Thread: drawer slides again - quality of operation

Damian, last night I bought two sets of Accuride 550mm full extensions from the big green box ($35.39ea) to replace the broken blum units in our very large saucepan kitchen drawer. I have now installed both (4 slides) on the one big drawer 570 x 600 x 500.

My experience is that ball bearings set in plastic carriages are not worth the hassle, try to get some set in a proper race.

Originally Posted by Groggy

My experience is that ball bearings set in plastic carriages are not worth the hassle, try to get some set in a proper race.

Are the ones on ebay in the plastic carraige of which you speak ? I'm not sure I understand which part your talking about. I thought most of these full extension slides were all steel ?

I wasn't going to buy the euro style ones wiht the plastic wheels. Not strong enough and too floppy.

By the way if you are going to load your drawer above the usual 45 kg you can install two pairs one above the other as suggested here:

Build a Deluxe Tool Storage Cabinet | Extreme How To, DIY - Do it Yourself, Home Improvement, Home Decorating

to get a higher load capacity.

I'd dissagree, the drawer will work on one roller set till it fails then use its other unused set, in terms of its load bearing capacity. In practicle terms what your suggesting is like stacking two cars on top of another and saying you now have twice the carrying capacity...its not quite the same as slides these days are different than just simple wheels and runners but you get the idea.

I think the second set is used much more specifically for allignment / captivity and anti wracking in a much deeper drawer in and at full extension.

very nice toolchest freebie article (although its all about selling his router guide) its still a neat article.

i think if you should buy the load bearing runners you'll expect to need, even if it costs more, even over engineering it, the old "if its worth doing, its worth doing right" thing.

thats my 2c.

Neal.

The thin inner slide often has plastic inserts, these break and the drawer then is next to useless.

Well, I suppose it depends. The drawer runners are loaded in shear. If the load is transmitted through both simultaneously then the shear capacity is signifigantly higher.

A better analogy is bolting two plates together using 3 bolts of a given diameter or 6, then loading them in shear..

If, as you say, all the load is carried initially on one slide then it'll deform until the second takes up, but unless the misalignment in the second slide is high it'll take up before the first ultimately fails. Even if the first exceeds it's yield strength it'll have some residual strength to contribute. Steel isn't a rigid material, like say glass for example. One of the reasons I ahve so terrible much trouble with wood

All the runners I'm looking at have about a 45 kg rating which is a lot more than I need, I just thought I'd reference the article because I'd seen so many posts during my search about load capacities. And like you I thought while it's an add it's not a bad project and it's free

Anyway thank you both for the followups.

Yeah you got the gist of what i was saying, even if the analogy wasn't perfectly accurate, and you've certainly looked into it more than i would have.

I tend to bring those kind of issues back into the simpler way of doing things, how were the old wood to wood slides done etc.

Neal.

Originally Posted by Groggy

The thin inner slide often has plastic inserts, these break and the drawer then is next to useless.

Right, got it, thanks.

We are using Grass full extensions as standard fitment for kitchens at work, with options for other brands/styles at extra cost.

The issue with load sharing stacked runners is getting the component positioning spot on on the carcase and drawer box. We cut and drill both on a CNC, and can be sure where we put the holes, but there is some room for adjustment on both slide components. Duplicate the slides and there could easily be half a mil variation, meaning that one slide does the work until the it has deflected by the variation. Yes overall it will hold more, but quite likely not double the ultimate capacity of a singe set of slides.

As an analogy to the plates bolted in shear concept, consider the situation with random mismatch of the bolt and hole diameters or position, versus tolerance matched bolts and holes accurately positioned. Ultimately one bolt will take more than its nominal share of the load and tend toward failure, at which time the next most critical set will be called upon to carry the load.

Good Morning Damian

Last year I built some drawer units containing 18 drawers and deliberately used four different drawer runners to test them side by side. I posted my views a couple of weeks ago:
Cabinet Drawer Slides - Woodwork Forums

The Hettich ball bearing runners at $15+ per pair are incredible value for money; nothing else that I could find under $40 even came close to matching their quality.

The only advantage that the other three have is the soft close feature - SWMBO says the price differential is justified.

I would be more inclined to buy higher rated runners than trying to fit two pairs to a drawer - this probably reflects my capacity to stuff things up - or KISS.

Cheers

Graeme

Damien.....this is truly is a case of 'you get what you pay for'.....the linear ball bearing slides are the best load-bearing slides you can use, but there is a vast difference in quality, so beware.

There are three major suppliers of European drawer hardware in the Brisbane area:
Lincoln-Sentry...Coopers Plains (Blum)
Hafele...Coopers Plains, and
Nover...Slacks Creek and Lytton (Hettich)
all three have excellent show rooms which allows you to pick and choose from the variable class of slides.

As for capacity....I have used 35kg slides both in the kitchen and shed and don't think I have ever come within their capacity limit....even with my 850mm drawer banks.
Consider that a 20lt drum of fluid will weigh in around 22kgs.....are you going to exceed that?

Cheers

John M

I cited your previous post above. I read it with interest yesterday.

Did you look at the accurides ?

Where would you recommend I look for a box of the hettich slides ?

_I_ am not going to overload the drawers, maybe 20 kg per at most. I was just mentioning it because a lot of the old threads I was reading people were having toruble sourcing slides either long enough or with sufficient capacity.

If you want a 1.5 meter slide to carry 150 kg or whatever and the only off the shelf solution is $500 then it's worth your while looking into accurately positioning a stacked pair of lower rated slides. I gave the link to the project to illustrate the concept, but I obviously didn't make myself clear.

I suppose as a metalworker I'm used to positioning everything accurately, the idea of being a millimetre off is hard to stomach. I should have thought of that...another problem I have with woodworking

John, thank you for that, your post came through while I was typing this up. Very useful information. If hafele are true to form their stuff will be very expensive. How are Nover's prices ?

I assume this thread will be of use to others buying slides in future.

Damien....I have bought from all three.....they are all competitive and at times have specials.

Last week for instance I rang Lincoln Sentry for some pull-out drawer units and they were on special with about 30% off and even less if I bought more than one unit.

John M

I've got quotes on a box of 10 600 mm 45 kg:

elraco from their website: $153.10 (hafele) The bottom mounts are even cheaper at $130.70
hafele themselves: $ 261.10
Nover: $351.78 +GST (hettich)

lincoln sentry's web form bounced. It may have gone to someone but I got a bounce message so I don't know. Trying to get a price on accurides aswell.

Anyway assuming the hafele's are ok I think I'll get the bottom mounts from elraco. Has anyone had issues with the hafele runners ? do they use plastic ?

Zinc , products new home , FULL EXTENSION RUNNER_br_ 600mm Bottom Mounted_br_ ZINC 45 Rating

Edit: They got back to me, accuride are $209 plus gst for 10 sets of 600's.

I used the soft closing version of those runners in our kitchen ( about 20 or so drawers) and they have performed very well. I believe from memory that they are all metal (or at least all the important bits are).