Avet EXW 50 thrust bearing mod

Started by limitdown, March 05, 2013, 12:46:30 PM

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limitdown

This is the first time that I'm posting on a reel modification. I spend most of my time modifying and upgrading my guns (1911's, STI/SVI's, AR15's, etc).

My Makaira 50W has Okuma's custom thrust bearing and I figured that I would try to add a thrust bearing to my EXW50.

Essentially, I just replaced the Belleville washers with a thrust bearing. The bellevilles measured 10mm ID x 18.5mm OD x 5mm thick (4 pieces stacked). I just happened to have a thrust bearing laying around from one of my Radio Controlled cars (used in the differential assembly). Dimensions are 10x18x5.5mm. These bearings are very cheap ($4 for 2 sets), but are quite strong.

The preset nut still pushes up against the right side plate bearing which then pushes up against the pinion gears. With the mod, the pinion gears now push up against the thrust bearing, which should take some lateral load off of the right side plate bearing.

What do you guys think?







akfish

That's very slick if it works. Does the reel feel good? What sort of drag have you been able to get? But for me, the Avet 50 gets plenty of drag; what I'd like would be thrust bearings in the smaller Avets. That would be quite a feat!
Taku Reel Repair
Juneau, Alaska
907.789.2448

limitdown

#2
I actually did the modification two months ago. Took the reel with me to the Maldives for a 5-day fishing trip last month.
Caught more than 20 fish with it, including a 40lb+ Giant Trevally with heavy enough drag to nicely bend my 130lb class trolling rod.
I haven't tested drags or free spool with a scale, so I don't have any hard numbers. The reel overall "feels" great, even on very high drag settings. My biggest peeve is still with the ultra-noisy pawl (dog) springs.

I actually emailed Alan about my modification before posting. He says that the bigger Avets are not too bad with side load, but that the smaller ones have that problem.
If you can get the dimensions of the bellevilles stacked together, maybe there's a thrust bearing out there that'll fit.

johndtuttle

I would be very interested in how this works out for you. If you can get a very good sense of what "preset" drag level leads to handle binding (the subjective measure of impending damage to the pinion bearing) before and after the mod we should have some good info.

However, the real question is can we find thrust bearings to replace the pinion bearings entirely and is the resulting compromise in free spool and handle binding (albeit with no damage to vital parts) acceptable?

Reason being is that even though your solution may improve free spool over the bellevilles, the force on the pinion will still be transferred to it as the thrust bearing is "floating".

Okuma's thrust washer increases the amount of free spool you get at "strike" as it eliminates binding on the spool bearings but it remains unclear to me if it actually saves the pinion bearing at all.

best regards

limitdown

John,
I actually thought about replacing the right side plate radial bearing with a thrust bearing. The thrust bearing would then just act as a bushing for the main shaft's rotation. Very small sacrifice if it would almost entirely eliminate the side load problem.
I didn't write down the side plate bearing's dimensions, but I remember it's in inch, not metric.

SoCalAngler

I thought the belleville washers only made the drag curve smoother? Won't replacing them with thrust washers, shims or what ever just make the drag curve more steep and you will still have the same side load on the pinion bearing?

The pinion bearing that I'd like to see replaced by thrust washer or angular contact bearing is .250X.625X.195 in size.

Robert Janssen

#6
I don't mean to come 'round and rain on anyones parade or nothin', but honestly, i just can't see this doing any good at all. This does nothing to alleviate pressure anywhere of relevance, and most certainly not the pinion bearing which seems to be of prime concern. (even though the load on it is shared equally by one of the spool bearings and a sideplate bearing)

I cannot see removal of the belleville washers being an improvement either. On the contrary- the washers are what allows smooth application of force with which to regulate drag pressure, as well as allowing room for thermal expansion and for mechanical bits being less than perfect. I'm not sure where the lateral movement of the cam mechanism's expansion is now taking place, but it must be in the form of frame distending, drag washers compressing, or maybe a washer behind the cam somewhere, or all of them.

Offhand I can think of only one reel that didn't use belleville spring washers or similar arrangement, and that would be the Fin-Nor Tycoon, which instead used a cam mechanism with incredibly fine adjustment; in the neighborhood of a few thousandths of an inch.

On the other hand, the idea of using of axial (thrust) ball bearings is not a bad one at all, and has been used with some success in the past, perhaps most notably by Everol in the 1960s and ABU in the 1970s. ABU used one in combination with a standard deep-groove bearing in the spool, and Everol used them in combination with another thrust bearing supporting the spool on needle roller bearings.

Come to think of it, there is an axial bearing in that miniature Ambassadeur 3.0 I made a while back. And, as usual, there is a slight increase in cranking resistance with increased drag. This is to be expected.

Quote from: SoCalAngler on March 06, 2013, 07:07:12 AM
I thought the belleville washers only made the drag curve smoother? Won't replacing them with thrust washers, shims or what ever just make the drag curve more steep and you will still have the same side load on the pinion bearing?

Yup.

.


limitdown

#7
Thanks for the all of the comments everyone.
There are definitely flaws in my modification.

When I looked at my Makaira 50W, I thought that I could just add a thrust bearing to the same location in my Avet 50 EXW. There isn't any additional empty space in the reel so the only way to create additional space was to rip out the bellevilles.

Replacing the bellevilles with the thrust washer is decreasing my drag curve smoothness. When I throw the drag lever up, small moves cause drag pressure to move up faster than when the bellevilles were in place.

As mentioned above by johndtuttle, the Makaira's thrust bearing would eliminate the axial load on the right spool bearing, but it might not help the pinion bearing.

After some email exchanges with Alan, it seems like the best solution might be to replace the pinion and spool bearings with Tapered Roller Bearings. These can handle both radial and axial load. A regular ball thrust bearing alone would act like a bushing for radial load.

I'm in the process of trying to source some tapered roller bearings. "Affordable" Inch/Imperial tapered roller bearings are quite difficult to find.

For the small Avets like the SX, MX and JX, it seems like all 4 of the bearings from right side plate to the left spool take axial load.
For the SX:
SX 23 pinion   0.25   0.625   0.196   1/4x5/8x.196
SX 17 brake   0.1875   0.375   0.125   3/16x3/8x1/8
SX 14 spool   0.1875   0.3125   0.125   3/16x5/16x1/8
SX 7 spool   0.1875   0.625   0.25   3/16x1/2x.196 (left spool : it looks like the bellevilles and Pusher Bushing put axial load on this bearing)

I don't actually own an SX so I can't measure. However, I'm seeing conflicting dimension numbers for some of the bearings. Probably due to different generations of production. Can someone confirm? And also for JX.

JX pinion   0.1875   0.375   0.125   3/16x3/8x1/8
JX spool 1   0.185   0.685   0.25   (the inner diameter number doesn't look right)
JX spool 2   0.185   0.375   0.125   (the inner diameter number doesn't look right)
JX Brake ??            

Hopefully my Makaira's metric ones will be easier to source
Right side plate   10x22x6

I'll share with everyone if I can source these tapered roller bearings affordably

Tapered Roller



SoCalAngler

The numbers I listed are for my JX 6/3's pinion bearing. Though I have found just fishing the reels within Avets specs I have never had a problem. The EX 50's get 50 lbs at strike and 57 at full with freespool (no damage to the pinion bearing) if you need more drag than that you may want to step up to a 80 and get the 3 speeds.

Robert Janssen


Ah, cool. All form of experimentation is commendable; that's how one learns things.

Um, yeah... talk of tapered roller (so-called Timken) bearings has circulated as long as i can remember. IIRC it usually ends when nobody can find the right sizes. Shaft diameters down to 17 or 15 mm is pretty much where common availability ends, and then you have a new OD and thickness to deal with. Which means that they may be made to fit with a little creative machining in the sideplates and spool, but there probably isn't a drop-in replacement available. (Once upon a long ago, one of the other reel tuners did find something suitable, but it was frighteningly expensive) Shaft size is probably not as difficult to deal with, since one could make a simple sleeve or bushing to fit.

However, at the time, we didn't have so many private consumer-oriented internet bearing suppliers to choose from. Maybe they are easy to find nowadays. You the OP seem to be into RC stuff. Maybe there is something to be found there?

Whether or not Timken bearings would actually offer an improvement in freespool remains to be seen... they tend to have a slightly higher rolling resistance than single-row ball bearings.

Quite recently, someone found a suitable angular contact bearing at one of the internet suppliers. Perhaps that would be more attractive, if it offers less rolling resistance.

Really though, standard deep-groove single-row 6200 and 6300 series bearings can take A LOT of side load without adverse effect, so perhaps the search should end there. I don't know why manufacturers insist on using as puny bearings as possible.

QuoteAs mentioned above by johndtuttle, the Makaira's thrust bearing would eliminate the axial load on the right spool bearing, but it might not help the pinion bearing.

Yes, it seems that way, strangely... The Makairas arrangement cleverly avoids loading the spool at all, but as far as i can see here in this cutaway view still loads the pinion bearing.



However, keep in mind that the EX type of reel is an entirely different animal than the SX and Makaira type reels in that it uses a live axle and thusly a slightly different constellation of rotating parts. (The spool bearings for example may very well be stiff when retrieving line, but you wouldn't notice, since they revolve with the axle anyway)



.

Bryan Young

I've been trusting the placement of the thrust bearing and I don't believe there are any issues with the perpendicular forces and the spool bearings of the Avets because the spools are provided with spool bearing sleeves that reinforce the pressure to the inner rice of an axial bearing to resist thrust forces. I don't know they call it, so I may just should like I'm rambling.

The best area for a thrust bearing is in the drive train side plate. There is nothing to support the material forces on that pinion bearing.  I hope I can experiment sometime soon
:D I talk with every part I send out and each reel I repair so that they perform at the top of their game. :D

Robert Janssen

#11
Good news... I found out that Timken has a tapered roller bearing in the TS series that starts at roughly 8 x 32 mm and up. Not stainless of course, but may be useable anyway.

http://www.gaessa.com/documentos/ROLLER_TIMKEN.pdf

QuoteFor the small Avets like the SX, MX and JX, it seems like all 4 of the bearings from right side plate to the left spool take axial load.

No. Pinion and left side spool bearings share the load equally.

Incidentally i found some AC bearings that fit those too.

.

limitdown

#12
Hi Robert, where did you find R4-sized angular contact bearings?

The only AC bearings I've been able to find are either too big, too expensive or would need to be custom manufactured with volumes of over 500 pieces.

If I can get 100 people to buy 2 pieces each, then I'll commit the capital and take inventory risk of getting a manufacturer to produce for me.

limitdown

I've put this project on ice until I can find decently-affordable angular contact bearings to fit.
In the mean time, I've installed an angular contact bearing in my Makaira 50W.
Check my Makaira thread

steelfish

Quote from: Robert Janssen on March 15, 2013, 11:55:39 PM


QuoteFor the small Avets like the SX, MX and JX, it seems like all 4 of the bearings from right side plate to the left spool take axial load.

No. Pinion and left side spool bearings share the load equally.

Old thread, but what if the OP changed only the left side spool bearing for Thrust bearing but leaving the benevilles stack to keep the drag smoothness.
would that aliviate the pressure on the pinion bearing and handle binding?
The Baja Guy