Freesteel Blog » 2005 » October
Just back from a long, cold and wet weekend in St Abbs. Three dives from a boat called the Silkie, and another two from our kayaks in less good conditions. It was very grey and dark and you could hardly see anything underwater without a torch. We didn’t have torches, because they were stolen from the garage last month by burglars. But I did take some pictures, one which came out of an octopus.
The kayaks were only good for surfing on the second day. We will go back to St Abbs in the summer and stay for up to two weeks exploring the place in better conditions.
Today I spent more time on testing the milling machine. I received a set of mills yesterday and decided to try one of our toolpaths on a piece of MDF.
Here some pics:
I am quite pleased with the results. I think I will try a higher feed rate next, maybe thats a way to avoid the cutter clogging up with burnt MDF. While cutting, something made the programme to loose its position and I had to stop it. I assume MDF is not an ideal material, I assume resin as used in toolmaker’s workshops would be much better.
Finally here’s a little movie. Light conditions were not good and I used my digital camera, so not the greatest quality.
Friday, October 21st, 2005 at 9:29 pm - Machining
The little milling machine I posted about a few days ago is finally working. Thanks to a friendly technician at the university I could replace the bended piece of stud that moves the x axis with a nicely machined new piece.
The original construction tried to maximize the motion limits of this axis, but we decided that the connection of the stepper motor to the machine table was too weak, and possibly the cause for the bent part. Getting a metal hack saw from the local DIY shop and cutting the axis shorter was quickly done, and soon the machine was moving nicely in all directions.
At the moment I use a DOS programme (PC-NC) to drive the machine, but I want to set it up to work under Linux using EMC. I have no idea yet if it will be easy to configure EMC to work with this particular stepper controller card and machine.
For both “Depocam” and “Machining Strategist”! Hooray! W’ve finally pipped off those pointless press-releases about these products from six years ago that have been dominating those pages.
Thanks to all who’ve helped.
Sunday, October 16th, 2005 at 9:03 pm - Machining
I’m still at the preliminary stages of writing a const stepover/scallop routine. I’m making the classical version first, before the fancy freesteel version which will be smooth, spirally and have no corners.
First function needed is a really fast measure of the distance between point and contour. I’m on my second attempt now as I work out more about this subdividing weave structure. It looks like it is not wise to be inserting new points into the weave that you are measuring your distance from. It may be better to always build up the offset in a second weave. This looks wasteful, but is probably the only thing you can do if you don’t want all your pointers moving around.
A new complete waste of time: Playing on eBay. Just trying to restock some diving equipment since our garage got burgled last month. Someone at the pub explained to me how to play the system properly, and I’ve been following his advice. (The trick is, you put a big bid in 15 seconds before the end so no one else has time to bid against you and drive up your price. It’s the person in second place who sets the value.)
We had been thinking about getting one for a long time, a desktop sized 3 axis cnc mill to play with and demonstrate Freesteel and the adaptive roughing. A visit to a friend in Norfolk http://www.technicalsystems.co.uk who owns such a machine made us more determined to get one, and his advice was very valuable.
It seems that Germans build these machines by the dozens in their garages and then auction them off on ebay. I tried to bid for numerous machines, and finally we could buy a modified Proxxon milling machine. The guy who sells them, modifies these hobby machines with stepper motors and controller card. Sadly, when the machine arrived it was damaged: one axis was bent so much that the poor motor could not turn it. Well, the machine is now in parts, and if all goes well a friendly technician at the uni here in Liverpool will manufacture the replacement part, and then we can try this little machine for real. I had some test runs on it using a DOS software called PCNC that came with the machine. Ultimately I want to use EMC, a Linux based machine controller, and I hope that all I need to do this is configure EMC for our machine, stepper motors and interface to the controller card. We’ll see.
Monday, October 10th, 2005 at 8:38 pm - Machining
We are not alone! There are readers of this blog, who have also tried to use the online version of the software we work on. It was quite a surprise: As I was doing some work on this online interface (which is in a bad state at the moment really, apologies for that), I found traces of you in the apache access logs, as well as a present in form of an STL file. (Thanks Nick.)
I hope it works reasonably, even though the layout of the online interface is terrible, not much interactivity, and the tapefile we give you still needs a little changes to be useable.
I am overhauling those pages at the moment: Expect to be able to interact with the STL file by rotating, panning and zooming, but not using virtual worlds and a VRML plug-in. Of course this will also include images of a toolpath.
Hopefully the new version will be online soon.
The code that makes the weaves which is used to do the contour z-slicing is now fully subdividing, and the tool paths can even be made on these subdivided weaves. Now the contours are true machining toolpaths which can be made to any tolerance.
This is a major step forward and only happened because the concept was coded into it from the start. This is the kind of long-term programming I like; taking account of all the features you’re going to put in when designing the original data structure. It probably helps that this is approximately the third time I’ve encoded this entire slicing system, so I know what I am doing. More so than the other times. For the amateur version, look in Machining Strategist.
Martin, meanwhile, has done more work playing with the online version. The features now are graphical viewing in the browser window with cached images. The full graphics dynamic interaction is the only part of the system which cannot easily be replicated with an online version, but with a bit of creativity we can get close.
Also, yesterday, he detected an interloper trying out the machining demo on this freesteel server, which was cool. It’s not done yet, so we hope it’s not put him off.
Francis pointed out a need directory of links:
We should add this site to that once it’s ready.
Friday, October 7th, 2005 at 9:58 am - Machining
Depocam, also known as Machining Strategist before the code forked and was sold to Vero in 2002, is now going to be shipped in the main Mastercam product, it seems. I don’t have a public link yet to the bumf about the Mastercam MR1 release (the first X Maintenance release, not to be confused with SP1) which it will be in, but it’s due out in November.
This is interesting. Now the code I wrote (as opposed to the code I own) is in 3 entirely distinct and competing machining packages…