High-Z S400 from 2008, gift horse or old nag?

I was visiting the workshop of chap I work with and learned that back in 2008 he bought a Heiz High-Z S400 direct from Germany, but hasn't used it much, or not much lately. He perked up considerably when I said it looked just the sort of size machine that I have wanted to play with, the up-shot being that he has let me take it away to try out and told me to figure out what I think it is worth and make him an offer.

His kit consists of the base gantry set up, the controller, a Kress 1050W router with 3mm and 8mm collets, a very elderly (and huge) desktop PC and CRT monitor running XP and WinPCNC-Economy and about 15 carbide cutters in 2mm and 3mm sizes for PCB profiling. I have no space for the PC and would need to figure out some way of running the machine from a laptop.

On the face of it his suggestion seemed very good, but figuring out how to work the system has not been smooth and I could do with all the advice I can get. It was left with MDF dust sitting around where condensation could form and there is a fair bit of rust on the router screw and corrosion starting on all the guide rails. Could this older machine be a good deal, or am I more likely to just be buying trouble?

My main concern is that I very quickly encountered the problem I have now read of with other people of the motors stalling and the machine losing track of its position. Worst case was by 92mm in X! Contacting Prototools here in the UK and was told to clean the spindles, which were pretty dirty and had been greased, but that if that didn't work and the spindles needed replacing it would be a back-to-Germany job to the tune of £850+VAT. Is it possible to get parts and do repair oneself, or is this machine built to defeat user repairs?

Contacting CNC-Step in Germany I learned that the old 2008 version of the S400 has a max speed of 15mm/s (900mm/min = 35ipm) whereas the new machines are quoted as 50mm/s (3000mm/min = 118ipm).

I was driving in air just testing tool paths at 15 to 17mm/s before I learned this, and the x-axis was regularly stalling so I expect that actual cutting speed will have to be a max of 10mm/s. Most of the advice on feeds and speeds quote cutting phenolic, acrylic and wood (which is pretty much all I want to work with) between 17mm/s and 34mm/s (40 and 80ipm). My interest is in 3D contour machining rather than 2D profiling and V-carving. How much of a handicap is a speed limitation of 10mm/s for 3D router work?

Finally, would anyone care to help me figure out what an 8 year old, slightly corroded and over-greased S400 system would be worth? It was around the £2200 mark when he bought it, and a new machine with router, controller and USB adapter comes to about £2500 now. Given its age and that it might need more than a little cleaning up I was thinking it might be worth £1000, but I really don't know what the market is.

As I said, I hope someone out there can offer advice!!

Cheers

Alex

I will leave it to those with more experience to advise you but personally I wouldn't dream of spending £1000 on a machine that I could build better for same money, I looked at many and decided to design/build my own and as a result I have a mill converted for £680 including new purchase price I used for my build (I did not like idea of extrusion personally), and a Router with 750x420x100mm work area 2.2kw VFD and spindle, extremely solid 12mm DOC in MDF 1/4" bit at 1500mmpm and had plenty left, and £1000 covers everything even pricing aluminium at the Ali Warehouse as I got most of it very cheaply. Add in my Mach3 Licence and I am still well under £2000 with two machines working well and doing all I require, if you use extrusion you would not need the mill and even cheapest supported rails would be better than the unsupported ones I believe these come with looking at site. I would offer him £300 and take a chance but once I got near cost of a half decent build I would run!

Hi
I have the 720 which is less than a year old and i like it for what i do but it has not come without problems.

If you search for my posts you can catch up with the problem i have regarding speed and yes the cost implication of getting the screw sorted is high. I now run at a much lower speed and get some great results but as Jazzcnc and others will tell you for the money i paid it should be running a hell of a lot quicker. As i cant afford to build or get another model i live with this restriction so my advice is definitely dont over drive it, if you cant live with low speed for whatever reason then its not going to be much cop for you i imagine.
I use WinPCNC which when i ran the setup all the default settings are there, i dont know what you will use but if i can give you a setting or 2 i will try.
I am a novice so would not give you advice thats really for the experts i just hope this adds a bit of info for you

Bernie

Rusty rails and old PCs need replacing, then you need to get the thing running which could involve more new hardware and possibly software too.
It's not worth more than the second hand value of the parts once stripped, as that's what you'll end up with if you can't make it work properly.

- Nick

Give it a Miss your buying trouble

Rusty is going a bit far for describing the rails. There wasn't any red-brown rust, just the spider-web black lines showing where corrosion had started.

I have got the machine for another two weeks at least, so will see what I can coax from it but I am coming around to your way of thinking, that it could be more trouble than its worth, or that it will still be worth more to its current owner than it will be to me.

There are a limited number of things that I have wanted to do on a CNC for a long time, but they are still a limited number, and I am not sure that I would ever manage to do enough to make it pay any significant contribution to its own cost. Simply working on it and the CAD/CAM is somewhat addictive, and I have a long list of other build projects that I should be working on....like turning the stack of 3m joists that have decorated one side of my dining room for nearly three years into a carpenters work bench! When Lucan07 suggested building a better machine, I thought about that pile of timber and the relative complexity of bolting a bench together vs construction of a precision power tool + wiring a computer interface. LOL!

I am still enthusiastic about CNC and its hard to keep reining that in to think about such a tool purchase in a rational manner. Thanks for helping!!!!!

My build totalled less than £1000 at full price from online suppliers I did grab a few bargains along the way I have spent under £800, I am currently using MDF Base 75mm thick top as an alternative to carrying almost half a ton of steel and cast iron upstairs (The base I designed my router for stored for later use). If materials brought cut to size from somewhere like Ali Warehouse or using Extrusion as many do there is little need for machining plenty of drilling and tapping, although a chop saw with fine tooth tungsten blade cuts aluminium reasonably well. Have been machining Aluminium as easy as on my converted Mini Mill as for the wiring and PC interface is quite simple plenty of documentation and help available in forums.