Newbie with some basic router questions

[num1bryanp]

Hello All,

It’s a newbie by the name of Bryan… I have just downloaded and installed Ubuntu 6.06 with EMC2 from LinuxCNC.org onto a PIII 800Mhz. (This is a great download) It took a while to get the step direction Alien controller to work. I found out I needed to apply a minimum 8 volts motor voltage on the controller before it would lock up and start. Newbie, so my stepper motors said 1.7 volts, 150oz in.

My goal is to build a router for cutting out model air plane parts and other things, but with the model plane parts in mind this brings me to my first question: is any one doing this currently and are they successful? It would also be great to know about their setup. Along with this, where can I find the small cutting diameter (.040, .020) router bits with the 1/8 inch shank? (I will need to cut out notches as small as 1/32 square.)

I have been looking at many plans found on the web for wood routing and am starting to like the jgro.pdf plans found here. Does anyone have any recommendations or better plans? (I would like a working area of at least 6x20 inches.)

I am also looking for good prices on ball screws for the project, or will a very good lead screw work?

I have decided that my real weak area is CAM software. Most of my plans are image files (.jpg, .bmp, .gif) and some are CAD files (.dxf, .dwg) so what open source software is out there to convert these files to G-codes? And are there any tutorials on how to do it?

Thanks,
Bryan
bryan@bryansweb.com
Nampa, Idaho

[C.Michael]

Hi Bryan..I built the David Steele wood constructed table for the same purpose..model airplane parts..there is a major size forum thread in this section with many builders of it on there..The end mills that I use are found on E bay..basically they are resharpened dental drills..but they work very well..what I have been doing is retracing the jpg images in autocad to true them up..these 1/32 notches are a bit off when it is hand drawn..autocad retracing makes them perfect..I guess you could call it ..re blue printing the blueprint..That takes time..alot of time ..these programs that convert a raster image to a vector file are really not going to cut it..try some ..there are some free ones on the web ...even the ones that you pay for are really not that good..There is a program from vectric.com that is called V carve pro..you can down load a trial if you like ..it has a feature called profile toolpath that lets you set up tabs and everything else you need to cut out a model airplane part..this program does a lot more than that..because you will want to do alot more than just cut out airplane parts..V carve pro converts your dxf file from autocad and turns it into G code..and it does a great job doing it..
if you build this table ,read thru the forum because there are lots of upgrades that you can do to it..to make it a better table..with out making it cost much more..It is a great learning table..when you feel it is time to make your next upgrade table ,you will be able to make the parts for it on the steele table and have Vcarve design the g code for you..Mike

[ViperTX]

I'm wondering if you could link two of widget's machines to get the length you need...just a far fetched thought....better yet he sells machined tops.....get two of them........wait better idea get an X3 from Grizzly and CNC it using the cncfusion kit....

[acondit]

Originally Posted by num1bryanp Hello All, It’s a newbie by the name of Bryan… I have just downloaded and installed Ubuntu 6.06 with EMC2 from LinuxCNC.org onto a PIII 800Mhz. (This is a great download) It took a while to get the step direction Alien controller to work. I found out I needed to apply a minimum 8 volts motor voltage on the controller before it would lock up and start. Newbie, so my stepper motors said 1.7 volts, 150oz in.

Several source have indicated that with modern drivers you can use up to 20 times the rated voltage [of the steppers]. You just need to make sure that you are not over the rated voltage of the driver you are using.

My goal is to build a router for cutting out model air plane parts and other things, but with the model plane parts in mind this brings me to my first question: is any one doing this currently and are they successful? It would also be great to know about their setup. Along with this, where can I find the small cutting diameter (.040, .020) router bits with the 1/8 inch shank? (I will need to cut out notches as small as 1/32 square.) I have been looking at many plans found on the web for wood routing and am starting to like the jgro.pdf plans found here. Does anyone have any recommendations or better plans? (I would like a working area of at least 6x20 inches.) I am also looking for good prices on ball screws for the project, or will a very good lead screw work?

Check ebay. Also I have purchased ballscrew stock from Homeshopcnc.

I have decided that my real weak area is CAM software. Most of my plans are image files (.jpg, .bmp, .gif) and some are CAD files (.dxf, .dwg) so what open source software is out there to convert these files to G-codes? And are there any tutorials on how to do it? Thanks, Bryan bryan@bryansweb.com Nampa, Idaho

Alan

[ahren]

I would consider what your needs are in terms of accuracy. While ball screws can have great accuracy if done correctly, I have had great success with multi-start ACME lead screws for a fraction of the cost. The key is to remove backlash from the system, and the two major sources for backlash are the mounting bearings for the screw and the nut. Both of these are issues for ball screws, and if they are not accounted for, you will have paid a lot for a system that isn't as accurate as a less expensive ACME system.

For ACME, dumpstercnc sells a great line of anti-backlash nuts. For 1/2-10 ACME specifically (a popular size for hobby machines), I sell a bearing mounting system that works well to eliminate backlash at the screw, along with other components for building a machine out of 8020 aluminum extrusion. I don't have full plans released yet, but they're coming soon.

As for CAM software, sheetcam and meshcam are inexpensive programs with free trials. I'm not sure about open source, however. There may be something out there.

Good luck with your build, and keep asking questions. You've definitely come to the right place!

Ahren
www.cncrouterparts.com