Post by timo on Jul 6, 2019 16:34:57 GMT
Hi All,
I had sort of hijacked silverfox's thread on buying X & Y axis feed motors for the WM16 and springcrocus rightly suggested that I created a new thread.
Basically there are no commercial feed motors that will bolt straight on to the WM16. There is one for the WM18 but it won't fit the 16 (no doubt it could be persueded but that would invalidate any warranty. All the feed motors I found cost between £300 and £500 depending upon the mill used (this is for the normal mills found in the model engineers workshop) which is a considerable proportion of the cost of the mill. I would rather spend that sort of money on a decent vice and some tooling. So the only option is to make something.
In looking at the problem and by doing some fly cutting recently, I decided that I needed something that would turn the feedscrew at 6 rpm at the slowest and some 180rpm for a fast traverse.
I then went on to consider technology. We could use a 12v DC motor and a P.W.M. controller. It would be cheap and cheerful but P.W.M. controllers tend to loose torque at low speed and that is where we would need the torque - a heavy cut needs a bit of grunt. Second option would be to use a mains motor and gear it down but then you would need a gearbox or pulleys which either make it quite complex or you have to change belts to change the speed and thus limit the number of speeds. Finally you can use a stepper motor with either a discrete for micro controller.
Sprincrocus suggests that you probably don't need more than one speed and can wind the handle to return the table at the end of the cut. He uses a recycled windscreen wiper motor quite successfully. I feell that a few speeds or a variable speed would make it more flexible and it would probably get used more often (perhaps it's just me but I find if something is easy to use it does get used more often).
I am about to start playing around with things before deciding on a way forward. I am quite happy designing electronics and micro systems as well as programming them so all options are on the table. I also have bits in stock which will allow for different solutions so that helps.
My latest 'middle of the night' thought is to try recycling an old 14.4v battery variable speed drill as it has a reasonable speed range, a built in speed controller and even a torque related clutch. A dismantle and ponder is planned!
Any thoughts or experiences gratefully received.
Tim
