New member to GearHeads

[ArtF]

Hi Bill:

  Welcome to the group. I saw your question on ticker scale size fly by on your group
request. When it comes to scimitar, the scale is really unimportant, other than all parts must scale
to generally the same size. If you print the dxf's in the zip file at 1:1 then you can use them
as templates for cutting on a scroll saw. While cnc is handy for scimitar ( or any whirligig.. ),
its not a necessity. You may find you wish to cut the ratchet differently, or modify one part or
another to fit, but its a very forgiving design and quite a simple contraption overall.

  Yell when you have a question.

Art


                     

[wfnickl]

Art, Thanks for the Welcome.  Perhaps I just don't know how to print the correct files.  I use a Mac - does that matter?  I don't have any CAD program - exactly what files am I looking for?  I apologize for not knowing anything about dxf files - so "unzipping" them is yet another step I am unclear about.  I feel a bit embarrassed not knowing the lexicon associated with what is clearly second nature to you.  Again any assistance you may provide is greatly appreciated.

Let me detail a few of my dimension issues:  When I printed out the files,(NOT dxf) the 10T spur gear measures ~ 29 mm in diameter, the 40T gear diameter is 108mm, the three spinning legs are 101mm long - each, the escapement ratchet diameter ~113mm and the trigger 125mm long.  This is how they printed out (pdf I guess) and are not nearly the correct sizes.  Your assistant is needed.

Thanks again, Bill

[ArtF]

Hi Bill:

  I know its hard to jump in when you dont have experience on the flavors of the drawing files.
Here is an overview zip file. This file, if you place it on your desktop and right click it, should give you the option to "unzip" or"expand" it.

  This will put out an overview of all the parts in several formats from eps, to ai to dxf.. if you can find a program to print one of them at 1:1 ratio, then you should be OK. I use a combination of a program
called Vectric VCarve ( a great program) and Gearotic for printouts. The main 40T gear should be about
180mm in outside diameter...

  I don't use a mac, so I'm not sure what program you would use, but I suspect one of the 4 formats
I include here should be open-able and printable with something...

  Let me know how you make out..

Art

[kit]

Welcome Bill,
I'm a bit of a newbie to Gearheads Corner as well but I've been around on a couple of other tech stuff forums for a while. I got into making wooden clocks as a test of the acuracy of my newly built CNC machine and got hooked. You'll find lots of people on here who have plenty of time for an new enthusiast.

Kit

[marklazarz]

Hi Bill:

Glad you joined the forum.  You should find lots of help here.

Mark

[John T]

Hi Bill,
I'm a Mac user so I know that you can use Mac very effectively.  As for using shop tools many of my first clocks were cut on a scroll saw - until my back muscles cause me so much pain (cramping) that I broke down and got a CNC machine.

Anyway for making patterns to glue on to wood, I simply used PowerPoint which worked just fine.  The only draw back was the communication from power point through to the printer so that "stuff" came out properly to scale.  (Prints tended to be off in one direction or the other resulting in oblong gears that won't work.  By making a transparency with a perfect circle, and having that in the background I could fix the powerpoint screens (scans) until they perfectly overlapped the transparency and guarantee things to be in the correct aspect.  Proof was of course in the cutting and they worked.  Lots of clocks I've made (I'm working on #34) are still working fine with this technique.

John

[marklazarz]

Regarding John T's comment:

I have purchased Clayton Boyer's clock plans and cut them on a scroll saw as well.  Clayton states that his plans should be printed on an ink jet printer instead of a laser printer because lasers don't print true circles, instead they are elliptical in shape.  I verified this with my printers by holding copies up to a brightly lit window for comparison and sure enough, it's true.

Mark

[wfnickl]

Kit, Mark and John - thanks for your words of encouragement.  I was hoping that I would not have to use a template to tweak gear print-outs, and I cannot explain the laser printout glitch (elliptical vs round)  As I use a laser printer (toner was way less expensive than ink) I am not sure how I will get accurate copies to attach to wood blanks for cutting with bandsaw.  I plan to check out our local library for a better printer however.  "The difficult takes time, the impossible, just takes a little longer" 

Bill

[ArtF]

hmm, I dont have a inkjet to verify with.. but I cant see easily an elliptical from my laser.. I wonder if it depends on the
printer.. Cant really see any technical reason for that..

Gearotic goes through some pain to figure out exact 1:1 scaling for the print. Always possible thought
but I dont think it'd enough to screw up most wooden gears.. depending on size.

Art

[marklazarz]

Art:

Just for the heck of it, print two large circles on your laser printer, stack them top of each other, hold them up to a light and turn one 90 degrees and see if they match.

Mark

[ArtF]

Mark:

Good idea. :)

  I printed from Gearotic two large circles, ( a functional gear with no eceentricity ) and
rotated. I can happily say on my Brother 2280DW, there is no change at 90 degrees, both
circles overlay perfectly.  I haven tried from other programs, which may indeed scale,
but the reason you hve to "acquire" the printer in Gearotic is that it interogates the
printer to figure out the proper scaling in each plane for as good a 1:1 as can be done.
That may or may not make the difference..

Art

[marklazarz]

Art:

Interesting results printing with Gearotic.  I can't remember if I copied an image or printed a PDF file but my laser printer made circles very slightly eccentric, not noticeable to the eye, but unacceptable for clock gears.  The ink jet was spot on.  At any rate, this discussion may help someone having problems depthing their mechanisms.

Mark

[ArtF]

Mark:

Definitely , Its always good such things are archived as a discussion, I know I find hundreds of useful discussions
that are similar on boards all over the world every year. I'm always happy to add to that collective. It almost always
ends up helping someone.

Art