Archive for January, 2013

H-Bridges

Posted: January 27, 2013 by kwood94xj in Events

The other day someone asked me about building a large H bridge to power some 25+ amp motors. Well after finding this Tutorial I then researched some higher current darlington transistors. These are rated at 50A and 120V up from the TIP-147/142 rating of 10A and 100V the price per BJT is about 7 times higher than the TIP series but if you need high current there is a cost.

PNP transistor link ON Semiconductor  MJ11033G $10.29/ea

NPN transistor link ON Semiconductor  MJ11032G $9.65/ea

These transistors would take the place of the TIP 147 & TIP142 BJT’s other than that the board traces would need beefing up to handle 5x the current. Also since these are in a different package (TO-3 vs TO-220) the board layout would need to be redesigned. I would think about mounting them on large heatsinks then running wires to the board.

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CNC Porn

Posted: January 26, 2013 by kwood94xj in CNC

Stumbled across this video of CNC fabrication of a circuit board. This is something I hope to be able to do with our new DIY CNC machine.

 

fink000 is in!!

Posted: January 25, 2013 by kwood94xj in Hackerspace News

I would like to take the time to welcome fink000 to the Hackerspace. He brings to the table a background in Programming, Linux, RC Aviation. We look forward to having him post updates of his MAME Arcade and RC Lawnmower.

Tutorials, Tutorials, and alas more Tutorials.

Posted: January 24, 2013 by kwood94xj in CNC

Tonight while perusing the Buildyourcnc.com website I noticed a Tutorials section. Being naturally curious I clicked it and was blown away by the amount of video tutorials. These guys have really made sure that anyone can build a CNC mill if they so choose. Keep up the good work guys.

For the lazy among us (Myself included in that) here is the link right to the Tutorials page.

CNC Software

Posted: January 20, 2013 by kwood94xj in CNC

Today we are trying out some of the various CNC control software out there. I use both Linux and Windows depending on what needs to be done. I prefer Linux for many reasons but its stability is the most important benefit in this case. I have installed LinuxCNC and I am quite impressed with it. It has a great config GUI for setting up each axis of your mill. It also surprisingly easy to use. We are looking forward to running this great software when our Mill is complete.

 

LinuxCNC                   LinuxCNC1

BatchPCB Service

Posted: January 19, 2013 by kwood94xj in Prototyping

We have been looking at prototyping PCB services for a good while now. There are many options out there but the one that has gotten us sold is BatchPCB.com. It is a service of the popular Sparkfun.com. At $2.50/sq.in for 2-layer .062″ FR4 and $8.00/sq.in for 4-layer .062″ FR4 and best of all there is NO minimum quantity. There really is no better option. We can etch our own boards but at a higher price and less quality. Previously when doing 1 offs in house etching and hand drilling would be the way we would go. But since the BatchPCB service we can now get quality PCBs with no headaches or hassles.

Nook Is Worth A Look

Posted: January 17, 2013 by getreelfishingpro in Events

Nook Indutries linear motion systems are worth a look.

Design Thoughts

Posted: January 16, 2013 by kwood94xj in CNC

Looking into ways to link the motors to the X,Y,Z axises. Originally thinking to use 3/8-12 stainless threaded rod and 2 nuts to reduce backlash. It should work but it may wear out quickly. Acme threaded rod is much better. DumpsterCNC carries anti backlash nuts at a reasonable price. The rod itself is on the pricey side at $20/ft. so we may start with SS threaded rod and upgrade to the acme rod later.

DIY CNC Resources

Posted: January 16, 2013 by kwood94xj in CNC

We have been scouring the web for information on DIY CNC machines. Tonight we came across CNC Zone. This a great forum with TONS of useful information. If your a veteran Machinist or just getting started this is the place to go.

Posted: January 16, 2013 by getreelfishingpro in Events

IT STARTS!