[MikeSibley]

I'm waiting on my new CNC machine to be delivered, so I have a lot of time to browse and learn. I've seen some of the videos on youtube that show homemade hold downs made of wood. It seems to me that the wood hold down would be both more forgiving than aluminum if accidentally hit, and cheaper to purchase and replace. Looking on Amazon, the aluminium ones run $20-25 per pair. Of course, there would be some cost associated with the t-bolts and knobs but maybe homemade would be much better than store bought.

Does anyone have a plan or drawing for those? The plans on the internet seem to be made for table saw situations and rise 3 plus inches above the work surface. I saw some on the videos that are more suited for CNC. I can make a design, but I'm assuming that some of you guys have juggled this and refined it.

If you can point me in a general direction, I would be appreciative.:smile:

 

[Gaffboat]

I use shop-made hold downs made out of 3/4" baltic birch plywood. They are easy to make and forgiving if you inadvertently hit one with a bit.

 

[difalkner]

Mine aren't as fancy as Oliver's but when I don't screw the piece directly to the spoilboard my clamps are just Maple with a hole for a screw - shop made in two sizes.

David

 

[MikeSibley]

Thanks guys! I found a video on youtube from Dave Gatton that seems to be a pretty good idea.

After talking with HonestJohn, I'm thinking that I will run 80/20 #1575 which is 3/4 x 1.5 t-tracks and running 1" MDF between them. So Gatton's hold downs might be good, they are very similar to Gaffboat's. I just think that this is much better than aluminum clamps, and cheaper too!

The only thing with the 80/20 1575 is I will have to countersink flat head screws through the bottom of that to connect the CNC frame via 8mm bolts and roll nuts.

I know I am probably overthinking all this, but trying to have a plan in place when my machine arrives. Easier to put things together as I am building the machine.

 

[difalkner]

Good video but he needs to learn his bolt types if he's going to call them by name in his videos. What he called a 'shoulder bolt' is a bolt with shank.

Bolt with shank -


Shoulder bolt -


David

 

[MEBCWD]

Mike here are some videos that might interest you.

Remember you are getting a new CNC machine. You need to learn to use your design software so this would be an easy project to start with and give you some design time and machine time. You will need clamps and these free ones will actually be free++ because you will end up with some clamps, some basic design time, and some simple quick projects to start you learning how to use your machine.

You can also design these basic clamps in different lengths, longer ones come in handy to help stay away from dust boots and things, it is no fun coming down on top of a clamp screw or knob and the longer ones help avoid them.

 

[ger21]

Personally, I much prefer CAM clamps that hold parts from the side, against a fence, rather than hold down clamps that clamp from the top. They are much less intrusive, and a lot harder to hit.

 

[MikeSibley]

Thanks Mike and Gerry!

Still involved in the hurricane recovery/restoration effort and this is my "sanity break" when I can break away for a little bit.

I guess I'm overly excited about this and scouring every potential "what-if" so I do thank everyone!

 

[HDVideo]

While not suitable for all setups, I use the painter's tape/super glue method whenever possible. When clamps are called for, I have a bunch that I made from 3/4"x1" oak in various lengths and at times I've screwed parts directly to the spoil board.

 

[Stick486]

Personally, I much prefer CAM clamps that hold parts from the side, against a fence, rather than hold down clamps that clamp from the top. They are much less intrusive, and a lot harder to hit.

https://www.routerforums.com/2122055-post5.html

 

[BalloonEngineer]

Regular T-track would be much cheaper than the 8020 1575. Cheapest source is Orange Aluminum https://www.orangealuminum.com/t-tracks-and-accessories-oa7150.html

I, as usual, chose to do things a little differently than most. I have a grid of t-track, and frequently use the Rockler stop blocks In addition to my clamps. They goal is to not only hold material down, but also prevent it from shifting sideways. Some materials are slippery, like corian or HDPE, just holding down may not properly secure. The little stops are great as index points when repetitive cutting multiple pieces of stock in the same place. Gerry’s idea of cam clamps is great, especially if using downcut bits (which I use for most wood cutting), but can have issues if using upcut bits.

Because I have a fairly large table, I also made it so I can insert clamps at any of the grid intersections, since always having to insert clamps from edge of table gets old real fast.

 

[MikeSibley]

That's nice!

The reason that I was thinking the 1575 was that I could get it cut to length. I looked on Amazon and all that I could find was 48 inch t-track. The 80/20 stuff is quite expensive, must be a little gold or platinum used for the alloy in those. I'll look at that site as at this time, the Chief Financial Officer (my wife) after paying for the new machine, purchasing a collection of various bits, buying some new LED shop lights to put over my table when it arrives, buying a new mini-PC for the machine, she's beginning to question 1) need and 2) cost!!!

 

[honesttjohn]

I've had both kinds and, hands down, the 80/20 is by far the the most sturdiest and strongest. It is more expensive, but, in my opinion, worth it. The blue channel also pulled out in some places after a while and had to have flat head screws/bolts all the way thru the bed with nuts and washers. Just my opinion and experience.

Plus, the clamp bolts will bend after a while, and 5/16 carriage bolts from Ace fit perfectly. This way you can have different lengths for different projects.

 

[MEBCWD]

You can cut the T-track yourself as simple as using a hacksaw or using a metal cutting blade on a tablesaw or bandsaw.

There are some people that have also built the top of their spoilboard so it was the T-Track like this.

You could also look into drilling your spoilboard and adding T-nuts or threaded inserts like this.

Or you can build it so you can use F-clamps or screw mounted clamps like this.

Do you need to route the ends of boards for joinery? you might add a section of vertical table like this.

How about vacuum? There are many designs, some work better than others. Here is just one design.

Or you can re-invent the wheel and design your own special clamping system.

 

[TimPa]

all good stuff...

just one caution, everything you "add" to the table will reduce your useable Z height, so make it count.

it seems that most every clamp has its pro's and con's. sometimes i just tap some wedges against the stock and a cleat screwed down to the table. you will find that some methods work fine for light duty cutting, and when you are really hogigng out, more substantial is required. when i get there, and its an expensive part, i use tabs, screw down, and superglue/painters tape.

 

[UglySign]

Note that Oliver is showing Nylon screws. Of which are easy to remove if they're cut into or useless.

I use shop-made hold downs made out of 3/4" baltic birch plywood.
They are easy to make and forgiving if you inadvertently hit one with a bit.

Hey... dont forget about vacuum pods or custom made vac pods.
A good place to look is at Joe Woodworker to get a vac setup started.
Or just visit an HF store and get a vac pump.


Wild times ahead.