Acceptable length for Workbench Overhang

[David Justice]

Hi all,

I am making a new sort of hybrid French/Roubo bench. Big stout base and thick top with a wagon vise on one end and a leg vise. This is my first one and am building this out of HD 2x6x8. With the lumber in mind and a 4 inch top, would 24" overhang on each end be ok and not cause the benchtop to dip on the ends?

I ask this because I originally planned on having the top be 65"x20" and built the base 46" long, but now I have decide that I want to use the whole 8' of lumber for the top. Just need to know if this base will be usable, or if I need to rebuild?

Thanks!

 

[Mike Davis]

If the base is heavy enough it should counterbalance, I’m sure there is a math formula to determine the leverage.

If it were mine I would want the legs closer to the ends.

 

[Breakyr]

Most of the benches I have seen use the full 8' had no real overhang. However, I don't see why you could do a single T post under the over hang. The only worry there is the dipping as you mentioned. A simple support should rectify that problem.

 

[zdorsch]

David,

I say try it and if it doesn’t work add supports later. I agree with Mike that a formula probably exists somewhere to calculate this, but I imagine that laminated 2x4s are plenty strong enough in this situation.

Slightly off topic, but this guy makes some good points about building workbenches:

https://www.theenglishwoodworker.com/best-wood-for-workbench-building/

 

[David Justice]

Thanks guys. Here is a picture of the bench in mid-build. The 2 end sub assemblies of the base are glued and bolted together, but the long stretchers could still be changed and the boards for the top have been dimensioned, but are just sitting on top of the base. Each end hangs over about 21". I can make the stretchers longer, make the top shorter, or leave it as is and see if there is any issue with the ends hanging over.

By the way, I couldn't find any calculations for this subject, but I did find this article by Christopher Schwarz where he talks about 4"-6" thick bench tops with 13"-20" overhang with no issues.

After setting the bench up and seeing and feeling it, I can't imagine gravity having any effect on this top.

 

[chris_goris]

Thanks guys. Here is a picture of the bench in mid-build. The 2 end sub assemblies of the base are glued and bolted together, but the long stretchers could still be changed and the boards for the top have been dimensioned, but are just sitting on top of the base. Each end hangs over about 21". I can make the stretchers longer, make the top shorter, or leave it as is and see if there is any issue with the ends hanging over.

By the way, I couldn't find any calculations for this subject, but I did find this article by Christopher Schwarz where he talks about 4"-6" thick bench tops with 13"-20" overhang with no issues.

After setting the bench up and seeing and feeling it, I can't imagine gravity having any effect on this top.

Unless youre planning on storing something VERY heavy on the ends, there is nothing except the weight of the top itself (negligible) to cause it to dip. I would think you would get more deformation from the lumber itself wanting to twist and contort as it dries. With the 2x4 oriented in that direction, I wouldnt worry about it.

 

[zdorsch]

I remembered the “sagulator” this morning:

http://www.woodbin.com/calcs/sagulator/

 

[frankc4113]

It seems to me that although there may not be any issues with the bench tilting over, The space underneath the table could be made better use of if the legs, ie: platform be widened and storage drawers built under the table. Also, if you place a heavy load on the ends of the bench, there stands a good chance that the top may fall out of "flat". In essence, I think the space underneath could be made better use of in that there probably is nothing to lose by making the stand wider.

 

[Mike Davis]

Found the calculator I was thinking about

https://www.engineersedge.com/calculators/levers/page_levers_1.htm

This isn't actually correct due to the weight distribution but I think it helps.

For a 24 inch overhang with 60 inch opposite the fulcrum and say the table weighs 200 pounds then it will take 500 pounds to tip the table.

Since some of the weight is center and forward of the fulcrum you can reduce that tipping weight.

My best guess is 300 pounds.

 

[David Justice]

Thanks again everyone for the replies. I can't imagine any situation where I would have 300lbs on either end of this bench, or even 100lbs. I think I will assemble the bench as planned and see what happens. I'm guessing with this lumber that I will have to flatten it a few times the first year, so I will be looking at it closely anyway.

 

[Jeff]

It looks disproportionate to me as pictured but structurally there shouldn't be any issues with the 20-21" overhangs bending or drooping down even with some weight on them. You could lengthen the stretchers with a little work but that's your call.

Do you really want an 8' long workbench? :eusa_thin

 

[Mike Davis]

I wish I had a 12 foot long bench, but my little shop won't support it. My bench is 6 feet and I make it work. It is nice to have when I need to take it some where, just four small screws to remove the long braces and everything comes apart. I can have it in the car in less than 20 minutes.

Not fun planing 10 foot long boards though.

 

[David Justice]

Although these long boards have been a struggle to work with, I do want an 8' long bench. My current one is 6' long and I constantly find myself wishing for a longer bench, mainly because I have found myself working on much larger projects than I originally thought I would. Also, I think an 8' flat surface would be really nice to have in the shop and I don't want a huge assembly table taking up a lot of room.

 

[Graywolf]

Well it's looking good David. I look forward to seeing it complete.

 

[AllanD]

I don't expect the overhang on the ends will ever cause it to tilt to the side, that would take a lot of weight. It would be more likely to tilt in the narrow direction, front to back but that is also unlikely for woodworking jobs. I had some rare problems working with metal in a big machinist vise on a smaller bench in the past, mostly trying to bend a long piece of metal or pipe, etc. But that won't apply to your plans.

 

[Jim M.]

You can try it as you have it, David, the if you find it too tippy, you can always trim it back.

 

[Breakyr]

Or add a simple T post support to extend the base. Simple, functional, and won't hurt the space efficiency.

 

[Dash]

Chris Swharz has a couple of great books on benches. There's a design one too. I restored windows from 2006 'til 2013 and was dying for a good bench that would hold various size sash. The euro bench did the trick. One important feature was to have the legs flush with the sides for clamping. Did somebody post a chart with overhang and stability numbers? I am building a base for a round table top and am scratching about looking for some math. I found a picture of a curvy Stickley base that looked stable, then the next picture had it extended with tow or three leaves in it. The overhang was tremendous. Proportionally, it looked like a plate spinning on a skinny dowel.

https://www.barnesandnoble.com/p/wo...j7HAtSKOitUGGhwOX9GAvDoM29oQYL4gaAkKVEALw_wcB

 

[danmart77]

David workbenches are as unique as the people working at them. The bench below is the 4th bench I have made and I think I am close to something that works for me and what I do -- casework, chairs, rifles and repairs. I don't do large sheets of plywood much any more.

Advice from others and books can be helpful but in the end you'll try it and rethink what would be best for you .. especially if this is you first build.

Not to pick on Chris Schwarz but I don't like low bench designs. I don't need to bend over to plane wood on my bench. That would be a departure from the start and one you will custom fit.

You don't mention your vise type or location on the bench. This is big. I use my face vise 10 times to every time I use my tail vise.

Why is that? If you set your top up with holes for holdfasts, you will not use your vises like you would if they weren't there.

I had a small bench like Mike Davis refers to and it was great for its portability but I could not use hold-fast devices. I was always frustrated with it.


Your central question on this thread was overhang and possible tipping?


Make your bench as heavy as you can. My bench is well over 400 pounds. It does not move and I really love it.

Tail vise and face vise are the same size. Both have easy replacement hard wood faces. I take them off and run them over the joiner to "fresh them up" and its easy.

in the staged photo above. you can see some of the possible attachments you can use with the bench you build. I show this picture to add to the comment another made about the shelf below the bench surface.

I use the planes on the shelf every day for something. I don't like drawers for my heavy use tools. My planes are a reach away and my chisels are to my right on the wall as I work. Mallets on the bench at all times. This is just me and not a formual for how another person should set up.

My bench is 82" x 30"

Like others have said- just go with it and see how it works. If it needs a little support here or there its not going to stop the train.

good luck and post some photos with your vise position/positions.​

 

[Mike Davis]

I use holdfasts. While my bench is smaller it is not light weight and it is very solid and functional.