# Hold down knobs



## difalkner (Jan 3, 2012)

I need some hold down knobs to secure fixtures on my table saw sled and also on the CNC to secure stock to be machined. But I don't want to buy any so figured I'd make some out of 1/2" MDF. This was my first time to use the circular pattern capabilities in Fusion 360 to create the grips and it works like it is suppose to so that's a good thing. These were fun to make so I made 20 of them - 12 in 2.5" diameter and 8 in 1.5" diameter. Some will have brass threaded 1/4-20 inserts and some will have hex head 1/4-20 bolts. The video below shows cutting the hex recess into four of the knobs.


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## JOAT (Apr 9, 2010)

I've made a few awhile back, but didn't need a CNC machine. Drill a hole, wood glue to hold the bolt fast. Works just fine.


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## difalkner (Jan 3, 2012)

JOAT said:


> I've made a few awhile back, but didn't need a CNC machine. Drill a hole, wood glue to hold the bolt fast. Works just fine.


And all this time I thought a CNC was _*required*_. That's why I built one, so I could make hold down knobs... :wink:


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## Shop guy (Nov 22, 2012)

Nice, David. I make all my knobs but don't have a CNC machine. I've found that T-nuts work better for me than the threaded inserts. I use the knob so that the T-nut is pulled into the knob when in use. Just a thought for you.


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## difalkner (Jan 3, 2012)

Shop guy said:


> Nice, David. I make all my knobs but don't have a CNC machine. I've found that T-nuts work better for me than the threaded inserts. I use the knob so that the T-nut is pulled into the knob when in use. Just a thought for you.


Thanks, Richard! I thought about T-nuts but decided on the brass inserts and bolts. 

Just curious - does the YouTube video play ok for y'all? It played fine after I posted it last night but now when I try to view it the opening screen (title, I guess) stays on for a long time but it's only suppose to be on for 10 seconds and then shows my putting the knobs into the fixture. My computer went through an update last night and one of the updates is to Flash so I'm wondering if it's my computer or the YouTube video. The raw native mp4 file plays fine and I'm wondering if I need to delete this one and upload it again...


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## RainMan 2.0 (May 6, 2014)

It stayed on a long time so I advanced it . Nice video regardless though


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## RainMan 2.0 (May 6, 2014)

Just looked again and the text is on for 55 seconds :|


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## difalkner (Jan 3, 2012)

RainMan 2.0 said:


> Just looked again and the text is on for 55 seconds :|


Thanks, Rick. I'll upload it again. Try it now, please sir.


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## woodknots (Mar 7, 2012)

Second video is much better


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## MEBCWD (Jan 14, 2012)

You can also epoxy nuts in the knob recess for a through knob instead of the threaded inserts.


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## 4DThinker (Feb 16, 2014)

Looks good. Just curious how long the MDF lasts. I've made some out of BB plywood as well as assorted hardwood scraps. Using t-nuts as well as pressed in hex nuts. So far they only thing that causes a failure is an unexpected trip through them with a spinning router bit. Never had one split or fail during use though. 

4D


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## tomp913 (Mar 7, 2014)

Very nice, the CNC certainly makes it easy to get a larger knob if needed. I bought some "rubbery" slip-ons for the hose bibs here at the house as my wife was having trouble turning them on when she wanted to water her flowers - just that little increase in diameter made it so much easier for her. 

Superior Tools - Faucet Mitts

I really need something like that for the leg locking knobs on my workbench as I'm starting to have trouble with the smaller knobs - wondering if I cutout a larger OD knob with an inside profile to fit the existing knobs whether that would work. When I bought the covers for the hose bibs, I was actually looking for a wrench that I'd seen that fits over the knob - I couldn't find it at the time but these have worked out OK - and no wrench to get lost


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## MT Stringer (Aug 15, 2012)

The second video is much better.


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## MT Stringer (Aug 15, 2012)

tomp913 said:


> I bought some "rubbery" slip-ons for the hose bibs here at the house as my wife was having trouble turning them on when she wanted to water her flowers - just that little increase in diameter made it so much easier for her.
> 
> Superior Tools - Faucet Mitts


Those are pretty cool. I haven't seem them before.


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## tomp913 (Mar 7, 2014)

MT Stringer said:


> Those are pretty cool. I haven't seem them before.


One of the many things we find is needed as we age. As I said, I'd seen (somewhere) and plastic wrench to fit the knob and couldn't find one but I think that this worked out better. I was looking for something similar for the little oval shut-offs under the sinks and couldn't find any so installed 1/4 turn shut-offs when I redid the downstairs bathroom - the others will get replaced as needed. I also have 1/4 turn ball valves to shut off the outside faucets from the inside.


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## difalkner (Jan 3, 2012)

MT Stringer said:


> The second video is much better.


Thanks, Mike! I don't know what happened with the first one. It uploaded fine but took a little while to process on their end. I played it last night when I uploaded it and it worked then but something must have gone wrong.


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## JOAT (Apr 9, 2010)

difalkner said:


> And all this time I thought a CNC was _*required*_. That's why I built one, so I could make hold down knobs... :wink:


Maybe I'm a neo-Luddite, but having a CNC machine would suck the fun out of woodworking for me.

However. There is always a however, law of the universe or something. However, I thought of a reason that would justify having a CNC machine. And that would be making toys for kids for Christmas, for Toys For Tots, and so on. Be a cinch to pump out things like Lincoln logs, toy cars and trucks, chess and checker sets. Now that would make having a CNC machine worthwhile. Now just need donations so I can afford to buy one.


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## 4DThinker (Feb 16, 2014)

Unless you are extremely patient and brilliant at CAD and tool path creation, no CNC will be the only thing needed to turn out finished for-sale/give-away toys and games. Even if you are (patient and brilliant) there is little chance a whole shop of more conventional tools won't also be put to use supporting the CNC projects. 

Since adding a CNC to my shop my other tools have gotten MORE use. Hardwood from whatever source rarely starts out the size you need it to be. Trim to length, rip to width, join and plane to final thickness are doable on a CNC, but still far easier to do on 2 saws, a jointer and a planer. Then I might cut a curvy profile followed by tenons at a compound angle off the end using my CNC. 

4D


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## difalkner (Jan 3, 2012)

JOAT said:


> Maybe I'm a neo-Luddite, but having a CNC machine would suck the fun out of woodworking for me.
> 
> However. There is always a however, law of the universe or something. However, I thought of a reason that would justify having a CNC machine. And that would be making toys for kids for Christmas, for Toys For Tots, and so on. Be a cinch to pump out things like Lincoln logs, toy cars and trucks, chess and checker sets. Now that would make having a CNC machine worthwhile. Now just need donations so I can afford to buy one.


To me, Theo, it's another tool in the shop. I have a table saw, jointer, bandsaws, drum sander, miter saw, drill press, scroll saw, routers, hand planes, files, needle files, razor saws, fixtures to bend sides for guitars, fixtures to hold necks and bodies to cut mortise and tenon, and on and on... oh, and now I have a CNC router. I use the one that's the best fit for the job. I'm quick to grab a plane or chisel or carving tool when that's the best option.

Since I'm building acoustic guitars I can assure you I do a lot of hand work but now my fixtures, templates, forms, and jigs, etc., are going to be spot on accurate. I can also guarantee you it's no walk in the park to 'just throw it on the CNC' and let it take care of my work.

But where it makes sense I'll use it first, partially because I designed, built, and sourced everything on it except the steel frame (well, I sourced that but had it built for me). Like any other tool, the more I use it the better I get at using it. And partially because it is very definitely one of the coolest tools in our little home shop!

And sometimes I'll do a simple task on the CNC like I did today; I needed a 2" x 4" x 0.5" piece of MDF for a fixture. I cut the rest of the parts last week on the CNC but forgot to cut this little piece. Now that is very simple to cut on the table saw but my dust collection is far better on the CNC for MDF and my table saw top is currently occupied with the crosscut sled and the other parts for this fixture so I had the little part cutting on the CNC while I worked on something else. In this case it would have taken just as long to clear everything off the table saw, cut the part, clean up the dust, and put everything back on the table saw to finish the fixture project as it did to quickly draw it in Fusion 360, generate a toolpath, and cut the part on the CNC (the right bit and 1/2" MDF was already in place on the machine).

One of my best friends is as much of a woodworking Neanderthal as he can be but he loves this CNC and wants parts cut out, even saying he wants one now that he's seen this one.

But I fully understand wanting to do it by hand or with limited power tools and appreciate the folks who simple don't want one. 

I doubt I'll ever have a project that is completely accomplished by the CNC alone; it needs support equipment. I've been asked to make 15 trophy blanks which will then be laser engraved and I'll cut those on the CNC even though I could do it on the 12" bandsaw and then over to the router table to make each one precise to the template (it has circles, arcs, points, etc.). One reason is that my dust collection is far better on the CNC, the other is they're going to want these in lots of 15 several times this next year and more importantly they're going to want to know that each batch is identical to the previous so their laser program doesn't have to be adjusted each time they engrave one. It just makes sense to use the CNC for this but each blank will have encountered the jointer, planer, table saw, miter saw, and drum sander before it ever gets to the CNC machine.

We haven't had time this year but last year Sandy and I made 90 snowflake ornaments out of Walnut and Maple for Christmas gifts to give out at church, also for family, and friends. The year before we made 28 end grain cutting boards for the same group - no CNC involved in either project. Next year we're going to double up on the gifts and take advantage of the CNC to do just as you suggest and that's for charities and fund raisers for church and school events.

Either way it's a cool tool and we are definitely having fun woodworking in this little shop!! LOL! Loads of fun! :grin:

PS - this wasn't a rant or soapbox time, I just like articulating how I work in the shop because I'm having a blast out there :wink:

Thanks! David


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