I bought 20 rod blanks in a grab bag deal but I'm having some difficulty figuring out how to order proper reel seats and handle components for each rod. I will be going to the Rod Building Expo and would like to buy the handle components there. The blanks are all different actions, lengths and sizes (5'-7') I am numbering and labeling each rod and will take OD measurements starting at the base and every 1" till the 15" mark up from the base. What if anything else is needed (measurement wise) so I don't have to bring all my rod blanks with me. I would like to buy with some confidence that I'm getting the right parts for each rod.

Thanks
Dave

Reel seats and winding checks are measured in millimeters (mm). The outside portion of a guide ring and frame dimensions are also measured in mm. The barrel of tip tops are measured in 64ths of an inch and sometimes in mm. A caliper is a good tool to have whether digital or dial and a tip top guide sizing gauge.

Dave,
Pretty simple.
! - figure out what you want to use each blank for in a built up fishing rod.
2- figure out what specific reel seat you want to use on the rod.
3- based on the specific use and the specific reel seat, figure out where on the blank you want to place the reel seat. - you also need to figure out whether you want a solid rear grip, a split rear grip and whether you want any fore grip - and if so - how long a fore grip.

Then, with these parameters in mind - simply measure the diameter of the rod blank butt using a good caliper. If you don't have a good caliper, buy one.
Then, measure the rod blank diameter at the location of the butt of the reel seat location and the tip of the reel seat location. Then, if you plan to use a fore grip, also measure the blank diameter at the location of the tip of the fore grip.

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Having said all of that; you plan to have detailed measurements of the rod blank from the butt of the rod in one inch increments up to 15 inches should cover all of your measuring needs. But, before goings, you still want to be armed with the desired specific location of your planned reel seat location on each blank. It is your call on the reel seat placement. So, get this piece of home work done before going to the sales location of the products.

p.s. for shorter rods of 6 feet and less, I generally use a rear grip of 7 inches.
For rods of 6'3" to 6'10 inches I will typically use a grip of 8-9 inches.
For rods that are 7' and up, I will typically use a rear grip of 11-13 inches.

Also, I have found that especially with longer rods, one has better control and use by using the rod in a two handed casting fashion. By using two hands on a cast, you can add a lot of distance to the cast, and you make good use of the added length of the longer rear grip to give a casting location for your 2nd hand.

p.s.
If you don't normally cast with two hands, do a test. Do a bunch of 1 handed casting to a distant location. Then, repeat the test using both hands and arms and see what happens to your ability to reach out to far away places. You may surprise yourself.

I first ran across this when I was fishing with a friend. I first noticed that he was outcasting me in distance using similar power and length rods with the same lure weights.
I also noticed the particular whistling sound that his lure made as it left the tip of the rod on a long cast. So, I asked why his rod was making the sound. He looked at me and smiled. He said, "Two handed casting." He explained, that by using both hands to cast, he added many mph to the speed of his his lure being cast. The added speed of the lure flying through the air caused the sound. So, of course, I tried it. He was right. Now my lure began to whistle as his did when I cast two handed and my casting distance was not being equal to his distance.

Although you can use shorter grips on longer rods, if you want a balanced rod, you are going to have to add weight to the butt of the rod, which doesn't seem to make a lot of sense. So, I would rather have a longer rear grip with a lighter rod, than a long rod with a shorter rear grip and a bunch of heavy weight added at the butt of the rod blank.

Good luck

If you want metallic winding checks then it will be difficult unless you layout each blank but I would still buy a 1 size up and 1 size down from what you think you need. As for the reel seat it will depend on what kind of seat you plan on using. If you are thinking about using something similar to a fitted seat like Fuji ACS or ECSM then measure the OD approximately where you plan to mount the seat then purchase a seat a MM or 2 smaller than your measurement then ream to fit when you go to install. This allows you to fine tune the location based on how you plan to build the rod. If you are going with a tube type seat just plan on stocking up on Graphite Arbors to glue in the seat then ream to fit the blank. You can also try out the Pac Bay Omni Arbors. If you want something a little more detailed such as seats with exposed windows such as a Fuji TVS then I would recommend laying out the blank completely with detailed measurements. Or if you can bring the blank with you so can test fit.

I might be wrong here but couldn't you just wrap a piece of tape around it and cut it like you would for measuring for snake skin. Then measure tape length in mm's. Now divide by Pi. (3.14159265359)

I don't work with number anymore so hopefully someone will chip in on that.

Mike, yes, circumference divided by Pi equals diameter.

In reference to the last paragraph of Roger's post referencing rear grip length ...... I'd just say that instead of placing the reel seat with the thought of having a balanced rod and reel in mind, I'd place it with the thought of what the rod is going to be used for. An 11 - 13 inch rear grip on a 7' rod may be fine if that rod is going to be used for making long casts, but it could be completely useless if the rod is going to be used for making short casts, flips, or pitches where the angler needs to be able to manipulate the rod more freely and easily.

Also, I don't feel all rod and reel combinations need to be perfectly balanced. Rod and reel combos use for slack and semi slack line techniques, yes. Rod and reels used for cast and retrieve techniques, not so much, if at all.

Adding weight to a rod and reel combination isn't a bad thing, if that weight serves a specific purpose.