My first build was a kit from Mudhole which I tweaked to my liking. I am assembling pieces for my second build which will be on an MHX HM SB812 blank. The Butt of the blank is listed as .517 or just over 13mm. I purchased 2 Fuji ECSM seats 1 13mm and 1 13.5mm. Common sense dictates that I use the 13mm seat as it fits the best at the seat location. Where the confusion kicks in is Mudhole and other suppliers have trim pieces for size 16 and 17 seats predominately. What am I missing ? Are the bore sizes of seats different than seat sizes? I hope I have made sense here.

Thanks,
Rick

In some cases they are. Pipe type seats will have an ID and OD that are very close. The seat size is generally the bore size, give or take about a half mm. Many of the exposed blank seats have an ID and OD that are quite far apart. The seat size is often the ID while the trim pieces are made to fit the OD.

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

Thanks Tom. So that said, when using an exposed seat, I should use the size that provides the " closest" fit?

Rick

Rick,
Ask Mudhole to size your seat with your blank, you just need to give them your grip length. Have the tip top sized also, this can fluctuate some.

Yes. Even if you get a 13mm inside diameter reel seat, the ECSM should have been a 16 or 17 reel seat. Basically non-exposed blank reel seats, you generally order the standard sizes which end up being 16, 17, etc. It's up to you to ensure that 1) The seat is not too small for the blank diameter and 2) That you place arbors / shims around the blank so the seat fits snug when you glue it. Exposed blank reel seats come pre "shim'd / arbor'd" with a hole on the side where the blank will be "exposed." Those need to be measured precisely to the blank diameter where you want to place them. If you look at the ECSM seats you ordered, they will still be size 16 or 17, just with a 13mm or 13.5mm inside diameter. For example, you might have ordered a a size 17 ECSM with I.D. of 13mm. Find out the reel seat size you got, then get the appropriate trim pieces. Its better to go a touch on the small side, as you can always ream the seats out a little. Good luck.

The ECSM 16 seat has variable iDs from 9.5 -15 mm to fit your blank. The OD of the threaded barrel is 18 mm, and the butt end OD is 27 mm. The size 17 ECSM will fit rods from 15 - 17 mm. The threaded barrel OD is 20 mm, and the butt end OD is 27mm, the same as the size 16 seat. This 27 mm OD is fairly standard for all casting seats. So butt end trim pieces will fit both, and for barrel end trim pieces need to get the 16 size or the 17 size depending on the seat you use. Hope this helps.
Norm

Rick,

Mudhole has a link to a web page that gives the blank diameter, (for all of their blanks), every 2" from the butt of the rod blank to 24", (as I recall), up from the butt. This takes the guess work out of selecting a reel seat I.D. and also winding checks. Just go to their website and select the balnk you are building. Once you're on that webpage you will see at the bottom of the page a tab that is entitled Resources. Select the Resource tab and you will see this listed:

"Dimensions for Winding Checks & Exposed Reel Seats"

The blank you are building, (SB812), is located on page 14 of the PDF. I would suggest you download a copy of the PDF for future reference, as it takes the guess work out of ordering reel seats & winding checks. Mudholes is outstanding with their support.

Don Campbell
don@sensorfishingrods.com

Thank you to all who took the time to help me out. What a great forum!

Regards,
Rick Elrod

Rick, I'm confused? Do you have the reel seats in hand? Or are you ordering them and you're just listing what you are ordering, or have already ordered? The reason I ask is, if the Fuji seats are sized a true 13 mm ID, (.512") then a 13 may be too big. That is if the blank actually measures the .517 at the butt. as you listed.

Assuming the blank has a linear taper, the taper of the blank is roughly .005" per inch of blank run. I doubt the taper is linear, but I have used a formula in the past that calculates the taper of the blank, per inch, to order winding checks and exposed blank reel seats and it has always put me pretty close. Never more than a half a mm either way.

Assuming a 7" handle (distance from the butt to the back of the reel seat) I'm thinking you may end up needing a 12 mm seat.

As I said earlier, I know the taper isn't linear over the full length of the blank, but a 13mm seat, it it truly measures 13mm, is only .005" smaller than the butt of the rod.

As was mentioned earlier, with blank exposed reel seats, give Mud Hole or any other distributor the distance from the butt to where you want the back of the reel seat to land, and ask them to fit the proper size reel seat. It will save you a lot of hassle in the future.

Please understand I'm just trying to help.

David Baylor Wrote:
-------------------------------------------------------
> Rick, I'm confused? Do you have the reel seats in
> hand? Or are you ordering them and you're just
> listing what you are ordering, or have already
> ordered? The reason I ask is, if the Fuji seats
> are sized a true 13 mm ID, (.512") then a 13 may
> be too big. That is if the blank actually measures
> the .517 at the butt. as you listed.
>
> Assuming the blank has a linear taper, the taper
> of the blank is roughly .005" per inch of blank
> run. I doubt the taper is linear, but I have used
> a formula in the past that calculates the taper of
> the blank, per inch, to order winding checks and
> exposed blank reel seats and it has always put me
> pretty close. Never more than a half a mm either
> way.
>
> Assuming a 7" handle (distance from the butt to
> the back of the reel seat) I'm thinking you may
> end up needing a 12 mm seat.
>
> As I said earlier, I know the taper isn't linear
> over the full length of the blank, but a 13mm
> seat, it it truly measures 13mm, is only .005"
> smaller than the butt of the rod.
>
> As was mentioned earlier, with blank exposed reel
> seats, give Mud Hole or any other distributor the
> distance from the butt to where you want the back
> of the reel seat to land, and ask them to fit the
> proper size reel seat. It will save you a lot of
> hassle in the future.
>
> Please understand I'm just trying to help.

David,
You have hit the nail on the head. I purchased a bunch of supplies to go along with my previously purchased "complete rod building kit" from Mudhole and bought my next blank and seat(s) to take advantage of free shipping >$150. I bought 2 ECSM seats, a 13 and 13.5. You are absolutely correct in that they are both too big. Fortunately they are not terribly expensive and maybe I will use them down the road. Thanks again for your help.

Regards,
Rick Elrod

Rick with those type of reel seats it is away better to buy one a bit too small, they can be easily reamed for a custom fit. David is correct get the supplier to fit the seat, or get a blank measurement a little in front of where the seat will be placed rather than at the rear of the seat. I have learned this the hard way.
Norm

I'd have to agree with Norm on having the seat fitted a little further from the butt than you want the back of the reel seat to land. As he said, they're easily reamed.

I recently needed to ream an Alps MVT reel seat (an exposed blank reel seat) out about .010" to get it to fit where and how I wanted it. I cut down the shaft of an old aluminum arrow and cut a slot in one end with a Dremel. I put a 3" long x 1" wide piece of 100 grit sanding belt in the slot, chucked it up in a cordless drill, and went to town.

It took me all of 5 minutes to get the ID to what I needed it to be, and the inside of the seat was prepped and ready for mounting.