Ducttapetech's MT.O Challenge Coin.

[ducttapetech]

Just a quick drawing.
While probably the not newest or coolest idea, I was thinking alongs the of a spark plug gap tool with a bit driver. It should be easy to make. And the script can just be stamped.
Anyways here is a pic.



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[ducttapetech]

Saddly, I can't do the cool techno voodoo designs but I will try to get some better drawings done. Not 100% sure if I will keep the MTO saying on it or not.

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[Etherealicer]

Ok, this feels a bit like dissing the competition and I'm sorry for that. I had no idea what a "spark plug gap tool" is, so I googled it and the pictures I got looked exactly the same as your design.

I like the idea of the rim having changing thickness, that is very handy. I'm not sure how easy it is to get the scale correct, so here is my suggestion:
Why don't you remove the scale and add something of your own? Something that makes it your design?

[Grant Lamontagne]

I have a gap tool that looks very similar to what you have there only the gauge part goes around most of the outside.  The non gauge part at the top flattens out into a screwdriver, which might be a good option for this one as well. 

Not a great pic of the tool itself, but you at least get an idea of what I mean:



Mine is a cheapo, but while searching for the above photo I came across some really nice ones that sort of give an idea of how nice this kind of idea could be.

This one for example looks like an ancient coin or even something you could see someone wearing as an amulet at a Renaissance Fair.



Really cool ideas so far- I am looking forward to seeing what everyone else comes up with!

Def

[ducttapetech]

Sorry, you lost me. My idea, granted not the greatest so far, is dissing the competition?
Could you please tell me how?

Edit:  I got it. I understand now. Sorry.
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[ducttapetech]

Thanks Grant!

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[kkokkolis]

It looks like a potential pendant challenge coin.

[Cogito]

That second coin looks pretty sweet.

[enki_ck]

Very cool idea, Nate.

Mine's similar to this but you'll have to wait and see till I get a bit free time and relearn CAD.

[Tofty]

I'm afraid that i have serious doubts about how possible it will be to make a tool like this one to the required accuracy, let alone trying to align the text on both sides with the correct gap thicknesses.
The tools that are sold for this purpose are stamped out using multiple forging dies, slowly shaping the edge features until the second to last die stamps the final shape and text (the final die trims the excess metal from around the edge). This is what's needed to get the precision required to make an accurate spark plug gauge, we couldn't possibly do something like that as the tooling would cost many thousands of dollars.
It would be possible to drill, form and stamp the central hex and etch the other text into the pre-existing gauge tools, but then would it be special enough?

Only one person has made a tool like this in any other way and that was the now famous Dave22. His titanium screwdriver coins were machined in a way that could only be described as very clever, on a single function jig that would cost a fair amount to fabricate , but even then the achievable precision would probably not be good enough to allow it's function as a gauging tool. Plus the tooling and man-hours required would give the tool an unattractive price.

[ducttapetech]

I have been wondering about my idea. At first iwas thinking it would be easy to make. I even made new, cleaned up design. Then I got online and check to see how they are made. So I have been thnking the samething as you. Not worth it. I have been thinking of going another way with it or just do a coin. Not to sure.

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[ducttapetech]

Same idea, but a little differant.

Here is the front so far.

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[ducttapetech]

The back.


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[ducttapetech]

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[ducttapetech]

Going with this idea, I took some of the more common gaps for spark pugs for the coin. Each side is of the coin is one gapping. So instead of an incline slow working its way around the coin, it will be more of a stairstep. The numbers can be stamped in the step itself. This also give the coin an octagonal shape. Which I think makes it look better and seems to really clean it up.
Tofty, is this a more doable design or am I just wasting everybodies time with this one?

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[Tofty]

It's certainly a lot more doable. After laser/water cutting, all the required machining can be done on a manual lathe with a turn-table. Whether the required accuracy could be achieved is debatable, but engraving the graphics in the correct place would no longer be an issue. I wouldn't recommend stamping, as it distorts the surrounding material, ruining the precision of the surfaces. Also i'd move the text off and away from the working surfaces.

For the sake of simplifying the machining process, this is probably how the upper face should look.



(the thinnest cut is at the top right, there's no real reason why i did it this way round)
The machining cuts pass right across the tool, this is a lot easier for the operator as they don't have to cut in more than one plane at a time and can use a much larger diameter mill cutter, than if they had to cut into the tool and then along it.

This would still work out not to be cheap, but much more achievable

[ducttapetech]

Thanks for the input Tofty!

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[n4vgm]

When I first saw the initial drawing I thought "Cool, a rolling ruler!"

That might be different than what you thought of, but a circular rolling ruler with English (or is it Imperial?) on one side and Metric on the other would be a neat idea. and likely handy for more people.

[ducttapetech]

That is a cool idea. Never thought about anything like that.

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[microbe]

When I first saw the initial drawing I thought "Cool, a rolling ruler!"

That might be different than what you thought of, but a circular rolling ruler with English (or is it Imperial?) on one side and Metric on the other would be a neat idea. and likely handy for more people.

I thought about this for a tool coin, but inches and metric dont match. 1 inch is 2.54mm. 

[Steinar]

When I first saw the initial drawing I thought "Cool, a rolling ruler!"

That might be different than what you thought of, but a circular rolling ruler with English (or is it Imperial?) on one side and Metric on the other would be a neat idea. and likely handy for more people.

I thought about this for a tool coin, but inches and metric dont match. 1 inch is 2.54mm. 

2.54 cm.

[n4vgm]

Why do they have to match? If you are rolling a distance from zero you just use whichever side you like.

I don't know how usable it would be in the field. It would almost require a round hole in the center to roll around your finger/thumb. Wait, if you had a 1/4 inch hex in the center you could then use a bit as the "handle" as you rolled across something to measure it. 

Anyone ever seen a tool like that before? I can't remember seeing one. The edge of a metal disk may be too slippery for any kind of accuracy.

[Grant Lamontagne]

I wondered that too, but I think the "match" idea is for simplicity and flat sides.  If the design is a simple hexagon or octagon it would be simpler to find a more "even" size to make use easier.  If the design went with rounded edges then the argument is moot, and a round coin would indeed measure well enough.

To that end, it might be interesting to put a notch in the 12 o'clock position so that you know by feel that there has been a complete rotation.  That way if the circumference of the coin is three inches you will know without even looking that you have rolled it all the way around four times, so the thing you are measuring must be a foot long.

Def

[n4vgm]

"put a notch in the 12 o'clock position so that you know by feel that there has been a complete rotation.  That way if the circumference of the coin is three inches you will know without even looking that you have rolled it all the way around four times, so the thing you are measuring must be a foot long."

Doing it that way makes it work for both measuring systems on either side whereas putting a wee bump every inch does nothing for the metric crowd.

Again, sorry to hijack the original concept especially since I'm only an "armchair challenge coin designer!"

[Etherealicer]

"put a notch in the 12 o'clock position so that you know by feel that there has been a complete rotation.  That way if the circumference of the coin is three inches you will know without even looking that you have rolled it all the way around four times, so the thing you are measuring must be a foot long."

Doing it that way makes it work for both measuring systems on either side whereas putting a wee bump every inch does nothing for the metric crowd.

Again, sorry to hijack the original concept especially since I'm only an "armchair challenge coin designer!"

Not really, so I roll the coin three times which results in 9" I then have to multiply it by 2.54 or I have to add up 3 times 7.62. The beauty of the metric system is that it always comes in tens. So for the metric crowd, the reasonable circumference would be 10 cm ( = 3.9 inch) (coin diameter 3.18 cm).

That said I prefer the different thickness design. I can see many uses for this other than measuring spark-plugs.

[pfrsantos]

I think in the past some coins have been made in different materials. Why not in (slightly) different sizes? One for metric and one for imperial? Or finding a "round" number where both measurements coincide (no fractions on either side).
 

This last option might be better, only one size/model to be made.

[Steinar]

I think in the past some coins have been made in different materials. Why not in (slightly) different sizes? One for metric and one for imperial? Or finding a "round" number where both measurements coincide (no fractions on either side).
 

This last option might be better, only one size/model to be made.

The obvious one is 4 inches vs 10 cm. Etherealicer said 10 cm, but I think it's pretty arbitrary for practical purposes whether you go for 10 cm or 4 inches:

4 inches =  10.16 cm
10 cm = 3.94 inches = 3 15/16 inches.

1 / 16 inch is a tad below 1.6 mm, so if choosing circumference from where the error will be the least "in the other system", it won't matter much whether choosing metric or American.

That's not too bad, either way. Not like you'll be able to roll a coin with only a mm accuracy anyway, at least not without quite a lot of effort.

And since this is a family friendly forum, I won't write exactly what I think about the Imperial/American/utterly outdated system of measurement.

[n4vgm]

"the reasonable circumference would be 10 cm"

We Americans were supposed to have embraced the Metric system decades ago anyway so if you do this just go Metric on one side and motto(s) on the other.

[microbe]

When I first saw the initial drawing I thought "Cool, a rolling ruler!"

That might be different than what you thought of, but a circular rolling ruler with English (or is it Imperial?) on one side and Metric on the other would be a neat idea. and likely handy for more people.

I thought about this for a tool coin, but inches and metric dont match. 1 inch is 2.54mm. 

2.54 cm.

my bad 

[ducttapetech]

"the reasonable circumference would be 10 cm"

We Americans were supposed to have embraced the Metric system decades ago anyway so if you do this just go Metric on one side and motto(s) on the other.

We were supposed to, but we didn't. I'm good either way. I tend to prefer the standard system a tad better. But I grew up with it. The US will go Meteric, but it will be slow. I learned both when I was in school, but a lot of people only learned the standard system only while they where in school. For them it will be hard to switch.

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