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Start from the scratch

Posted: Wed Sep 25, 2013 12:05 am
by Dimitar
Hey folks,

let`s introduce ourselves - we are 3 passioned snowboarders from Bulgaria.
We found this site 8 months ago. Skibuilders changed our life. Thanks for the great source.

So, we started 2 weeks ago with renting a big house near by Vitosha Mountain (2290 m). There is fresh powder 3-4 months/year and gondola lift on 10 minutes walking..

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The house - it`s more than 300 sq.m...
We have big garage, a lot of warehouses, 3-phase electricity, mountain view, one very friendly dog... Everything needed for snowboard building...
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Now we are shopping materials for pneumatic press and crafting one huge workbench from euro pallets...

Fresh pics coming soon... Cheers!

8) 8) 8) 8) 8) 8) 8)

Posted: Wed Sep 25, 2013 2:05 am
by gozaimaas
Thats what I call living the dream!

Posted: Wed Sep 25, 2013 8:21 am
by Dtrain
WoW Dude, Living the Dream for sure. Better back up the boasting with some killer photos. Naked chicks around the hottub...and some kickass boards. HAHAHAHAH

Posted: Wed Sep 25, 2013 8:23 am
by Dtrain
Gotta say though, your logo looks very JONES-ISH! DEEPER FUTHER,DUDES

Heat blanket

Posted: Wed Oct 30, 2013 1:45 am
by Dimitar
We just finished our second heat blanket (the first one is in process of dissection, because one of the circuits is not working :D )

Materials:
- Resistance wire "Kanthal D - 0.25 mm, 27.5 ohms/meter
- Heat resistance silicone rubber - 1 mm thickness
- RTV silicone (for gaskets)
- Fiber glass tape
- Some nails

Dimensions of the heating surface: 33x180 cm.

We made 8 circuits (7.2 meters each). The distance between the wires is 1 cm. The calculated maximum power is 1998 W (220 V)

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We connected the kanthal to the main wires, using Chrismp` method (luster terminals)

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We fixed the wires to the silicone, using fiber glass tape (some tape for bathroom finishing, bought from hardware store). The tape holds the wires very well and it is great reinforcement in the blanket. With more tape we achieved better adhesion in the second blanket.

We did not make any pictures when the RTV silicone was spreaded, but the procedure is very simple - this process was carried out in 2 stages. First we glued the middle of the blanket, then we pulled out the nails and did the rest.

Heat control system includes one very simple power regulator. We found it in local online store:

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One of its parts overheats when the power is more than 300 W. So we installed that black radiator additionally.

This power regulator is very delicate and its quite difficult to fix the temperature exactly. So we added digital temperature controller to the system.

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We tested the blanket up to 95 C degrees. It worked for 1 hour without any troubles.

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The double control system consists of a lot of components including contactors and protection. We made a box to put all of them together.

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We grounded the main cable to the press frame using M8 bolt.

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... and the final look

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Any advices/critics will be appreciated ;)


Description and pictures of the press coming soon..

Posted: Wed Oct 30, 2013 3:19 am
by Richuk
Are your power regulators going in the box too? If so, you might want to use a computer fan to keep them cool and stop the system backing up.

Posted: Wed Oct 30, 2013 3:43 am
by vinman
^^^ definitely more ventilation and a heat sink.

Nice looking blankets and controller box but that MDF will trap heat.

Might want some fuses in there to protect your components. Maybe they are there but just not pictured.

Posted: Wed Oct 30, 2013 4:14 am
by chrismp
Nice work! Just FYI, I've stopped using luster terminals since I found a method that allows me to solder the resistance wire. You just need to sand the ends with some fine grit sandpaper until the wire gets a silvery finish. Then you can solder the prepared ends with regular solder-tin.

Posted: Wed Oct 30, 2013 4:19 am
by Dimitar
Vinman wrote:^^^ definitely more ventilation and a heat sink.

Nice looking blankets and controller box but that MDF will trap heat.

Might want some fuses in there to protect your components. Maybe they are there but just not pictured.
We did not notice any overheating in the box, however we will measure the temperature inside and if there is heat, we will install a fan for sure.

There is one main circuit breaker 20 amp.
Normally, maximum possible current is 18.2 amp (4000W / 220V = 18.2 amp)

Balkan press

Posted: Wed Nov 13, 2013 5:32 am
by Dimitar
We finaly finished our pneumatic press.
It was real challange for all of us, just because sourcing all these materials is not easy at all here in Bulgaria.

We were looking for second hand I-beams for a while. We did not find nothing attractive. Also all procedures as cutting, drilling and transportation are big adventure when you buy scrap metal.

So we ordered brand new I-beams. In order to take more light but still strong I-beams, we observed all available kinds.

The most optimal solution was combination of HEA200 and HEA140.

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We assambled the frame using M18 bolts - 56 units.

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There are 2 pieces of fire hose D110.
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This is the air connection - tyre valve for tractor. This is the thing, no additional gaskets, nothing special. It is completely airproof.
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We tested the bladder up to 5 bars. Safety was important in this moment, so we went behind that tough steel door during the first try.. :D

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The air supply hose is 10 mm. in diameter. Its quite flexible, but still there is not enough space for bending, so we installed some fittings.
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This is the air control kit
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Heat blankets electrical connections are integrated on the back side.
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This is it. Not perfect, but it works great.

Pictures of the first board pressed sooon ;)

Posted: Wed Nov 13, 2013 6:52 am
by skimann20
white press = Sexy. I like it. looks like you did your homework.

Posted: Wed Nov 13, 2013 3:15 pm
by skidesmond
Nice job. The first time you inflate the press is always a bit scary. Good idea to take cover :)

Posted: Wed Nov 13, 2013 10:29 pm
by MontuckyMadman
Badass journal.

Posted: Wed Nov 13, 2013 11:36 pm
by Dimitar
skidesmond wrote:Nice job. The first time you inflate the press is always a bit scary. Good idea to take cover :)
We calculated the force before the initial start and the result was quite scary:

Approximately, the contact area is 5400 sq.cm. (180x30=5400)
The pressure is 5 bars = ~ 5.1 kg/sq.cm.

So in total the force shall be 5400 x 5.1 = 27 540 kg. = 27 tons

This is huuuge, very heavy tank is round 30 tons. And we don`t want to see how this force is smashing our shop... :)

In fact, there is 3-4 mm deflection in the middle of the press, when it is on 5 bars. This is not a big trouble, right?

Posted: Thu Nov 14, 2013 3:39 am
by skidesmond
If it's flexing 3-4mm you'll be losing at least that much camber in the ski and you may want to re-enforce the mid-section. Or cut back on the pressure.

Overall excellent work!