Folsom's great little 7297 Chip Amp

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Folsom

Re: Folsom's great little 7297 Chip Amp
« Reply #1140 on: 8 Apr 2019, 08:25 pm »
I'd go for like 3mm.

I can't find the thread again. It's buried in DIYa. It's something that I just didn't get around to forever, turns out that was a mistake.

rockdrummer

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Re: Folsom's great little 7297 Chip Amp
« Reply #1141 on: 10 Apr 2019, 11:20 pm »
Hey, I am wondering, I have 5 of the shoulder washers. Are there 5 on the bom in case one breaks while attaching the chip to the heatsink? Or is there another place to use them and I don't know where?
Ben

Folsom

Re: Folsom's great little 7297 Chip Amp
« Reply #1142 on: 10 Apr 2019, 11:50 pm »
Just an extra

Peter J

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Re: Folsom's great little 7297 Chip Amp
« Reply #1143 on: 12 Apr 2019, 08:22 pm »
We move along some.

Drill and tap left side for power supply










It's tight but looks good for clearance so far







First time cutting aluminum on CNC router. I learned a few things...and broke two 1/8" bits.

Here's toolpaths and cut preview:








Some frustration and three bits later:







A potential problem. I cut hole for RCAs 5/16" and binding posts 3/8", not realizing that there's a tiny little lip on plastic washer for RCAs. Oops. Do I need to open that up to 3/8"?






Folsom

Re: Folsom's great little 7297 Chip Amp
« Reply #1144 on: 12 Apr 2019, 08:36 pm »
Not if you can still get isolation (good luck). That lip stops conducting between chassis and RCA barrel.

Great job so far.

Peter J

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Re: Folsom's great little 7297 Chip Amp
« Reply #1145 on: 12 Apr 2019, 08:49 pm »
Not if you can still get isolation (good luck). That lip stops conducting between chassis and RCA barrel.

Great job so far.


I'll just goop a bunch of caulk in there...


or


I'll see if I can ream it out. Slots will make it harder, but I'm stubborn.

WireNut

Re: Folsom's great little 7297 Chip Amp
« Reply #1146 on: 12 Apr 2019, 09:50 pm »




Looks like there's another CNC machinist / Cadcam Programmer working on the Folsom amp. Love that drawing Peter J  :wave:.
I haven't started mine yet.

Couple pics from a project I was playing around with a few years back.........Not as cool as yours but I was just messin..........





Peter J

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Re: Folsom's great little 7297 Chip Amp
« Reply #1147 on: 13 Apr 2019, 01:48 am »


Yeow, I'm cringing at the thought of Twisting My Nutz  :o You be my guest!



CAD programmer? Wannabe would be more accurate, methinks, but am having fun learning.



Unlikely the dragonfly will be engraved in the existing front. My practice piece was a dismal failure. I may work on something else while Lacro is doing his thing on the amp...we'll see.

WireNut

Re: Folsom's great little 7297 Chip Amp
« Reply #1148 on: 13 Apr 2019, 02:30 am »
Yeow, I'm cringing at the thought of Twisting My Nutz  :o You be my guest!

CAD programmer? Wannabe would be more accurate, methinks, but am having fun learning.

Unlikely the dragonfly will be engraved in the existing front. My practice piece was a dismal failure. I may work on something else while Lacro is doing his thing on the amp...we'll see.


I'll pass on twisting anyone's nutz. I'm a retired CNC machinist/Cadcam programmer. Aerospace / Military, just about anything any costumer wants, Job shop machinist.

Anyway, it's nice to find someone that does DIY, and is a machinist/programmer. Not very many of use out there.
Being retired I know longer have access to machines but if I need something done my employer will machine it.
I can still program like a bitch and make G-code programs which I pass along to my old employers.

Again, glad to meet you and I'd love to play with your Dragonfly cad file :D.

Jeremy, continue on with your awesome amp thread, :popcorn:.
Sorry if I derailed.

WireNut

Re: Folsom's great little 7297 Chip Amp
« Reply #1149 on: 13 Apr 2019, 03:40 am »
Peter J.
I built one of Jeremy's projects including three Fo-Felix filters, along with a DC Blocker into a single enclosure and I absolutely love it.
My plan is to build 4 of them given time.
 
Being retired, my old employer was nice enough to shear up enough pieces of aluminum sheet metal to build 4 enclosure's per my specs.
Thank you Roger Hasler.

With that sheet metal and aluminum angle iron purchased from Lowes I built my first unit pictured below.
Many audio purest won't like all the screws but I think they look pretty cool.
I didn't want to ask them to weld it together for me.

FWIW, If you can get scrap aluminum sheet metal for free and bolt it together with alum angle iron it will save you a lot of money and it's rewarding to do.
To me, the screw's look pretty cool but I'll try and keep them to a min on my next build.
Jeremy is a very good designer and I can't wait to build his amp.

Sorry Jeremy, didn't mean to derail. On with the thread.















lacro

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Re: Folsom's great little 7297 Chip Amp
« Reply #1150 on: 13 Apr 2019, 02:17 pm »



A potential problem. I cut hole for RCAs 5/16" and binding posts 3/8", not realizing that there's a tiny little lip on plastic washer for RCAs. Oops. Do I need to open that up to 3/8"?




Peter, Looking good! I would definitely open up the holes to 10mm (3/8") In one of my e-mails to you, I mentioned the step washer, and included the Mfg. parts drawing which shows the 10mm hole to accommodate the step on the plastic washer.

Peter J

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Re: Folsom's great little 7297 Chip Amp
« Reply #1151 on: 13 Apr 2019, 03:30 pm »
Yeah, somehow I got it in my head that was only for speaker binding posts. They're more obvious and I should have looked closer. Not to worry, I fixed it with a reamer. Photo makes them look off-center, but they're not.





I somewhat remember you posting that stuff Wirenut, having haunted here a long time. Cool.

 I'm happy to send CAD file if you want to eyeball. Drawn in VCarve Pro, so it's a .crv file. I'm slowly learning more about G Code, but depend on software to generate it at this point.

rockdrummer

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Re: Folsom's great little 7297 Chip Amp
« Reply #1152 on: 14 Apr 2019, 06:18 pm »
Peter j and wirenut, looking great!

I installed my neutrik input and switch.





Really enjoying the build. I do have another question.
The bleeder resistor I got from mouser is 10kohm and 1 watt, but it is tiny compared to others I see in this thread. I tried to research the kind of resistor, and maybe I ordered the right specs but the wrong kind. Does the resistor in this pic look okay?



Thanks for any advice.
Ben

Folsom

Re: Folsom's great little 7297 Chip Amp
« Reply #1153 on: 14 Apr 2019, 07:43 pm »
If the specs are right, it's fine.

Peter J

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Re: Folsom's great little 7297 Chip Amp
« Reply #1154 on: 15 Apr 2019, 06:44 pm »
Bulkhead complete. Time to get it Lacro-ized!





Peter J

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Re: Folsom's great little 7297 Chip Amp
« Reply #1155 on: 16 Apr 2019, 02:13 am »
Since engraving looks like a dud for now, I've been messing with V Carving the dragonfly in black solid surface.  I can leave the carving as is, color and fill with clear epoxy, or fill with tinted epoxy which is mostly opaque. What do y'all like?






 







undertowogt1

Re: Folsom's great little 7297 Chip Amp
« Reply #1156 on: 16 Apr 2019, 09:54 am »
Since engraving looks like a dud for now, I've been messing with V Carving the dragonfly in black solid surface.  I can leave the carving as is, color and fill with clear epoxy, or fill with tinted epoxy which is mostly opaque. What d


I like the tinted Orange first, because it looks more unique. The blue comes in a close second. You do great work

Peter J

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Re: Folsom's great little 7297 Chip Amp
« Reply #1157 on: 16 Apr 2019, 02:21 pm »
I like the tinted Orange first, because it looks more unique. The blue comes in a close second. You do great work


Orange was a (lame) attempt at copper with a limited palette available. But orange is a possibilty as well.


For anyone  reading, had I not cut the back panel on router, I would have used a Rotabroach. They cut on their rim and leave a cleaner, more concentric hole than a twist drill. I've had this little set for years. You can get new cutters when they're dull.





https://www.nationaltoolwarehouse.com/Rotabroach-Cutter-Kit-Fractional-P44942.aspx?gclid=Cj0KCQjw-tXlBRDWARIsAGYQAmeiJ-C8f_4Y_14lOTMJS3NoeNa61QHkbiiYzUj4Y3nnBXc-wwMKu-4aAkLuEALw_wcB




lacro

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Re: Folsom's great little 7297 Chip Amp
« Reply #1158 on: 16 Apr 2019, 03:01 pm »
I vote for all black. I like it's subtle (KISS) statement. However, I would add 1-1.5 mm holes (eyes) on both sides of the head with the rear of the panel counter-bored to 3mm to receive 2 red LED's. When powered on the red  eyes will draw attention to the subtle black image.  :drool:




uncola

Re: Folsom's great little 7297 Chip Amp
« Reply #1159 on: 16 Apr 2019, 03:22 pm »
thanks for mentioned those rotobroch, seems like it's better than a stepped bit for rca sockets etc and not more expensive