I finally completed these boards. The topmount is listed in the 2008 summer open theme thread. The other two are drop throughs. I'm going to adjust the kicks for the next series. More angle, shorter WB. Details of the finish are described in the above thread. I am quite stoked to ride these and to present these to you.
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If you don't do it this year, you'll be one year older when you do.
- Warren Miller
Tomorrow may rain so I'll follow the sun.
- The Beatles
Well, over the last few months, using Baltic birch wood, I have been experimenting with different wood presses, testing different shapes, designs, forms, and press designs. I have assumed a taste for carving boards, and most recently been trying to achieve a simple press to create that coveted concave/camber shape with just the right balance of curves this way and that, with just the right flex. The right press design should produce a reasonable product consistently, be easy to use, and easy to make without requiring much precision. My press will be presented from start to finish with a “How to” approach.
Why not just get a Roarocket Kit and vacuum press it? I don’t know. I guess I am just obsessed with the medieval urge to press down with screws, nuts, and bolts. The whole idea is sick.
I will stop here and say that, I, like many of you, hate reading a lot of words, so, you can probably just review the images and, with some insight, get the gist of this thread. For others that wish to hear the whole story, and discuss some board making theory (don’t worry, no numbers/equations), read on.
A carving board should have some flex therefore; camber is advantageous to offset the bend in the board. Concave obviously holds your feet better, therefore, IMO, the concave/camber design works best. The press should be easy to use in that, there shouldn’t be several screws to fiddle with, and should not have too many elements or variables.
I have tried a number of rib presses for this form, and have always had some form of waviness. Probably any ribbed press will, regardless of the number. In addition, the precision required making those individual ribs identical or to the specified shape is extremely difficult. Although, I have seen some unbelievably precise wooden creations on this site. But alas, I only have a jigsaw and a belt sander. No band saw. Certainly no CNC machine or computer design program. I suppose my craftsmanship is a bit lacking as well.
This press design is essentially a combination of Brodie’s two presses. I know several folks before and after Brodie have created similar presses, but I’ll use his an example mainly because his were some of the earliest that I was exposed to.
Lush Longboards: View topic - The Brodie Press This press is indeed a concave/camber press using three longitudinal ribs. I have tried this, and the result was good but the concave was somewhat V-shape (my cuts were not angled). In addition, it is harder than it looks to create three long (36-42”) ribs, flush against each other to the exact specifications required. This is a testament to Brodie’s skills, and anyone who has recreated this.
What if we took the simplicity of the “press-down-the-middle” press and applied it to a camber shape. By bending a simple concave press over camber, if you will.
Fig 1: Let’s not list everything you will need. I hate recipes. Let’s just star with a jigsaw, drill, 2” by 12” by 8’ pine (A), 2” by 8” by 8’ pine (B), and two 1” by ½” by 36” runners (these are poplar and are actually about 1 ¼” in width). You will also eventually need some rulers and a belt sander. Note; the 2 by 12 is actually about 11” wide.
Fig 2: Now for a little methodology. The camber should be strategically shaped to best resist flattening. When standing on a board, it bends, with most of the pressure in the middle of the board. This is where overflexed boards eventually snap. Therefore, the board must work the hardest in the middle to resist bending. Or in other words, the camber must be most curved at the middle (think of an upside down “V”). Maximal concavity should reside at the point of inflection. This should also provide for the least amount of snap back. I am not sure how to explain this mathematically, but it just makes sense. A rounded shaped camber will snap back more and provide less resistance to flattening. Incidentally, this is the camber shape achieved with the toothless method is employed. Weighting the middle of the board causes most of the bend to occur right under your weight. I know, Enough already. On to the picture. Take a relatively flexible piece of wood, in this case, a 3/8” by 1” by 45” strip of pine wood from the home depot trim section. Screw in three wood screws such that the strip of wood can be placed between the two outer screws (over the strip) and the middle screw (under the strip) such that the curve rises approximately 1.5 inches over 45 to 48 inches or so. You will lose about 50% due to snap back if using 1/8” BB with 3/8” to 5/8” concave. So you say, 1.5” giving 0.75”? Is that all? I have made two previous similar presses, 1st with 3.5” and 2ndly with 2.75”, and both resulted in too much camber. I have found that for camber, subtlety is king, and less is more. 0.75” of camber is plenty. For 1”, start with 2” of rise. Onward.
Fig 3: Mark the camber curve on the board and cut. Use this cut piece as a guide for the other piece B to give you a total of 2 F pieces and 2 E pieces. Screw the two F and E pieces together as shown by the arrows. Now, and this is key, drill a pilot hole through the wood before screwing any of the wood screws in, otherwise they will cause the wood to crack. The screws are 8 by 2.5 inch exterior wood screws from Home depot. Drill a hole slightly smaller than the diameter of the screws.
Fig 4: Now this is the only part of this that requires some precision. The surfaces must be sanded a bit such that when the F pieces are placed on the E pieces, they are flush. Take your time and do it right.
Fig 5: The F pieces will forever remain screwed together. Unscrew the E pieces and screw them down to the long 2 by 12, piece A, such that they are aligned and flush with the side of piece A. Piece G will be used soon.
Fig 6: This is the underside of piece A, showing screws through the bottom of A into pieces E.
Fig 7: Piece G goes across the middle flush with the top of piece E. This will prevent the plywood roof from sagging (piece H) in the middle during the press process. Pieces J will have a similar task on the ends.
Fig 8: Cut a 3/8” plywood piece such that it is as long as piece E and as wide as piece A. Place it onto the two E pieces. Take your two side strips (pieces C) and lay them along the side of the plywood roof. Use clamps to press them down onto the E pieces. While pressed, screw the strips (piece C) through the plywood (piece H) into the E pieces. The arrows note screws.
Fig 9: Piece J is shaped like the end of piece E. Instead of pieces G and the 2 J’s, you could have made a third E piece, but I guess I was just lazy, and anyway, this is easier, and works just fine. I am all about easy. Note that my C pieces are about ¼ too fat so the ¼ inch over hang will be jigsaw off later, resulting in 1 inch wide side strips. Ah, the F pieces are so flush.
Fig 10: How about another look.
Fig 11: Now for the clamps. Clamps K are simply pieces of 2 by 4, well wider than the press. 3/8” screws 24” long with nuts and washers are used to couple the top to the bottom. Make sure your holes are well wider than the screws; ½” wide for 3/8” screws. Clamps L are similar. The wood pieces are 2 by 2’s from a prior press. Why waste good wood. For pressing 1/8”BB, 2 by 2’s are fine. For pressing ¼” BB, using nothing less than a 2 by 4’s, unless you want splinters poppin’ you in the head.
Fig 12: This is taking a long time. Finally, 4 layers of 1/8”BB in the press. If I can remember, I like to use some wax paper under the wood to prevent gluing my board to the press.
Fig 13 and 14: Some more looks at the press.
Fig 15 and 16: A look at the pressed blank. Less pressure will give less concave.
Fig 17 and 18: An unfinished shape. Notice the hourglass cutouts in fig 18. There are often questions regarding flex and WB. One can adjust the WB to affect flex. IF you are like me and want a WB of 32-33”, you are not going to be to crazy about lengthening your WB to get flex. Just make some hour glass cutouts to increase your flex. 1st, cut your shape, then place on the trucks or blocks, and cut until the desired flex is achieved. This will also give more torsional flex. This is going to be a drop through for a friend.
Fig 19-22: These pics depict the press with double kicks and the pressed blank. You guys are experts now so you can figure out the rest.
I am going to press two double kicks, one for a drop through and the other a topmount. Finished pics will be shown hopefully soon. The cutting/finishing/graphic/gripping method is an entirely different animal. Perhaps another time.
It's pretty cheap. 5 to 10 bucks. I have since made some minor mods to this press. The most significant is that the side runners should be about 3/8" thick to get a concave of 3/8" to 1/2" across 9 1/2". This seems to be the best curve to hug the feet and retain a nice round curve. Check out the LDP deck I made with this press Ldp. To save money, instead of a 2 by 12 board, just use what ever you have available, as long as it is stiff and at least 11" wide.
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If you don't do it this year, you'll be one year older when you do.
- Warren Miller
Tomorrow may rain so I'll follow the sun.
- The Beatles
I built a press loosely based on this post, and it rocks. Not that i've built anything to compare it to, but I've put two boards down on it and they both came out sweet. No camber, yet (wanted to start with simple concave) mostly because I haven't found a good source for BB. Small boards and concave makes the cheap American/Chinese birch usable, but so far I don't think I'd trust anything past 38" or so. By winter I hope to find some BB and try my hand at the full method and get some flex into these decks...
Thanks to hoch and brodie, and all the Fish who put their knowledge and experience out here for everyone to benefit from.
"...If I have seen a little further, it is by standing on the shoulders of Giants." - Issac Newton
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awesome press! but i have a question yet. I noticed that your concave turned out perfectly and was wondering how you did that. maybe im just dumb and didnt read something but it looks really good.
awesome press! but i have a question yet. I noticed that your concave turned out perfectly and was wondering how you did that. maybe im just dumb and didnt read something but it looks really good.
The concave is achieved by pressing downward onto wood that is suspended under the sides. Check out the Two Brodie presses mentioned here for more info and insight.
Quote:
Originally Posted by benmasters
you should make sure the top piece is centered w/ the center line of your board and the plys you are pressing are centered on the press.
Centering and concave can be discussed with a few updates on this press.
Centering the middle piece is easier if the end "L" clamps are placed and secured first. Clamp them against the middle "F", and it helps lock things into place before pressing the central 3 clamps "K".
Also, IMO, side runners 1/2" or thicker give too much cave. 3/8" is plenty, locks you in without space under your foot, and does not aggravate your feet. That's 10 mm or so for you metric blokes.
Try to press just enough such that your plies just touch the base "H". This will give a nice round cave. Too much will render a U shape.
Regarding camber, from my measurements, two ends of the spectrum are:
1.5" over 48" is just enough,resulting in a camber of 1/2" over a 40" board, stiffer board.
and
1.75" over 39" (steeper), resulting in just over 1" for a similar length board, flexy board.
I have used this press a few more times, and it has performed well with consistency.
Two solid pieces to press (such as foam or concrete), would be better, but this easier to construct.
__________________
If you don't do it this year, you'll be one year older when you do.
- Warren Miller
Tomorrow may rain so I'll follow the sun.
- The Beatles
I just had a small addition to add to this press design. I have always had trouble getting things centered. To finally fix this, I have used some cross grain 1/8" BB and some 1/2" wooden doels. The main press beam is glued to a long 10" wide piece of cross grain BB, along the exact center line. Four 1/2" wooden dowels are screwed down on all four corners at exactly 10" apart (exact is of course a relative term) just beyond the side struts. This ensures centering of the upper press beam. It also helps ensure concave with less potential of delam, because the cross grain presses the cave truer.
Her is a top view.
Here are two presses with different amounts of camber. Notice the further one has two 1/8" BB plys. You can press Vlams this way. If the bottom layer is a Vlam core, the lower 1/8" BB ply helps to prevent splitting.
Also, I have tried simply pressing, a fiberglass laminate, and the result was suboptimal. You just can't get even enough pressure to get an adequate result. It will be thin under the ribs, and it will be thick with bubbles in the other areas.
__________________
If you don't do it this year, you'll be one year older when you do.
- Warren Miller
Tomorrow may rain so I'll follow the sun.
- The Beatles
Re: My press, My method, a "How to" guide.
but i have a question yet. I noticed that your concave turned out perfectly and was wondering how you did that. maybe im just dumb and didnt read something but it looks really good.
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