Outstanding! Watching with great interest!
McIntosh C20 - can and should I bring it back from the dead?
- Thread starter neevo
- Start date
neevo
Super Member
Parts all cut up from 3 sections of pallet racking. Whilst I had an idea of how I wanted to do it, the plan is still evolving a little:
A load of grinder dust that I had to clean up but I had the makings of a press. This is the plan for the layout:
Not a huge amount of travel but it should be more than enough for the preamp. I wanted a fixed lower guide as I planned on having a rod through there that I will later attach a pressing die to.
I also attached some l shaped steel to the bottom as legs and it now stands on its own.
I wish I had some argon as I would have TIG welded it as my stick welding is appalling (don’t look too close), but again for setting 3mm rivets it should be more than enough. My bottle jack is only 2 ton anyway, so I’ll likely be limited by that.
The big blue section of square tube is going to be the arm that the jack sits on. It will have the springs attached to it and underneath the rod for pressing will be attached.
Here is the rod “test fitting”:
All that’s left to is:
1. Make the lower bracket the bottle jack
2. Buy and attach 2 springs
3. Make the lower section that is the base to press on
The lower section I’ve changed the original plan. I now have 2 sections of the pallet racking that I will bolt together with 2 long sections of the pallet racking that’s been split down the middle. I’m hoping this will be strong enough to take the force of the jack. It will have steel pins through the uprights as with all shop press’ to adjust the height.
The plan is the make a flat plate with another 12mm rod pointing upwards. Then I’ll have to make some dies and setters for the ends of the rods. Plenty wide and tall enough to get the whole amp in.
Fingers crossed it works
Not bad for $12
A load of grinder dust that I had to clean up but I had the makings of a press. This is the plan for the layout:
Not a huge amount of travel but it should be more than enough for the preamp. I wanted a fixed lower guide as I planned on having a rod through there that I will later attach a pressing die to.
I also attached some l shaped steel to the bottom as legs and it now stands on its own.
I wish I had some argon as I would have TIG welded it as my stick welding is appalling (don’t look too close), but again for setting 3mm rivets it should be more than enough. My bottle jack is only 2 ton anyway, so I’ll likely be limited by that.
The big blue section of square tube is going to be the arm that the jack sits on. It will have the springs attached to it and underneath the rod for pressing will be attached.
Here is the rod “test fitting”:
All that’s left to is:
1. Make the lower bracket the bottle jack
2. Buy and attach 2 springs
3. Make the lower section that is the base to press on
The lower section I’ve changed the original plan. I now have 2 sections of the pallet racking that I will bolt together with 2 long sections of the pallet racking that’s been split down the middle. I’m hoping this will be strong enough to take the force of the jack. It will have steel pins through the uprights as with all shop press’ to adjust the height.
The plan is the make a flat plate with another 12mm rod pointing upwards. Then I’ll have to make some dies and setters for the ends of the rods. Plenty wide and tall enough to get the whole amp in.
Fingers crossed it works
Not bad for $12
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neevo
Super Member
You might be exposing me now. I’m a serial long term project poster
I have a thread on DTT that’s stalled a bit (Audiokarmas fault) but I track all the posts here so people can just read the content:
http://idiotsguidetocustom400f.blogspot.com/?m=1
neevo
Super Member
I’m nearly finished with my shop press. I’ve surprised myself with the fact it appears to work!
The frame all done:
Then I turned a couple of pins for the lower shelf:
The lower shelf is a bolted together mash of parts:
All together with loops for the springs:
And the bottle jack in place:
The springs I’d bought were too long so had to swap them over at Bunnings. The new ones are fine. I’d like a little shorter but the jack is adjustable and I can take up the slack with that:
Here it is in action:
I wanted to give it a run, despite the fact I need to do a lot more refining.
It’s not the neat spread I’m after, but it’s significantly improved:
I have to refine a few bits still; like shortening the upper rod as it’s bending slightly and I don’t need all that length. I also need to think of some solutions to getting the rivets set right by making a die and setter that I can attach to the upper rod and the lower shelf.
The frame all done:
Then I turned a couple of pins for the lower shelf:
The lower shelf is a bolted together mash of parts:
All together with loops for the springs:
And the bottle jack in place:
The springs I’d bought were too long so had to swap them over at Bunnings. The new ones are fine. I’d like a little shorter but the jack is adjustable and I can take up the slack with that:
Here it is in action:
I wanted to give it a run, despite the fact I need to do a lot more refining.
It’s not the neat spread I’m after, but it’s significantly improved:
I have to refine a few bits still; like shortening the upper rod as it’s bending slightly and I don’t need all that length. I also need to think of some solutions to getting the rivets set right by making a die and setter that I can attach to the upper rod and the lower shelf.
rufleruf
Poor Impulse Control
This was fascinating - I hope to follow along in real time now - hint hint.
A hard luck case from my past: https://preservethesound.com/2011/08/07/roland-juno-60-part-1-project-or-parts/
A hard luck case from my past: https://preservethesound.com/2011/08/07/roland-juno-60-part-1-project-or-parts/
rufleruf
Poor Impulse Control
McIntosh probably had some WWII surplus battleship grade hydraulic rivet press.
Have you found someone that does a screening process that will work for this? There was some discussion on the Fisher forum about getting brass faceplates re-screened, but nothing came of it.
Have you found someone that does a screening process that will work for this? There was some discussion on the Fisher forum about getting brass faceplates re-screened, but nothing came of it.
arts
Addicted Member
I have two options for rivet installation.In either case,I figured out very early on that proper tooling was quicker,easier and cheaper to buy than making in-house.Squeezer dies are readily available,and I highly recommend the folks at Hansen Rivet for anything of this nature.Great prices,painless to deal with and fast shipping:
https://www.hansonrivet.com/
https://www.hansonrivet.com/tools-machines/riveting-accessories/riveting-squeezer-dies-2/
One is a commercial foot-operated machine for smaller jobs using soft tubular rivets,usually chrome plated brass.
The other a heavy duty frame I welded up for jobs requiring a deeper throat and much more pressure using harder tubular or solid rivets, usually stainless.
arts
Addicted Member
Apologies,I got carried away blabbing about my stuff,and completely lost my point
What I had meant to suggest was that the whole trick is in the tooling used to form/compress the actual rivet.Your press looks great,but the rods just need a little finessing.If you can,center-drill them to the appropriate diameter to accept comercially available squeezer dies. You can make your own,but it is not easy.
neevo
Super Member
Yeah that was the plan. I’ll check out Hason for commercial options.
@rufleruf i haven’t found a solution to screen printing yet but I have a good potential option. I’ve found a printer in Sydney that does UV printing:
https://www.arcsigns.com.au/Products/ProductsList?CategoryID=69&ListAll=true
I spoke to someone there who said it was easy to print on metal (painted) and glass I just need to head down there at some point, but that means I need to finish anodising the rear panel first. The only challenge might be the panel with a big 90° bend in it as that might not fit in the printer but again I’ll figure that out when I go down and see them.
So really I need to get the anodising done before I can do anything else and everything is pretty much ready to go for that I just need to re-polish the top and bottom rails to the same shine as the end panels.
The other thing I need to do to get ready for the screen printing is have some new front glass panels made, as on mine the whole spacing is wrong, but I might check they can print it first before I have glass cut.
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I love the dogged persistence of this. Go, neevo, go!!
neevo
Super Member
Look what’s back on the bench!!!
I have a real problem finishing projects but my commitment this year was to actually finish some stuff in the queue. Second on that list was my C20 and I’ve gotten it out of mothballs to push ahead and try and get it finished.
Step 1 is to check the Alu, bag it all up and send it away to be anodised. That will get done on Monday. Once it’s anodised I will be in a position to have the print put back on.
The other piece I’m getting done next week is having some new glass made up. As I’ve mentioned before the replacement glass I bought looked perfect but the upper hole spacing is 3mm too low.
Here you can see the overlap on the new glass with the old broken one underneath:
So I’ve cracked the old Mac out and I am adjusting the artwork to move the holes and artwork.
As I was doing that I’ve also discovered that the artwork on the reproduction panel is not centered in the upper holes. It’s half a mm out, so I’ve adjusted that in my artwork too. This adjustment was just 72pp up and 12pp across but if I’m going to the effort, I want it done right!
This adjustment has also created more space in the middle (3mm), so I have lifted the McIntosh logo up 1.5mm to keep the spacing consistent with before.
Because of this glass issue, I’m going down the path of having custom glass made, so I can create a new front panel myself and pass the reproduction one on to someone else. I will likely have a few made so I have spares but also do I can choose the best one.
Once the glass and Alu is all done, then I need to talk to the printers I spoke to years ago and see if they can print on my panels for me with the accuracy that I need. With the front panel I am aiming for the white and gold to be lit from the back if I can. I’m still deciding on how I will do the gold, whether I print a gold from 4 colour or ideally I’d like to see if the printers can actually print gold foil
I have a real problem finishing projects but my commitment this year was to actually finish some stuff in the queue. Second on that list was my C20 and I’ve gotten it out of mothballs to push ahead and try and get it finished.
Step 1 is to check the Alu, bag it all up and send it away to be anodised. That will get done on Monday. Once it’s anodised I will be in a position to have the print put back on.
The other piece I’m getting done next week is having some new glass made up. As I’ve mentioned before the replacement glass I bought looked perfect but the upper hole spacing is 3mm too low.
Here you can see the overlap on the new glass with the old broken one underneath:
So I’ve cracked the old Mac out and I am adjusting the artwork to move the holes and artwork.
As I was doing that I’ve also discovered that the artwork on the reproduction panel is not centered in the upper holes. It’s half a mm out, so I’ve adjusted that in my artwork too. This adjustment was just 72pp up and 12pp across but if I’m going to the effort, I want it done right!
This adjustment has also created more space in the middle (3mm), so I have lifted the McIntosh logo up 1.5mm to keep the spacing consistent with before.
Because of this glass issue, I’m going down the path of having custom glass made, so I can create a new front panel myself and pass the reproduction one on to someone else. I will likely have a few made so I have spares but also do I can choose the best one.
Once the glass and Alu is all done, then I need to talk to the printers I spoke to years ago and see if they can print on my panels for me with the accuracy that I need. With the front panel I am aiming for the white and gold to be lit from the back if I can. I’m still deciding on how I will do the gold, whether I print a gold from 4 colour or ideally I’d like to see if the printers can actually print gold foil
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neevo
Super Member
Small jobs today, I’m making some stainless inserts for the top and bottom Alu rails. Annoyingly I drilled one of the insert holes out to 5mm before I realised the steel inserts were press fit but that’s not the end of the world, 1 will just be more custom than the others (1x 5mm insert and 5x 4.5mm insert).
I’m using 316 Stainless and tapping it is a bitch. It work hardens so quick that whilst I have 1 insert made already, I’m thinking I will abandon the stainless and just make them out of steel instead. I’d like the longevity of stainless but steel is a better thread material anyway and I don’t plan on taking the preamp to the ocean
I’m using 316 Stainless and tapping it is a bitch. It work hardens so quick that whilst I have 1 insert made already, I’m thinking I will abandon the stainless and just make them out of steel instead. I’d like the longevity of stainless but steel is a better thread material anyway and I don’t plan on taking the preamp to the ocean
I’d like the longevity of stainless but steel is a better thread material anyway and I don’t plan on taking the preamp to the ocean
I'm reasonably sure it will outlive you ( no offense).
It doesn't seem like you're cheaping out on the effort.
I'm very impressed by your efforts and your attention to detail. Seems like if you were doing this for pay, your hours would outstrip the value of the 20.
I understand. It's sort of therapy for us
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