General comments about this re-build process (after it is all done) :
Disassembly and Cleaning
This board wasn't all that dirty originally - standard board chow under the keys, oil buildup on the keys. The keys cleaned right up soaking in water with detergent - came out looking brand new. I spent more time rinsing and drying them than it took soaking them to get off the years of grime. The case had a few scuffs in the paint, and quite a bit of ink marks. It was my inability to effectively clean the paint, the led to my desire to get it powder coated. The bottom plate and barrel frame were in pretty good condition, only a few small spots of rust. I did notice that two of the screws were cross threaded as well. I think the longest part of the cleanup was scrubbing the outsides of the barrels clean with and old toothbrush.
I did make it a point to remove the PCB from the bottom plate and remove the plastic sheet on the back of the PCB, so I could fully inspect the PCB. I wiped down everything with 100% isopropyl to get everything squeaky clean - bottom plate, plastic sheet, top and bottom of the PCB. Where the edges of the original foam were there was some adhesive - this came up easily with acetone.
Replacement Foam
The orignal foam all came off in one peice, but it was entirely too thin anymore. The middle three rows of barrels moved easily. First I tried 2mm craft foam across the entire plate - found that it wasn't thick enough for the home row. Tried 3mm craft foam across the entire plate - found it was too thick for the top and bottom rows. I then cut the home row strip out of both pieces, and tried the 2mm foam on the top/bottom with the 3mm foam on the home row. This ended up sort of cantilevering one edge of the barrels on the home row and they wiggled pretty good.
I went back to the store and picked up one foot of automotive headliner foam, which came on a roll 54" wide - and is about 1/4" or 3/16" thick and very soft. It was a pain to cut holes in compared to the craft foam (don't have a punch) - but it applied an even pressure on all of the barrels across the plate. I also found I much preferred the key feel with this softer foam compared to the much denser craft foam.
Screws
Since two of my original screws were cross threaded, I was worried I would need to drill out and tap in new threads of a larger size. But - inspecting the threads in the holes - they weren't actually that bad. I used the screws that had good threads on them, and very carefully used them to chase the original threads in those two holes. It worked, but those screws picked up a lot of extra material from doing so. I didn't have any M4x.07 nuts to drive these screws through to remove this material, so I just ordered some new screws - phillips driven instead of hex driven. Only had one problem with the new screws - the heads and split lock washers were the correct 7mm diameter, but they came with 9mm washers which wouldn't fit in the recesses of the case. Thankfully a dremel with a cut off wheel, and a pair of needlenose pliers allowed 'easy' removal of the 9mm washers.
Powder Coat
This was a pain. I emailed some powder coat shops near my home. No response. Called these shops near my home - and they would only say no. Finally left work early one day and drove to more shops nearby. Went to the first one - no. Drove the 2nd - nope. Went to a third - they immediately asked to look at the parts, as soon as they saw what they actually were - they said yes. Told them about my experience with the other shops, they were suprised the other places said no. Proceeded to explain that though they were a 75K sqft facility now, they started out with small jobs like mine. Took less than 5 minutes to discuss options, pick colors, write up the paperwork and get a date for when I could pick up (dropped off on a Monday - picked up that Friday). I wanted to get the case in a textured biege color and the barrel frame in black - but this would have resulted in two minimum charges due to the two colors, plus more for the texture; so ended up getting all three parts done in the same color with no texture. They took care of the sandblasting and masking the screw holes - and they did a great job.
Keys
I had debated using the original keys versus ordering new ones from Unicomp. In the end to get the near ANSI layout I wanted, was easier to put all new keys on it. They even have the front function number row.
Reassembly
As Fohat always says - it helps to have plenty of clamps for this. When I was re-assembling with the craft foam, this was especially true. I think I used 8 spring clamps on the edges of the assembly, and then I just used wood blocks and hammer to tap the barrel frame and bottom plate together. Did not want to buy a bar clamp just for this // hammer worked well enough.
Controller
De-soldering of the original controller was pain free - using a solder sucker made this go quickly. Had to wait a few days for shipping for the new controller from xwhatsit to come in. Soldering in the new controller was super easy - just had to spend a few minutes lining up all the wires. I think I am lucky I started with a Rev2 board here - the larger holes for the ribbon wires made it a breeze. Had to fab up a small metal spacer as shown in the pics above for grounding so that the expansion header cleared the nearby barrel frame tab. xwhatit's app the program the controller is very easy to use - the only item I had any question on was the timing to use for the buzzer (which I am using 20ms/40ms). I find that I keep it turned all the way down though.
USB
I used two cables to extend USB from the controller out. First was a 9" micro USB 90 degree 'down' cable, the 2nd was a standard beige 6' USB A to A cable. Cut one end off each, verified the wire color to pinout on each (they each used the standard red/black/green/white) and soldered them together, each also has heatshrink. I did have to shave down the 90 degree end of the micro USB cable a bit - so it would clear the barrel frame tab and so that it had no trouble making that 180 degree turn from the side of the controller towards the case exit. I also reused the original cables tin mounting strap - complete with the star washer and bonding the USB cables sheild to it.
Usage
I only brought this board in to my office today, to replace my Unicomp Model M as my daily driver. I find that it will take me a couple days to get used to it. The biggest things I have noticed so far is when moving my right had to the 6 pack, arrows or numpad - is the case on the 4704 has bars in between the blocks, where the Model M just had empty space. I find myself feeling the bars and having to take an extra second to locate. The other change is the 10 pack on the right side; where I am used to the Model M where the main keys used to be all the way on the left side of the board, now that 10 pack is on the left.
Overall - I prefer the key feel on this Model F over my Model M. Hard to explain really - it is both more solid, and yet lighter in touch at the same time.
Now we just need more of these great boards brought back to life!
