Hi Adam,
Thanks for your detailed response. I was not trying to suggest that POM was really new but new to Lista in this application.
Having seen, sold, installed, and worked on 1000's of Lista cabinets we have some real world experiences with the suspension systems. These are my observations ...
Steel Roller Bearing configuration:
1) The steel roller bearings work great when they are properly cleaned and lubricated.
2) Virtually
nobody ever cleans or lubricates them
3) They wear out primarily due to 2) above. The tracks also wear out as well as the drawers
4) They have been out of production at Lista since July 2007.
5) They were made to specification and are not generally available. We have some in our stock.
6) The drawer design used steel u-channels, a roller tray, and a drawer.
POM Bearing configuration:
1) The Polyoxymethylene (POM) bearing went into production in July 2007
2) The new design was a joint effort with Lista USA, Lista Switzerland, and a company in Austria. The glides are made in Austria.
3) To date, the only failure we have seen was with one of the drawer glide locks. We have seen no other failures or issues with wear.
4) The drawers glide open and closed with ease. I think even easier than good clean, well lubricated steel bearings.
5) The POM bearing are also riveted on. Replacement would be at the glide level, not at the bearing level.
Solutions:
1) If you purchased a brand new Lista cabinet with the POM suspension, it came with a lifetime warranty so replacement of a glide is a non-issue.
2) If you purchased a used Lista cabinet, or one of our Junkyard Specials, contact me if you need a replacement glide. Even though we have not seen a POM bearing failure, we would be happy to provide a no charge replacement.
3) If you have the old steel roller bearing suspension and need repair parts, contact me. We are often able to help out with parts or at least some good advise.
Regards,
Joe
I like Listas cabs and may buy some for my shop. I also like the drawer design. BUT- I'm not 100% comfortable with some of the marketing speak here.
1) POM is not a new material or new technology. Most of us know it by it's brand name DELRIN. It is also called acetal. It is a high density plastic, harder than UHMW, which is a step up from PTFE (Teflon).
2) Acetal is a good bearing material BUT it has a couple issues:
a) It is not best suited to low PV applications (such as high pressure low rotation). Possible it can become flat spotted due to high pressure (i.e. sliding instead of rotating).
b) Acetal is better at other common materials for grit, but grit, metal swarf etc can become embedded in the material and subsequently become sandpaper, wearing out mating components. Once this happens, replacement is the only solution.
To overcome these issues it is important to keep slides clean. I would avoid any coatings or lubricants that can attract dirt or grit (such as greases or heavy oils- better nothing than grease). Yearly maintenance might be a good idea.
Also important is the ability to swap the rollers with new rollers. If Lista is happy to provide them, I would do that. Might even be worth stocking up. Hopefully this will satisfy those who rightly suggest the new design isn't old enough to evaluate.
In general, I would say steel rollers (the old design) would be better over the long term. But the plastic wheels offer a few advantages:
1) They probably feel better, less industrial, with a smoother feel of quality. Acetal does that. It has a nice low friction quality, but isn't "squishy" at all like PTFE.
2) As the wearable item, the POM wheels should be easy and cheap to replace. Replacement wheels should make the drawers feel brand new again whereas the steel rollers will also wear the runners, causing replacement of the entire carriage.