Spoilboard setup

[Carl Beckett]

How do you setup your spoilboard?

I have a small desktop cnc with aluminum channels and T slots for hold downs. On top of that are strips of MDF. Sometimes I screw a reference board or even a corner to locate to.

But I keep changing things up and am curious what tricks you have that work well for you.

I was considering milling an X/Y slot into the spoilboard that I could slide stops in and out of. That would give a 'corner' to locate to (and wondered if limit switches were accurate enough to repeat back to that same x/y each time?)

Or a board on top of the board that I put in place when I want to locate to a corner (and have stops screwed onto that board)

Additional inserts that hold downs could be used with?

I have seen a lot of different holding clamps so it is the location tricks I am more interested in.

Or do you take a cut on 'everything' to ensure it is square (vs locating the piece) - so far, I end up doing a lot that locates the piece to reference then cutting from there.

And some of the location features get in the way, so thinking lower profile the better.

[Jim Becker]

Carl, the machine "should be able to maintain exact registration of X0-Y0 if it's of any quality at all. Some controllers permit multiple relative X0-Y0 locations to be saved and recalled which is really valuable, especially if multiple fixtures might get used by the creator.

I do not use a specific. fixed point for relative X0-Y0 because most jobs I design and run use the center point of the material. The few that do use front-left for X0-Y0 (usually large sheets) get pegged to the machine absolute X0-Y0. When running multiples of something, I sometime tack scrap strips of wood/ply to the spoilboard with composite "nails" so that each piece following the first has the exact same registration for the run.

There are so many ways to do things!

[John TenEyck]

I would not trust my OneFinity to have a consistent X0 Y0 from a restart. Once it's booted up, though, whatever you call X0 Y0 will stay in that location part after part. My machine only has one X0 Y0 but it's still possible to machine multiple parts each in a separate location on the spoilboard if I use stops to register them in that location. But I'm generally only machining one or more parts from one piece of material, and usually use the X, Y, Z probe block to find the bottom left corner and material thickness.

I have a removeable piece of wood attached to my spoilboard that acts as a fence in the Y direction. I machined it after I installed it, so I know it's parallel with the X axis. It starts about 6" from the left side of the machine and extends most of the way across. Most pieces I machine get registered against that fence, with the left edge beyond the left end of it a few inches so I can use the XYZ block. If I'm going to machine multiple jobs that day, I attach a fence to the spoilboard on the left side of the first piece of material to be machined. Subsequent jobs can be indexed against those two fences w/o having to probe again for X and Y, only for Z if the jobs have materials of different thickness.

I have T-nuts in the bottom of my spoilboard every few inches. I can install clamps (shop made ones of wood) using those T-nuts, as well as fences, and even bolt parts down directly to those T-nuts. I use clamps when I'm cutting out large parts or when adding tabs around the perimeter of the parts to be cut are acceptable. But for tiny little parts and parts I don't want left with tabs to clean up, I use blue tape and CA glue to hold them to the spoilboard. A composite nailer would be a great addition for many jobs, but for those tiny little parts (less than 1 x 1" and often less than 1/2" diameter, or something long and very skinny) the best option I've found so far is blue tape and CA glue. I let the parts dictate how I hold them to the spoilboard.

An option I've used a few times is to cut a biscuit slot in the side of the workpiece. Some of my clamps have tongues on the end to fit into those biscuit slots. That allows me to machine off the edge of the part w/o worry of hitting the clamp.

John

[Kevin Jenness]

I use the bottom left corner of the spoil board on my Camaster machine as a X0Y0 reference. When I periodically replace the spoilboard I trim its margins using a 3/8" diameter bit running at the default limits of the WINCNC control system and I use a .187" offset from machine 0 labelled "table corner" in my home positions settings menu.

Your machine should have a reliable, repeatable machine home position based on limit switches on all 3 axes. You could do as I do and mill the spoilboard's x and y lower limits to establish a fixed corner and edges and reference them with your control system.

[Carl Beckett]

All useful comments, thank you. The type of ideas for consideration as I ponder and test some new ways.

My CNC is an older ShopBot. It does have limit switches. But I have not tested the repeatability of those (at least not the x/y home at the lower left, which would be my most likely to use)

Most of my work to date has not been complete profiles. So locating a working piece is key. And like Jim, I end up referencing centerline a lot (a separate thread on ways to accomplish this and still working some ideas on that). I havent done many of the little pieces that some of you have, but no doubt it will happen (am intrigued about cutting 'almost' all the way through then flipping and sanding the back side to get them to fall out)

The concept of splitting up work areas is intriguing. Keep the indexer mounted in one area. Vertical work in an area. Secondary platforms to index at a corner or centerline that can come on/off with some locating pins. Maybe one of these modules is the indexer even. Vacuum table as a module.

Essentially modules that serve different locating/hold down functions.

Which might be more trouble than just treating each piece uniquely.

A thought exercise and appreciate the experiences of others.

[Steven O Smith]

Nothing fancy here, but I can just see myself forgetting and running a cutter into the fasteners that hold the spoilboard down. I use nylon screws.

[David Falkner]

Nothing fancy here, but I can just see myself forgetting and running a cutter into the fasteners that hold the spoilboard down. I use nylon screws.

Ditto. Bought a bunch of them when I built my machine. And it's a good thing because I've hit a few.

[Brian Tymchak]

Nothing fancy here, but I can just see myself forgetting and running a cutter into the fasteners that hold the spoilboard down. I use nylon screws.

Ditto. Bought a bunch of them when I built my machine. And it's a good thing because I've hit a few.

Sounds interesting. Can you provide a link to what you used?

Thanks!

[Michael Burnside]

Most of what I do is one-off custom work. So, I don't really use G55+ work offsets all that often for setup. I know this is a popular YouTube topic, but I'm just never batching out a lot of the same jobs. If I did, maybe it would be different.

I certainly have multiple park locations after a job/tool is done, which I employ as part of my post-processor depending on the job/toolpath.

Even though I don't use repeat work offsets, I certainly believe in registration references. These references can be used to identify X/Y (on topic to the OP's question) and I would 100% trust my machine, after homing, to get back to that spot +/- 0.001". That said, these references can also be used to ensure the workpiece is perpendicular/horizontal to one or more axis. This is quite important when milling hardwood panels, etc. so you don't have to waste material to compensate for a slightly skewed panel. I do use workpiece center, as Jim pointed out, but often this isn't practical if say I'm milling out 4 legs or different parts of a furniture build that is comprised of different material sizes.

My spoilboard consists of 20MM dog holes and 4 vertical t-tracks. The use of TSO dogs and TSO dog stops give me untold flexibility in work registration, mentioned above, while at the same time being good for lateral support, preventing the work from shifting. Typically the use of two clamps and the dogs/dog stops is all I require for work holding. I have done probably close to 100 jobs in the last two years with this refined setup and have not had a single job slip/move, ever. In this time I have used double-sided tape probably less than 10 times, and I still use the dogs/dog stops so shifting is never a concern. I also have a unique setup I designed where I use two aluminum bars along the horizontal axis, held down by the t-track, using Woodpeckers "combo track", which allows me to have stops on all sides of a workpiece. Happy to share this setup sometime if interested.

Slightly off topic, but in my opinion people focus too much on clamping and not enough on lateral support. Even an upcut bit on 8/4 walnut being hogged out with a 1/2" bit is quite easily tamed with 2-4 clamps either on the top/bottom or 4 corners. The lateral stress going at 225 IPM is much greater and clamps, even those little detents for registering material edges, aren't as solid as a dog or dog stop that can't twist. Plus they are much lower profile.

[Jerome Stanek]

All useful comments, thank you. The type of ideas for consideration as I ponder and test some new ways.

My CNC is an older ShopBot. It does have limit switches. But I have not tested the repeatability of those (at least not the x/y home at the lower left, which would be my most likely to use)

Most of my work to date has not been complete profiles. So locating a working piece is key. And like Jim, I end up referencing centerline a lot (a separate thread on ways to accomplish this and still working some ideas on that). I havent done many of the little pieces that some of you have, but no doubt it will happen (am intrigued about cutting 'almost' all the way through then flipping and sanding the back side to get them to fall out)

The concept of splitting up work areas is intriguing. Keep the indexer mounted in one area. Vertical work in an area. Secondary platforms to index at a corner or centerline that can come on/off with some locating pins. Maybe one of these modules is the indexer even. Vacuum table as a module.

Essentially modules that serve different locating/hold down functions.

Which might be more trouble than just treating each piece uniquely.

A thought exercise and appreciate the experiences of others.

If you have the 4g or alpha controller the limt switches are pretty much right on if you have your offset in the setup

[David Falkner]

Sounds interesting. Can you provide a link to what you used?

Thanks!

The screws I bought are black with Philips head but the last time I checked they weren't available from that supplier. Here are some that are similar - https://www.amazon.com/Hard-Find-Fas...0L1KZOEK/?th=1

[Kevin Jenness]

Most of my work references off the milled spoilboard edges, whether indexing directly off the edge or aligning with an adjustable square or pencil mark gauged from the edge or a "trace" cut milled a few thousandths into the spoilboard. Sizing every part on the cnc because of imprecision in locating them on the spoilboard would not work for me as I often have to machine panels already cut to size.

Industrial machines use pop-up pins which you can mimic by attaching rotating cam stops to the edge of your trued-up spoilboard. Another indexing method involves boring holes for index pins which can be used to align edges or accept locator pins bored (on the cnc) into the bottom of workholding fixtures or can accept low profile dogs and clamps. For me, all these reference off the X0Y0 table corner, a fixed and easily checked point.

The limit switches should be very accurate and repeatable. It is worth checking that your machine lines up to the same machine home every time, cuts square, cuts to accurate size over the full length of the axes, is set up level and the spindle is square to the table.

[Brian Tymchak]

The screws I bought are black with Philips head but the last time I checked they weren't available from that supplier. Here are some that are similar - https://www.amazon.com/Hard-Find-Fas...0L1KZOEK/?th=1

Thanks David!

[Bruce Page]

Carl, this is my setup. I use the dowel pins to help align pieces when needed. They often come in handy. I do remove the pins before cutting. I used regular “Truss Lath Screws” from the blue borg to attach the SB to the black machine bed. They are recessed deep enough that I don’t worry about hitting them.

[Carl Beckett]

Carl, this is my setup. I use the dowel pins to help align pieces when needed. They often come in handy. I do remove the pins before cutting. I used regular “Truss Lath Screws” from the blue borg to attach the SB to the black machine bed. They are recessed deep enough that I don’t worry about hitting them.

Almost identical to my setup. I have some 1/2" Al rod I was making the dogs out of. Need to decide how many and on what pattern to space them.