Bent Green Things 13/14

Document your personal work here. Show photos, movies, and share your secrets.

Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp

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chrismp
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Post by chrismp »

Great thinking! I'll look if there are any possible points to mount it to and maybe buy a donek drag knife.
knightsofnii
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Post by knightsofnii »

splice a nice kill switch into the lines supplying the spindle?

whatever the case... wow, you should have that anyway for safety!!
Doug
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chrismp
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Post by chrismp »

knightsofnii wrote:splice a nice kill switch into the lines supplying the spindle?

whatever the case... wow, you should have that anyway for safety!!
won't work without some serious programming or rewiring. and now worries, since this is a big commercial cnc, it's got plenty of safety mechanisms ;)
knightsofnii
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Post by knightsofnii »

yet no way to power on or off the spindle?
Doug
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chrismp
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Post by chrismp »

knightsofnii wrote:yet no way to power on or off the spindle?
there's definitely no hard- or software on/off switch and the software won't let me set the spindle speed to zero...has to be at least one. the support team is on holiday atm, but i'm sure they can help me out.
Alex13
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Post by Alex13 »

Possibly stupid question here chrismp, but how slow can your router spindle speed be set?

If the knife is on a bearing at the bottom, does it matter it the router is spinning?

Obviously it isn't ideal and you probably don't want it going at 4000rpm, but it may well still work if you can go slow enough.

The only issue may be the fact that it's weighted on one side, and while the knife is "in the air" it will cause vibrations.
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chrismp
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Post by chrismp »

Already tried that...the router will go as low as 1rpm. But using a drag knife with a bearing even at this low speed caused the knife to chatter.
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skimann20
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Post by skimann20 »

Holy Highjack Batman!
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chrismp
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Post by chrismp »

skimann20 wrote:Holy Highjack Batman!
Haha i know...wasn't my intention. The questions just kept coming!
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skimann20
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Post by skimann20 »

Hey Gang! I've got everything cut out, cores and bases are all lined up on the cassette. This will be my first bamboo core and they feel stiffer than my ash/poplar cores, granted these skis are fatter than my "normal" pair.

Ski shape is 180cm, 132-97-120, core: 2-12-2. 22oz tri-ax.

I'm thinking about adding some stringers of CF, I have 4.2 and 9oz CF. I like a fairly stiff ski and would appreciate it if anyone would care to give me some "Beta". *I will not hold you liable if the ski comes out to stiff or soft. ;-)
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SHIF
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Post by SHIF »

My latest two pairs of skis have very similar dimensions as yours and also have vertical laminated bamboo cores. I added Ipe sidewalls to both.
One pair has 10 oz unidirectional E glass and 12 oz biaxial carbon fiber on both sides of the core. These came out very soft but are rock solid in torsion. The next pair is identical but with added 9 oz uni carbon both sides (3" wide strips). These came out having a medium-stiff flex and are also rock solid in torsion. The biaxial carbon layers act like having metal in there. My next build will be similar but with full-width 4 oz uni carbon below the core and a 3" wide strip of 9 oz uni carbon above.

For your build I would suggest adding some uni carbon strips to stiffen the flex and also add some "pop" to the ride.
Also very important to create some shallow steps in the bottom of your cores to provide a space for the edge tabs to fit. This will yield much flatter bottoms than not having such steps. My skis tune up easily and have an edge to edge stone grind structure.

-S
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skimann20
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Post by skimann20 »

thanks Shift. very good info! I look forward to the day i start playing with combinations of e glass, biaxel and uni. still trying to keep it simple right now.

Rabbet in place!
4 strips at 1.5" 9OZ cut and ready to go. keeping my fingers crossed!

cheers all.
twizzstyle
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Post by twizzstyle »

Good luck! Sounds like a beast of a ski.
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skimann20
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Post by skimann20 »

task completed! pulled them out, cut the flash, trued up the sidewalls. the only thing left to do is grind the bottoms and put a sidewall profile. I'm thinking about trying the strait bit with wedge technique instead of my dovetail bit.

My initial thought. Hardly any camber (let them cool under pressure in the press until 110F). they are softer than I was hoping but snappy as hell! I'm going to look into making a pair with Vectorply. I'm starting to wonder if my 22oz fiberglass (fiberglass supply) is sub-par? Don't get me wrong, they are great! and I'm totally excited to get them mounted up!

I'll get some photos up soon. Getting ready for the family first ski trip tomorrow. Then some night skiing on Thursday, when then storm comes in... I'm applying my Boston 1/3 weather rule to this one. Cheers all and happy new years!
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skimann20
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Post by skimann20 »

Hey Gang,
pre-layup, new for this pair. alignment blocks and pins. can't say enough good things about this technique. My beer during the press was so much more enjoyable knowing they were in there:
Image

"hot" out of the press:
Image

one thing I noticed about this pair is the 9oz Carbon was noticeable in the base on the base grind (slightly noticeable in the top sheet). Do others see the same. One company (can't remember who) puts a rabbet down the center of the core to account for this. thoughts? I really don't like it and thinking about going back to 4oz or just doing thicker core.

the carnage! here is a photo of all the blades that I've tried. I bought a new jig saw for this year, a DEWALT DW331K, this thing is a serious horse compared to my old el cheepo skill:
Image
for those of you with adjustable speeds, what speed do you run yours at?


after SEARCHING my balls off, i now have no balls now... i ordered up some hitachi ja10 blades and they showed up today. I hope they last because man they were not cheep. They are made to cut fiber cement board, they should work. :-)
Image

picked up some hardware, via Al's ski barn. great price:
Image

they were mounted up yesterday. really excited to ski this pair.
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