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I didn't understand a bit. You can see it in my pictures. The last picture is after pressing the shaped hole, on the bottom tool. The tool does not touch the upper part of the relief. It only threads the material onto the relief at the bottom of the tool. The space between the walls of the tool determines the sharpness of the details.
I'm not in the workshop and I didn't take a picture of a specific tool, sometime next time. I like to press into free space. I can afford a lower quality tool. I will give one example of a colleague from Sweden. Very nice production - perfect job. Hats off.... BUT I found one error in the production process. At about 18 minutes into the video, he applied putty to the lower part of the tool and made a radius in it. In this I see a big mistake and an increase in labor in finishing and correcting details. Are you asking why? Is it stupid of me to point out a detail that is wrong from my point of view? Sorry mate. This is my opinion, but experience allows me to point it out. The application of hard sealant caused minor defects in the bearing surface. During pressing, these small errors were imprinted into the shaped material. A colleague had to repair these minor mistakes with a hammer. In my opinion, useless work. How would I do it - if I'm so clever? I would not apply putty. Make a quality radius tool on the air hammer to finish. This is the point - I would be pressing into the free space. You only print on one side. It's a slightly different case, but the basic principle is the same. It wasn't a criticism, just my warning about a small detail that spoils a great job. Sorry mate for making an example of you. With to You could see it... This is the video. https://www.youtube.com/watch?v=IP5Z28Zmz6o Of course, if it is possible to produce a very high-quality tool using modern technology, sputtering, tool-making and similar demanding processes, my amateur advice is useless. We know how it should be produced properly, but it is very expensive.
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Jaroslav Last edited by Jaroslav; 12-30-2022 at 12:30 PM. |
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Updated progress
Thanks again for the replies. I got myself a 20T press and was able to start experimenting with pretty good results. I created a one sided die. I used my laser machine to cut out numbers from a sheet of 1/16" acrylic. I attached the numbers to a piece of plywood using permanent double sided tape. I placed a square of 10mil copper on top of the die. I then placed a piece of urethane on top of the copper. I then placed a 1" thick piece of steel plate on top of that. I was able to press out a 7"x 7" clock dial without any issues. I have two pieces of urethane and found that the 1/16" thick 95A durometer rating worked better than the 1/8" thick 80A durometer. The 95A is harder and provided better definition. I was getting some unwanted lines showing up from the edge of the urethane since it is only a 6x6 square. I ordered a larger sheet 12x12 sheet of urethane so I could cover the entire piece and avoid overlap lines. I still have some experimenting to do. Overall I am very happy with the results and will make the process of making clock dials much easier!
20230121_153218.jpg 20230121_153224.jpg
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David Last edited by galooph; 01-22-2023 at 05:07 AM. |
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Hi David. I see good progress.
A few notes: Plywood is not a good base material. Take a steel or duralumin sheet of good thickness. It is good to lubricate the numbers - fine oil. Polyurethane. Hard will describe everything, soft will leave out small irregularities on the pad. Wavy - it's good to hold the edges. Screw on the outer frame and press the sheet or make the frame as numbers at the height of the letters around the outer circumference and press at the same time. After pressing, you cut it. The outer frame will tighten the sheet and the molding will be straight. If you use pressing into the grooves, the contours of the numbers will be very sharp.
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Jaroslav |
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You could also make a female mold from an existing clock face you have done. The reason I would make female as much easier to rework individual numbers or features on the mold.
These alloys could be used to make said mold from clock face you did with your old method. These alloys melt at a low temp and are harder than epoxy. https://www.rotometals.com/low-melt-fusible-alloys/ Jaroslav gave you great advice about clamping the edges so the all the stretching will happen at the letters and sheet can stay flat.
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Greg Last edited by lots2learn; 01-22-2023 at 01:05 PM. |
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Great feedback and suggestions! Eventually my copper faces are mounted to a board which helps flatten it out. I will continue experimenting and keep these pointers in mind. Thanks again for the feedback.
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David |
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