Custom Walking Cane

[childofgallifrey]

Hi there, for a while I have been cooking up a parallel universe, where the history of the doctor is changed a bit. Colin Baker and Peter Davison's doctors are different, and from 8, the timeline changes entirely, with the shalka doctor, the nelvana doctor, me, and a doctor devised by Deviantart user JoeEngland:

I'm planning to make the cane shown here:

just one question, any ideas on how to engrave a ball...

[Volpone]

A brainstormed one--if you have access to a university art department.  Acid etching.  Going from memory from another lifetime but basically there's a waxy paint that you put on the metal (zinc plates if you're making prints) that is impervious to acid.  After it dries you use wood(?) tools to scribe away the coating from the areas you want etched.  Then you drop the bugger in an acid bath.  When the acid has worked enough, you pull it out, wash it off(?) and then plunge it into a tub of solvent soaked sawdust that strips off the wax.  I don't know if you could do it at home or how it would work with brass or anything, but it's an idea.  Acid etching. 

[galacticprobe]

Is that design on the cane's ball on a metal plate? And if so, is it a flat spot on the ball? If the answer to both is 'yes', then you could always get a piece of scrap metal from a machine shop (volpone's idea of a university art or industrial art department is perfect there - even a high school industrial art shop should have some scrap that's too small for them to use - whether it be stainless, aluminium, brass, etc., whatever metal you might be looking for). They'll usually let you have it for nothing since they'd normally toss it in the bin anyway.

Once you've got the piece of metal (and the arts shop might even cut it into a circle and smooth the edges for you if you ask nicely), then you could always take the metal disc and the design to an engraver or etching place and have them do it. Then it would have a really professional look to it. This would be relatively easy and inexpensive if the design area is flat; it would cost more if it's curved like the rest of the ball - but that's hard to tell from these images.

I hope some of this is helpful.

Dino.

[childofgallifrey]

I was thinking more along the lines of a full ball top cane, with a completely round top. I have no access to university equipment, just a secondary schools workshop, the only etching thing I can use is the laser cutter. Is there anyway I can do acid etching at home?

[galacticprobe]

Is there anyway I can do acid etching at home?

Erm... well? Have you tried looking up an engraver, showing him the image, and telling him what you want to get a cost quote? It might be safer, and might even cost the same (especially when you take into account the time and energy, and effort, you'd be putting into home-acid-etching), or even maybe cost a little less (in the grief department) to have an engraver do it. (And if the engraver messes it up, you don't pay; he has to fix it first. If you mess it up, then you're stuck with it and you have to start all over again while hoping it works out the second time round.)

Just my 2p on that. (Acid isn't fun to work with.)

Dino.

[asimov]

Does it have to be metal. Could it not be hard resin plastic? Which may be easier to work with.

[Volpone]

Hmm.  I thought I replied to this.  I wonder if I ran afoul of some rule for posting links or if an automated function killed the post, thinking I was a spambot.  I did a Google search for "diy brass etching."  I found a blog by a "Dr. Brassy Steampunk" that, upon scanning over, looked useful.  There was also a YouTube video called "etching copper or brass with ferric chloride step-by-step" that I didn't actually look at, but it might have been useful too. 

I closed by saying that in Olden Dayes, we didn't have engraving lasers in our high schools.  You might have access to better tools than my crude options.  But there is something to be said for old fashioned analog methods. 

If you want, I can make another attempt at sharing the links I found, but I suspect Google will get you fine results.  Just look at a couple to see if they agree with each other to try to weed out any bad advice. 

[childofgallifrey]

i'm thinking of using a metal door knob, maybe???

[galacticprobe]

I think I found your links, volpone. I'll try posting them to see if they get through this time. Others might find them useful.

First, there's Dr. Brassy's: http://drbrassysteampunk.blogspot.com/2013/09/brass-etching-dr-brassy-way-jump-into.html

And then the Youtube vid:

(and the actual URL: https://www.youtube.com/watch?v=CN_X8RAy2hg)

Let's see what happens.

Dino.

EDIT NOTE: It went through!

[Volpone]

Maybe I forgot to hit "post".

[childofgallifrey]

does anyone know if this would work on aluminium?

[kolchak92]

You could see about designing it on a software and sending to a 3D printer and paint it to make it look metal. You can always commission it as well. I came across this gentleman who had made the most accurate McGann Audio Sonic replica for me when I met McGann this past September. http://johnsonarmsprops.com Brian is very nice and professional and always e-mails replies in a timely manner. Also, LOVE the concept of the parallel universe Doctor story idea. i've been playing with that as well. Wish they would do it on the show so Cushing, The Shalka Doctor, and others can be "canonized." Love the design!

[Volpone]

I'd have to defer to a chemist, metallurgist, engineer of some sort, or possibly even a jewelery maker on that.  I would imagine it would have some effect on aluminum, but likely not as quickly as on brass, copper, or zinc.  In my laymen's thought processes, all these metals are fairly heavy and fairly malleable.  It may mean that this allows the acid to effect them more, um, effectively.  Of course lead is also heavy and malleable and don't they use lead in old car batteries to react with acid?  I don't think you could etch lead.  Also, you can etch glass (although it may be that the acid etc is totally different for that) so it would probably have some effect on aluminum.  But maybe a chemistry teacher would be a better resource. 

[childofgallifrey]

well, I have a great chemistry teacher at my school (who really likes me- and the crazy projects I do in my shed!) so he'd probably be able to tell me about the effects of hydrochloric acid on aluminium....

[kenny_z]

Please talk to your teacher before you try this. Hydrochloric acid and aluminum foil can be explosive if mishandled.

I know the company my father works at uses a diluted form of some sort of acid to wash their signs before the reflective material is baked on. This cleans all oils and contaminates from the metal and gives it a light etching so the material has something to grip.