Hi All- I'm about to embark on designing and building a new router. I thought I'd record its progress here. I've had two starts at it but have been interrupted. I decided to start clean sheet as some issues with two of my other routers have highlighted some of the long term wear issues with some components. So I've rethought a few things:

So the rules of engagement: 1) target working envelope is 2400x700x300. I'd like to make it a full sheet machine but where it will live will not have the width. 2) Must be simple. All of my machines have been very simple and reliable as I have put the time into reviews and contemplation and full 3D modelling. 3) This one must cut aluminium as I want to make some parts for the next machine. The next machine will be a 5 axis router and I want to make the machine head. I'm tempted to make it a mill with a sliding table design but I have some long hydrofoils to make and I need a 2400mm plus cut capacity. 4) I have researched rack and pinion (plain and helix) but have not found an economical source for these yet so my current thought is to use 25mm wide AT belt. Very stiff. 5) I usually start designing the bench or base and work towards the tool. This time I'm going to start at the tool and work towards the bench. The Z axis is very important for cutting accuracy and I find I eventually compromise some of the geometry by starting at the base. This is because its like a pyramid and you run out of geometry as you get to the top. So by starting at the top I may end up with a bigger pyramid then I thought but at least it will be very solid. 6) I usually use routers but it's time to graduate to a spindle. So I'll do some more research on that. 7) I have to decide whether to use 15mm rail or 20mm rail. I usually use 20mm but the cost has gone up. Waiting on more quotes from local OZ suppliers. This has made me look for an asian supplier. Anyone know of a good one? I've used PMI, STAF and now WON brands.8) I've attached the napkin sketch of the Z axis and will get this into CAD asap. I use Alibre for this sort of mechanical design. I also use Strand7 and simsolid for FEA analysis of various bits. This helps in deciding which way to go if I have two designs. The stiffer one wins. 9) I usually use stationary motors on the y axis vs having a moving motor design. This is to lessen the weight of the gantry, make the wiring slightly easier as the motors are stationary and it also removes one idler. Idlers are expensive by the time I get them bored and buy bearings. The downside is that the belt run is twice as long so its half as stiff. To counter this I intend to put a motor at each end of the run. The stepper is nearly the same cost as the idler and this will increase the belt stiffness as it will be pulled and pushed along the drive side of the belt. I've had a play with this and it seems to work. I wire the two motors in parallel and drive them from the same driver. 10) Most parts will be laser cut stainless steel or aluminium as is Brevis and Scoot my other machines. Powder coat works out more expensive due to the extra handling involved. Plus I've had trouble with thick powdercoat making assembly difficult. 11) I'd like to get something metal 3D printed so will look at these parts for an opportunity or I'd like to make some of the parts in carbon fibre so will look at that as well. I made Scoot to make moulds and I've only done one mould in 2 years of use!!

That's about it for now, when I get the Z axis modelled I'll put it up here for comment. Cheers Peter S