Monday, December 14, 2009

What drives you



What type of bit/drive do you prefer and tell us why?

Robertson screwdrivers also called a square drive screwdriver are easy to use one-handed, since the tapered socket retains the screw, even if it is shaken. They also allow for the use of angled screw drivers and trim head screws. The socket-headed Robertson screws are self-centering, reduce cam-out, stop a power tool when set, and can be removed even if painted-over or old and rusty. In industry, they speed up production and reduce product damage"
read more

"The Robertson socket head screw soared in popularity. Craftsmen favoured it because it was self-centring and could be driven with one hand. Industry came to rely on it for the way it reduced product damage and sped up production. The Fisher Body Company, which made wooden bodies in Canada for Ford cars, used four to six gross of Robertson screws in the bodywork of the Model T and eventually Robertson produced socket screws for the metal bodied Model A"
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"In a recent ranking of great Canadian inventions, the Robertson ranked seventh, ahead of the zipper and the retractable beer-carton handle, just one spot behind the pacemaker. But the Robertson is the real lifesaver, rescuing us from both flatheads and Phillips vastly inferior products. That sham artist actually had the nerve to suggest that his screwdrivers were designed to slip, to prevent over-tightening.

The Robertson never slips, and it never strips, and it can be driven one-handed with no stripping"
read more

Woodweb: A discussion of screw characteristics and preferences

Decking Screw





What do you think about the new decking screw and for what application did you use it for?

Monday, March 23, 2009

Eureka Expansion Bolt Project




An expansion bolt is a very handy and versatile fastener. It can be used for many applications and in the articles mentioned below it is used with a threaded rod and nut instead of the bolt that comes standard with the product.
If you have any new ideas for different applications, please send us your comments.
If you have problems with installation please send the details and we will reply with our solutions.

An expansion bolt is quite a difficult product to use. There are many aspects to take into consideration when using this fastener.
The two main things that can go wrong:

1) Not drilling the hole deep enough for the bolt causing it to strip the thread of the shell when tightening.

2) The next problem is that an expansion bolt has the ability to break or crack an object or surface when tightened. This happens because of the very big expansion of the shell as the bolt is tightened.

Here are links to two projects where expansion bolts are used:

1) A ceiling-mounted hanging shelf will provide you with ample storage space in your garage. These shelves should ideally be mounted into a roof made from concrete, although it can also be done through a normal ceiling by securing the threaded rod through strong wooden crossbeams placed inside the roof on the roof trusses. Read more

2) Get to grips with expansion bolts and threaded rod
and hang a ceiling-mounted shelf. Read more

Also see this 3D video on how the bolt and shell work together to anchor itself in an object:


I will be glad to assist and listen to your ideas.
Regards,
Willem Marais