The aluminum box is made of two welded 6061 or 6063 L angles. Internal dimensions have small tolerances and must be held in order to fit exactly to the plastic detector frames. First, it's necessary to machine a solid steel, cooper or brass block to that dimensions. Then, the L angles will be trimmed and welded togheter around the block. To release the box from the block it may be necessary to hit the box sides and corners with a plastic hammer but do not deform the box. After welding it can be milled to achieve the external dimensions with the block still inside the box. After that, the borders must be chanfered and the two square windows opned. Remove the block and drill the four lateral holes.
The tube is made from commercial 3 1/2" IPS Sch. 40 6061 aluminum pipe. External dimensions have small tolerances and must be held. Internal dimension is the nominal I.D. and is not critical. The two lateral openings must be done before making the external finish. It may be necessary to plug the tube end with a round Nylon or aluminum to maintain the center with the thin wall. Do not drill the four seting holes yet.
The lid1 is made fom .190" thk. 6061 aluminum flat sheet. Machine the disk, mark all the holes circle and drill the more external eigth holes only.
The collar is made from 1 1/2" thk. x 6" 6061 aluminum rectangle. Machine the collar holding the internal tolerances. The tube end must slide freely by hand into the collar but with no lateral play.
Lid and collar can have some interference. With lid and collar togheter, drill the others eight holes on both parts.
Drill and tap all collar holes.
The cilinders 1 and 2 are made from 8" IPS Sch. 80 6061 aluminum pipe. This pipe provides enough material to get a good circularity and center after the machine process.
Machine the cilinder 1 to get inside and outside dimensions. Note the tapered end and hold tolerances.
Open the internal groove.
Drill the seven lateral holes.
Attach the lid to the collar and carefully position the lid on the cilinder end. Drill and tap the holes on the cilinder end.
Machine the cilinder 2 to get inside and outside dimensions. Note the tapered end and hold tolerances.
The two cilinders must fit togheter easily by hand without any ply at the end.
Open the small lateral notch.
The ring is made from the same 8" IPS pipe. Machine the pipe to get the internal and external dimensions as is in the drawing for the relaxed condition.
Cut the ring from the machined pipe. Hold the width tolerance.
Open (cut a piece of) the ring as is in the drawing for the relaxed condition.
Drill the two lateral holes near the extremity.
Squeeze the ring using the two holes, two pins and a plier. Be carefull with the spring action of the ring. It's a hazard.
Fit the squeezed ring inside the cilinder 1 groove with the opening oriented as is in the drawing and let it expand in place.
Drill and tap the hole thru the ring using the hole previously drilled on the cilinder as a reference.
Attach the ring with the screw.
Do not drill the other holes yet.
Machine, drill and tap the three rectangular blocks as is in the drawing and attach to the cilinder inside wall using six screws.
Adjust the block to touch the ring.
The plates are made from .190', .125" and .125" thk. 6061 aluminum flat sheet.
Plate1: Machine the square holes around the center pilot hole. Hold tolerances.
Drill the three 5/16" holes. Note the position angle values.
Drill all the other small holes.
Machine the outside circle (larger diameter). Hold tolerance. The plate must slide freely inside the cilinder 1, by hand, without lateral ply until the stop ring.
Open the central hole holding tolerance.
Position the Plate 1 inside cilinder 1, then drill and tap all holes on the ring side.
Plate 2: Machine the square holes around the center pilot hole. Hold tolerances.
Drill the three 25/64" holes. Note the position angle values.
Drill all the other small holes.
Tap the assigned holes. The tap tool must be very perpendicular to the plate.
Plate 3: Machine the square holes around the center pilot hole. Hold tolerances.
Drill the three 13/32" holes. Note the position angle values.
Drill all the other small holes.
This plate must move freely inside the cilinder 2. There is some lateral play .
It's made from .090" thk. 6061 aluminum flat sheet. You can drill a central pilot hole and you can leave it open.
Drill the three 5/16" holes. Note the position angle values.
Drill all the other holes.
Machine the outside circle.
Position the lid on the cilinder 2. Drill and tap the holes on cilinder 2 end.