Greetings,

A simple question. How much VARIAIBLITY is there form blank to blank in the identical model? Lets say I get ten identical XYZ blank form ABC company. I then do a complete static, casting and whatever else tests I deem necessary. Would the guide spacing I come up with be usable for all 10 blanks or do you guys test every single blank by itsefl, starting from scratch? (That would be tedious indeed.)

Thanks,
Mo

I would start from scratch. There are certain allowable tolerances each company has that each blank can differe from the specs posted in their catalouges. If tip-top sizes are allowed to be off by 1/2 a size, that means a rod that should have a size 9 tip, can have anywhere from an 8.5 to a 9.5 tip - I would think this is a fairly larger enough difference to make me static deflect each rod.

I do not knowwhat the allowable diference if, but I do know I called one to complain about a tip size being off by 1 full size (a 10 instead of a 9), and was told that was "normal". Which means that same blank could have had a size 8 tip.

This is my guestimation based on my limited experiances with the blanks I build.

Blank manufacturing is still a very labor intensive process. Any time a good amount of hand labor is involved, the door is open for variance between blanks of the same model. The better companies with strick quality control, offer blanks that vary very little from one to another. Not to say that an oddball can't creep in once in awhile, but generally the tolerances are pretty decent. One of the biggest complaints on the offshore oriental made blanks for so many years was that they varied so much from blank to blank. Thankfully they've tightened up their quality control a great deal in the past decade and you don't see those terrible variances from blank to blank nearly as often as you once did.

.................

Tom,

So, would I be correct that with high quality USA made blanks, generally they are quite consistent and I'd do OK duplicating setups across the same blanks with quick check?

Thanks,
Mo

I have been told by a excellent rod and blank company that every blank of the same number they produce has a slight variable that is built in to the blank when it is built. They can not control this variable. So each blank then has its own characteristic built in to it. So I test all my guides spacings.
Good Wraps Bob

Was at a seminar where Don morton had 10 blanks made that were suppose to be all the same. Just to show what differences there is in the blanks, he had the blank held only by th tip section. The butt ends all varied in their positions. I don't think there was any 2 that were the same.

Thanks to all who responded. Not surprisingly, no blanks are exactly identical. However, my question is that for all practical purposes, are the differences LARGE enough to produce a real difference in guide placement? (i.e. Guides are 1-2 inches off from blank to blank, or evern that some blanks may take one less guide than another.)

Thanks,
Mo

Mo
That is why all blanks should be Static Tested to find out where the guides should be placed. The flex of the blank tells you this and since no two blanks flex the same, do it on all

Bill This is what I have been telling this young man. If he does not do the flex test hecould build a rod that may fail
Good Wraps Bob

I don't think I would go that far as to say it would fail. If the factory specs are used the rod will perform, just could be better if tested
Mo
If you have several of the same blanks and are making the same rods, do a test on them with the same guide set up and see how different they may be