Hi guys,

I have another cork question.

I bought a lathe a few months ago to start making my own grips. I’ve successfully turned four grips now after wasting probably 60 rings worth of grips. I thought I had a solid process down (I’m learning as I go) by gluing the rings, clamping, taking a sanding block to the grip on the lathe to get a uniform shape, then shaping (with strips of sandpaper) the final shape (I am eyeballing this, doing minimal sanding) and then I ream to fit the blank. Once the grip fits the blank, I center the reel seat on the blank and outline the hood onto the grip and cut a recessed hood using my dremel.

I am starting to build a 10 wt fiberglass rod and when I went to do my grip I am having trouble. Like I have gone through three grips worth of cork rings. The issue I’m having is after I shape the grip after using the sanding block and ream, I can visibly tell the top hole in the grip is off center. What am I doing wrong? Is something I am doing on the lathe causing this issue or is it happening during the reaming process?

[www.rodbuilding.org]
Even though I’m not power reaming, should I keep this advice in mind? I have been holding the cork in the same position when I ream so maybe it’s getting off center because of that? Should I turn the cork on the reamer more?

I should also add that this is the biggest rod I’ve made so far in terms of butt diameter. Everything prior has been graphite rods with thinner butt sizes.

Thanks,
Alex



Edited 4 time(s). Last edit at 05/07/2022 03:57AM by Alex purvis.

You need to rotate the grip as you dean otherwise you will not remove material evenly. Make a few turns with the reamer. Let the grip turn slightly in you palm and repeat. Things should improve. You may also benefit by starting with the work side diameter a little closer to the final size. You can do this by drilling out the cork rings and using tape arbors on your turning mandrel for a snug fit.

Your problem appears to me to clearly be eccentricity of the bore introduced by the reaming process. If the hole is concentric before reaming and is off center after reaming then it is the reaming process.

Reaming is a skill which should be improved with practice, but there are a couple things you can do to improve the process:

The reverse drills will help since they will reduce the amount of material needed to be removed during reaming. They will give you a concentric hole that is closer to the final diameter you need.

The other thing is to keep rotating the reamer whille reaming and keep rotating the grip. I believe that working from both ends alternately will help, too. Check for eccenticity often in the process.

The longer the grip the more challenging it is.

If the eccentricity is not too much you might salvage the grip by working the bore onto center then shimming the blank to get it onto center. I have not had to do this but it is an idea that might work.

There is another string of posts starated here recently that offers advice on reaming, too. "Best method for reaming . . . ." About half way down page 1.



Edited 1 time(s). Last edit at 05/06/2022 07:32AM by Michael Danek.

This should help with keeping the bore concentric to the outside of the grip - [www.youtube.com]

......

Alex,
Please email me: hladen@hotmail.com
Your email is hidden
Herb
CTS Rep

Thanks guys! Looking back I think my issue is the reaming because I’m having to make the hole so big for this rod I have had a death grip on the cork and am digging out with the reamer. I don’t think I had this issue with the other rods because I wasn’t having to ream hardly anything out.

I’m thankful for this community and the wealth of knowledge found here!

When you have to make a grip with a large inside bore, do the bore first, prior to the gluing up the rings. Then use a larger mandrel to mount them on.

Doing it this way leaves only a very small amount of reaming left to be done. Just enough to match the blank taper, which won't be much back towards the butt area.

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

Alex,
You made a very good discovery.
You indicate that you have a lathe.

Since you have a lathe, take each ring and use a brad point drill bit to drill out each ring to be just a bit smaller than the location of where the cork ring will be on the blank.

This will save you so much time and the hole will be perfectly centered.

Simply chuck the cork ring in your head stock chuck.

Then, take the appropriate brad point drill bit and chuck it into your jacobs chuck that you insert into your tail stock.

Finally, with the ring spinning just advance the drill bit into and through the cork ring using the tail stock line feed.

The following picture is doing the drilling of a wood grip that I had turned for a rod:
[www.rodbuilding.org]

Of course, if you were drilling cork, you would put each ring into the head stock chuck, tighten the chuck, turn on the lathe and advance the drill through the spinning cork ring.

Since the drill bit is stationary and the cork ring is spinning, the hole will be 100% absolutely centered in the ring.

From harbor freight - inexpensive brad point drill bits:
[www.harborfreight.com]

[www.harborfreight.com]

The nice thing about a brad point drill bit is that the two razor sharp points on each side of the drill head act as razors slicing through the cork without tearing it and thus leaving very clean holes in the cork.
Note: Have the lathe on a high speed, because the hole will be cleaner, the faster you turn the drill bit.

Then, as Mr. Kirkman pointed out, you can then use your reamer for the small amount of additional reaming necessary for a nice fit on the grip, before gluing the cork together. Be sure to use a gloved hand and let the cork ring slip a bit in your hand as you are doing your final reaming to insure that your hole remains centered.

Best wishes

Alex, you have a lathe, are you not using a chisel as Tom does in the video link he posted, to make sure the grip is concentric before you start the shaping process?

I watched the video that Tom linked, as part of my decision to start building some cork grips. I do as he did and use a half round chisel to make sure the grip is concentric prior to the shaping process. I even use the half round chisel in the shaping process. I'm not saying your grip isn't concentric doing it the way you described doing it, but if you do it with a chisel you are assured of it being concentric before you start shaping.

As far as the reaming process goes, you've gotten plenty of good advice. The only thing I would say is to caution yourself against complacency. If you think it's no biggie, that could lead to rushing and a lack of attention to detail. And we all know what poor reaming leads to........ poor fit and finish. And we all want our components to fit properly. Or at least we should.

I like to get the bore of the grip to size first, then put it on an arbor in the lathe and shape the OD as needed.

Steve

Steve,

I thought of doing it this way as well. What size mandrel do you have? What do you use to arbor the mandrel?

I have read a lot about people chucking their rod in the lathe but I have two issues with that at the moment: first, my lathe is very small. Second, I’m too chicken to chuck my rod blank in anything at the moment lol

Tom Kirkman Wrote:
-------------------------------------------------------
> When you have to make a grip with a large inside
> bore, do the bore first, prior to the gluing up
> the rings. Then use a larger mandrel to mount them
> on.
>
> Doing it this way leaves only a very small amount
> of reaming left to be done. Just enough to match
> the blank taper, which won't be much back towards
> the butt area.
>
> ..............

Tom,

What if I don’t have a larger mandrel? Can I arbor up a 1/4” mandrel and be fine?

As I mentioned before, I drill my rings to 5/16 before mounting them. My mandrel is a 5/16 threaded rod. Very cheap. I load the rings during gluing with nuts and washers.And use the threaded rod a a mandrel for machining them.

One could use any size mandrel he wants, just pre-drill from 1/4 to the larger size and mount onto the larger size drill rod. I have adapted my drill press to "machine" the cork (or other soft materials) with sandpaper, can provide details on how to do this if one emails me. It is easy and cheap and results in any shape grip one wants.

It does not solve the reaming eccentricity problem totally, but makes it less an issue because the drilled bore is closer to the final required diameter so less reaming is required. This is basically what Tom K is suggesting exc I don't use a lathe; I use a drill press as a lathe.

Alex, I have a bunch of different size aluminum arrow shafts that I use as arbors. The arrows have aluminum inserts in each end and I chuck over them, or just slip a center into them. I just pick one close to the size I need then add some tape to make it tight. I use this same method when making my foam cores for my home made carbon fiber handles.

I was using arrow shafts for mandrels as well. They work great!! I stopped using them because I bought one of the reverse spade bits that Flex Coat makes. The shaft of the bit was only slightly smaller than diameter of the arrow shafts I was using, and I wanted to go with a slightly larger bore in the rings to make building tape arbors on the spade bit shaft a little easier.

I ended up getting an Alps mandrel from board sponsor on the left, Custom Fly Grips LLC. Top notch place to deal with BTW. The mandrel is labeled on the web site as 3/8", but the actual O.D. of the mandrel is .390". It's also listed on the mandrel as having that O.D.

It works out beautifully as I bore the rings out to 3/8" (.375") and the fit is tight enough on the mandrel, that even with waxing the mandrel prior to sliding on the cork rings, that I haven't had any slippage while turning or shaping any of the grips I've made thus far.