Donek Posted March 25, 2010 Report Share Posted March 25, 2010 HUH , consider your knowledge updated;)Does this also compensate for wood density variance? Based on Plate theory (the model I used for determining laminate stiffness) a variation of 20% in core stiffness will only affect the laminates stiffness by 0.62%. This is because the core stiffness has much less affect on overall stiffness than the the outer laminates (ie metal and carbon). As an interesting note 0.004in (0.1mm) will affect the laminates stiffness by the same 0.62%. I've seen variation in lumber properties that probably excede 60% to 70% within the same species, but have stopped using that supplier. I think my process is a little less susceptible to variations in lumber densities because my cores usually have lumber from multiple trees. I laminate blocks and resaw them on a saw mill. The properties of multiple trees will average out. As I understand your process, you laminate core blanks one at a time, most likely using laminates from the same board to produce one blank. As a result, you probably encounter greater variation in core blank properties from one blank to the next. My cnc, can typically reproduce the same core from one day to the next accurate to about .002in (0.05mm). There is a small variation there, but it is quite small (less than 0.5% I estimate) I guess my earlier statement was really with respect to predicting and repeating results before the materials are actually touched. Your technique of adjusting after production obviously works well, but does require extra work. Quote Link to comment Share on other sites More sharing options...
Bruce Varsava Posted March 25, 2010 Report Share Posted March 25, 2010 I mix up the wood also but still figure that even if I use the same plank, different grain direction can still changes overall stiffness so I prefer not to make any assumptions of wood density and final adjust at the end when the process is pretty much complete and no variables left. I feel the law of averages can work for or against so I don't take the chance Quote Link to comment Share on other sites More sharing options...
Donek Posted March 25, 2010 Report Share Posted March 25, 2010 Ya, I'm really confused about the stiffness thing. How stiff will it be? And is that stiffer or softer than what I think I want? Do I try Jack's (dumbell on board between to supports) method and see how stiff my boards are. And compare to his data on the donek metal fc. Unless you are trying to compare two boards from the same manufacturer in the same construction, such a measurement is virtually useless. Every manufacturer produces a flex pattern that is different from anothers. Unless you plan to plot the shape of the curve that the board bends to and compare it to that of another manufacturers, you stand to learn very little from such a measurement. Give me a call and we can discuss what you like in detail before beginning to build your board. I'm confident I can translate your needs into a stiffness that will be appropriate. I've been successfully doing this for many years. Quote Link to comment Share on other sites More sharing options...
Donek Posted March 25, 2010 Report Share Posted March 25, 2010 I don't plan on riding it in deep powder. But 6" to a foot of tracked powder is possible, deep untracked stuff will be left for the tanker. Actual moguls aren't very common on my home mountain anymore, so that is not a concern. so i'll be riding it 75% groomed terrain. Free carve boards turn to long in the size I want. So am I looking for a custom shape freecarve board. maybe. Maybe I'll phone and talk to you sean. What days and time are best for you? I'm almost always here, but I prefer to talk after noon as I reserve the time period of 6:00am to noon for production. Quote Link to comment Share on other sites More sharing options...
energyrail Posted March 27, 2010 Author Report Share Posted March 27, 2010 Hey Sean Sorry I didn't call yesterday work was busy.(one machinist off on holiday) leaving the hydraulic specialists(me) to fill his shoes. Are you ever around on sunday? yes but in hiding I suppose. I try to phone next week. Quote Link to comment Share on other sites More sharing options...
Donek Posted March 27, 2010 Report Share Posted March 27, 2010 Hey Sean Sorry I didn't call yesterday work was busy.(one machinist off on holiday) leaving the hydraulic specialists(me) to fill his shoes. Are you ever around on sunday? yes but in hiding I suppose. I try to phone next week. You can try in the morning. Quote Link to comment Share on other sites More sharing options...
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