Lyman 450 Luber/Sizer Rebuild
A few years ago I acquired a well used Lyman 450 luber/sizer, but for various reasons I didn't start using it until a few months ago. I noticed several problems:
1, The ram was not concentric with the die cavity, being off-center about 0.008" - 0.009". Since I use a "universal" flat nose punch for SWCs it wasn't a real problem but with other nose profiles it created some difficulties.
2. The based leaked lube - badly.
3. Lube also leaked out from around the O-ring under the sizer die retention nut.
After being annoyed long enough, and not wanting to buy a new luber/sizer, I decided to turn up the heat in the machine shop and rebuild it to MY specifications.
After studying the problems, I worked out the following sequence of operations:
1. Machine a flat surface on the base. This would aid in setting up for all future machining operations and would also allow for a flat plate and gasket to be secured in place.
2. Fabricate a baseplate and drill and tap the luber to secure it in place.
3. Flip luber over, line up properly, and bore out ram guide the minimal amount necessary to clean up hole.
4. Cut minimal amount necessary to clean up rough casting surface where the O-ring under the die retention nut meets the luber.
5. Turn down ram the minimal amount necessary to allow for a sufficiently thick-walled bushing.
6. Make a bushing to fit in ram guide and glue in place.
7. As an in-process addition, the crookedly pressed-in lube cavity cap at the base end of the lube cavity was replaced with one of a modified design.
Step 1: Flycut Base
(a). Mounted luber upside down in machine vise, leveled up with flat plate and bubble level on base.
(b). Used a single-tooth flycutter and with a series of 0.015" cuts cleaned up 90%+ of surface.
Notice that the pressed-in lube cavity cap is partially cut. Because the pocket it is mounted in is not square to the base, the cap is crooked. It leaked around the edges and the screw hole.
Step 2: Fabricate Baseplate, Drill and Tap Holes in Luber
(a). A piece of high strength aluminum plate cut from the side of an old hydraulic valve body was milled to about ½" thick. The outline of the base was scribed on it and a series of punch marks was used to highlight the outline.
(b) The extra material and the slots cut away with an endmill, and the outline was sanded smooth on a disk sander.
(c). The base was coated with Dykem, and after determining the best place to put the screw holes perpendicular guidelines were scribed onto the surface. The intersection point was located and the digital readout was used to accurately position the holes, which were drilled and counterbored deeply enough to allow the head of a 10-24 socket head cap screw to be fully recessed.
(d). The baseplate was clamped to the base of the luber, and a transfer punch was used to transfer the hole locations. The plate was removed, and after squaring it up in the drill press vise the tap drill holes were drilled into the luber. Care was taken to control the depth of the holes so they would not break out on the top of the luber.
(e). The baseplate was then clamped to the luber and used as a tap guide.
Step 3: Bore Out Ram Guide.
(a). As an aid to lining up the ram guide to be straight with the die cavity, an alignment rod was turned on the lathe. The rod was first turned down to 0.625", and then one end was turned down to 0.4295". The end was drilled and tapped for a ¼-20 screw.
(b). A 0.430" sizer die was mounted in the luber, and the alignment rod was pulled down in place with a screw from the bottom. A 5/8" collet was put in the milling machine and clamped to the rod. The luber was lowered onto a set of parallels, shimmed in place, and lightly clamped. An indicator was used to check the vertical alignment of two sides of the shaft. After minor shimming under the base, the rod was brought into alignment with the spindle. As a check, the sizer die nut and rod clamp screw were loosened, the sizer die was rotated 180 degrees, and everything was retightened. The indicator was used to recheck alignment, which was within 0.001" in any direction.
(c). A center finder was used to align the spindle with the center of the die cavity. A boring head was used bore out the ram guide hole. The hole was bored out to 0.840"
Step 4: Cut O-ring Face
(a). The sizer die and retention nut were removed, and the face of the casting around hole was machined off just enough to square the face up and make it smooth. This would keep the O-ring from getting chewed up and help the retention nut start square in the hole. This is important with the fine threads used here.
Step 5: Turn Down Ram
(a). The ram was turned down to 0.700" diameter for enough length to allow for a full ram stroke.
Step 6: Make Bushing and Glue in Place
(a) A 13" long piece of oil-impregnated powdered metal bronze bushing material with a 1" OD and a 5/8" ID was purchased from Enco. A bushing with a 0.839" OD and 0.701" ID was turned on the lathe. The center section of the OD was cut down to a 0.015" smaller diameter to allow for glue space.
(b). JB Weld was used to glue the bushing in place.
Step 7: Make New Lube Cavity Plug
(a). To create square face on the luber to mount the lube cavity plug against, an aluminum post with an OD sized to fit the luber cavity was turned on the lathe and one end was drilled and tapped for a ½-13 screw. The post was screwed down to the milling machine table and after removing the lube cavity plug the luber was mounted on top of it and clamped down. A light flycut was taken to square up the base. No more than 0.005" was removed.
(b). The cavity was centered up using the center finder and a counterbore was cut in the face to square it up. Note that there is still just a little bit of orange paint showing as a "witness" to minimal material removal.
(c). A new plug was turned on the lathe. The old plug had an O-ring on the inside which didn't seal properly because it was mounted crookedly. The new plug had an O-ring groove machined in the face, to seal against the baseplate.
(d). The plug was then glued in place with JB Weld.
A picture is worth a thousand words.
After reassembling the luber and doing a little hand fitting, all the moving parts were given a good coat of lithium grease. A 0.358" sizer die was inserted and over 800 Lyman 358429 bullets were sized and lubed, effectively breaking in the unit. The ram is centered perfectly with the bore (or close enough not to matter) and the leaks are gone. The unit operates smoothly and well. I am satisfied with the end product and feel that the trouble was worth it.