sds1
Friend of Leo's
What sweet relief when the chassis arrives with all the cutouts done and ready to populate.
The problem in my experience is finding a shop that will do just one of anything at all, let alone at an affordable price.
Stainless Steel Chassis: Never Again
- Thread starter cometazzi
- Start date
The problem in my experience is finding a shop that will do just one of anything at all, let alone at an affordable price.
Lingwendil
TDPRI Member
Cobalt drill bits, and a firmly supported chassis will help. Use some light oil, or motor oil in a pinch (boy does it stink when it gets hot though!)
Use firm but not excessive pressure, let the bit do it's work. It's really unusual that it took that long per hole! I've done a bunch of these and it was a few minutes each.
Use firm but not excessive pressure, let the bit do it's work. It's really unusual that it took that long per hole! I've done a bunch of these and it was a few minutes each.
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echuta13
TDPRI Member
Stainless steel work hardens at a very high rate! Lingwendil's info is spot-on. I've heard the tears of amp builders make great lube for stainless steel...
That's funny, as that's kinda what I was doing. I thought I was doing most of the correct things-
1) light oil (3-n-1, works a beaut on regular mild steel)
2) slow rotation (slow as I can on my drill, anyway)
3) firm but not excessive pressure.
4) If I saw smoke I backed off a little so as not to overheat the bit.
5) Said all the requisite swear word combinations I could think of (had a lot of time to think some new ones up).
I guess not having the chassis clamped was where I went wrong. I had it resting on a couple stubs of 2x4s, and I was pressing it down against them with one hand. I was holding it pretty firmly, but that's obviously not the same as clamping it to, or between two pieces of wood like @bottlenecker suggested. I was drilling the holes indoors on the floor in a big Rubbermaid storage container (I learned that trick from someone around here, possibly @Peegoo).
So maybe the clamping and tears as @echuta13 said. Fwiw I found a rubber faucet O-Ring that let me put the cable gland on fairly straight, so I'm possibly back in biz now.
Sorry for the amateur rant everyone.
Lingwendil
TDPRI Member
Never apologize for trying to learn or find solutions man. Lesser men would have trashed it and ordered something else.
Stainless can be a pita but they sure are nice once finished.
I have a 4' x 6' sheet of heavy gauge stainless that I'd been fantasizing about using for chassis. Trying to make a jack plate for a speaker cabinet (three #4 screw holes, one 13/32" hole for the jack) cured me of that idea with a quickness. Since I don't have a box brake or a mill. Frankly, even if I did I'm not sure I'd try it. The cost-benefit is way out of whack, even though the stainless was free.
jman72
Friend of Leo's
Man, that sounds like a TON of work! When I built my 5e3 several years ago, I bought a piece of 18 gauge steel from the local HVAC shop for $20 and built my chassis in less time than you've put into drilling your holes! Always a possibility to think about (or buying another chassis). Mine doesn't have pretty silk-screened lettering, though. And yes, when I drilled the large holes for the tube sockets (with a step bit from Harbor Freight) I almost killed myself when the bit caught and the whole sheet of steel started spinning wildly. Could have been ugly.
But now I've got a stack of 18 gauge scrap steel sheets that I've picked up over the years from various places that I can use to make any chassis I need pretty easily.
But now I've got a stack of 18 gauge scrap steel sheets that I've picked up over the years from various places that I can use to make any chassis I need pretty easily.
tubedude
Tele-Afflicted
Aluminum chassis.
Commiserations. I got quite far along wiht a stainless GA-5 chassis, managed to cut the transformer etc and control panel holes quite well but when I'd spent a couple of hours on the octal hole, one step bit ruined and the other one struggling, while even my (cheap) drill press started playing up, I realised a sheet of aluminium costs less then more step bits. So I cut my losses. Perhaps I'll try mild next time.
Lowerleftcoast
Poster Extraordinaire
Been there done that. I went through exactly your description... hours to drill a few holes. Uttered too many bad words. Bought other than Belden octals. If I had only thought to take them to a machinist. smh.
I like aluminum.
I like aluminum.
Aluminum indeed.
My first go-round was a one-off in a regular steel chassis that I bought from zachH. I did some drilling on that one. Second build was in an aluminum Hammond chassis, and third was in another aluminum chassis that I got from MongoPark. In both of those I had to do all the drilling/cutting/etc. The steel chassis was definitely doable, and the aluminum ones were an absolute dream.
I could probably do another mild steel chassis, but not stainless. As many have mentioned, my next 'major' tool purchase is likely to be a drill press.
OOF. Then Double OOF. How'd that eventually work out?
My first go-round was a one-off in a regular steel chassis that I bought from zachH. I did some drilling on that one. Second build was in an aluminum Hammond chassis, and third was in another aluminum chassis that I got from MongoPark. In both of those I had to do all the drilling/cutting/etc. The steel chassis was definitely doable, and the aluminum ones were an absolute dream.
I could probably do another mild steel chassis, but not stainless. As many have mentioned, my next 'major' tool purchase is likely to be a drill press.
What the heck, older picture. No nibbler, more than one way to skin a cat. Afterwards realized wrong transformer.
OOF. Then Double OOF. How'd that eventually work out?
bottlenecker
Poster Extraordinaire
Anchor lube is the best for drilling and tapping stainless. Probably not a huge difference on thin material though.
joulupukki
Tele-Holic
@jman72 that chassis looks nice!
@cometazzi I feel for you. I also burned up a couple of cheaper step bits trying to make the bigger holes.
I will never use SS again. I repurposed a panel from an old tankless water heater (https://www.tdpri.com/threads/repurposing-a-tankless-water-heater-into-an-amp-chassis.1120092/) to build my latest amp. I finally had to bust out my tin snips to make the octal socket holes (https://www.tdpri.com/threads/single-channel-ab763-build-s.1120924/post-11763126). It was a royal pain! I do need to make another chassis for the amp head version, but I'm thinking either 18ga steel or aluminum bent with a break in the same way.
@cometazzi I feel for you. I also burned up a couple of cheaper step bits trying to make the bigger holes.
I will never use SS again. I repurposed a panel from an old tankless water heater (https://www.tdpri.com/threads/repurposing-a-tankless-water-heater-into-an-amp-chassis.1120092/) to build my latest amp. I finally had to bust out my tin snips to make the octal socket holes (https://www.tdpri.com/threads/single-channel-ab763-build-s.1120924/post-11763126). It was a royal pain! I do need to make another chassis for the amp head version, but I'm thinking either 18ga steel or aluminum bent with a break in the same way.
I have had this project on hold for a long time due to changing the circuit design. Wish I did the holes differently, added a 7 pin socket and enlarged the 9 pin output tube holes to hold octal sockets.
Just need to drill the holes for the bolts/rivets (unsure which yet) and then mounting them. I think I may still add a couple of holes for an effects loop. Actually most of the way there.
Also doing an aluminum chassis at the moment, super easy, much lighter than any here would use. But the transformer will be mounted to the cabinet and the only stress will be from the tubes and inserting the jacks (pictures at 7:00). Have a competing project at the moment, need to build an acoustic body in the next few days whit the weather being warmer for the next few days and I can increase the humidity in the house. Seems I do have a picture of the chassis, will take a picture of it when it gets turned into Swiss cheese.
Going to try and fit a single channel Bassman in it with EL86, a lower voltage EL84. An 8" speaker, reduce the 15-20W that the circuit should put out. No power transformer, using a laptop PS and the high voltage booster in the picture. Crossing my fingers that all works out.
Same here. From now on I'll either do a pre-built chassis from a domestic manufacturer (i.e., known to have everything the correct size for parts we get here), or do aluminum. I did buy a set of punches for the noval and octal sockets a couple of summers ago. One is a used Greenlee from eBay, the other is a new TEMco. They make the big holes a breeze when you don't have a hole to start with, but they wouldn't have been any help on this chassis. My step-bit was great for cutting out holes for jacks, switches, pilot lights, etc. I don't know if it's any good any more. I've got an aluminum cake pan that I bought at the GoodWill that I used to practice with the punches. I'll have to see how well it cuts that once the weather warms up.
Of course, neither the punches nor the step bits help with drilling the mounting holes.
I have had this project on hold for a long time due to changing the circuit design. Wish I did the holes differently, added a 7 pin socket and enlarged the 9 pin output tube holes to hold octal sockets.
Just need to drill the holes for the bolts/rivets (unsure which yet) and then mounting them. I think I may still add a couple of holes for an effects loop. Actually most of the way there.
Also doing an aluminum chassis at the moment, super easy, much lighter than any here would use. But the transformer will be mounted to the cabinet and the only stress will be from the tubes and inserting the jacks (pictures at 7:00). Have a competing project at the moment, need to build an acoustic body in the next few days whit the weather being warmer for the next few days and I can increase the humidity in the house. Seems I do have a picture of the chassis, will take a picture of it when it gets turned into Swiss cheese.
Going to try and fit a single channel Bassman in it with EL86, a lower voltage EL84. An 8" speaker, reduce the 15-20W that the circuit should put out. No power transformer, using a laptop PS and the high voltage booster in the picture. Crossing my fingers that all works out.
Pretty cool projects! I'm curious how the 'modernized' Bassman turns out with the SS supply and all. Hopefully the laptop brick has enough current.
JPKmusicman
Tele-Meister
I had to drill one single small screw hole for a terminal strip in my ss chassis. Wow, glad I only needed one. Those drill bits are junk. The Boothill's chassis is cut perfectly for supplied components.
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