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 Post subject: My First Enclosure
PostPosted: 13 Jan 2013, 06:34 
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Joined: 16 Mar 2012, 11:15
Posts: 76
Location: UK
I'm currently building a Poddwatt amp as my first project (apart from CMOY headphone amps). I thought I'd put up a few images of the chassis as it's built. It's 3mm brushed stainless steel which is much harder to work with than I imagined. However on the plus side it's massively strong. I had to use a pillar drill to get through it as a pistol drill simply wasn't working. Luckily I managed to use the workshop at work for the job.

I started with drilling the chassis for the various inputs, outputs, valves and transformers which took almost 2 hours.

I needed to bend the steel and that would have been nigh on impossible without a decent machine. Luckily they have this in the workshop:

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It's an ancient machine bought by Rolls Royce many years ago for the fabrication of Blue Streak rockets. That made light work of the bending. Here's the chassis at the moment. I know it look rough with the plastic wrap but that's just to protect it while I manage the last few jobs. It weighs around 6Kg (13lbs).

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The ends will be capped with solid oak boards with a channel routered into them to accept the steel.

Opinions?


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 Post subject: Re: My First Enclosure
PostPosted: 13 Jan 2013, 09:29 
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Joined: 14 Feb 2010, 13:13
Posts: 715
Location: Lisbon, Portugal
That´s quite a heavy-duty chassis! I can imagine how hard it was to drill those holes. Now you can get some good and heavy transformers for your project! :)

What kind of finish will it get? Maybe some glossy car-paint?

Have fun!
Miguel


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 Post subject: Re: My First Enclosure
PostPosted: 13 Jan 2013, 10:32 
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Joined: 16 Mar 2012, 11:15
Posts: 76
Location: UK
Thanks Miguel. The chassis is staying as stainless steel, it's a brushed finish so it should look good against the oak. I've got some nice Edcor transformers, the audio ones aren't very big but the power unit is a bit of a beast. I'll post some more images as I further my progress.


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 Post subject: Re: My First Enclosure
PostPosted: 14 Jan 2013, 13:16 
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Joined: 28 May 2008, 21:53
Posts: 4592
Location: Winnipeg, CANADA
Looks like you can have some real fun in that metal shop! 3 mm is thick so that likely contributes to the difficulty. For a medium sized amp like the PoddWatt (EL84 push-pull) you could use a thickness of about 20 Ga (1 mm). For a big amp 18 Ga or 1.5 mm should be sufficient. That would be much easier to work worth. But who wouldn't love a big heavy DIY enclosure for their tube amp? ;)

I'm looking forward to your progress.
Cheers

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 Post subject: Re: My First Enclosure
PostPosted: 15 Jan 2013, 15:44 
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Joined: 16 Mar 2012, 11:15
Posts: 76
Location: UK
The enclosure is currently away with a fiend of a friend to have the oak boards made as the end pieces. He's a very skilled carpenter who restores antique furniture in his spare time and is doing some very complicated woodwork to prevent me from having any mounting holes on display as I want a very clean looking chassis. He's countersinking some holes in the oak very deeply, screwing 2 joining dowels across the breadth of the chassis then filling in the screw holes with machined pieces of oak that match the original grain thereby making the screws invisible! It's something that I would never have even considered.

I assumed (incorrectly) that 1mm steel would be too flimsy for the power transformer in the middle of the chassis originally. It was only when I started working with 3mm steel that I realised just how strong stainless is. As you have said Gio, a heavy duty chassis will be nice in the end, it's just taking time to get there! 6 holes to drill and 2 oblongs to remove now, one USB sized and one IEC sized. I'll update the thread with images when I get the chassis back.


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 Post subject: Re: My First Enclosure
PostPosted: 11 Feb 2013, 13:47 
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Joined: 16 Mar 2012, 11:15
Posts: 76
Location: UK
So I'm getting somewhere with this again. A mate of a mate was making the wooden end pieces for the chassis and had the entire chassis for 3 weeks. I couldn't really moan as he was supplying the materials and labour for nothing. He's done a pretty nice job. I only have one week left at my current workplace with the good workshop so I'm planning to get as much as possible done this week.

Here's the amp from the front. The steel is still covered as I had some work to do on it.

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The front with the power switch, 6.35mm input jack and selector knob loose fitted

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The back with speaker posts, fuse holder and USB port fitted. I need to drill the chassis either side of the large hole to fit the filtered IEC connector.

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The pictures don't do it any justice at all yet. Once it's built I'll clean it up and post some images. I@m hoping to get a full day working on it tomorrow and another full day on Friday. I'm getting pretty excited about it already.


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 Post subject: Re: My First Enclosure
PostPosted: 11 Feb 2013, 23:07 
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Joined: 06 Jun 2008, 18:23
Posts: 5318
Location: Australia
That is one solid chassis.

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Projects: "Sortilege" - 180W Tripath Class D Mundorf upgrade amp | “Mantra” - tube MM phono preamp | "Carbon” - MM phono preamp | 180W RAW Class D amp |


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 Post subject: Re: My First Enclosure
PostPosted: 12 Feb 2013, 14:37 
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Joined: 16 Mar 2012, 11:15
Posts: 76
Location: UK
I've done loads of work on this today. About 7 hours all in. Most of the fiddly time consuming bits are fitted. It looks pretty much the same as yesterday but removing the plastic sheeting has improved it a lot. The knobs on the front are loose fitted at the moment. I like them but think they might be a bit deep.

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 Post subject: Re: My First Enclosure
PostPosted: 15 Feb 2013, 11:54 
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Joined: 16 Mar 2012, 11:15
Posts: 76
Location: UK
So it's fully assembled but I need to do some fault finding before running it in. I'm not getting the right outputs for the valves from the 205V/210V board for some reason. It also needs a good clean up.

Opinions?

Image

Image


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 Post subject: Re: My First Enclosure
PostPosted: 24 Feb 2013, 10:15 
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Joined: 16 Mar 2012, 11:15
Posts: 76
Location: UK
And now the finished article.

Image

Image

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