First Watt F1 Construction Diary [pics]

[DIY_newbie]

Day 1: I decided to work on the mechanical work first. Chassis is assembled, binding posts and IEC module are mounted. Pilot holes for the XLR drilled. I need to find a 13/16" bit to drill the final XLR jack holes. I can't find a bit this size locally For reference those are 250VA toroids.





--Chris

[mpmarino]

Looks nice. Lately I have been making some pretty neat and professional looking holes in all thicknesses of alu up to 1" using my 'wood' forstner bits! They need a pilot hole 'cause the guide tip won't cut alu but they work real nice... I've been chucking them up in my drnll press at whatever speed I normally use for metal, give good firm even pressure and lube it well to keep it cutting and cool (wd40 has worked fr me). I have done 1/2" alu and ended up with a single 6 foot curled shaving representative of the metal that was removed. The only problem is that at the very end of the cut it ends up punching a very thin 'disk' of alu at the end. Run it 'good' side up and clamp the work down 'cause if it catches your going to get hurt. Don't ask how I know! It looks like a Bridgeport did it....

[moe29]

There's a special bit you can get at Home Depot or any other like
store for drilling larger diameter holes... the make i have is an
Irwin Unibit. It allows you to drill many different diameter
holes with one bit.

it's shaped like a cone, the deeper you drill the larger the diameter of the hole.

In fact, just do a search for Unibit and you'll find a pic of it

[DIY_newbie]

Day 2 Update: I think it counts as day 2 since its 2:15 am ... My local Lowes has one of those Unibits so I'll pick it up today. I laid out one of the power supplies. Comments on the layout apreciated.. I'll proably start working on one of the output channels tomorrow.



--Chris

[DIY_newbie]

Day2 : I ended up buying a unibit from lowes and mounted the XLR connectors. Finished up the power supply layout and added drill guides. I started working on the L/R channel on paper. So far I have a n idea that will requre 2 jumper wires per channel.

Updated Pics:





--Chris

[Nelson Pass]

Ooooooh....Nice.

[DIY_newbie]

Originally posted by Nelson Pass
Ooooooh....Nice.

Thank you sir, It is an honor that you approve of my humble copy

A question. I used 1/2" traces for the Power supply. I plan to use 1/8" for all the current carrying paths in the channels and 1/16" for the low current paths. Are these sufficiently wide? I'm planning on using one sided 2oz copper PCB traces with a ground copper foil shield on the other side.

--Chris

[steenoe]

That amp looks pretty good so far
Do you have plans for some kind of heatsink arrengement?

Steen

[DIY_newbie]

Originally posted by steenoe
That amp looks pretty good so far
Do you have plans for some kind of heatsink arrengement?

Steen

I'll be using thermaflow E1387 extrusions on both sides. at 100W they will be 34 degrees above ambiant. Just ordered these, will be a few weeks before I get them so I'm trying to get the PCBs done and the FETs matched in the meantime.

Details of parts/gathering materials can be found on this previous thread :

FirstWatt F1 Gathering materials

--Chris

[Blues]

Originally posted by DIY_newbie


I'll be using thermaflow E1387 extrusions on both sides. at 100W they will be 34 degrees above ambiant. --Chris

Chris, summertime in Dallas would kill your F1 at 34deg above ambient...