How to surface wasteboard


(Byrne Pedit) #1

I see recommendations to use a 1" Whiteside bit to surface an MDF wasteboard, perhaps that was on the ShapeOko. I also see someone being chastized for using a 3/4" bit on the Nomad. I have a Nomad on order and I’d ike to keep it in top order. Even without burning out the board it would seem larger diameter bits will put more stress on the spindle.

Is there a recommended method for surfacing wasteboards on the Nomad? Extensive passes with a 0.25" end mill? Run it through my drum sander and shim with metal tape? My biggest uses will be for fine line-enrgaving on flat stock so a truely flat Z will be a priorty.


(William Adams) #2

You can surface the aluminum table with a 1/8" square cutter, going 0.002"–0.003" at a time.

For the MDF with suitable passes you can use a 1/4" endmill, possibly larger — we have a bit about this here: How to write gcode to surface wasteboard?


(mikep) #3

A few things:

  1. Because of the way it’s built, Nomad really doesn’t have this problem.
  2. It’s not a “stress” issue on the nomad - it just doesn’t have the power to swing the bit. It’s <70 watts. Shapeoko is closer to 700 watts.
  3. Use a 1/4" bit. It -does- take longer than a 1" bit…but then, it’s a pretty small wasteboard by comparison.
  4. Try it before getting too worried about this. I’ve found that good clamping on Nomad is a bigger deal than it’s native accuracy - it’s very accurate, and very square, but a more challenging than you would think to get flat material clamped down to.

(Byrne Pedit) #4

@WillAdams Thanks, I’ll stick to the 1/4" endmill. I would hope not to machine the table. I read a post where someone’s Nomad was missing a washer attaching the table which resulted in its not being alligned. Supposing the table is flat enough and only needs squaring with the spindle axis, could one insert thin metalic shims at the attachment points?

@mikep Thanks for the suggestions. I’ll stick to the 1/4" bit for surfacing. I’ll be cutting a lot of material (MOP, abalone, silver, brass, copper, hardwood) all about 1.5mm thick. I’ve ordered some fixturing wax hoping that will be up to the job of holding.


(William Adams) #5

I believe it’s better to have the top of the table surfaced flat rather than the underside unsupported, but I’m a terrible idealist.


(Phil Gorsuch) #6

Think Will and Mike covered it, but I will throw in my tidbits.

I use a 1/4” bit to surface the MDF and it makes short work of it. I have yet to surface the Nomad table directly but I do use shims betwen the table and the stock to true the material as required when not using the wasteboard. Worked so far. One day I’ll get to surfacing the table itself - as Will mentions this really is the proper way to go.

Take heed of @mikep when he mentions work holding is key. Ultimately when you are working with large sheets of thin materials the real trick is actually keeping them flat relative to the mill. Those materials love to bow with clamping and are tricky to get perfectly flat with fixturing wax, carpet tape, or the masking tape/glue method.

I have a dial indicator I connect to the Nomad carriage and sweep over the stock after fixturing to ensure there are no unexpected high or low spots before starting an engraving job. Extra time yes (and a right pain when you have to rip it up and secure it again) but rarely disappointed by the outcome.

Hope that helps!


(Phil Gorsuch) #7

And almost forgot - welcome to the Nomad owners club!


(Byrne Pedit) #8

@WillAdams I’ll trust your judgement on this, thanks.

@PhilG Thanks. I have a dial indicator I was intending to use for this very purpose. Most of my materials will not be “large sheets”, probably thin pieces no more than 50 mm wide. My thought was to secure them with wax or glue to a slightly larger piece of 12 mm thick maple. I can then screw the maple into the wasteboard and shim under it to gain a true surface. The maple would then be sacrificial leaving the “wasteboard” intact. The threaded table would work for this too but I’ve spent that money on bits!


(Jesse Glessner) #9

I don’t know if you want to try this or not, however, in our Kokomo meetings some of the guys were talking about using a large router bit meant to mill out holes for door knobs.

The few who commented on it seemed to thing that it worked well for them. These are guys who have been CNCing for several years. One commented that you shouldn’t be having to use those bits that often anyway!

The bits are much cheaper than bits being marketed as the greatest wonder bit for the same job at 6 to 10 times the price.

AS IN ANYTHING NEW THAT YOU TRY USE CAUTION AND ALSO MAYBE SLOW DOWN THE FEED RATE!

AND, USE AT YOUR OWN RISK!