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6th Mar 2017, 6:21 am | #1 |
Heptode
Join Date: Aug 2013
Location: Bradford, West Yorkshire, UK.
Posts: 888
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Dynatron TP11 Knobs - Success?
I am hoping I have these right but the two round ones are modelled using the Hacker Herald RP10 knobs - are they the same as the Dynatron TP11?
These are straight out of the printer so they need to be polished, but so far I'm pleased with them. EDIT: I will need to think about how best to make the brights for these - some kind of press, perhaps...
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Jon. Last edited by Ti Pwun; 6th Mar 2017 at 6:32 am. |
6th Mar 2017, 6:47 am | #2 |
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Re: Dynatron TP11 Knobs - Success?
Those are looking good Jon, which are the originals? Ha ha.
Brights I press in a vice with a pair of hardwood dies my shed mate turned for me. The dies need to be the same size as the required bright, I cut and file a circle of 22 gauge brass sheet or thin stainless, put between the dies and apply plenty of pressure. |
6th Mar 2017, 6:53 am | #3 |
Heptode
Join Date: Aug 2013
Location: Bradford, West Yorkshire, UK.
Posts: 888
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Re: Dynatron TP11 Knobs - Success?
Thanks Sam - none of those are original!
I figured that would be the way to make the brights. I have an old Black and Decker pillar drill attachment and I am thinking about modifying that to take care of this job - pull down the lever and presto... We'll see. Thanks for the tip, though. The light overhead is shining through the edges on these but without that glare, they are just white.
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Jon. Last edited by Ti Pwun; 6th Mar 2017 at 7:07 am. |
6th Mar 2017, 7:22 am | #4 |
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Location: Middlewich, Cheshire, UK. & Winter in the Philippines.
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Re: Dynatron TP11 Knobs - Success?
I think you will need far more push than a drill stand will withstand, I use a 5" vice and swing on it. (especially with stainless ) Or, have you a fly press?
{ I did know they were all new ones, no dirty grooves! } |
6th Mar 2017, 7:54 am | #5 |
Heptode
Join Date: Aug 2013
Location: Bradford, West Yorkshire, UK.
Posts: 888
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Re: Dynatron TP11 Knobs - Success?
No, I don't have anything like that. You're probably right on the stand. The name alone probably means it won't handle it.
Maybe a jig, then, to hold the blank, and a simple die and a big mallet! I'll come up with something. I knew you knew they're new! Ha!
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Jon. |
6th Mar 2017, 10:48 am | #7 |
Heptode
Join Date: Aug 2013
Location: Bradford, West Yorkshire, UK.
Posts: 888
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Re: Dynatron TP11 Knobs - Success?
Oh, that is excellent - never knew such a tool existed. That and a doming block is exactly what I need.
Perfect - thanks, Frank!
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Jon. Last edited by Ti Pwun; 6th Mar 2017 at 11:04 am. |
6th Mar 2017, 12:52 pm | #8 |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,763
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Re: Dynatron TP11 Knobs - Success?
The knobs look excellent Jon!
You've certainly mastered how to set the software to scan and faithfully replicate objects, which holds much promise, as is already evident. As regards the discs, I don't know about the Dynatron discs, but I've just measured a Roberts one and it's 17.8mm diameter, which equates to 7/10" in 'old money'. An 18mm disc cutter wouldn't quite be large enough to cutting suitably sized discs as when domed, the discs would lose a little of the diameter, so 19mm would, I think, be necessary. The brass sheet they're made from is 0.57mm - about 22 thou, so I guess that 0.5mm brass sheet would suffice. A 300mm x 100mm sheet would probably be enough for upwards of 40 discs. EG: http://www.ebay.co.uk/itm/Brass-shee...vRPS-HDIMSi7JQ In terms of 'doming' the discs, I think it may well need a much larger diameter doming block and punch than 18mm because an 18mm doming punch would make the dome far deeper than is called for. The depth of doming on Roberts discs is only 2.6mm (near enough 1/10"). As best I can, I'd estimate the 'curve' of the dome to equate to a 30mm diameter sphere - about 1.25". If I were to make any discs (which I've no intention of doing), I'd probably turn matching convex and concave dies in boxwood or beech to the same profile as an actual disc, with one die held the headstock of the lathe, the other in the tailstock, then insert a disc between the dies, and wind in the tailstock to use it as a press. I guess that a half decent drill press would do the doming job just as well. Whatever method is used, it's a fiddly, monotonous, time-consuming task to punch, dome and polish the discs, which doesn't easily lend itself to a viable commercial proposition. It's a road well travelled: http://www.vintage-radio.net/forum/s...ad.php?t=26740 Every good wish in your endeavours Jon.
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David. BVWS Member. G-QRP Club member 1339. |
6th Mar 2017, 1:15 pm | #9 |
Heptode
Join Date: Aug 2013
Location: Bradford, West Yorkshire, UK.
Posts: 888
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Re: Dynatron TP11 Knobs - Success?
Thanks David,
The models are hand drawn, which involves a lot of measuring, but I think the results are worth it. I was going to get a 3D scanner but I didn't feel the technology is quite there yet. Although it is improving all the time, I have to say. I will experiment with the discs - I am looking at the options now. The knobs with brights are just something extra I am exploring. Thanks for the best wishes. EDIT: And thanks for the info, of course - very useful.
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Jon. |
6th Mar 2017, 2:31 pm | #10 | |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,763
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Re: Dynatron TP11 Knobs - Success?
Quote:
When they show 3-D printers on TV, they make it look so effortless - they just scan the object and away the printer goes. Common sense and a healthy scepticism suggests that it's not so simple. I recently saw a printer in Clas Ohlson (about £1k) which had some neatly printed small animals as examples. No indication as to how the printer is programmed or how long it takes - not that time matters much when the printer is going about its business. I think there are various nozzles according to the standard of finish that's required. Presumably a larger nozzle can be used first, then for the final finish, a finer one? I believe that it isn't possible to print clear objects (as a replacement for clear polystyrene say), as the filament goes milky when heated. A steep learning curve I guess! One thing you can be sure of, your services will be much in demand.
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David. BVWS Member. G-QRP Club member 1339. |
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6th Mar 2017, 2:59 pm | #11 |
Heptode
Join Date: Aug 2013
Location: Bradford, West Yorkshire, UK.
Posts: 888
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Re: Dynatron TP11 Knobs - Success?
Yes, a few failed prints and experimentation got me to this.
I use a .25mm nozzle for everything, which is the smallest, and it can print some nice detail, but that nozzle is used to print the entire model so at the highest resolution, it takes quite a long time. The ridges on the knob, for example, would not look so good printed with a larger nozzle. 0.4mm is the standard nozzle that comes with the Ultimaker 2 but I opted for the Extended + model, which includes a .25 nozzle and a taller print height. Clear filament is available and I will be experimenting soon, but I haven't tried it yet. I was just saying to Graham the other day, it will be great when filament can be purchased like paint where a swatch of the desired colour is scanned into the computer and the filament is produced and dispatched. I can definitely see that happening one day, and reproducing these things will be so much better. Already now there are some pretty impressive filaments out there... After a model is produced, it is sliced horizontally so the entire thing is made up of many layers, all stacked on top of each other. Then, when that sliced model is sent to the printer, the bottom layer is printed and the print bed is moved down a layer (other printers may move the head upwards). Then the next layer is printed. And so on. Fascinating stuff.
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Jon. |
6th Mar 2017, 3:59 pm | #12 |
Hexode
Join Date: Dec 2013
Location: Torrington, Devon UK.
Posts: 446
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Re: Dynatron TP11 Knobs - Success?
Great job Jon. I spent all morning yesterday trying to draw one of these knobs. The basic shape was no problem but I just couldn't get the ribbed effect. You will have to enlighten me as to how you did it. These will sell very well as they fit the Roberts R200/300 and the early Hacker RP10 and quite a few more radios of the same era.
All the best Graham |
6th Mar 2017, 4:09 pm | #13 |
Heptode
Join Date: Aug 2013
Location: Bradford, West Yorkshire, UK.
Posts: 888
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Re: Dynatron TP11 Knobs - Success?
I've been studying how to do that since I created the first (inner) knobs.
I was going it about it the wrong way but I have it cracked now - I'll email you...
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Jon. |
29th Apr 2017, 1:16 am | #14 |
Heptode
Join Date: Aug 2013
Location: Bradford, West Yorkshire, UK.
Posts: 888
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Re: Dynatron TP11 Knobs - Success?
Quick Update on these now that I have mastered making the 'brights' as well. Image below. Now available via the link in my sig if people are interested.
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Jon. |
29th Apr 2017, 9:02 am | #15 |
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Join Date: Jan 2015
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Re: Dynatron TP11 Knobs - Success?
Very nice job, Jon. What system did you eventually choose for punching the brights?
Cheers, Frank |
29th Apr 2017, 9:43 am | #16 |
Heptode
Join Date: Feb 2013
Location: Yarm, North Yorkshire, UK.
Posts: 535
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Re: Dynatron TP11 Knobs - Success?
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29th Apr 2017, 10:08 am | #17 |
Rest in Peace
Join Date: Jan 2015
Location: Cottesmore, East Midlands, UK.
Posts: 858
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Re: Dynatron TP11 Knobs - Success?
The link works OK for me...
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29th Apr 2017, 2:10 pm | #18 | |
Heptode
Join Date: Aug 2013
Location: Bradford, West Yorkshire, UK.
Posts: 888
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Re: Dynatron TP11 Knobs - Success?
Quote:
I was initially concerned that I night end up with a brass disc embedded in me but the rubber top and bottom firmly holds the disc so it can't move. I stand with the disc sizing guide nearest to me and sand the disc from the opposite side so even if it were to work free, it could only hit the plastic guide. It is rock solid, though, and the discs spin nicely on the bearing without slipping. Obviously, when the guide fits snugly around the disc, it is sanded to the correct diameter. Little bit more work than I would have liked but it doesn't take that long and it gets the job done. After doming I go over the disc with 0000 steel wool and then use the Dremel to polish to a shine using some polishing compound. It works well enough, I think. I am working on the website so for now the sig link goes directly to the parts I have on eBay. EDIT: the disc I have in the jig is the first one I ever cut and I hit the punch/cutter way too hard, hence the rough edges. They now come out smooth but they are adjusted, of course, so the finished edge is very smooth and not sharp.
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Jon. |
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