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Impatience?
In the past, hoping to get the boring mechanical bit over and done
with, I drilled my aluminium freehand, with the result that a lot of filing then had to be done to align the screw holes of different bits. But, now I have a drill press and an engineer's vice to hold everything down, it's a different world! The only skill that I have yet to master is that the bend in the aluminium is where I marked it, and not a couple of mm distant! |
Impatience?
On Wed, 15 Oct 2014, gareth wrote:
In the past, hoping to get the boring mechanical bit over and done with, I drilled my aluminium freehand, with the result that a lot of filing then had to be done to align the screw holes of different bits. But, now I have a drill press and an engineer's vice to hold everything down, it's a different world! The only skill that I have yet to master is that the bend in the aluminium is where I marked it, and not a couple of mm distant! This is why things like bezels were invented. Michael |
Impatience?
On 15/10/2014 11:31, gareth wrote:
In the past, hoping to get the boring mechanical bit over and done with, I drilled my aluminium freehand, with the result that a lot of filing then had to be done to align the screw holes of different bits. But, now I have a drill press and an engineer's vice to hold everything down, it's a different world! I found that the best way to align holes was to print out a full sized drawing of the hole layouts, glue it on and then centre punch the holes. As long as you have accurate reference points on all parts then the holes line up. I gave up drawing and marking the individual parts as being too error-prone and labour intensive. But drill presses are good kit. Andy |
Impatience?
AndyW wrote in
: I found that the best way to align holes was to print out a full sized drawing of the hole layouts, glue it on and then centre punch the holes. Seconded, totally! Also, can't beat a good X/Y machine table on a drill press. 1mm dril, 1mm increments, any shape you want. Join the dots... For one-off projects the speed is good, the precision, amazing. |
Impatience?
On 10/15/2014 6:31 AM, gareth wrote:
In the past, hoping to get the boring mechanical bit over and done with, I drilled my aluminium freehand, with the result that a lot of filing then had to be done to align the screw holes of different bits. But, now I have a drill press and an engineer's vice to hold everything down, it's a different world! The only skill that I have yet to master is that the bend in the aluminium is where I marked it, and not a couple of mm distant! I was taught that a brake is used to bend sheet metal. It's not a power tool so can be had fairly inexpensively. I found one at the top of a google search with removable fingers for $300. The removable fingers let you bend things like four sided boxes. If you don't want to spring the cash for one, you can just use angle iron and your vise. To do four sided boxes you need to cut the angle iron to the right length for each bend. -- Rick |
Impatience?
rickman wrote in :
If you don't want to spring the cash for one, you can just use angle iron and your vise. To do four sided boxes you need to cut the angle iron to the right length for each bend. Either that, or cut the metal after the bend, which introduces another indispesible tool: a bandsaw. Given a drill press and a bandsaw, and an accurate X/Y table for the drill, it can go a long way before any other tool is needed, though a small Proxxon IBE drill with various widgets is also vital, especially if you make PCB's and get a stand and X/Y table to go with.. Carbide bits seem to last forever with those tools. |
Impatience?
On Thu, 16 Oct 2014 04:28:00 -0500, Lostgallifreyan wrote:
rickman wrote in : If you don't want to spring the cash for one, you can just use angle iron and your vise. To do four sided boxes you need to cut the angle iron to the right length for each bend. Either that, or cut the metal after the bend, which introduces another indispesible tool: a bandsaw. Given a drill press and a bandsaw, and an accurate X/Y table for the drill, it can go a long way before any other tool is needed, though a small Proxxon IBE drill with various widgets is also vital, especially if you make PCB's and get a stand and X/Y table to go with.. Carbide bits seem to last forever with those tools. Don't forget to allow for the thickness of the material and it's minimum bending radius. A few practice bends in scraps of the same material will get that settled. You have to use the same material since different alloys and different thicknesses behave differently. And, unless you bought the metal from a metal dealer, you probably don't know the alloy. Good luck, -- Jim Mueller To get my real email address, replace wrongname with dadoheadman. Then replace nospam with fastmail. Lastly, replace com with us. |
Impatience?
Jim Mueller wrote in
eb.com: Don't forget to allow for the thickness of the material and it's minimum bending radius. A few practice bends in scraps of the same material will get that settled. You have to use the same material since different alloys and different thicknesses behave differently. And, unless you bought the metal from a metal dealer, you probably don't know the alloy. I usually get round that lack of knowledge by using a good hard edge on the inside of the bend and also one on the outside, then hammer gently on the outer bar held right onto the bend to press it against the immer supporting bar (or vice edge, whatever I can make fit). It's a bit tedious, but can result in very nice clean and sharp angles at 90° regardless of metal used. Penalty for error is usually no worse than a slight thinning at the crease. I've considered trying to build a DIY tool based on a good quality hinge, but never done it. |
Impatience?
On 17/10/2014 01:32, Lostgallifreyan wrote:
I usually get round that lack of knowledge by using a good hard edge on the inside of the bend and also one on the outside, then hammer gently on the outer bar held right onto the bend to press it against the immer supporting bar (or vice edge, whatever I can make fit). It's a bit tedious, but can result in very nice clean and sharp angles at 90° regardless of metal used. Penalty for error is usually no worse than a slight thinning at the crease. I've considered trying to build a DIY tool based on a good quality hinge, but never done it. Some lightweight alloys I have used have cracked on a sharp edge. Often I just use sheet steel a blowtorch, flux and braze it together. A LOT easier than bending without the right kit. Andy |
Impatience?
AndyW wrote in
: Some lightweight alloys I have used have cracked on a sharp edge. Yep, I gate those. :) If that happens I either chuck it or use it where it won't get bent. Most thin Al sheet is very ductile though, if anything, too much so, hard to make clean edged holes in without good tools. |
Impatience?
AndyW wrote in
: I just use sheet steel a blowtorch, flux and braze it together. A LOT easier than bending without the right kit. I've never done that. :) Could be a good way to waterproof a box though. In another radio group someone mentioned that only welds would really seal a box (in a marine environment, specifically), but a braze goes a long way. I have brazed. just not used it this way.. Also I haven't thought about galvanic corrosion with brazed steel before either. I suspect a very good painting might be in order. |
Impatience?
On 17/10/2014 09:43, Lostgallifreyan wrote:
AndyW wrote in : I just use sheet steel a blowtorch, flux and braze it together. A LOT easier than bending without the right kit. I've never done that. :) Could be a good way to waterproof a box though. In another radio group someone mentioned that only welds would really seal a box (in a marine environment, specifically), but a braze goes a long way. I have brazed. just not used it this way.. Also I haven't thought about galvanic corrosion with brazed steel before either. I suspect a very good painting might be in order. A lot of modern paints will last forever in the elements as long as the user repaints any nicks and dings. I usually braze up a box and clean it with brake cleaner to get rid of the flux and grease then bung on some paint. Never really had a problem. Brazing is a lot simpler than welding or bending. Andy |
Impatience?
AndyW wrote in
: A lot of modern paints will last forever in the elements as long as the user repaints any nicks and dings. I like hammerite.. I think it even has some prevention of galvanic corrosion even if it gets damaged a bit. There are also paintable zinc-based layers specifically to extent the life of steel. I guess the impossible thing tio grant is totally maintenance free seals, but many methods likely don't need much more than one reworking per decade. I just wouldn't trust my estimate on milage in sea spray. |
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On 19/10/14 08:33, Lostgallifreyan wrote:
Brian Reay wrote in news:63445296435368038.386267no.sp- : I've not looked into a source of this tape but it would seem to be an easily technique, if a suitable tape can be obtained. Definitely! If you can find out what is is, where to get it to try it, and the temperature and duration needed for the ovenm, please post what you find. Point taken about aluminium, but I used to collect scrap metal in a city at one time, and noticed that anything that got thrown out was usually a tad less than exotic. :) Mostly very ductile. When I want anythign better I invariably have to pay for it, and then I know what I'm getting. eBay's not bad for loose bits. I'd not even looked for it until just now. But a quite 'google' produced this: http://www.hexcel.com/products/indus...adhesives-main It refers to 'film', which I assume is the tape I was thinking of. As for sources, that may be an issue. Many of these specialist chemically type things are so-and-so's to get hold of if you are not in the industry. I still have some contacts who can sometimes point me at suppliers willing to help. I tend to buy boxes, a lot of my projects are more for the technology than 'looks' so diecast boxes are de-riquer in most cases, especially for RF projects where you can have several modules in isolated boxes etc. 73 Brian |
Impatience?
On Sun, 19 Oct 2014, Brian Reay wrote:
On 19/10/14 08:33, Lostgallifreyan wrote: Brian Reay wrote in news:63445296435368038.386267no.sp- : I've not looked into a source of this tape but it would seem to be an easily technique, if a suitable tape can be obtained. Definitely! If you can find out what is is, where to get it to try it, and the temperature and duration needed for the ovenm, please post what you find. Point taken about aluminium, but I used to collect scrap metal in a city at one time, and noticed that anything that got thrown out was usually a tad less than exotic. :) Mostly very ductile. When I want anythign better I invariably have to pay for it, and then I know what I'm getting. eBay's not bad for loose bits. I'd not even looked for it until just now. But a quite 'google' produced this: http://www.hexcel.com/products/indus...adhesives-main It refers to 'film', which I assume is the tape I was thinking of. As for sources, that may be an issue. Many of these specialist chemically type things are so-and-so's to get hold of if you are not in the industry. I still have some contacts who can sometimes point me at suppliers willing to help. I tend to buy boxes, a lot of my projects are more for the technology than 'looks' so diecast boxes are de-riquer in most cases, especially for RF projects where you can have several modules in isolated boxes etc. When looks don't count, you can get away with all kinds of things. I've seen people build up modules in old IF transformer, though now that source has mostly dried up. Real old IF transformers have a lot of space, AA5 type transformers more for a couple of stages. Cans that food comes in has been used as chassis in some famous projects, but slap a piece of circuit board across the top, and you've got a shielded box to build a module into. I've played with making more traditional boxes out of cut up tin cans, that works but didn't seem worth the effort. Module boxes can be made out of copper circuit board, but getting them nice requires some effort. For larger boxes, computer power supplies offer up nice boxes. Cover any side with the wrong holes with circuit board (well it could be aluminum, but I have more circuit board lying around than sheet aluminum. Those are really pretty common, I'm not finding new enough computers on the sidewalk to bother bringing home, but I may strip out the power supply, to use as a power supply or for the box. I see lots of satellite and cable boxes, thsoe can useful for larger projects, though sometimes one has to come up with a new front panel. Sometimes the power supplies are separate inside the box, so you can reuse that as is. Michael |
Impatience?
"Michael Black" wrote in message
xample.org... I've seen people build up modules in old IF transformer, though now that source has mostly dried up. As have the capacitors from the defunct rig that provided them? :-) |
Impatience?
Brian Reay wrote in :
http://www.hexcel.com/products/indus...adhesives-main Thanks. I'll do a bit of hunting and see if I can get it. By the way, nothing wrong with a painted diecast box, I really like them. Very cheap, and thet stay looking better than many 'project boxes' look right off the shelf. For isolated (separately screened), but interlocking boxes, Maplin sell (or used to sell) some extruded box sections that dovetail onto each other. The end plates are that nasty ductile aluminium I mentioned, but they can be easily used as templates for something better. |
Impatience?
Michael Black wrote in
xample.org: Module boxes can be made out of copper circuit board, but getting them nice requires some effort. I came close to solving that, a small cheap Proxxon circular saw with a carbide blade. The edge was awesome, so clean the FR4 was almost polished, but it's extremely dangerous because the blade binds against the FR4, so this method is ONLY safe to trim small flexible strips. But as a finish after using a hacksaw to do the grunt work, it would work. A hollow-sided carbide blade would be great, but I've never seen one, and dread to think what it would cost! |
Impatience?
Michael Black wrote in
xample.org: For larger boxes, computer power supplies offer up nice boxes. Cover any side with the wrong holes with circuit board You do like some rough-and-ready boxes! :) Normally I hate them, but one very nice exception is old rack units. There are things so cheap on eBay (and audio junk wherever it might be had) that is valued far lower than the box it's in is worth. In this case a blank panel bought on eBay can make an awesome case. One of my computers is based in one. ITX, 1.2GHz, should be fan cooleed, but I made it totally silent, rack only 18cm front to back, 1U. All kinds of very high quality work can be based on old rack units, whose original innards may well be chosen for some otherwise expensive, rare and exotic spares too. |
Impatience?
On Sun, 19 Oct 2014, gareth wrote:
"Michael Black" wrote in message xample.org... I've seen people build up modules in old IF transformer, though now that source has mostly dried up. As have the capacitors from the defunct rig that provided them? :-) Well I was thinking of the time when there'd be endless IF transformers at the hamfests and the like, I remember buying a bunch of them for nothing much in the seventies. But now that you mention it, you could take those metal-cased eletrolytics that have dried up, and build modules in them. I know I have a bunch of thsoe around, and chances are good they aren't in good shape now. Michael |
Impatience?
"Michael Black" wrote in message
xample.org... But now that you mention it, you could take those metal-cased eletrolytics that have dried up, and build modules in them. I know I have a bunch of thsoe around, and chances are good they aren't in good shape now. And you'll even have the capacitor clips to hold them down? :-) |
Impatience?
On Sun, 19 Oct 2014 02:47:46 -0500, Lostgallifreyan wrote:
Brian Reay wrote in news:1207878279435369714.592439no.sp- : As far as aluminium's finish goes, why not just leave it bare? Not so pretty, You can make it look better by using a fine wire brush on it; most easily done with a wire wheel in a grinder. Just make sure all the scratches run the same direction. You can keep it from leaving blackness on your fingers by spraying it with clear plastic afterwards. -- Jim Mueller To get my real email address, replace wrongname with dadoheadman. Then replace nospam with fastmail. Lastly, replace com with us. |
Impatience?
Jim Mueller wrote in
eb.com: You can make it look better by using a fine wire brush on it; most easily done with a wire wheel in a grinder. I didn't think of that.. I've done something like it with small laser cases built in extruded 1 inch square tube though, using emery paper glued to a flat MDF board. It's a very nice finish, but it's not a method for large parts, too much work. I used to get numbness from gripping sharp edges under high pressure, and that never entirely healed. It was worth it at the time, but no-one could make a lot of them that way unless they wanted permanent injury. I did try one wire brush at the time, but for whatever reason it failed, I couldn't get consisteny the way I could with the emery board. That brush was only good for derusting steel before painting with hammerite. Maybe a larger and faster one, used lightly, might have worked better, but not on small parts I think (would have damaged the fine edges). |
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