holdfast diameter?

[Jim Koepke]

Try setting the piece of wood in line with the top of the holdfast. It looks like yours is just beyond the point of where it should be holding.

Hold Still.jpg

This may not be the clearest picture, but it shows the curved area of the holdfast is doing the holding.

jtk

[Augusto Orosco]

Try setting the piece of wood in line with the top of the holdfast. It looks like yours is just beyond the point of where it should be holding.

Hold Still.jpg

This may not be the clearest picture, but it shows the curved area of the holdfast is doing the holding.

jtk

Thanks, Jim. I see what you mean by your picture. I think I have tried at different points, but not systematically... I will test it again this weekend. But I am skeptical it would make a real difference given that there is not even a little catch on it.

[Jim Koepke]

But I am skeptical it would make a real difference given that there is not even a little catch on it.

For my use in the photo above the holdfasts were pressed into the dog holes with only hand pressure. They can hold fairly well for many tasks this way.

It should be possible to insert the shaft into the dog hole, hold the shaft at an angle and feel resistance or move the bench when it is pulled out.

jtk

[Augusto Orosco]

For my use in the photo above the holdfasts were pressed into the dog holes with only hand pressure. They can hold fairly well for many tasks this way.

It should be possible to insert the shaft into the dog hole, hold the shaft at an angle and feel resistance or move the bench when it is pulled out.

jtk

That's why I am skeptical, I don't get that resistance at all when I hold the shaft at an angle. Perhaps I need to use the "punch" trick and go to town to get more 'grab'. At this point, I am tempted to just buy another pair, but I want to make sure that there is nothing wrong I am doing that will be replicated with a new pair. My money right now is on the thickness of the top (well, the leg, in this example). Trying it on a 2x4 should be easy; once I have more than 10 minutes to spare in the shop.

[Jim Koepke]

That's why I am skeptical, I don't get that resistance at all when I hold the shaft at an angle.

What little could be seen of the hole in your bench leg it appears the side of the hole is shiny.

If you can make your holdfast hold in a 2X4 with a hole bored by an auger bit or spade bit, it may be that your holes in the legs are too smooth.

jtk

[Augusto Orosco]

What little could be seen of the hole in your bench leg it appears the side of the hole is shiny.

If you can make your holdfast hold in a 2X4 with a hole bored by an auger bit or spade bit, it may be that your holes in the legs are too smooth.

jtk

Yes, the LV bits and a Drill Press make for an extremely clean cut. But if that's the case, given that we only care about the three points of contact (two of which being the top and bottom of the hole), then Brian's suggestion might be the ticket:

Relieve the hole on the top and the bottom by tapering it lightly with a rasp or a tapered cutter. All of mine required tapering (either self inflicted or by my hand) to work, they are LN.

I'll try to do as much experimenting as possible this weekend; hopefully it will be useful for other folks who experience similar issues.

[Jim Koepke]

Today a video was made in my shop demonstrating how my holdfasts work:

https://www.youtube.com/watch?v=2eCf7TTsp2E

These are just as the arrived from Junior Strasil.

jtk

[harry strasil]

100grit would be considered a polish on the shank of a holdfast! The rougher the better,20-40or60Gri twould work well. IF NOTHING ELSE WORKS, USE A COLD CHISEL TO ROUGHUP THE SHANKS,OR TRY DRILLING A LARGER HOLE IN A SCRAP PIECE THE SAME THICKNESS .MY 5/8" hholdfasts will holdfast in a 1" hole. Most people want to polish things up and in this case that is th worst case cinerio. There will be nomore holdfasts from me as I am not physicaly capable of making them anymore.I had back surgery gone bad then I had a bad fall and spent a week or so in the hospital. I CAN HARDLY STAND AND WALK,so I set and hone my carving chisels.

[Augusto Orosco]

100grit would be considered a polish on the shank of a holdfast! The rougher the better,20-40or60Gri twould work well. IF NOTHING ELSE WORKS, USE A COLD CHISEL TO ROUGHUP THE SHANKS,OR TRY DRILLING A LARGER HOLE IN A SCRAP PIECE THE SAME THICKNESS .MY 5/8" hholdfasts will holdfast in a 1" hole. Most people want to polish things up and in this case that is th worst case cinerio. There will be nomore holdfasts from me as I am not physicaly capable of making them anymore.I had back surgery gone bad then I had a bad fall and spent a week or so in the hospital. I CAN HARDLY STAND AND WALK,so I set and hone my carving chisels.

So sorry to hear about your back, Harry; hope carving will provide you wit a good outlet.

I'll use coarser sandpaper or rough them up with a cold chisel or a punch. What you say about the larger hole makes a lot of sense... see my next reply.

[Augusto Orosco]

Today a video was made in my shop demonstrating how my holdfasts work:

https://www.youtube.com/watch?v=2eCf7TTsp2E

These are just as the arrived from Junior Strasil.

jtk

Thanks a lot for all the help on this matter, Jim. Yesterday I did a quick test, too. I took a 2" thick piece of soft maple and drilled a 3/4" hole using the drill press and the LV bits. So, these holes are as smooth as the other ones and in the same material, simply on a 2" thick piece instead of an effective 4". As soon as I inserted the holdfast, I noticed some "grab". Then, I was able to easily hold a piece with a whack of the mallet. So, it seems that the issue was the thickness, and therefore, If I want them to work on the leg (or the top), I need to counterbore deeper, or use a wider hole (as Harry suggested above). The wider hole is out, because I want to keep my holes on 3/4" so I can eventually use other gadgets that fit on a 3/4" diameter as well, so I probably would have to counterbore deeper.

Here's a quick video of the holdfast now grabbing and holding easily a piece of scrap on a 2" thick simulated "top".


https://youtu.be/dg89sgqt8Po

[harry strasil]

Counter bore from the bottom to compensate for the thickness and you can still have the 3/4" holes on the top. good luck!