Friday, December 15, 2006

Ready for the Milling Machine


Got the Xylotek kit yesterday. The Sherline motor mount kit and leadscrew came in last week. I have not had the time to drill and tap the ways and mount the kit. Maybee this weekend.

I opted to go with the xylotek kit that includes the installed and tested 4 axis driver board. The first one did take quite a bit of time and that is one thing I am in short supply on right now. It looks pretty decent from first glance. I have not opened it up yet to see what is inside. It comes prewired with 6'cables for the stepper motors and uses 6 connector molex plugs. All for a extra $75 on sale. After doing the first one, I think it is a pretty good deal.

Saturday, December 02, 2006

Overall Progress on CNC Conversions

The Sherline Lathe is running on Turbocnc. It is connected but not in what should be a permanent manner. Wires are dangling and enclosures are not enclosed. But the joy of it is that the Machine works. I mades squares and circles on paper by using the carriage as a x-y table under a separate drill press that was there to awkwardly hold a marker. It was joy to have the efforts culminate into some thing that works and shows so much potential to work as it was planned.

I ordered the Sherline Motor Mounts for the Milling Machine Sunday Nov 26, the fedex ship delivery estimate is Dec 5. I think it is the xmas slowdown. 1.5 weeks it will be. The lathe mounts took a week. I have other things to do and that is fine. I may even get the motor mount holes drilled and tapped before I get the mounts.

The future goal will be to make the milling machine operational on a basic level. Since everything is kit form, I may leave it a bit "messy" so I will have more flexibility to change it to be more functional as I get a better feel for the actual operational needs. I am not inclined to invest more effort than neccesary it things I might change, but the investment in time into the basic necessary functionality of having it run is obviously unavoidable.

I came across a makeblog on fabathome.org It is a promising machine. The machine is a "fabber", basically the idea is to make the technology easy enough for people to make stuff at home. An ambitious idea, delicate and sweet and probably more ideals than practicality. That said, a pretty good show!

I was gratified to see they used the same choice of motor control that I picked for my cnc conversion which is the xylotex board. The enclosure they use is a project in itself to build of course. And uses lasercut acrylic, it looks very cool. Interestingly they use a usb converter to run the parallel port driven motor controller. I am not sure why though, there are plenty of parallel ports still on computer and on plenty of obsolete computers that would be able to run something like this. After all that is the strategy behind turbocnc. I suspect it is to offload the work of running the stepper motor control board to the Olimex microprocessor to make the programming on the computer simpler. That is a good reason. They use a Olimex LPC-H2148 Microcontroller Board
which is $39.95. Also "needed" (I guess you could make one yourself) is a nice breakout board, the Winford_BRK25F-Breakout_Board is $19.50.

They got the job done, but I want to point out that that is about $60 of hardware, and extra setup time, versus just using the included parallel port connection to the xylotex board. Even if you have a computer sans parallel port you can get a pci parallel port board for about $15. All things being equal (and of course they are not) the $45 in pocket would be nice. And I believe you need to get the Olimex microprocessor programmed also.


The heart of the fab@home system is the software, I don't know enough about comparable open source programs, but if the sofware is good it will be very helpful in making a FDM like machine. Also the syringe "extrusion" toolhead is interesting.

Another Kudos fof the fab@home is that the software is open source. I have not looked at it yet but it sounds like they are on the right track.

We have a Dimension BST 1200 Fusion Deposition Modelling Machine at work and that is basically what the fab@home is trying to duplicate. (with some compromises of course) Without the $20,000 pricetag.

TurboCNC and Dak Engineering

I finally got those 16F84s from dak engineering to drive the stepper motors of the parallel port. I have a test computer for it that is basically my oldest sacrificial computer that runs turbocnc. Just in case I somehow fry the parallel port. I should be able to drive 4 steppers with the 2 ics, just have to get it all straight.

I ordered the items on the webpage, paid paypal on Nov 15 and recieved them today (Dec 2). Order to delivery in 17 days or 2.5 weeks. I am getting spoiled by companies like Newegg.com, Jameco.com and Sparkfun.com and Xylotex.com where I get items in less than a week from paypal or credit card orders.

I am willing to cut the company some slack since the product is really a great one and the cost for what you get is probably just a fair deal. In fact the ICs I ordered are probably more a service they do than any real source of profit.

After ordering the ICs from dak, Pete cut me in on an order with sparkfun to get the Serial Port Programmer. It is a PIC programmer for $12.95 and I have to admit I was totally scamming in on Pete's research on the topic. It will program the IC that dak sells, and I have to really give Dak Engineering a thumbs up because they provide the assembler code and hex file to program the IC. Anyway I got the Serial programmer Monday of this week and if I had not been expecting the ICs from Dak to come in "any time now" I would have ordered some 16F84s to program them myself. Not a big deal and probably not worth mentioning.

Anyway I have got the ICs and when I have finished a bit with the PIC Programmer I will get to it.

Comments on Blogger

I have to comment on blogger, It is pretty cool , it is free. But the gripes are:

1. Dies on PUBLISH. I type up my ephemeral thoughts, hit PUBLISH, and they give the appearance of uploading but disappear forever.

2. Dies on SAVE AS DRAFT. This is rarer but happens to me as follows. I type up my ephemeral thoughts, hit SAVE AS DRAFT, and they give the appearance of uploading but disappear forever.

My solution to the above is copy and paste to Notepad. Works but cramps my style, but not as cramping as having nothing to post.

3. Dies on picture upload. This is more annoying since there is no cut and paste of what I am uploading. Usually it is after going through a bunch of pictures and that is more timeconsuming.

I am posting this because it has actually stalled me in posting pictures and getting the documentation for my project up.