Saturday, 13 February 2016

CNC Machining a 1/10th Scale Sailboard

Here is a quick video of a 1/10 scale model I machined of the HD Slalom 83.  The objective was to view both the hull and deck concaves and to check all of the other contours looked ok before I sent the template files off for laser cutting.  The plan is to cut the full sized board when I have finished my large scale CNC router.

Normally the hull would be machined before the deck since it is more critical for performance than the deck.  Also you can vac dag the hull before machining the deck for added dimensional stability, and machine trim the hull sandwich and rail tuck below the wide point of the rail.

In the video the deck was machined first as it was easier in this case, but, unfortunately I squeezed the polyester bog supports out wider than the tape on the foam and a few small strips of the deck got eaten.

Hopefully I can post about modelling the board in SolidWorks and what works for me.

Sunday, 7 February 2016

HD Customs - Slalom 83 (150L)

I have finally finished my latest build - the Slalom 83 (formally Creeper 83, I am reserving creeper for the speed boards ;)

The final specs are:
Width: 83cm
Length: 247cm
Volume: 150L
Weight: 8.5Kg

I went in a new direction with this design and incorporated a double vee flowing into a tri-panel vee in the tail.  The intention is that it will plane early but not become flighty at speed or with smaller sails.  I tried the board out yesterday at the top of its range and couldn't find fault. The shoulders never caught in the chop or dragged in the troughs and wheelies were predictable and easily controlled.

Gybing was fascinating as there was so much variety on offer.  I could bury the full rail for a drawn our slalom style turn or snap it around quickly off the back foot.  Alternatively, I could use a combination of the two which worked well in the lulls - Fast entry with a sharp tail turn after the rig flip to enter the new tack squarer to the wind.  Also since the board planes so early and the straps are free from the flow I was going a slow as 8 knots on the exit and remained on the plane.

The board is made solid and there is a bit of extra weight in twin delta stringers, this board is made to last and take the punishment of the chop and my local.

Needless to say, I can't wait for my next session closer to the middle of the boards sail range.

Saturday, 29 August 2015

Board Building Project - HD Creeper 48 - Stage 8 - Clear Coat, Pads & Non-skid

Time for the final clear coat, sanding and non-skid.  I will keep a matt finish which shows the weave when wet - just like the finish on fins.  My non-skid was late night inspirado and I already don't like the waistcoat looking front - this will change down the track.  Also had a bit of trouble with the non-skid fisheyeing over to 1200 finish underneath - another experience for the memory bank.  This will be the last clear finished board I do, opaque sanding coats are so much quicker to finish.

 Clear coat, none under the pads to save weight.

 Clear coat tail.

 Wet and dry of the clear coat.
 Wet and dry finished.

 Pads and non-skid finished.

Hull sanded.

 Nose clear coat.

 Finished tail.

Ready to Rock.

Board Building Project - HD Creeper 48 - Stage 6 & 7 - Hull & Deck Lamination

Deck is bagged(200g Twill carbon, 130g plain glass + patches) and initial sanding is almost finished. Next up is to fill a few low spots I should have filled before glassing but couldn't be stuffed, then a finishing coat for polishing.

I glassed(2 x 130g plain glass + patches) the hull old school(not bagged) and everything was sweet until some gassing of the dcell combined with some crimped glass to form a few bubbles.  Yet more repair work.  The newer surfboard glass(130g) seems to use smaller glass bundles(and have larger openings in the weave) which leaves more resin on the layup table.  I think the layup might have been on the dry side as a result which doesn't help.  I probably should have glassed the hull on the board then feathering the 2 layers around the rail would have been easier.

There are a few tricks I tried for the hidden (under carbon) inserts which worked well.

 Deck Laminate Vacuum Bag

  Mast Track Bagged

Tail Bagged

Unwrapping fun!

  Deck Weave
Footstrap Insert Plugs revealed

Footstrap Insert Plugs sanded flush

Footstrap Insert Plugs flicked out

  Deck lightly sanded (sacrificial glass layer on top.
  Deck Sanded

   Deck Sanded


Sunday, 16 August 2015

HD Creeper 83 - Sneak Peek

Here is a sneak peek of my latest board build. There will be more detail to follow...

Its an 83cm slalom which is a bit of a Frankenstein with bits inspired by this and that.

The final design is a development of this design I was working on almost 3 years ago -

HD Creeper 83 Cad Model - Perspective

HD Creeper 83 Cad Model - Plan and Side Elevation
 HD Creeper 83 - Toolpaths

  HD Creeper 83 - Mowing Foam

 HD Creeper 83 -Foam Side

Monday, 10 August 2015

Board Building Project - HD Creeper 48 - Stage 5 - Inserts

Foot strap inserts, track, box and breather base are in.

 Marking out the fin box.

 Fin box router template.

 Routed Fin box on hull.

 Fin box trimmed to deck line.

 Fin box flush with hull.

 Foot strap inserts dry fitted.

 Edge of foot strap holes chamfered for glass wings.

Inserts fitted and glass wings taped flat.

 Goretex vent base fitted.

Tape removed and filler applied. 

Tuesday, 16 December 2014

Board Building Project - HD Creeper 48 - Stage 4 - Deck Sandwich

Well I have been meaning to finish off this series of posts on the Creeper 48 build but one thing led to another and I haven't! Comments are from the my seabreeze post at the start of the year during the build.  Creeper 58 coming soon...

I have got the tricky stage out of the way, now I can sleep easy not having to worry about the vacuum running all night. Tried out the aluminium clamping system on the bag and it worked a treat although it is pretty tight with 2 x 200um sheets/1 tube. I used 12x12 channel with 6mm PVC tube. Next up are the fittings...

Using up scraps, 3mm plain on the left, perforated on the right. 

Pre-forming the Dcell with a heat gun. 

Softened the winglet for continuity of the sandwich, will restore the wing with filler after the deck is laminated.

Tail panels fitted so that they can support the deck sandwich from below. 

Gunking the rails for the Dcell wrap.  

Fitting the bag and critical rail join. 

Flipped over in the morning with the heat lamps on - bit of a cold spell at the moment with nights in the low 10's.

Bag seal with 12mm channel and 6mm ID PVC tube. 

Deck sandwich trimmed with the snap-off knife blade.  

Finished composite Dcell deck - no more scraps left, just in time as my bulk shipment of Corecell and Dcell has just arrived for the next 3 boards! Love it!