Questions about upgrading Wasteboard

It has been awhile since I have posted as it’s been awhile since I have used my S3XXL. Honestly the biggest downfall for this machine is the wasteboard/bent steel frame. I feel like every time I want to use my machine, I need to resurface my wasteboard.

As I want to use my machine more, I have some questions. I plan on purchasing some 1020 extrusions, and making some aluminum brackets to replace the base of the S3XXL. To avoid expansion/retraction of MDF I am looking at stress relieved HDPE. Has anyone ever used threaded inserts in the HDPE for workholding?

Finally, I am thinking about laying down some butcher paper for every job just in case if the bit cuts a little deep, to keep my HDPE as new as possible. Anyone see any issues with cutting into paper? Maybe dulling the bit faster?

Thanks for the replies.

Hi Kyle, check out these threads HDPE Milling Gears - #41 by LWSIV, HDPE Wasteboard question - #6 by LWSIV. I upgraded my bed to a subframe of aluminum extrusions with a HDPE spoil board. I installed a grid of threaded inserts and find they hold well. I use mostly side pressure (cam clamps and fences) or blue tape and super glue for hold down so I’m not pulling on the inserts too hard. I set my zero on the spoil board with the bit zero on a few layers of tape so I just touch the tape or leave an onion skin. Butcher paper if not rosin treated is just really thin wood so I would not expect any issues, it would be less of a mess than adhesive from blue tape on your endmill.

Thank you for your reply! I just wanted to make sure I was going down a decent path before investing the money into the 8020 frame/HDPE, etc.

You don’t need threaded inserts for HDPE. I tried heat inserts for plastic and they were pulling out. Tried wood inserts with external threads and they were doing a lot of mess distorting HDPE. HDPE board was only 1/2" thick so maybe too thin for wood inserts.

Just drill and tap the hole and it will work great. I used HDPE on both of my machines to isolate aluminum fixture plates from the machines’ frames and it’s been a solid solution. I actually use hdpe for some fixturing as well, and it holds aluminum very firmly.

Many many years ago this machine used to be a shepoko as well. :rofl: :rofl: :rofl:
On this router I actually bored holes to the thread’s minor diameter (m5 in this case) and simply forced bolts in to form threads. The same way I sometimes do with 3d printed parts. This fixture plate isn’t going anywhere.

Thanks for your insight.

I figure, if I am going to spend the money on a 33 X 33 X0.5 inch HDPE sheet, I can buy something smaller and test threaded inserts, etc.

I used T-nuts installed in countersunk holes from underneath in HDPE on a wasteboard for my SO3 back before I upgraded it to an XL — they worked well, and I didn’t worry about the threads wearing out.

Not wild about paper underneath — it’s surprisingly abrasive and will probably wear endmills. A better option would be some sort of thin plastic film or MDF.

Another option that came to mind, is using 1mm shim rings and put them in strategic locations, to avoid the endmill:

I just don’t anticipate using my S3XXL often enough that a wooden spacer wouldn’t expand/contract, and with the double sided machining I plan on doing, I need some consistency.

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I have a Shapeoko 3 XXL. I built a torsion box and put a piece of foam under my Shapeoko to prevent the central sag. I also documented the torsion build and how to create an optimized spoil board for an XXL. Attached are both documents.

torsion_box.pdf (2.0 MB)
spoilboard_considerations.pdf (1.3 MB)

Take a look and see if these will help any.

I live in a hot and humid environment in East Texas and I dont have any issues with the spoil board.

I have considered going that route, but it would time and money on a solution that still has a potential to not work for me. Instead I can spend a few more dollars, and get something that can square the frame by adjusting the extrusions, stiff, and is not effected by moisture.

Understand, I am just trying to find what I think works best for me and what I intend to machine.

I can see what you are talking about but the document Spoilboard Considerations i still valid about making a spoilboard out of HDPE or any other material. Any material you make the spoilboard will need to be surfaced on occasion. The advice given in the document will help you size the supplemental spoilboard so it can be surfaced.

Are you going to replace the MDF base board that comes from C3D with another material and then put a spoilboard on top of that or just a new base board and use that as a spoilboard?

I plan on removing the bent steel frame, all of the MDF and replacing it with aluminum extrusions and the HDPE wasteboard.

I understand the HDPE will need to be surfaced a few times throughout it’s life. But right now I don’t use my S3XXL at all because everytime I have used it over the last year, I had to resurface the MDF. If I can reduce that to once a year or less, then I will be happy.

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