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Eccentric turned reel seat inserts


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#1 Boris L

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Posted 04 January 2010 - 07:37 AM

I've just come across a post on the list serve that asked how to turn eccentric real seat inserts. I'm no expert but I have done a small batch using Australian desert timber burls. This is still a learning process for me but I thought I'd post what I've learned so far. This is the eccentric/offset fixture fitting used for a 3 jaw chuck. See Gary Dabrowski's drawings

http://brooksiderod....eatworkshop.pdf

This fixture it able to turn fillers with an OD of .660 with an offset of .100. The depth of the finished eccentric cut is .100 which allows a standard reel foot and a sliding band to fit comfortably.



Here it is mounted in the chuck with the centric turned and bored wood with some eccentric cutting visible. This first piece was done without the live centre tailstock attachment.



You can see the halo surrounding the timber as it turns off centre. This means very light cuts with a very sharp with a tool rounded for the arch in the cut.



This is the only successful seat I was able to make without using the live centre in the tailstock.



The rest ended up like this. The flex in the timber as it turned off centre was enough to bite into the tool, grab and break the timber.



So I ended up boring the timber almost to the end allowing about a half inch of solid wood for a new offset centre to turn in the tail stock. This prevented breakages and allowed me to bore the centre hole from the end side after the eccentric cut. Then simply cut off the waste. I did try to bore the entire hole after the eccentric cut but since the timber is very thin on the eccentric face the heat generated - no matter how carefully I proceeded or allowed time for cooling off between boring small sections at a time - caused expansion and checking/cracking in that area rendering the seat unusable. This picture shows the timber removed from the eccentric fixture in the chuck with the solid end being bored. It will then be cut to size and finished off to take the cork check.



This is how I found the new offset/eccentric centre in the end for the live centre in the tail stock. It meant I had to calculate the difference using a "V" block and ground surface block with a gauge to minimise discrepancies. There's got to be an easier way but I haven't worked it out yet. At the time I was trying to get a result with what I had.



Here it is just before finishing the eccentric cut checking the fit with a reel foot.



Here's the finished piece needing to be polished.





Here's a few with hardware sitting in place.



Now all I have to do it workout how to waterproof the wood effectively and I'll be pleased.

Hope this helps.

#2 BowBound

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Posted 10 January 2010 - 01:58 PM

Thanks for that. I have seen Dabrowski's pdf but the step by step and tips will make my life easier. I have a lathe, but no router or fancy chisels, so eccentric mortise it is.

Do you think you could achieve the same effect by shimming one jaw of a three jaw chuck by the offset (say 0.10") and securing the insert (or with proper adjustment on a four jaw chuck)? Bad idea? I am a complete lathe novice, so I always worry about doing something stupid/unsafe.

The fixture looks like a better idea, but I'm not quite sure how I would go about boring an offset hole to an appropriate ID (assuming a standard drill bit diameter wouldn't be close enough).

An aside: do you use Dabrowski's drawn cups for your reel seats? Thoughts?

#3 Baithog

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Posted 10 January 2010 - 06:44 PM

QUOTE (BowBound @ Jan 10 2010, 01:58 PM) <{POST_SNAPBACK}>
Thanks for that. I have seen Dabrowski's pdf but the step by step and tips will make my life easier. I have a lathe, but no router or fancy chisels, so eccentric mortise it is.

Do you think you could achieve the same effect by shimming one jaw of a three jaw chuck by the offset (say 0.10") and securing the insert (or with proper adjustment on a four jaw chuck)? Bad idea? I am a complete lathe novice, so I always worry about doing something stupid/unsafe.

The fixture looks like a better idea, but I'm not quite sure how I would go about boring an offset hole to an appropriate ID (assuming a standard drill bit diameter wouldn't be close enough).

An aside: do you use Dabrowski's drawn cups for your reel seats? Thoughts?

Shimming a 3 jaw chuck works. I have done it that way. I would love to have a 4 jaw chuck again for a lot of reasons, but it would work too. The Dabrowski fixture is probably easier to set up than the 4 jaw. Old rule of thumb was not to exceed 5 diameters for a chuck only support. I haven't had problems with well stabilized wood and sharp tools if I stayed around 3 inches of unsupported blank.
Larry Lohkamp

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#4 Lazer

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Posted 10 January 2010 - 07:10 PM

QUOTE (BowBound @ Jan 10 2010, 11:58 AM) <{POST_SNAPBACK}>
Thanks for that. I have seen Dabrowski's pdf but the step by step and tips will make my life easier. I have a lathe, but no router or fancy chisels, so eccentric mortise it is.

Do you think you could achieve the same effect by shimming one jaw of a three jaw chuck by the offset (say 0.10") and securing the insert (or with proper adjustment on a four jaw chuck)? Bad idea? I am a complete lathe novice, so I always worry about doing something stupid/unsafe.

The fixture looks like a better idea, but I'm not quite sure how I would go about boring an offset hole to an appropriate ID (assuming a standard drill bit diameter wouldn't be close enough).

An aside: do you use Dabrowski's drawn cups for your reel seats? Thoughts?


Now THAT is some serious lathe work.

I think if I was so inclined to attempt to duplicate it, I would make a round plywood insert for my four jaw chuck similar to the way he is doing it..... something similar for the live center.... I sure wouldn't do it without a live center on a wood lathe... just not sure how I would rig up the live center side...

Something to ponder, but I think it would give me a headache! wallbash.gif

L

#5 BowBound

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Posted 11 January 2010 - 12:27 AM

http://brooksiderod....nsertmaking.pdf

This is where I read about Dabrowski's fixture etc the first time. I'm glad I found it again. This tutorial is a great supplement to the article. Thanks, again, Boris.

Has anyone tried eccentric turing with figured woods. Dabrowski's article warns against it (chipping, splitting, etc)? I'm pretty hung up on figured woods. Maybe I'll try to build a jig and milling tool as described in the article.

Phew! This lathe stuff is a slippery slope!

#6 Boris L

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Posted 11 January 2010 - 08:07 AM

Ok, I'm a newbie to lather work also but the fitter at work who has been teaching me tells me you can set up eccentric turning with a 4 jaw chuck by counting the number of turns of the key adjacent to the offset etc etc. But the problem is that it's very difficult to reproduce consistently. This is the beauty of the Dabrowski fitting which is inexpensive to make or get made.

The timbers I used so far are burls which are very hard but have a very twisted grain making it difficult to prevent breakoffs if done without live centres in the tailstock. The tailstock live centre set up isn't difficult but can be a bit fiddly.

I'm on holidays for 3 more weeks but when I get back to work I'll do some more seats and take the photos of how to set up the live centre in the tailstock as well as some of the minor but important steps I didn't explain or photograph.

Here are a few examples of the timbers I've used;




Oh, BTW Bow, so far I've only used Bellinger cap & ring; I've only just completed my first rod in December so take my advice with a grain of salt ..... whistling1.gif during the learning process - many broken pieces of wood, undersized diameters etc. I toyed with using the pocketed cap & ring shown in Dabrowski's papers as there's no need to offset turn your seat timber.



#7 fishbum

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Posted 11 January 2010 - 10:04 AM

The problem of overhang is easy to solve. When turning the insert round be sure to face off the end thet will be at the tailstock of the lathe. Mount in the Dabrowski fixture. You could mount a dial indicator on the tool post to make sure the work is parallel with the carrage travel/bed. Now use a #0 center drill and drill a spot hole in the end of the piece. Now drill a center with a #4 center drill. Mount your live center and proceed to turn your reel seat. The overhung end is now supported by the tailstock.

This is the way I done this task for a good number of years untill I wised up and made an off-center mandral to turn the eccenctric on.

fishbum


#8 Lazer

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Posted 11 January 2010 - 01:24 PM

QUOTE (fishbum @ Jan 11 2010, 08:04 AM) <{POST_SNAPBACK}>
The problem of overhang is easy to solve. When turning the insert round be sure to face off the end thet will be at the tailstock of the lathe. Mount in the Dabrowski fixture. You could mount a dial indicator on the tool post to make sure the work is parallel with the carrage travel/bed. Now use a #0 center drill and drill a spot hole in the end of the piece. Now drill a center with a #4 center drill. Mount your live center and proceed to turn your reel seat. The overhung end is now supported by the tailstock.

This is the way I done this task for a good number of years untill I wised up and made an off-center mandral to turn the eccenctric on.

fishbum


You nailed the tail stock mystery with the off-center mandrel.... If I get REALLY bored, I'll give it a go...

L

#9 Boris L

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Posted 11 January 2010 - 05:51 PM

QUOTE (fishbum @ Jan 12 2010, 02:04 AM) <{POST_SNAPBACK}>
.................... untill I wised up and made an off-center mandral to turn the eccenctric on.

fishbum


Fishbum, that sounds pretty interesting, can you show a picture of the mandrel and a brief description of how it's made? Also can the same mandrel be used for different OD & ID reel seats or is it limited to a single dimension seat?


Cheers



#10 fishbum

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Posted 11 January 2010 - 11:14 PM

Here ya go guys and gals. If you don't have a mill to do the off center drilling you can use a cross-slide vice and drill press or you can use a four jaw chuck on a lathe. With a four jaw chuck you set up a dial indicator to set how far to move off center. Do the same type set up with a cross-slidr vice and drill press. Make the shaft and mount as two separat pieces then assemble. The hole in the base part that is put in the lathe chuck is reamed for a very good fit of the mandral shaft. There is a pin holding the mandral shaft in the base. The hole for the tailstock center is drilled with a #0 center drill. It must be by necessety be small, however, it doesn't take much to steady that end of the mandral. The threads are cut on a lathe to keep them concentric with the centerline of the mandral shaft. You will need a dial indicator to set the shaft into the base to get things lined up correctly. I suppose there are other ways if making a gadget like this but this is how I done it.

My mandral is 21/64" minus 0.002" and long enough to mount a 4 1/2 in blank. the longer blank allows some trimming to get the best of the wood for the reel seat. This size fits most of the little rods I make. If the hole needs to be larger it is an easy mater to put into a collet with a hard rubber shim and drill out to a larger size. If you don't have collets you could make a special one to fit into a three-jaw check.

I only use this system for little rods with ring and cap style reel seats. Most of the rods I have been making the last year and a half 8 and 9 weight, 10' 6", two handed salmon/steelhead rods and they get a screw-lock seat.






#11 Boris L

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Posted 14 January 2010 - 05:34 AM

Thanks Fishbum, I might try to make one of those when I get back to work.

Cheers

Boris

#12 gxl

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Posted 26 January 2010 - 11:47 PM

Boris, how do you make the smooth tranisiton from the ecentric cut to the full rounded portion. I turned a couple of seets and the transition from the ecentric cut to the round portion is not coming out as nice as the one in your picture.

#13 Boris L

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Posted 27 January 2010 - 03:42 AM

QUOTE (gxl @ Jan 27 2010, 03:47 PM) <{POST_SNAPBACK}>
Boris, how do you make the smooth tranisiton from the ecentric cut to the full rounded portion. I turned a couple of seets and the transition from the ecentric cut to the round portion is not coming out as nice as the one in your picture.



The shape of the curve or radius corresponds with radius of the tool edge. See below

Diagram_for_eccentric_cut___tool.JPG


I've found that the tool needs to be very sharp - I hone it on a stone like I would any carving chisel - and each cut must be light. As I approach the curve with each pass I very carefully make sure the tool takes some very fine material from the the face of the radius so that each cut comes together at the radius and the final result has no steps but is smooth.

Hope that helps.

#14 Mungo Park

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Posted 27 January 2010 - 10:36 AM

Kudos to you guys, very good thread.

Cheers Ron.
In my limited experience, never pet a burning dog.

#15 tonkin36@hotmail.com

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Posted 24 July 2010 - 05:53 PM

Who makes the offset tooling for a lathe as has been discussed?



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