Flashlight drawing & renderings... [Complete light posted! 3/9]

[jch79]

Update 3/9/07 - I put up the light I've been working on for the past few days... obviously still a work in progress, but it's something to at least look at & scrutinize!

Update 3/7/07 - I drew some components in a post below - a reflector, LED emitter, and a battery.

Update 3/3/07 - I did a practice rendering in a post below of an Aleph 1x123 tube.

Hey guys :wave:

I've finally learned enough of VectorWorks (awesome program - apparently much more user-friendly and intuitive than AutoCad) to be able to maybe get started on a flashlight design, and wanted to ask some questions:

1) For threading, do you draw your own, or just specify to the machinist the threading specs?

2) Units - inches or mm?? :shrug: Or does it not matter for CNC stuff?

3) Any general advice or guidelines!!!! (This is the biggie!)

I don't have much of a background using CAD programs, so try and keep that in mind, as I'm a drafting NOOB!

Thanks - so far, so fun! :naughty:

john

 

[gadget_lover]

Re: Flashlight drawing & renderings...

The threading can be a major source of problems, so you should make sure that you at least put place holders in the drawing.

As in instance, if you design a flashlight with walls that are .025 thick and specify 20 tpi threads the CNC will
happily cut off the end of the light. The threads will be deeper than .030. You can adjust the wall thickness or the TPI to make it work. The more TPI, the shallower the threads.

The thread depth for a unified thread will be the pitch times the constant .86603 times 5/8. Given this, a 20 tpi is ((1/20) * .86603 ) * (5/8) = .02706 deep if it's cut properly using a flat root.

A real thin wall with a deep thread will sometimes fracture under stress at the base of the thread and literally unwind. It's a neat effect, but very frustrating. It's worth adding a little extra material to keep that from happening.

Look for the CPF thread on single pointing threads for information on determining thread sizes, major/minor diameters and such.


Daniel

 

[jch79]

Re: Flashlight drawing & renderings...

Thanks Daniel - I found this:

Common Dimensions reference thread

It has dimensions of some common flashlights, which is handy. I suppose it just takes some practicing and messing around to get it right.

Is there a source where flashlight plans can be made available for example? I know that I'd be protective over my own plans, but there has to be some sort of cheesy flashlight design that's been posted before in CADD format, to toy around with how they drew it?

It's somewhat daunting, but I'm getting there. :candle:

Thanks!
john

 

[gadget_lover]

Re: Flashlight drawing & renderings...

Hi John,

That's one thread, but there are several others.

You can look at my TPI generator page ( http://www.tanj.com/cgi-bin/tpi.cgi ) for MY basic understanding of how threads work. No-one has given me feedback as to the accuracy of what I have posted there, and I've not tried to follow my own instructions since the last update, but the theory should be good.

I've not seen a lot of cad files for flashlights. I 've seen quite a few renderings, but as you say, the cad files themselves invite rip-offs.

Daniel

 

[jch79]

Re: Flashlight drawing & renderings...

You can look at my TPI generator page ( http://www.tanj.com/cgi-bin/tpi.cgi ) for MY basic understanding of how threads work. No-one has given me feedback as to the accuracy of what I have posted there, and I've not tried to follow my own instructions since the last update, but the theory should be good.

I've not seen a lot of cad files for flashlights. I 've seen quite a few renderings, but as you say, the cad files themselves invite rip-offs.

That's a great link and resource - it's more accurate than nothing, that's for sure!

I'm wondering if anyone out there would be willing to make available to all of us the working files of an abandoned or obsolete flashlight project? It is asking a lot, however if you aren't familiar with CAD or a similar program, it's hard visualizing how to get from a blank board to a complete flashlight!

Is there a soul out there that's courageous enough for such a thing? :candle:

If not, in the interest of CPF (and my own learning!), I would be willing to pay someone to create a CAD drawing of a SIMPLE light, that they could post for everyone to view/download/play with/learn from? Any takers?

john

 

[modamag]

Re: Flashlight drawing & renderings...

1) It's easiest to specify on your drawing with cosmetic thread.
If you master the spline then draw it.
As for specification it best to be upfront with the machinist whether you're gonna plate the unit or not. If you plan to plate, you need to know EXACTLY the buildup so they can adjust the thread pitch.

Here are some of my rule of (crushed) thumb.
a) Try to avoid smaller thread if possible. It requires tighter tolerance, gauges, and ultimately increase the cost of manufacturing.
If you really do understand your thread (I recommend). It's best to specify them with the following info.
eg. outside thread.
Min Major
Max Major
Min Pitch Diameter
Max Pitch Diameter
Min Minor

There are cases that calls for holding these threads within 0.001-0.002" tolerance but that will cost you big $$$ because the operator will have to spot measure the units after the run which add to the time required and thus more $$$.

b) Loose thread is not a BAD thing. Try to be as loose as possible and still have the strength is a GREAT design. IMHO.
c) Watch out for oring. I try to keep dynamic compression to ~15-18% anything more is too tight. Again I'm not designing dive lights.
d) Avoid double contact, Surefire E-series. It's a PITA to make it right and too many opportunity for something to go wrong.
e) Keep the number of tight tolerance to a minimal and only where they REALLY need to be.

2) Units - inches or mm?? Or does it not matter for CNC stuff?
Does matter in the modeling phase but matters ALOT during manufacturing.
If it's produce in the US try to stay English and vv Metric for oversea.
Most small shop will not run your drawing thru a CAM program (thus conversion). They will program by hand.



As for CAD drawing files, its relatively easy to generate one, but I think it destroy the following if you look at it.
1. The learning process. You WILL force yourself to learn all the intriquite details if you design from scratch. Sometime paying big $$$ for the mistakes.
2. Creativity. If you see another design you tend to lean toward doing the same thing. At least this is what I see from the few design posting out there.


John, I don't have alot of time on my hands but I'm willing to help you out anyway I can. Just post and we will try to respond (sooner or later).

 

[jch79]

Re: Flashlight drawing & renderings...

Great post Jonathan! Like I said, I'm getting there... and you're right - getting a drawing might actually hurt me more than help me in my learning. I hadn't thought about it that way! :shrug:

It seems like there is even more to consider when designing than I thought, ie tolerance in threads and O-rings... I'm trying not to be intimidated by the software, let alone the actual reality of how these darned lights actually work!!!

Thanks guys - I might post a working drawing at some point, however I don't want to ruin the surprise! :laughing:

 

[jch79]

Re: Flashlight drawing & renderings...

Well, I've been fooling around for a couple of hours tonight, trying to start my first sample project (a 1x123 E-series tube - nothing that I'd actually make, but something I had sitting around and could somewhat easily measure), and while I was finishing up for the night, and performing a 3D rendering preview, the program crashed, and the file disappeared! Well, lesson #1 - backup your stinkin' file!!!

OK, time for bed. :sleepy:

john

 

[hikari]

Re: Flashlight drawing & renderings...

...the program crashed, and the file disappeared! Well, lesson #1 - backup your stinkin' file!!!

Check in the folder where your data is kept or in the program folder. It might still be there... Most programs by default periodically back up your data file (working drawing) as some kind of temp or .bak file.

I've used AutoCAD 12, 14 and 2000 for years and I can attest that this auto back up can be a lifesaver. If it's an informal dwg, I don't worry about saving a file until I'm done for the session--but if it's a critical dwg, I try to remember to save it every time I put in a critical element.

 

[jch79]

Re: Flashlight drawing & renderings...

:wave: Just a quick update.

I've taken a lot of the VectorWorks tutorials in trying to get this all worked out, and there's still a LOT to learn. I'm getting there... mostly!

I finally found an acceptable price on the digital caliper I wanted - the 6" Starrett 797B - $139 from eBay - not bad, considering I saw one of their Dial calipers for $135 at a tool show up in Milwaukee this past weekend!

I'm taking measurements off of batteries and existing lights to determine some rough standards for tube lengths, wall thickness, etc.. It's been fun so far, and not as frustrating as I thought it might be. I'm trying to just do a concept light that exists purely for practice's sake. :thumbsup:

One question: has anyone messed around with drawing knurling? I found some texture patterns that kind of look like knurling, however nothing that really shows the dimensionality of the knurl. Granted I don't think anyone uses VectorWorks, I believe that if it can be done in AutoCAD, VW can do it as well.

john

 

[modamag]

Re: Flashlight drawing & renderings...

John,

Although Starrett is a nice caliper, for $139 you can get alot more than that.
A new digimatic Mitutoyo 6" only goes for $89 plus tax/shipping.

The wall thickness is by no mean "standard". It's more or less what thread you want and how small you want your light. Wall thickness ranges anywhere from 0.005"-0.100". The thicker the wall the more durable. Thinner wall, well you got to open up the tricks book. Try to get/borrow one of Larry's (tvodrd) light or pick up couple of Rob's (orb) and you'll see what I mean.

Knurling, and thread, don't bother drawing them use texture/cosmetic thread and callouts to same time, unless you want to learn more about spline and helicoil. Becareful with your knurling treat them the same as thread (major & minor) this will help make the knurling come out sharper and avoid laying them down multiple time.

 

[PEU]

Re: Flashlight drawing & renderings...

Great post Jonathan, saved me from typing a lot

For orings when I started I downloaded the Parker O-Ring Handbook, lots of info and best of all you have all the sizes there

For a begginner a $18 digital caliper will do the job too

For designing I go from function to beauty, meaning I first design the contacts, threads, oring placeholders etc etc and then when everything fits then I unleash the creative side of the mind.

I found this utility years ago for setting up my minilathe gearbox and never looked back: gears.rar (21kb)

Good luck


Pablo

 

[jch79]

Re: Flashlight drawing & renderings...

Thanks for the notes guys...

On the caliper that I bought - I realize that Mitutoyo is a great standard, however I try exclusively to purchase Made in USA, or other fair wage countries (yes, even Argentina ), so the Starrett 797B was the only digital one our that made the cut. I saw some $20 digital calipers at the tool show I was at this weekend, however if I buy something, I prefer to get something that is built with quality, and that will last. That may put me in the hole for a while, but I feel better in the end.

Thanks for the O-ring handbook Pablo! That's perfect. Also, your note on going "from function to beauty" goes along with my mindset as well - I think it was the architect Louis Sullivan that said "Form follows function" - what a great saying.

Jonathan, thanks for the note on knurling - it does seem a bit tricky, and I'm glad that some textures exist that can somewhat take the place, but even if to show what it might look like (cosmetically), I'll take a few stabs at it later on. :shrug:

Thanks!
john

 

[Anglepoise]

Re: Flashlight drawing & renderings...

One thing I have had problems with is 'O' ring groove depth.
On a small light, the required depth can sometimes weaken the light at that point.

I have found that Metric 'O' rings with 1mm cross section can sometimes come to your rescue if you run out of metal.

Good luck

 

[modamag]

Re: Flashlight drawing & renderings...

David, great catch on the metric oring. They are a life saver.
If all else fails you can make your own at a very pricey cost.

Parker O-ring Handbook is a great resource. However, we are not designing for 500m under the sea application. So don't try to use 30% compression for your dynamic oring. Go for something more reasonable 10-20%. I normally use 17% post plating.

BTW: standard tolerance for orings is +/- 0.003" cross section and +/- 0.003" internal diameter. Yes you can call out exactly what you want but I GUARANTEE you they will not be exact even with custom form. So give it some "slack".

 

[jch79]

Re: Flashlight drawing & renderings...

However, we are not designing for 500m under the sea application. So don't try to use 30% compression for your dynamic oring. Go for something more reasonable 10-20%. I normally use 17% post plating.

So... for example, if I have a .500" OD that needs to get an O-ring, using for example your 17% figure, you would select an O-ring with an internal diameter of ~.415"?

And the width of our average O-ring on a flashlight is usually 1/16", correct? It seems like 3/32" is used as well. Unless you go metric, in which case it seems to be 1mm or 1.5mm?

I know that I'm generalizing, but at this point, I'm just trying to soak up the info. I have a feeling this thread is going to come in handy when I actually figure out exactly what I'm doing! I can't wait to get a drawing up for you guys to look at.

Thanks,
john

 

[jch79]

Re: Flashlight drawing & renderings...

Hey guys! :wave:

Well the calipers came in, and I got to take some measurements of an Aleph 1x123 tube for an example, and applying what I've learned so far with VectorWorks, and came up with this...

The threading is cosmetic, although fairly accurate. I didn't do any knurling, as I am going to try a better way to learn to do it with this program as well. :shrug:

VectorWorks is a great program - it has machine design built into it, which lets the user calculate and insert threading (I haven't mastered that yet), same with springs, shafts... you name it! Very cool.

john

EDIT: I thought it'd be OK to draft the Aleph tube, as Don has made these designs public on the Aleph FAQ site. I have no intention of producing anything remotely similar to this - this is just for learning.

 

[TranquillityBase]

Re: Flashlight drawing & renderings...

Very cool...

TB

 

[Mirage_Man]

Re: Flashlight drawing & renderings... [New rendering 3/3]

Sweet! I guess I have to add another thing on list of what I need to learn. This would have come in very hand in designing the 18650 body.

 

[jch79]

Re: Flashlight drawing & renderings... [New rendering 3/3]

Thanks guys - it actually is fun (if you consider sitting in front of your computer all day figuring out what the heck you're doing is fun!)...

I didn't have much going on yesterday, and started a design for a new light, as that's why I'm learning this skill in the first place!

I have most (or at least some!) of the basics down for the design, and I'm going to hopefully work on it tonight some more, and maybe even post my progress. I obviously don't plan on producing the light, as I've still got a ways to go to become even close to knowledgeable, so I'll be happy to share it and see what people think. It's just a simple 1x123 twisty light. :shrug:

Thanks,
john