CNC Hold Down Methods: Workholding and How to Clamp Material to Your Spoilboard

Рет қаралды 6,754

Күн бұрын

Hey CNC Woodworkers! This video covers 10+ different ways to do work holding on a CNC table. I have different techniques that I prefer for different types of CNC router work, which have evolved a bit over the years. I specifically discuss ways that work best for a t-track spoilboard table, but I used some of the same hold downs with my 1/4-20 pronged t-nut table. Some techniques are better for toolpaths that are only cutting in the middle of a workpiece, others are better for flattening the entire worktop, and some others are best when you are machining away the entire sides of a piece (like CNC'ing a bowl). I briefly discuss vacuum tables and chucks, but I personally do not have one of these (yet!).
You are free to copy my 3D printed designs, and would be a great exercise in CAD. If you want to just get the files I made, I have them available here:
CAD Design / STL Files
* Low Profile Toe Clamps for 3D Printing: www.corbinsworkshop.com/shop/...
* Cam Side Clamps for 3D Printing: www.corbinsworkshop.com/shop/...
Materials / References
* Preferred double sided tape: amzn.to/3PG5oYP
* Alternative double sided tape: amzn.to/43At2eS (cheaper, but it doesn't rip as easily)
* 2nd Alternative double sided tape: amzn.to/3Tyd4O1 (A little "thick" for my preference)
* T bolts for T-track tables: amzn.to/3VFxDLc
* T-tracks: amzn.to/3TDfIlA
* CA Glue: amzn.to/43z6rQ1
* Blue Tape: amzn.to/4adEW0R
* Omer B17P Composite Nailer: www.avidcnc.com/omer-b17p-com...
* Composite Nails on Amazon: amzn.to/3x8HWgi
* Raptor Composite Nails: www.avidcnc.com/raptor-compos...
NOTES:
Double Sided Tape: I prefer the Intertape brand listed above for the reasons I listed in the video, but I have used the other tapes, and they do work, and are cheaper.
Composite Nailer: I have NOT used the composite nailer. Usually I only put links to things I actually use on a regular basis, but I want to give a full disclaimer that I have not tried them myself. I would definitely give it a try if I didn't have a vacuum table and was doing sheet goods on a regular basis.
Blue Tape/CA Glue: I don't like to use the Blue Tape and CA Glue method anymore, but it is worth trying if you have it around and don't have double sided tape, and you can find the materials locally (Home Depot, etc). I found that a higher quality blue tape works better than cheaper blue tape. Thin CA glue works best, and accelerator
"sometimes" causes issues, so I stopped using it. The glue also doesn't work as well as it ages, even in un-opened bottles.
thanks!
Corbin Dunn
www.corbinsworkshop.com // Products and CNC Files
www.corbinstreehouse.com // Blog
Chapters:
0:00 Intro & Overview
0:29 1 - Low Profile Toe Clamps
3:12 2 - Slotted Wood Top Clamps
5:29 3 - Scrap Wood Top Clamps
6:36 4 - Metal Top Clamps
7:13 5 - Side Cam Clamps
10:21 6 - Wedge Clamps
13:47 7 - Double Sided Tape
16:42 8 - Blue Tape & CA Glue
17:41 9 - Screws & Nails
18:53 10 - Vacuum Table / Chuck
19:27 Conclusion
* The usual disclaimer - some links are Amazon affiliate links, where I earn a small commission from your purchase at no cost to you. If you only knew how much crazy amounts of time I spend making videos!

Пікірлер: 36

@dominaspina 25 күн бұрын

Wonderfully informative video. Thank you for going through the pros and cons of each method. As a CNC beginner I get to benefit from all your trial and error.

@CorbinDunn 24 күн бұрын

Thanks, I'm glad it could help! There's never one best way to do a hold down...and I still swap through all the different techniques for different reasons.

@MarkLindsayCNC 4 ай бұрын

Excellent video, Corbin! I guess it goes without saying that sometimes there is no single "best" method. They all have their place. We just need to learn the different application that works best for the job we're getting ready to run.

@CorbinDunn 4 ай бұрын

Thanks Mark! Yeah, it's good to have a lot of ideas in the work holding bag of tricks.

@Curtis-Randall 2 ай бұрын

This video was super informative! Thank you for going every method, it helped me decide which kind of bed to make for my cnc.

@CorbinDunn 2 ай бұрын

Cool, glad it could help!

@mikegoins5663 4 ай бұрын

Thanks. I learned something new. I liked the good and bad for each hold down.

@CorbinDunn 4 ай бұрын

Cool, I'm glad you liked that part! I see a lot of other videos saying "this is the way to do things", and they really don't consider all the options where it might be bad. Of course...give me another year or two and I'll probably have some new ideas that I like better!

@robertyack1661 Ай бұрын

Great job. I'm about to pull the trigger on DIY ATC based on your video series. I have a 5x10 Avid CNC. You may be hearing from me, sir. Love your style of teaching

@CorbinDunn Ай бұрын

I'm happy to help if you have any questions! CNC Depot has some great new ATC spindles.

@samrix5793 4 ай бұрын

I really like your videos and content!

@CorbinDunn 4 ай бұрын

Thanks!!

@maximazur4854 4 ай бұрын

Hi Corbin! Great video! I made a 100mm grid of tnuts that go through the spoilboard and the backing MDF, so I can tight any bolt lengths. Another great addition to my CNC router was to design an auxiliar spoilboard as a vacuum table: with a square grid, a hole in the center, a 3d printed adapter for my shop vac and a long gasket to close a perimeter. You should try that! Works like a charm

@CorbinDunn 4 ай бұрын

Just the shop vac works for it, that is super cool! I should definitely give it a try. I also know small vacuum pumps are pretty cheap these days. A removable vac table would be really nice for a lot of the stuff I do. I also think my next spoilboard will be a combo of t-nuts and t-tracks; the t-nuts are handy for certain situations. on my PCNC, they would bottom out on the PCNC's table, which was a pain.

@dangoras9152 4 ай бұрын

That's one way to use a body hammer 😂.. Good information brother I think I will stick to double sided tape.. Keep it up brother

@CorbinDunn 4 ай бұрын

Haha..yeah! Double sided tape and the toe clamps are really all I use these days.

@iderryan 4 ай бұрын

Depending on what I'm cutting, I can add a tool path for screw divots as the first cut. By doing this, I know that my screws aren't in the way of other tool paths. If I know the exact locations of my dog holes and t-track (because I have the file I used to create them in the beginning) then I can use those locations for nylon hardware. Mostly, I use maple, ash, or oak for simple bar hold downs. 0.75" thick, 1.25 wide, and 3-5 inches long. A slot in the center for the t-bolt, and then cut a rabbet on each end 3/8" square. This is super easy with scrap hardwood on the cnc, then just cut them to width on the table saw.

@CorbinDunn 4 ай бұрын

Awesome - that sounds like a good method for doing hold downs, especially if you have a consistent size work that you do a lot. I know a lot of people do the layout file technique with VCarve that you are talking about, and it can work great.

@ClintonCaraway-CNC 3 ай бұрын

PwnCNC sells toe clamps with square washers for reenforcement.

@CorbinDunn 3 ай бұрын

Awesome! I hadn't seen the ones PwnCNC makes - they look similar and probably work great! The square washer probably helps avoid the flex issue that I see in the long clamps - that is a great addition! Their pre-made Toe Clamps at $13 are a pretty good deal. I talked with PwnCNC not too long ago about helping with some of their ATC stuff on Mach 4; they are some nice guys.

@bloho_design 4 ай бұрын

Another great video! I’m pretty scared about running into hardware so I’ve done nylon 1/4-20 hardware, and am lazy so will tap the hardwood for threads instead of embedding a nut (since I don’t want to use metal t-nuts..)

@CorbinDunn 4 ай бұрын

Thanks, and nylon 1/4-20 hardware!! That's actually a great idea...I hadn't ever thought of it.

@AndyBlackman 4 ай бұрын

The AirWeights Workholding System seems to be promoting itself on the socials lately. Kinda pricey. Looks interesting though. I think its is directed towards more production level workloads.

@CorbinDunn 4 ай бұрын

I do recall seeing an ad for those a while back! I just googled it again, so I'm sure I'll be seeing more ads in the future (hah!). They do look nice, but pricey. I bet one could DIY the same setup for at least half the cost. The usual time vs money tradeoff.

@braunproductions3254 Ай бұрын

Love your channel. Since you are the youtube channel that most resembles what i would do with a router table I would like to know what you would order if you were to start over today? Basically tell me what to order from who and hopefully I can afford it and place my order right away. Thank you in advance

@CorbinDunn Ай бұрын

Thanks! It's still not an easy decision on what to buy. I still go by a lot of the statements in my first video about the Avid CNC (link at the end). I still think that is a great machine and a good buy. In my use, I don't think I really needed an 8'x4' table; a 4'x4' would have probably been better, and I don't think I needed the high HP spindle I got. I'd maybe look more into the StepCraft series of machines with an ATC, mainly to get more accuracy and precision with a ball screw, but at the expense of not as much power or speed. In general, I don't cut too fast due to bad quality when doing that, so speed may not be as essential as I was initially thinking. I'd also possibly consider Phantom CNC's 4x4 ATC machine, however, shipping is still prohibitively expensive to California. An Avid CNC with a CNC Depot ~4hp ATC spindle is probably still a good option. Link: kzfaq.info/get/bejne/jNmInN1l096ld5c.html

@braunproductions3254 Ай бұрын

@@CorbinDunn I have watched that video. I guess i am asking for more details for what you suggest i get from avid and other companies when I order an avid 4x8. I plan on building my own Table Base and really want an ATC. Thanks again

@CorbinDunn Ай бұрын

@@braunproductions3254 Oh cool - Aside from Avid's basic kit (minus legs, if you make your own base), get the RM 40 kit: www.cncdepot.net/products/newavidkits -- that's mostly it!

@CorbinDunn Ай бұрын

Or RM40C, for higher RPM

@billysmether6237 4 ай бұрын

A vacuum will not hold down small parts. There is not enough surface area to create downward pressure. It can hold down a small part if it is connected to a larger base piece. I have tried them all. I screw everything to the machine bed (MDF). Super fast, super secure, and nothing for bit to jog into. Thanks for video!

@CorbinDunn 4 ай бұрын

Awesome, that works! I've heard of some people making more specific small-part vacuum chucks -- some work for wood lathes..I might investigate those at some point and see how well they work for CNC

@maddogtungate6740 2 ай бұрын

I don't understand how people seem to always run in to their hold downs when you can program the cnc to go above them.

@CorbinDunn Ай бұрын

Yeah, for sure...I still do it by accident on occasion (like, yesterday, doh!)

@cliffart7398 3 ай бұрын

The 1/4-20 you used is not a nut but a bolt. I have made mine out of wood.

@CorbinDunn 3 ай бұрын

Making them out of wood is a great idea! No chance of hitting metal with a bit. I might have mixed up the words nut and bolt at some point...hopefully my point came through.