Not entirely sure this is the right place to be asking this, but I’m hoping any Kiwis around here may be able to offer me some advice.
I’ve been considering the Nomad 883 (and now the new Pro version) for quite some time, with the intention of using it to cut master models for casting video game and TV show prop replicas. However, my reluctant to put an order down for a machine right away is due to my inability to find a steady supply of RenShape 440/450 of the right dimensions to work with:
I recall that the Carbide 3D store sells RenShape as “Synthetic Wood”, but 2x3x1" is a bit too small for many of the pieces I want to cut.
I’ve heard that one glue up several smaller blocks with specialty adhesives made by Huntsman Advanced Materials themselves, but I haven’t been able to find a local (New Zealand) supplier, nor am I confident I’d do a decent job gluing them together.
I’ve tried asking both Huntsman and Freeman Supply (USA), but they refused to give me a quote and instead referred me to their Australian supplier
I’ve tried the Australian supplier (Meury Enterprises). The salespeople there said they stocked them, but informed me the shipping cost alone would be far greater than the cost of even the smallest boards themselves, and suggested a supplier in New Zealand
Finally, I asked the NZ supplier (Nuplex Construction Materials), who only stocks RenShape not from the 4xx series, and quoted NZD$700 for one board, excluding tax, shipping, administrative fees etc.
A friend of a work colleague suggested MDF, with the caveat that I mill slightly smaller than my original dimensions to allow for swelling, impregnate the MDF with epoxy, then re-machine to the final dimensions, although I suspect this process may adversely affect the finer details on my models.
Said contact (who worked as a technician at Crown forestry institute) alternatively suggested a rather expensive and exotic New Zealand hardwood species that apparently would not require further surface treatment. Unfortunately, this contact went incommunicado after being laid off as part of the Crown institute’s downsizing, so I couldn’t pursue this avenue further either.
Finally, a local company called Kiwi Tooling Ltd offers proprietary urethane tooling boards, but their recommended applications seems to be aimed at making large plug molds for laying up composites sheets for automotive/boat/RC airplane, and I don’t have enough information to determine whether these proprietary boards have similar mechanical properties to / can hold the same level of detail as RenShape.
Any ideas what a Kiwi could do to get RenShape at affordable prices? Or a convenient alternative that doesn’t involve casting my own tooling boards out of sawdust/cornstarch?
Remember that MDF is a friable (“easily crumbed”) material (e.g. wood, MDF, FR4, Garolite, carbon composite, Fiberglass) that generates particles which are extremely damaging to your lungs and health.
While all MDF is dangerous, some MDF is SIGNIFICANTLY more toxic and dangerous than others. YMMV.
Renshape and similar are relatively non-toxic but boarder on friable. I would strongly recommend proper air safety issues when milling it.
Starboard/HDPE can be used too. They are relatively inexpensive. Delrin - pricy - would give a really nice feel.
Or a convenient alternative that doesn’t involve casting my own tooling boards out of sawdust/cornstarch?
In that case, I’m definitely steering well clear of MDF - I’ve worked with small bits of it before with hand tools, definitely not a fan of the resulting burnt wood smell.
Thanks for the heads-up.
I’ve been looking at alternative medium density polyurethane tooling boards as well, just not too confident I’ll find smoething reasonably priced that will perform well and happens to be something most Nomad’ers are familiar with (don’t want to spend more time characterizing the boards instead of doing more productive work)
I’ll definitely check that out, thanks.
By inexpensive, I presume you mean compared to tooling boards?
How does its machinability compare to RenShape? Is it particularly brittle? Does it hold fine details well? (In the order of millimeters and smaller)
Do you have one of those white, somewhat slippery cutting boards? That’s HDPE.
HDPE has wonderful machinability. It can be roughed on the Nomad in the 50-60 IPM range. I’ve hogged it (really aggressive roughing) at 70+ IPM but it’s makes quite a racket. I finish down in the 25 IPM range.
It’s not brittle at all.
I’ve machined features down to 0.01" and smaller with excellent results.
I use TAP plastics as I live on West coast of the USA and they are based here. They sell whole sheets, blocks and have a cut to fit service. I just picked up 6 3x3x1 blocks - US$10.98 (with tax). I use 0.5", 1.0", and 1.5" for many projects.
An alternative to HDPE is Starboard. That’s modified HDPE that makes it slightly tougher and UV light resistant. It comes in several colors.
It’s denser than Renshape so it would have a nice “feel”.
I’m not sure how well one can put a finish on it though, the “slippery” nature may not be what you want.
If you’re doing resin casting it might be a good fit. YMMV.
It would be worth getting a sample block and eyeballing it… or get a cutting board!
I’m not too fussed about having a glossy finish - just as long as it doesn’t leave a grainy texture, even a smooth matte texture would do fine.
Not grainy at all after machining. Definitely a grainy feel to raw stock.
Starboard is SLIGHTLY preferable to HDPE… but they machine at the same rates.
One thing to keep in mind is that the STL file one feeds to MeshCAM should have the highest number of triangles you can get your CAD to emit. The more data, the better the surface fit, especially for round features.
It’s also important to turn the MeshCAM tolerance to 0.0001" (or the metric equivalent) and let MeshCAM wail on the data. The more time spent in MeshCAM, the less machining time and the best finish.
Next comes the size of your end mills and the type. I recommend AlTiN coated end mills for everything other than Al and Al alloy. Small end mills can be easy to break so learning to use them properly - to get the finest features - is important.
I would rough with 0.125" and work your way down to 0.0625" or even 3/64".
I would seriously consider Onsrud specialty plastic cutting end mills. They look expensive… but they aren’t! They are works of art and last for a long time.
Absolutely. I always set SolidWorks to export STL at the highest possible quality - not taking any chances there.
Cool, thanks for the heads-up.
Just had a look at your post in the linked thread - what about the bog standard endmills from the Carbide 3D store? Okay for learners / occasional jobs?
I presume this is King StarBoard, the marine-grade stuff?
Yup. That’s it.
Prices from a New Zealand supplier1 (Yikes!)
It’s cheap here. HDPE is the most used plastic in the world. It should have a good source locally.
Go to the TAP Plastics WEB site and see what their pricing is. Multiply by 1.51 (todays exchange rate). Could VAT and tariffs be a factor?
Just had a look at your post in the linked thread - what about the bog standard endmills from the Carbide 3D store? Okay for learners / occasional jobs?
Nothing wrong with them at all. They are good carbide steel end mills (I said so in the posting). That said, you can do much better. Going micro grain, solid carbide with a coating will allow for faster machining and longer end mill life.
