BenHawkins Posted December 24, 2020 Author Share Posted December 24, 2020 1 hour ago, andypugh said: Would these do? I should think so, they look great. Sufficient coffee will also be expensive so I will have to wait until the steel stockholders reopen. Quote Link to comment Share on other sites More sharing options...
andypugh Posted December 24, 2020 Share Posted December 24, 2020 On 12/22/2020 at 6:03 PM, Asciidv said: Andy, Ben, if you want sharper corners I can wire EDM the bits. It might be an advantage to wire EDM everything from tool steel so that hardening is not necessary, I think that I could slightly re-design the existing punch and die so that EDM-ed pieces would cut the profile, while keeping hardened silver steel for the parts that do the forming. Probably an idea to keep in reserve if tool life proves to be an issue. Quote Link to comment Share on other sites More sharing options...
Old Bill Posted December 24, 2020 Share Posted December 24, 2020 Nice job Andy. Is that one action or two? Steve Quote Link to comment Share on other sites More sharing options...
andypugh Posted December 25, 2020 Share Posted December 25, 2020 1 hour ago, Old Bill said: Nice job Andy. Is that one action or two? One action to make the square, torus and petals. But no petal-turning-over. https://youtu.be/j0FX1ER4URY In the video above I make 5 in a minute. So 14,000 would be 46 hours of work. It could be much faster with a stripper to pull the sheet off the punch, and with an air-blast (maybe on a foot switch) to kick the finished part into a hopper. Quote Link to comment Share on other sites More sharing options...
andypugh Posted December 25, 2020 Share Posted December 25, 2020 Productivity enhancement. I added a stripper and a foot-operated air blast to clear the completed parts. https://youtu.be/Bpb68xB6zTc 8 parts in 45 seconds, down to 20 hours to make the set. I had the idea last night that I should have drilled the lower follower for air blast, and then could have used the piston action to valve an air blast from the pressurised lower section. But it's all hardened now, so too late to be drilling holes. Soldering is likely to be fun. I would imagine that assembly with solder paste and then running over each tube with a torch would be the cheap way. (melting enough solder to dip a complete tube would be the quickest and easiest). I have experimented and found that the fins sucept well in an induction heater coil, which would be a high-tech way to melt solder paste. 5 Quote Link to comment Share on other sites More sharing options...
David Herbert Posted December 25, 2020 Share Posted December 25, 2020 If one is going to make the gills out of tin plate then I would think that dipping would be the best way of soldering as it will protect the cut edges which would rust very quickly otherwise and would not take paint very well. As we are not talking about a great total weight of material, would it be better to make the gills out of copper or brass ? Better thermal performance, no corrosion, and one could use solder paste. Any commercial press operation buys the material in coils of the width required which is fed into the punching machine through rolls that straighten it and a gripper that advances it one pitch per cycle so eliminating more handling. Happy Christmas everyone, David Quote Link to comment Share on other sites More sharing options...
andypugh Posted December 25, 2020 Share Posted December 25, 2020 1 hour ago, David Herbert said: If one is going to make the gills out of tin plate then I would think that dipping would be the best way of soldering as it will protect the cut edges which would rust very quickly otherwise and would not take paint very well. Yes, definitely the best way. But even a trough built specifically for doing one tube at a time (40 x 40 x 700mm) would need about 10kg of solder and some way to heat it. And that would be £250 of solder just to fill the trough, before any tubes are soldered. (And I think that is why it is hard to find anywhere that can dip a complete radiator, that's a _lot_ of solder to have tied up, and a lot of energy to melt it) Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted December 25, 2020 Author Share Posted December 25, 2020 13 minutes ago, andypugh said: Yes, definitely the best way. But even a trough built specifically for doing one tube at a time (40 x 40 x 700mm) would need about 10kg of solder and some way to heat it. And that would be £250 of solder just to fill the trough, before any tubes are soldered. (And I think that is why it is hard to find anywhere that can dip a complete radiator, that's a _lot_ of solder to have tied up, and a lot of energy to melt it) Merry Christmas! Thanks Andy for all your work on this. Tin plate seems like a good idea, my 1914 Dennis radiator showed some signs of tin or lead on the gills (possibly just solder) before I painted it. My 1908 Singer just has plain steel gills suggesting they were not dipped. I once tried a repair on a gilled tube with a propane torch so know that is a bad idea; the thermal mass of the gill is too low so they burn before the tube is heated enough to solder. A hot air gun will almost certainly be fine but I need to try that. The glamorous assistant purchased a White and Poppe catalogue for me. Here is the page for the engine in this project. Quote Link to comment Share on other sites More sharing options...
Asciidv Posted December 25, 2020 Share Posted December 25, 2020 48 minutes ago, andypugh said: Yes, definitely the best way. But even a trough built specifically for doing one tube at a time (40 x 40 x 700mm) would need about 10kg of solder and some way to heat it. And that would be £250 of solder just to fill the trough, before any tubes are soldered. (And I think that is why it is hard to find anywhere that can dip a complete radiator, that's a _lot_ of solder to have tied up, and a lot of energy to melt it) Andy, when through hole PCB soldering was superseded by surface mount technology I couldn’t bare to get rid of our Hollis wave flow soldering machine. It has at least a 50kg solder tank and 3 phase heating. There is a fluxing tank at one end a long conveyor with titanium fingers which passes the boards over pre-heaters and then the wave solder tank at the opposite end. By adjusting the wave height it would probably solder gilled tubes in a longitudinal manner easily. Quote Link to comment Share on other sites More sharing options...
andypugh Posted December 25, 2020 Share Posted December 25, 2020 2 hours ago, BenHawkins said: I once tried a repair on a gilled tube with a propane torch so know that is a bad idea; the thermal mass of the gill is too low so they burn before the tube is heated enough to solder. I suspect that induction heating would have the same problem, but even worse, as induction doesn't really heat copper at all. Quote A hot air gun will almost certainly be fine but I need to try that. And they are pretty cheap. I use one of these for repairing pewter tankards: https://www.ebay.co.uk/itm/220V-SMD-858D-Soldering-Repair-Desoldering-Station-Hot-Air-Rework-Tool-3-Nozzles/123935889600 Quote Link to comment Share on other sites More sharing options...
andypugh Posted December 25, 2020 Share Posted December 25, 2020 Further experimentation has shown that by adjusting the height of the spike, so that it doesn't quite "iron out" the petals against the inside of the top bore, it is possible to get the required turned-over tips. For consistency the press would need to be operated to a consistent point every stroke. This probably needs a slightly thinner spring seat shim, as there is a positive internal stop, but currently it isn't obvious by feel. Quote Link to comment Share on other sites More sharing options...
andypugh Posted December 26, 2020 Share Posted December 26, 2020 I have put up a slightly more informative video about how the tool works. https://youtu.be/NlFNOK4abeE 4 Quote Link to comment Share on other sites More sharing options...
MatchFuzee Posted December 26, 2020 Share Posted December 26, 2020 (edited) Impressive, especially as I'm only hand filing two 28mm x 38 mm oval mirrors. Edited December 26, 2020 by MatchFuzee Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted December 27, 2020 Author Share Posted December 27, 2020 I have started a conversation with a very knowledgeable solder dipper. He stated that for early radiators the tubes were usually solder tinned so the gills could be threaded on with flux; the assembly was then put in an oven where the solder would fix all the gills to tubes. With that information in place it explains why virtually no solder is visible on the gills of my 1908 Singer radiator. This radiator is the closest in construction (horizontal tube) and age (1908) that I know of. Dipping the whole tube would offer better corrosion protection. 1 Quote Link to comment Share on other sites More sharing options...
andypugh Posted December 27, 2020 Share Posted December 27, 2020 1 hour ago, BenHawkins said: He stated that for early radiators the tubes were usually solder tinned so the gills could be threaded on with flux; the assembly was then put in an oven where the solder would fix all the gills to tubes. This is very similar to how some aluminium parts are assembled nowadays: https://www.aluminium-brazing.com/2010/09/29/cladding-alloys/ 1 hour ago, BenHawkins said: Dipping the whole tube would offer better corrosion protection. And, thinking about it, there is no reason that the tubes need to be dipped in solder, they could be dipped in pure lead, probably at a much lower cost. I have a bullet casting pot (that I use for pewter casting) which is a stainless pot with what looks like a kettle element wrapped round it. A Stainless tube with a similar element and some mineral insulation would probably do the job (dipping the tubes vertically) Or sticking out the top of the gas fired casting forge (which you haven't built yet, but surely you need one). Quote Link to comment Share on other sites More sharing options...
Old Bill Posted December 30, 2020 Share Posted December 30, 2020 Whilst we are on the subject of radiators, I have another challenge for you Andy! Our Los Angeles Peerless radiator has another gill variant in that they are wrapped around the tube in a continuous spiral without being crinkled to bend them around. How was that done? The original core that we acquired has been 'repaired' by cutting out faulty tubes and then filling the gap with a bolt and washer. How do you repair individual tubes? I cannot see how to remove them without destroying the whole core. This core appears to have gills of the pattern you have made Andy but this time, they are round. This is much more sensible as they don't have to be aligned when assembling them. I may have to treat myself to a fly-press and punch out 20000 of them so I shall be very interested to follow your progress, Ben. More challenges! Steve Quote Link to comment Share on other sites More sharing options...
andypugh Posted December 30, 2020 Share Posted December 30, 2020 59 minutes ago, Old Bill said: Our Los Angeles Peerless radiator has another gill variant in that they are wrapped around the tube in a continuous spiral without being crinkled to bend them around. How was that done? I can only suggest witchcraft 🙂 I think it would require a die to keep a metal strip straight as it was wrapped. Possibly the strip could be heated by a gas jet as it went in to help with stretching the outer edge? 59 minutes ago, Old Bill said: The original core that we acquired has been 'repaired' by cutting out faulty tubes and then filling the gap with a bolt and washer. How do you repair individual tubes? I cannot see how to remove them without destroying the whole core If you were to leave off some gills at one end you could slip the new tube in, lift it too high, drop it down and then somehow finagle in some gill with a slit cut in. Maybe. 59 minutes ago, Old Bill said: This core appears to have gills of the pattern you have made Andy but this time, they are round. I have already designed a set of dies for my tool for the circular crinkled gills. But I haven't bothered to make it yet. Quote Link to comment Share on other sites More sharing options...
Old Bill Posted December 31, 2020 Share Posted December 31, 2020 8 hours ago, andypugh said: I have already designed a set of dies for my tool for the circular crinkled gills. But I haven't bothered to make it yet. Aha! You may get an order! I will have to go and source a press..... Steve 😉 Quote Link to comment Share on other sites More sharing options...
Doc Posted December 31, 2020 Share Posted December 31, 2020 11 hours ago, Old Bill said: Our Los Angeles Peerless radiator has another gill variant in that they are wrapped around the tube in a continuous spiral without being crinkled to bend them around. How was that done? Hi. Are these fins copper? If so, perhaps they were wound over hard tubes from strip in the annealed state. Is the fin measurably thinner at the tip compared to the root, or did they start with trapezoid strip, as you would if coiling a rectangular section spring? Similar heat exchanger tubing is still made though with aluminium fins. Take a look online at profins.com Not exactly what you're looking for but interesting read on a freezing cold morning. Andy Quote Link to comment Share on other sites More sharing options...
andypugh Posted December 31, 2020 Share Posted December 31, 2020 2 hours ago, Old Bill said: Aha! You may get an order! I will have to go and source a press..... Or make one. I would suggest a servo-controlled actuator for the ram and an XY stage to move a piece of sheet under it, with machine vision to ensure that the die is clear before moving the sheet to the next position. Like a Trumpf CNC punch. Quote Link to comment Share on other sites More sharing options...
ruxy Posted December 31, 2020 Share Posted December 31, 2020 On 12/25/2020 at 4:09 PM, David Herbert said: If one is going to make the gills out of tin plate then I would think that dipping would be the best way of soldering as it will protect the cut edges which would rust very quickly otherwise and would not take paint very well. As we are not talking about a great total weight of material, would it be better to make the gills out of copper or brass ? Better thermal performance, no corrosion, and one could use solder paste. Any commercial press operation buys the material in coils of the width required which is fed into the punching machine through rolls that straighten it and a gripper that advances it one pitch per cycle so eliminating more handling. Happy Christmas everyone, David Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted December 31, 2020 Share Posted December 31, 2020 On 12/30/2020 at 10:13 PM, Old Bill said: Whilst we are on the subject of radiators, I have another challenge for you Andy! Our Los Angeles Peerless radiator has another gill variant in that they are wrapped around the tube in a continuous spiral without being crinkled to bend them around. How was that done? The original core that we acquired has been 'repaired' by cutting out faulty tubes and then filling the gap with a bolt and washer. How do you repair individual tubes? I cannot see how to remove them without destroying the whole core. This core appears to have gills of the pattern you have made Andy but this time, they are round. This is much more sensible as they don't have to be aligned when assembling them. I may have to treat myself to a fly-press and punch out 20000 of them so I shall be very interested to follow your progress, Ben. More challenges! Steve Hi Steve, From your photo it looks like the gills are slightly crimped, you might be interested in the attached link to a Youtube video of a fairly simple set up to wind strip metal on to a tube using a lathe. regards, Richard 1 Quote Link to comment Share on other sites More sharing options...
Asciidv Posted January 1, 2021 Share Posted January 1, 2021 (edited) Tube Fins Limited here in the U.K. seem to do everything that is needed including solder tank dipping, http://www.tubefins.co.uk/WireWound.aspx and they are almost just round the corner from Ben and Steve! Edited January 1, 2021 by Asciidv Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 1, 2021 Share Posted January 1, 2021 Thanks for the pics Ruxy. Not quite sure what I am looking at though? Steve. Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 1, 2021 Share Posted January 1, 2021 What a brilliant video clip, Richard! If you have the kit, making tubes like that is far faster than threading loose gills onto tubes. I guess there must be a lead-screw on the far side of the machine to set the pitch. More food for thought there! Steve 😀 Quote Link to comment Share on other sites More sharing options...
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