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i'm on a roll... the kgsshv


kevin gilmore

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KGSShv milling is proceeding :)

 

I had to buy a new controller for the mill.  I had one a cheap ebay one from china and it just messed up too often.  I ended up with the gecko g540.

 

This is the bottom plate.  It is 8.25" W x 14.25" D x 3/16" H.  I decided to go a 1/4" wider just incase I want to put a larger transformer in.

 

mtge.jpg

 

 

c4ny.jpg

 

 

uwcu.jpg

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Thanks.

 

@Cee Tee - I was always thinking about doing a curved face.  I always thought to mill it out, but printing might provide alternate options. 

 

I looked at the site and went to the materials section to look up alumide. 

 

I'm not clear that this material would be acceptable for a face plate.  What were your thoughts?

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Hi Kerry,

 

My plan is to prototype the faceplate design, revise until "good", and then go to CNC with a brushed aluminum faceplate as the final product.  I was hoping to see more custom case design and fabrication by everyone on the boards...so it's nice to see your work and machine! 

 

The gray model that you see is only a small-scale 3D print I made to try out the www.shapeways.com service and to give me an idea of the look with color applied. This "aluminide" material can only be printed in a fairly small size and I think it is just a white substrate sprayed with aluminum powder/dust (as it seems to come off easily).  In this small of a size, it isn't even that helpful for being able to visualize a full-sized part.

 

I also had a hollowed out but full-scale file (prepped for 3D printing parameters) to get a better idea of the shape.  This larger print showed me that my curves are too aggressive. I am going to reduce the thickest area of the plate and elongate/flatten the curve out a bit plus increase the thinnest portion of the "wave".  Glad I made a large prototype.  (This is my first design and DIY faceplate.)

 

For the small and large faceplates + the four knobs it cost me about $120 in two shipments for the 3D prints.  The gray one is very much like sandstone and sheds powder.  The white one is very thin and actually a bit pliable.  

 

Note: Text was enlarged on the white model to meet service's recommended 3D printing spec. Will retain much smaller text in the design and final CNC production.

post-2754-0-34956100-1379458398_thumb.jp

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i got a good torque screwdriver and tested the M3 peek screws at the recommended torque which is 50% of the max torsional strength or 1.3lb-in.  This is no problem if you have the PEEK screw threaded into a thick heatsink or flange, but if its being secured with a standard M3 nut (stainless) that only has a few threads, the threads will strip on the screw long before there is an issue with the screw head. The max torque with a M3 machine nut is about 0.9 to 1.0lb-in.  If you are using a M3 nut, i would recommend getting a longer PEEK screw and instead of a nut get a M3 standoff of around 5mm length and use that as the nut instead so there are more threads

Edited by justin
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That's a lovely box you have there.  :)

 

i got a good torque screwdriver and tested the M3 peek screws at the recommended torque which is 50% of the max torsional strength or 1.3lb-in.  This is no problem if you have the PEEK screw threaded into a thick heatsink or flange, but if its being secured with a standard M3 nut (stainless) that only has a few threads, the threads will strip on the screw long before there is an issue with the screw head. The max torque with a M3 machine nut is about 0.9 to 1.0lb-in.  If you are using a M3 nut, i would recommend getting a longer PEEK screw and instead of a nut get a M3 standoff of around 5mm length and use that as the nut instead so there are more threads

 

Good point.  We need Kevin to start work on some stronger, non conductive screws... 

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i got a good torque screwdriver and tested the M3 peek screws at the recommended torque which is 50% of the max torsional strength or 1.3lb-in.  This is no problem if you have the PEEK screw threaded into a thick heatsink or flange, but if its being secured with a standard M3 nut (stainless) that only has a few threads, the threads will strip on the screw long before there is an issue with the screw head. The max torque with a M3 machine nut is about 0.9 to 1.0lb-in.  If you are using a M3 nut, i would recommend getting a longer PEEK screw and instead of a nut get a M3 standoff of around 5mm length and use that as the nut instead so there are more threads

 

This is the TO-220 torque guidance that I usually reference: http://www.vishay.com/docs/72674/72674.pdf

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I agree that every DIY project is a opportunity to learn, and the KGSSHV is an excellent example.

 

I am mounting one of the Amp PCBs provided by Lil Knight. Because of the lack of some parts, I made some substitution (probably some mistakes). So, I am using two BC550 glued with cyanocrylate to replace the LSK389,

 

BC550_zps5f97b01a.gif

 

for Q20 I am using BC550 rotated 180º, BC556 for Q17 and Q18, and KSA1156 for Q15 and Q16. Would be possible to use KSA1156, with the correct pin connection, for Q5 and Q6, if the power supply do not pass +/-350VDC?

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