As the title says. Has anyone machined or created a filter cartridge from scratch? I have either plastic or metal cartridges in 2 different purification stacks. I thought my next fun project would be to create reusable, repackable cartridges from stainless tubes. I have access to raw stock, a lathe and mill. My thought was to recreate one of these disposable filter cartridges with a much more robust, reusable and repackable unit. Any thoughts or concerns I need to know before I begin? I have a LF single 27" plastic cartridge on my electric powered 5406 and three 27" tin cartridges on my diesel powered 4S25. I did see a thread about modifying a metal cartridge to a removable cap but thought it would be a fun project to just build a custom one. Can it be steel, brass or aluminum? Any concerns with the construction material and the chemicals packed within?
Yes both the 303 and 316 stainless re pack cartridge tubes and the 7075-T6 hard anodised 4:1 5000 and 6000 psi Aluminium body shells with bottom plug and cap. Also for the MAKO male spigot and the female Bauer base and a few other specials for folk.
The repack assembly I think your describing was done for LF before they sold the company to IR and was manufactured from a 2-1/2" inch diameter stainless stock thin wall tube for the cartridge shell.
The base plug was machined from 2-1/2" stainless solid round bar and the top cap was from aluminium anodised red
Two small countersunk holes opposing each side of the wall of the stainless repack tube located the red top cap with a couple of 10-32 UNF (or 1/4) stainless countersunk hex set screws each side opposing.
The base hole was the gas inlet end a simple female with a undercut groove for and o-ring recess to seal on the filter base spigot
Now the interesting consideration you have was that the stainless cartridge base for LF was undercut to slide into the shell with a face chamfer for orbital welding the pair together. You may consider avoiding this welding procedure as a weld prep is required on both the tube and the base requiring you to machine the tube to length you can't just stick it on the band saw.
In addition the 27 inch length needs also to be bob on as far as angle is concerned welding it banana shape won't wash or fit and neither does scraping the carefully hard anodised internal wall of the filter shell as you ram down the repack cartridge.
In addition for Bauer as they have a 70mm OD filter cartridge (not the same as the LF 2-1/2") you may find thin wall metric stainless tube difficult to get your side of the pond.
Only other point I would suggest is make all the base plug generic and use adaptors for the Robbins.
