I'm planning my first Raw Inventive 2.5 build and would appreciate some advice before I start ordering parts.

My intended machine size is relatively small, around 750 mm × 750 mm overall dimensions, and the primary use will be guitar building (acoustic + electric)

fretboard slotting

inlay work and rosettes

truss rod channels, maybe neck carving

body shaping + pickup cavities

templates, moulds and jigs

I do not expect to machine aluminium, at least not regularly. The machine will be used mostly for wood, hardwoods, plywood and occasional plastics.

I already own a complete NEMA23/TB6600/Mach3 electronics kit, so I plan to use that.

I have a few questions:

1. Ballscrews vs Timing Belts

For a machine of this size and intended use, would you still recommend ballscrews over timing belts?

I'm interested in good repeatability and accuracy for fret slotting and inlay work, but I'm not running a production shop and cutting forces will be relatively low.

For those who have used both systems, is there a noticeable real-world advantage to ballscrews for guitar work?

2. Makita Router vs VFD Spindle

I'm debating between a Makita trim router and a VFD spindle.

For fine work such as:

fretboard slotting

small inlays

detailed engraving

is the Makita's runout a practical limitation?

Would I actually notice a difference in accuracy or finish quality, or is the main benefit of a spindle reduced noise and smoother operation?

If you were building this machine today specifically for lutherie work, what would you choose?

3. Steel Plates vs Valchromat

The plans recommend steel plates, which I can order, but I already have a substantial amount of 19 mm Valchromat available.

Given the relatively small machine size (750 × 750), would 19 mm Valchromat be a reasonable alternative for:

gantry side plates

Z-axis plates

carriage plates

motor mounts

provided that it is properly sealed and reinforced where necessary?

Has anyone built a smaller Raw Inventive machine using Valchromat or another engineered wood product for structural plates?

If so, were there any issues with rigidity, long-term stability, or mounting rails and bearing blocks?

I'd love to hear opinions as well as feedback from anyone who has built a similar-sized machine.

Thanks in advance!

Saïan

You do not need anything exotic for these parts. Normal mild steel / low carbon steel is a good choice because it is strong, stiff, easy to cut, easy to weld if needed, and usually easy to source locally.

The main plates are 6 mm steel, and some of the smaller or less critical plates are 3 mm steel. As long as you follow the thickness specified in the drawings, the exact mild steel grade is usually not critical.

Aluminium can also work for some plates, but steel will be stiffer. That is one of the reasons I prefer steel in the more critical parts of the machine. Aluminium is great for the frame and for keeping the machine builder-friendly, but steel plates help add stiffness where it matters.

So if you talk to a local laser cutting or metal supplier, I would simply ask for mild steel / low carbon steel plate in the specified thicknesses. In the US, A36 or 1008/1010 type material should be a good and common option.

Powder coating is a good finish, but paint, zinc coating or even a good primer and top coat can also work. The most important thing is that the plates are flat, accurately cut, and protected from corrosion.

Does it make a difference at all?

I found this Dutch page: https://proleantech-com.translate.goog/nl/v-slot-vs-t-slot-aluminum-extrusion/?_x_tr_sl=fr&_x_tr_tl=nl&_x_tr_hl=nl&_x_tr_pto=wapp
But I still don't get it.

regards
Henk Schouten

Where are the files to download? I cannot find them.

I’m planning to built the belt version using parts I already have and later maybe change to rack&pinion. Can a 2.4 meters long belt machine work ok, knowing that maybe change to r&P in the future?

thanks

This should now be fixed, so members should be able to start new topics under the existing forum sections.

If you notice anything else that does not work as expected, please let me know. There is a lot to set up and organize right now, so small mistakes can happen while everything is being built.

Thanks for your patience and for helping improve the forum.