Large Shopmade C-Clamp

[Herb Stoops]

For the 2018 2X4 Challenge I made a pair of RH,and LH wooden C-Clamps out of an 8' long 2X4.

The first picture is the inspiration I found on the internet, and then just went from that for my own version. I bought the 1" 8 tpi. lead screw all-thread from McMaster Carr along with the matching nuts.

The pictures pretty much explain the build.

Herb

[Cherryville Chuck]

Thanks Herb. Approximately what is the overall length of each clamp? It looks like you cut out about a 1 1/2" wide piece on the arms.

[Herb Stoops]

I don't know why I can't enlarge the pics. I had a devil of a time getting them posted here I couldn't find them on my computer, so had to go to Rf and copy them to a zip file, then email them to myself, then Copy image to a folder on my desktop that I could attach to the file on the forum. It took hours literally to get them in the right order, If I attached them in too large a group they came in forward for some and backward order for others. So I ended up dragging and dropping one at a time in reverse order so that they came out the way you see it.
I will get the measurements in the morning for you.
HErb

[Cherryville Chuck]

Thanks Herb. I just enlarged them on my screen. That was good enough to give me the details I needed about how you made them.

[tomp]

Like those big knobs, easy on the old arthritis. Did you go with the strap hinges because of problems with the screws pulling out on a butt hinge?

[Herb Stoops]

The strap hinges give a larger hinge because they are narrower. To use a butt hinge, max 1 1/2" long X 1 1/2" W , leaves only 3/4" bearing on each side, and there is a lot of strain on the hinge. This hinge spreads it out more.
I thought the flat knobs were easier to store also.
CORRECTION>>> That should read 1/2"diam. X 8tpi lead screw(square thread) threaded rod and nuts.
HErb

[Cherryville Chuck]

The strap hinges give a larger hinge because they are narrower. To use a butt hinge, max 1 1/2" long X 1 1/2" W , leaves only 3/4" bearing on each side, and there is a lot of strain on the hinge. This hinge spreads it out more.
I thought the flat knobs were easier to store also.
CORRECTION>>> That should read 1/2"diam. X 8tpi lead screw(square thread) threaded rod and nuts.
HErb

I agree with you that they need strap hinges and the longer the better. I kind of thought that 1" by 8 tpi was a bit overkill but 8tpi is standard coarse thread for a 1" bolt so it didn't look like a typo. You're using Acme rod and nuts. That makes them quite a bit more pricey to make and up here I would have to order them in so I would probably go with SAE hardware. Oddly when I looked at McMaster Carr a 1/2" by 10 tpi was less than half the price of the 8tpi.

[Herb Stoops]

It is just personal preference on the Allthread. I found over the years that an Acme thread seems to clean itself better than an a standard thread. Most C-clamps use the acme thread.
Hinge = 1 1/4" X 8"
Each leg =16" X 2" throat
Threaded rod = 1/2" x 8tpi X 14 1/4"+ 2 nuts, 2 flat washers, one nut epoxied into handle, one nut drilled and pinned on outer end.
Knob= 6"l x 3 1/2" w made from center cutout of legs.

Herb

[Cherryville Chuck]

I finally finished the first of my long reach clamps. I'll probably build one more. As I was building mine I kept thinking of how to accomplish the same things as you Herb with as simple a solution as possible and in the end I wound up with quite a few modifications. The first came when I thought about how to attach the threaded rod to the bottom arm. I realized the easiest way was with a T nut embedded in a piece of ply and just let it butt up into a pocket. Once that idea took hold I realized I could make more than one pocket and alter the reach and leverage pressure. Then I realized I could take the bottom arm and fix it to a beam and drill holes in the beam for the upper arm and change the gap between the arms to fit different thicknesses.

I was going to build the arms from 1" lumber but when I went to buy some I couldn't find any straight enough so I opted for 5/8" fir ply underlay instead. I bought it at the local HD outlet. The ply turned out to be only marginally better than their lumber. To make the ply arms strong enough I added blocking and cross bracing and in the process I formed the pockets that would locate the threaded arm. I formed pockets at about 24", 20", and 16" from the arm tips. The shorter the span the more force can be applied. I also added swiveling tips on the end of the arms.

The first picture shows how I was building the pockets. The horizontal clamps are holding a jig that keeps the blocking the same distance from the arm bottom. The second picture shows how the threaded rod will fit in the pockets. Next is the finihed clamp clamped onto my work bench at the 24" setting. Last is the clamp changed to clamp at the 16" setting. I'll shorten the threaded rod to a suitable length now. The wing nut by the way is from a car and was used to hold a spare tire in place. For some reaon threaded knobs are hard to find in 3/8 by 16 thread which is the smallest rod I wanted to use.

[Herb Stoops]

That looks like it will do the job,Chuck. To even add more adjustments if needed you could drill a series of holes in the hinge block, or add a longer hinge block as long as your threaded rod will take it.
HErb

[Stick486]

That looks like it will do the job,Chuck

I'll say...

[DaninVan]

Herb; i may have missed the explanation, but why are the tightening knobs so large (in height). Thickness and length I can understand. Just seems like a lot of bulk(?).

[Cherryville Chuck]

That looks like it will do the job,Chuck. To even add more adjustments if needed you could drill a series of holes in the hinge block, or add a longer hinge block as long as your threaded rod will take it.
HErb

That hinge block has 3 holes in it. You may just be able to see the bottom one if you blow the picture up. I needed to use the top one for something as thick as my work bench. The lowest one will work for clamping something thin. At the moment I can't think of anything I'd need to clamp that is thicker than my bench but if I do the riser is just a cut down 2 by 4 so it will only take a few minutes to make another one. That one was just a scrap that was handy.

I do have a job for it sometime soon. A young fellow who went to school with my kids wants his counter tops redone and he can't even get any shops in town to return his phone calls so I said I'd do them but one side has to be joined in place with zero clearance to spare so I'll need the clamp to hold those 2 sections level while I tighten the connectors to join them. The back side will be tight against the wall so I have to reach across to clamp that side.

[Herb Stoops]

Herb; i may have missed the explanation, but why are the tightening knobs so large (in height). Thickness and length I can understand. Just seems like a lot of bulk(?).

I guess I had that much 2X4 left over, so I made them Big.
Herb

[DaninVan]

Herb; i may have missed the explanation, but why are the tightening knobs so large (in height). Thickness and length I can understand. Just seems like a lot of bulk(?).

I guess I had that much 2X4 left over, so I made them Big.
Herb

Good thing it wasn't 4x4 scrap!