions of the bit. The mark only needs to be sufficient to locate the bit tip when the hole is drilled. A transfer center punch can also be used, but it needs to be the correct size, or the hole will need to be drilled oversize to let the screws line up.
Once the drawer face is marked, the jig can be removed and the holes drilled. The hole size is really not that critical, and for a #6 screw, a unibit could be used to get 9/64 or 5/32".
After drilling, deburr the holes. Always deburr. Always. You can use a countersink tool, a larger drill bit, a specialized deburring tool, sandpaper, whatever works. But always deburr.
Step 3: Putting the Threads in the New Pull
Now, we use the drill and tap jig to help thread the holes straight.
Threading plastics can be a challenge, FDM 3-D printed parts being about the worst. The jig helps keep the tap straight and helps locate the tap so the holes will line up.
Since my pull was already painted (sandable primer and Kennedy brown paint), I padded with some kraft paper. The jig is lightly clamped to the pull and the plug tap (about five threads are tapered at the start) is inserted to locate it exactly. The jig keeps the tap straight. Rotate the tap clockwise while pushing axially to cut the threads. After the plug tap reaches the bottom- you will feel it , but be careful, as it is easy to strip the threads or push through- thread it back out, blow the chips from the hole, run it in again to be sure that it really reached bottom, remove, blow out chips, and follow with the bottoming tap. This will get the threads complete as close to the bottom as is practical. Take care to keep the taps straight. The jig helps, but you still need to look.
To insure the holes are all aligned, a screw is used to keep the jig lined with the first hole as the others are tapped. Snug the screw, then the tap is used to properly line up another hole, and the clamp is snugged to hold everything aligned. Then the three remaining holes are tapped.
When tapping, be VERY careful to feel for the bottom of the hole. If you go too deep, you will first raise a pimple on the face of the pull. A small one sands off during finishing. Go further, and you will pop through.
Step 4: Cutting the Screws
If the screws are not the correct length- they should be long enough to go through the drawer front and engage about five threads in the pull, if it is tapped to the bottom- they should be cut down. I used a screw cutter that is part of an electrical terminal crimp tool. After cutting, be sure the threads are good at the lead end, or the plastic pull will be damaged.
To get the length repeatable, I run the screw until the head touches the face of the cutter, then back it out the correct number of turns. The first one is a guess, but when checked against the pull, adjustment can be made. My trial screw was about 1-1/2 threads too long, so that told me how much less to back them out for the correct length.
Step 5: Mount the Pull
Be careful putting in the screws. They are going into plastic. Don't tighten any until they are all started straight.
I put in the end screws first, then the two in the middle are easy.
Snug them up, tape or glue the lining back in place, and done!