Thread: Woodwork Bench design issue.

Hi raven

welcome to the forums.

1. what is most likely happening is that the coach screws can't drill their way into the hardwood end grain and are jamming and then breaking when you torque them up. Ideally the pilot hole should be around the same diameter as the base of the screw thread and the same depth as the screw is long. If the screws still break, enlarge the pilot hole to a diameter that approaches the outside diameter of the thread.

2. in terms of your design, I suggest that the cross members be arranged so that the 90 mm dimension is parallel to the bench top. 50 or 60 mm of depth will be plenty deep enough to span the width of a bench and with the 24 mm thick top (total depth 70 to 80 mm) have more than enough meat for hold fasts and bench dogs.

3. coach screws into end grain don't have the holding power of screws into side grain. But being hardwood and a bench, they may work for you long term. If over time they become a little loose you can fix the problem by installing 12 or 16 mm diameter cross dowels.

4. design issues.
a. A single front vice -- at the left of the bench if you're right handed -- is almost certainly a better choice than two face vices.
b. Install the second vice as an end vice at the opposite end of the bench to the face vice.
c. glue battens to your front apron between the cross supports, into which you can drill dog holes for use with the end vice.

have you considered applying some form of lube ,grease is pretty good on the coach screws?[not too much if you intend to apply some form of finish to bench or the grease will stain]

You probably need to use something like these bench bolts rather than screwing into endgrain. You can bury a normal nut and washer in the cross piece, it doesn't need to be a brass dowel.

Originally Posted by Fuzzie

You probably need to use something like these bench bolts rather than screwing into endgrain. You can bury a normal nut and washer in the cross piece, it doesn't need to be a brass dowel.

I'm a big fan of this style of connection and have even used small versions when joining aluminium tubing.
It produces a very strong connection that can be easily tightened if required.

If you cut the bolt hole with a hole saw you can cut a semicircular slice off the material that comes out of the hole and use that as the circular washer.
Make sure you arrange the grain in the wooden washer to run perpendicular to the hole - if the grain is parallel, tightening the bolt will snap the washer.
If you want a more neatly fitting washer you will have to cut one from another piece of wood.

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Welcome to the forum Raven.

Welcome, Raven

Those coach screws that you mention are absolute crap, renowned for having detachable heads. Even though they may be labelled 6mm, check their sizing - bet its different!

Suggest that you go to a specialist fastenners store and buy some real coach screws or, better still, some bench bolts as suggested by Franklin and Bobl.



Cheers

Graeme

You can use normal bolts to save a few bucks. I did this to attach my bench legs to the long side rails. Normal washers too. Just square off the hole with a chisel.
Regards
John

Cheap bench bolts - great service.

https://mcjing.com.au/searchresult.a...d=bench%20bolt

Originally Posted by Not enough!!

Cheap bench bolts - great service....

Certainly better, but still quite a lot more than you need to spend, NE. - 200 x 10mm bolts were a few $s apiece, last time I bought them. Barrel-nuts appeal for the looks, but I can tell you from experience that they are a right pita to fit. It's exceedingly difficult to drill the intersecting holes with the accuracy required, & if you get them off, a lot of fiddling & enlarging of the holes may be required to get them to take up! I rout a slot with a 1/2" bit instead of drilling the space for the nut, gives lots of room to get an open-end spanner in there, but Orraloon's method has great merit, because if you make the cut-out a neat fit, it captures the nut and you shouldn't need a spanner when undoing or tightening the nut. Of course, I could chop out a nut recess in my routered slot, now you've pointed out the bleeding obvious, John!

Agree with Bob, this method makes a very strong & sound joint. The stretchers on my bench have given no trouble at all in the close-to 30 years since I built it. I check them occasionally, but have not had any come loose, yet...

Cheers,

I've done pretty much as John describes, it allows use of a washer and room for the bolt to be drawn into. A spanner can also get at the nut if needed.


However, has the original poster ever been back here?

Originally Posted by Fuzzie

....However, has the original poster ever been back here?....

Can't tell, Franklin, unless he replies, the counter only records you once.... But 103 others have read the thread, so far, and there's been a good discussion, and I picked up a tip from John (so obvious, but I hadn't thought of it myself!), so all's well in our little world, I think.....

Cheers,

Originally Posted by Fuzzie

However, has the original poster ever been back here?

according to his profile, the OP was last here at 05:26 AM on March 6th. so he (or she) has missed nearly every post.

But they would have been notified of the content of Post#3