LumberJocks

Assembly Table Joint Strength

  • Advertise with us

« back to Joinery forum

Forum topic by Leadbelly posted 01-26-2022 03:24 PM 539 views 0 times favorited 11 replies Add to Favorites Watch
View Leadbelly's profile

Leadbelly

6 posts in 119 days


01-26-2022 03:24 PM

Good Day All!

I designed an assembly table for my shop and have a few questions about a couple joints I’m using. For background, this is a hobby for me – not industrial/commercial. Basically, this assembly table is going in the garage and is expected to get light use (6-7 projects, like tables and other furniture, per year).

The 4×4 frame is probably just going to be kiln dried douglas fir #2 from Home Depot since it’s getting painted gray.

The upper joint is a castle joint. Is this strong enough for intended purpose?

The lower joint is a mortise and tenon with 4 dowels to pin both connections. I sort of just made this one up. Is this strong enough? My thoughts were the long span gets a through-put mortise joint for support, and the small span is simply for frame rigidity and racking forces.

Thoughts?

Cheers,
Ryan


11 replies so far

View brtech's profile

brtech

1216 posts in 4382 days


#1 posted 01-26-2022 03:36 PM

Of course a purist would use a sliding dovetail, and a hacker would use pocket screws. I personally think the castle joint is a very nice touch, but I’d probably make both of them pinned tenons with a single large pin. Of course if you wanted to be able to disassemble it, you could use a wedged tenon.

Some other ideas I’ve lifted from other plans: electrical outlet strips built in, a butcher paper roll holder, a caddy in the back to hold an air compressor (possibly with sound insulation)

But mostly what are you doing on the top? These days, I’m recommending the Microjig MatchFit, but the Festool MFT hole pattern is also nice. There are folks who have added the holes to a MatchFit system so they could use both styles of hold downs. If you do add holes, there needs to be room underneath the top for the clamps.

View Leadbelly's profile

Leadbelly

6 posts in 119 days


#2 posted 01-26-2022 03:55 PM



Of course a purist would use a sliding dovetail, and a hacker would use pocket screws. I personally think the castle joint is a very nice touch, but I d probably make both of them pinned tenons with a single large pin. Of course if you wanted to be able to disassemble it, you could use a wedged tenon.

Some other ideas I ve lifted from other plans: electrical outlet strips built in, a butcher paper roll holder, a caddy in the back to hold an air compressor (possibly with sound insulation)

But mostly what are you doing on the top? These days, I m recommending the Microjig MatchFit, but the Festool MFT hole pattern is also nice. There are folks who have added the holes to a MatchFit system so they could use both styles of hold downs. If you do add holes, there needs to be room underneath the top for the clamps.

- brtech

Thanks for the quick reply – much appreciated!

As for the 3-axis pinned tenon joint – is the image below what you’re thinking? Or how do you do this for the lower joint where the vertical post runs through adjacent lateral members?

Definitely appreciate the other feedback on functionality additions. This will also likely serve as an outfeed table for a while as well. On the backside of the cabinet I have a horizontal clamp rack and more peg board for hand tools. I’ll likely incorporate the power strip in this area.

The top of the table is melamine to help with cleaning glue, etc. I don’t need a completely flat surface, so no need for torsion box or anything crazy. I’m thinking of potential surface systems down the road like the ones you mentioned (dog holes or T-Track types), but frankly, not sure I’ll use it enough to justify the upgrade. Going to use it for a year or two, and make a decision at that point.

Best,
Ryan

View Leadbelly's profile

Leadbelly

6 posts in 119 days


#3 posted 01-26-2022 04:02 PM

Or maybe like this with a single pin on the front face (rear of the photo)

View therealSteveN's profile (online now)

therealSteveN

9992 posts in 2033 days


#4 posted 01-26-2022 05:55 PM

Obviously your table, your choices. That said I think you are looking to do a lot more work than required for the work expected from an assembly table, unless you plan to do Monster trucks. A lap joint with a screw shot through it, or even a butt joint with a screw is how 99% of your brethren would approach that task. Or some combination of Pocket screws. If you want to do it, just for fun, and practice by all means. But it likely will never fail, even doing it with what most would consider weaker joinery.

-- Think safe, be safe

View Leadbelly's profile

Leadbelly

6 posts in 119 days


#5 posted 01-26-2022 06:56 PM

Thanks for the input SteveN! Totally understand this is overkill, but doing it for two reasons:

1. I want to work on my woodworking joinery skills as a hobbyist.
2. Aesthetics matter to me. I’m energized and motivated when my shop actually looks good. Seeing better joinery and craftsmanship makes me want to up my game on projects I’m working on. I don’t look at woodworking as fast-paced production mode, and this is one way to make that readily apparent within my woodshop.

Using advice above with the sliding dovetail joint, I think this might be a cleaner approach:

View brtech's profile

brtech

1216 posts in 4382 days


#6 posted 01-26-2022 07:05 PM


Or maybe like this with a single pin on the front face (rear of the photo)

- Leadbelly


That’s what I would use, yes. The sliding dovetail is better, but for an assembly table, I wouldn’t bother. YMMV

View Leadbelly's profile

Leadbelly

6 posts in 119 days


#7 posted 01-26-2022 09:02 PM

Thanks again!

Any other ideas on improving the overall design? The cubbies will house a series of Harbor Freight Portable Storage cases (hardware bins). Back side will have a clamp rack and additional peg board:

Cheers,
Ryan

View Aj2's profile

Aj2

4455 posts in 3257 days


#8 posted 01-27-2022 12:51 AM

I have a idea. Make each corner a different joint that should really make it complicated.
Unless your too scared Bak Bak :)
Good Luck

-- Aj

View pottz's profile

pottz

25822 posts in 2444 days


#9 posted 01-27-2022 12:59 AM

yeah it’s an assembly table dont over think it.but if you wanna go their,hey do it. here’s my table i made a few years back.plus some add ons.no fancy joinery,i saved that for real projects.
Click for details
Click for details
Click for details
just some ideas to ponder.

-- working with my hands is a joy,it gives me a sense of fulfillment,somthing so many seek and so few find.-SAM MALOOF.

View Lazyman's profile

Lazyman

9602 posts in 2847 days


#10 posted 01-27-2022 04:32 AM

I am not so sure that your dovetail joint would be all that strong over the long term. On the bottom stretcher, another option to consider is simply blind M&Ts using drawbores to pull them tight. Bevel the ends of the tenons (or notch one of them) where they would hit each other. I just built a base for my work bench using drawbores to pull the blind M&T joints tight and it creates an amazingly tight joint that doesn’t require any glue, though you can glue it if you want.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View Leadbelly's profile

Leadbelly

6 posts in 119 days


#11 posted 01-27-2022 10:00 PM


I am not so sure that your dovetail joint would be all that strong over the long term. On the bottom stretcher, another option to consider is simply blind M&Ts using drawbores to pull them tight. Bevel the ends of the tenons (or notch one of them) where they would hit each other. I just built a base for my work bench using drawbores to pull the blind M&T joints tight and it creates an amazingly tight joint that doesn t require any glue, though you can glue it if you want.

- Lazyman

Great advice all – I’m simplifying the joint and that way they all match. The drawbore technique is especially useful – definitely doing that. The simplified joint also allows me to install levelers and casters a little easier (not in conflict with the lower joint).

I’ll try posting pics of the build process once I start. Wish me luck!

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com