I have a chassis question.
To secure the sides and bottom of my chassis together, I have used #10-24 machine screws with nuts. For the top of the chassis, I am not able to put nuts on the other side. What are the things called that allow create a screw thread on a surface, allowing for securing two pieces together without a thread.
That is not a good description, but here is a picture of what I am talking about:
Wayne Sankey's chassis
If you look at the picture, you will see one side of Wayne's chassis. He used rivits for the bottom and sides and screws for the top. What are those things on the top L bracket that allow for screwing screws in? I have looked in stores, but I do not know what they are called, so I can't find them.
Thanks for any insight you may provide.
--
Brian
gte619j@prism.gatech.edu
To secure the sides and bottom of my chassis together, I have used #10-24 machine screws with nuts. For the top of the chassis, I am not able to put nuts on the other side. What are the things called that allow create a screw thread on a surface, allowing for securing two pieces together without a thread.
That is not a good description, but here is a picture of what I am talking about:
Wayne Sankey's chassis
If you look at the picture, you will see one side of Wayne's chassis. He used rivits for the bottom and sides and screws for the top. What are those things on the top L bracket that allow for screwing screws in? I have looked in stores, but I do not know what they are called, so I can't find them.
Thanks for any insight you may provide.
--
Brian
gte619j@prism.gatech.edu
I guess one could name it a "threaded insert". He had to use it because his L bracket was very thin. Why not use something more substantial (1/8 or 3/16") and thread it directly without inserts.
When I use taps to make threads I mount the tap in cordless drill with a clutch and drill it through the hole. When there is enough resistance created, the clutch engages and protects the tap from breaking. Then I put the drill gun in reverse, remove the tap, clean it and repeat the process until I finish my thread. Very fast and convenient way to thread holes. Don't forget to put some oil on the tap.
When I use taps to make threads I mount the tap in cordless drill with a clutch and drill it through the hole. When there is enough resistance created, the clutch engages and protects the tap from breaking. Then I put the drill gun in reverse, remove the tap, clean it and repeat the process until I finish my thread. Very fast and convenient way to thread holes. Don't forget to put some oil on the tap.
I am using 1/8" L brackets and 1/8" aluminum 6061 sheets, but I just wanted to use the threaded inserts to make sure that I do not strip the threads.
I used a tap for threading my heatsinks (1/4" thick baseplate), I just used a drill press for making the holes and manually tapped the holes using a tap wrench, and lots of oil. I broke 2 taps on a scrap heatsink, but if I went in a little bit and backed it out to clean off the aluminum waste, then did it again, going the whole way, it worked fine. I used #10-24 screws and the cases seems to sit quite solidly.
I will try the clutch method next time with my portable drill. Thanks for the suggestion.
I found them (searching for inserts), and they are called panel nuts:
McMaster has a decent selection of different kinds. Home depot does not seem to carry them in their hardware section.
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Brian
gte619j@prism.gatech.edu
I used a tap for threading my heatsinks (1/4" thick baseplate), I just used a drill press for making the holes and manually tapped the holes using a tap wrench, and lots of oil. I broke 2 taps on a scrap heatsink, but if I went in a little bit and backed it out to clean off the aluminum waste, then did it again, going the whole way, it worked fine. I used #10-24 screws and the cases seems to sit quite solidly.
I will try the clutch method next time with my portable drill. Thanks for the suggestion.
I found them (searching for inserts), and they are called panel nuts:
An externally hosted image should be here but it was not working when we last tested it.
McMaster has a decent selection of different kinds. Home depot does not seem to carry them in their hardware section.
--
Brian
gte619j@prism.gatech.edu
The other advantage of using cordless drill is that you can position it straight against the hole and maintain the proper alignment all the time which is not always easy when using a wrench.
My father was a "Fitter and Turner" and offered me this advise for tapping my heatsinks. Worked for me.
1. Use kerosene for lubrication
2. Put heatsink in vice
3. Tap until you feel resistance, back off, clean hole and tap, add more kero
To keep things square and stop braking taps, he has this little tool made from 20mm of a broom handle with a hole thru the middle. Looks a little like the panel nut. Place the tap thru the hole and hold the wood flush with the heatsink with one hand and turn the tap with the other.
Greg
1. Use kerosene for lubrication
2. Put heatsink in vice
3. Tap until you feel resistance, back off, clean hole and tap, add more kero
To keep things square and stop braking taps, he has this little tool made from 20mm of a broom handle with a hole thru the middle. Looks a little like the panel nut. Place the tap thru the hole and hold the wood flush with the heatsink with one hand and turn the tap with the other.
Greg
There are modern tapping fluids that work far better. Tapmagic for Alumnium is one of them, is very inexpensive and will give you threads in alumnium so clean it will amaze you. I've used it for years.
Mark Gulbrandsen
Salt Lake City
Mark Gulbrandsen
Salt Lake City
Its available form many machine shop supply companies, or local nut and bolt suppliers. Their web site is here....
http://www.tapmagic.com/
A small bottle will last you for years and I also believe it is far safer to use than kerosens is.
Mark Gulbrandsen
Salt Lake City
http://www.tapmagic.com/
A small bottle will last you for years and I also believe it is far safer to use than kerosens is.
Mark Gulbrandsen
Salt Lake City
While we're on the subject of building chassis, does any one know where to buy the amp handles? I'm thinking of installing 2 handles at the back of the amp for easier carrying around - one possiblilty for me is moving amps to different rooms instead of moving speakers. I estimated that the amp would weigh about 30 to 40 lbs each - that's not light at all. The handles that I'm thinking of are the ones that Pass Labs use for their amps and I believe Audio Research use them on the front of their pre-amps. I've check out Home Depot but none there. I don't think it would be too expensive. Suggestion please. Thanks.
On the subject of the aleph 2, could I run two channels off a 1000kVA transformer, and how much capacitance would be optimal for two channels?
I was estimating that the transformer should be alright, and maybe 160,000uF - 200,000uF per channel (with soft start).
Any comments on this estimation? Does it look alright?
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Brian
gte619j@prism.gatech.edu
I was estimating that the transformer should be alright, and maybe 160,000uF - 200,000uF per channel (with soft start).
Any comments on this estimation? Does it look alright?
--
Brian
gte619j@prism.gatech.edu
Both those calculations look reasonable although i'd rather see a little more in the transformer department. Absolute minimum to account for power factor using bridge rectifier + caps is V x I / 0.62 and when you take into account peak current draw etc you'll find that a larger transformer could be quite beneficial. Having said all of that, due to the stereo nature of the amps and the likelyhood that at any given time the amps will receive signals that are quite different from each other, the suggested transformer should be ok.
Capacitance should be fine.
Capacitance should be fine.
I also have the option of running 2 x 1kVA transformers for the stereo aleph 2, possibly with seperate power supply caps, rectifier, etc. Would this draw too much power for one standard power outlet? (assuming soft start).
--
Brian
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Brian
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