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On the Ice => The Pro Shop => Topic started by: Christy on September 02, 2015, 03:07:42 PM

Title: How to do a blade tracing
Post by: Christy on September 02, 2015, 03:07:42 PM
I thought it might be useful to trace my blade profiles but just wondered how others have done it. Today I tried just holding the boot and I wasn't sure if I should let the boot fall to the paper or hold it level? The tracing looks very flat, yet I know my blades do have a fairly pronounced rocker so I'm assuming I did the tracing incorrectly. Any tips please?
Title: Re: How to do a blade tracing
Post by: lutefisk on September 02, 2015, 03:41:28 PM
I place my blades on top of some paper at the end of a table.  The boot is not on the table.  The blade is flat on the paper.  I then use a pencil to trace the shape of the blade.  I did this when my blades were brand new and plan to do so again after a few sharpenings to see how the rocker changes over time.  Make sure to draw around the toe picks so that you have a registration point to line up future drawings.
Title: Re: How to do a blade tracing
Post by: Live2Sk8 on September 02, 2015, 04:18:05 PM
I use the same method as lutefisk, lay the blade flat on the table and paper, not the boot.  I also trace around the back of the blade as well so I have 2 reference points to line up.  The resulting profile does look very flat, but when I compared the tracing of my brand-new blades to my blades that got ruined, the difference was striking (same model and size of blade from old to new).  It is amazing that I skated on ruined blades for 5 months!  Unfortunately because I completely adjusted to the ruined blades, it made my transition to the new blades horrendous.  I've had 2 sharpenings on the new blades so far with no visible changes whatsoever in the profile.
Title: Re: How to do a blade tracing
Post by: Query on September 02, 2015, 05:06:00 PM
Keeping a record of blade profile is a really great idea! Whether you sharpen your own, or take it to a skate tech, it can be useful to know how the shape changes.

I like to place the blade portion on the edge of a photocopier (or printer with a scanner built in), and photocopy it... Be very careful not to scratch the glass. After you are done, lay the blade against the copy to make sure the scanner didn't distort the image. This captures the entire blade shape, and may even see the name of the blade. If the toe pick teeth aren't symmetric, photocopy both sides, so you can see the shape when flat against the paper of all the teeth. (The relationship of the rocker portion of the blade to the toe pick is very important. E.g., blades feel a lot different when you don't have to roll forward as much from the sweet spot to the first toe pick as you used to.)

But I have also tried tracing the blade with a pen or pencil. Again, on the edge, so the blade is flat against the paper, like the other two said.

Any time you trace something, you have to be careful to keep the pen or pencil vertical, so it's wobble doesn't affect the line drawn. You also want the point that rests against the blade as thin as possible, to reduce shape distortion. technical pen works well. technical pens (https://en.wikipedia.org/wiki/Technical_pen) like this (http://www.ebay.com/itm/Koh-I-Noor-Rapidograph-Technical-Pen-Drafting-Art-Alvin-Faber-Castell-Refograph-/291532203058?hash=item43e0ac6432) you can buy in art supply stores or eBay for $2-$4 are great. Pick a good brand like Koh-I-Noor Rapidograph, or Faber-Castell. That's far more expensive than the 10/$1 pens I usually get at dollar stores, but they produce very thin consistent lines, darker, better and more symmetric than a typical ball point pen or sharpened pencil, and have very thin points. Maybe that is why engineers and artists like them...

BTW: Most good skate techs, including some mail order places, do an initial sharpening in which the skate tech modifies the shape to match what they think it should be. Especially with MK and Wilson blades, which are ground a bit inconsistently. (Ultima tend to be more consistent, IMO.) That's good, because it helps get rid of manufacturing defects. It's also bad, because the effective blade shape associated with a given blade model differs from one skate tech to another. But, we can only do the best we can.

Don't be surprised if your left and right blade have a little bit different shape. But that's not intentional, unless your skate tech has customized the blade shapes for your needs, something very few skate techs would ever do.
Title: Re: How to do a blade tracing
Post by: Bill_S on September 02, 2015, 05:24:36 PM
...and if your paper is a little too small for the tracing, cut it in half down a diagonal.

A diagonal is longer than either edge.
Title: Re: How to do a blade tracing
Post by: AgnesNitt on September 02, 2015, 06:00:08 PM
I used foam board rather than paper. It's sturdier.

Title: Re: How to do a blade tracing
Post by: Christy on September 02, 2015, 07:05:00 PM
I knew I was missing something   :-[ :-[ :-[
I was in a hurry and not thinking through the process.
Title: Re: How to do a blade tracing
Post by: Query on September 03, 2015, 03:07:47 PM
...and if your paper is a little too small for the tracing, cut it in half down a diagonal.

A diagonal is longer than either edge.

True! Legal size paper (8.5*14 inches) is bigger too.