Thrust Bearing and LnL (and general) lesson learned

[mongoose33]

My Hornady LnL progressive has a tendency, as I think many such presses have, to flick the occasional granule of powder out of a case as it indexes from powder drop to lockout die to seating die.

I'd read of a possible solution http://castboolits.gunloads.com/showpost.php?p=596542&postcount=6 which sounded like it might work for the LnL.

So I ordered up a couple thrust bearings and 4 thin washers (extras), and set out to see if it would smooth out the indexing. (Though I ordered a different size to fit the LnL center bolt).

I removed the center bolt and washer, and put down a thin washer, the thrust bearing, a second thin washer, then topped the arrangement with the washer and bolt I'd removed from the shellplate.

So far so good. It seemed to smooth things a bit, though not as much as I'd have liked.

To really test, though I had to reload some rounds, so I proceeded to set up to reload 9mm. All sorts of problems ensued. The case mouth expander wasn't working as well as it should, and the OAL wasn't right (It was long). Taper crimp wasn't working as well either.

It took me a while to figure it out (about 25 minutes, actually), but eventually I discovered that by adding the extra washers and thrust bearing, it increased the height of the center washer such that it would bump into the top of the press before reaching the end of the upstroke, where the hole exists for the bolt to enter on that upstroke.

That's why case mouth expansion and OAL were screwed up In fact, the press didn't feel right as I cycled it while producing rounds. I kept producing them, after adjusting the case mouth expansion and OAL.

What I should have done--here's the lesson--was stopped and figured out why both the OAL and case mouth expansion should have been screwed up, as well as why the press felt different (it was bottoming out too soon). I didn't change anything from the last time I ran 9mm through it. Same dies, same settings.

Lesson learned. If something is not right, or doesn't feel right, find out why.


I ended up removing one of the extra washers so that the thrust bearing would rest on the shellplate, and that reduced the height of the center washer/bearing/bolt assembly enough that the press returned to cycling normally.

The bearing seems to reduce a bit of the snap as shellplate rotates, though not as much as I'd hoped. It was an interesting exercise, and I'll probably try some variations on the theme, but in the end, the entertainment value was worth the money expended.

And I learned a lesson.

 

[UltimateReloader]

Sounds like an interesting mod- do you have pics to show of the parts you installed?

I have not had much trouble with this on the Lock-N-Load AP due to the fact that it does 1/2 index on the way up and 1/2 index on the way down, effectively cutting the angular acceleration in half --although you could argue that when the detent balls engage the shellplate to finish the indexing, that's when it accelerates (negative, slowing down) the most. My test for spillage is usually is something fluffy in 45ACP (like unique).

 

[mongoose33]

The first pic below shows how it's installed on the press:

What's shown above is the thrust bearing, the thin washer on top of the thrust bearing, then the normal LnL washer, then the bolt. The powder is obvious. I'm not normally a neatnik but when it comes to reloading I tend toward being exactly that. The powder is messy and I don't like having spilled powder, period.

The second pic, below, shows the thrust bearing, the two thin washers I bought for it, and the normal LnL washer on the right. What you see on the thrust bearing is grease I used to see if it would create a bit more friction.

What I may try next is to see if there's a stiffer grease that could be used that would slow down the indexing snap a bit more.

 

[pinkymingeo]

I get more spillage than I like when loading short 45acp's. Longer brass, no mess. Analyzing the situation, I've decided my problem isn't with the press, but with my bench. I'm getting too much vibration, which is shaking the powder over the rim. I plan to rebuild with a thicker top, which should fix things.

 

[Walkalong]

Just drag your finger a little on the shell plate as it clicks into the detent.

 

[clelaj]

The thrust bearing is Torrington pn NTA-815 and the thrust washers are Tiorrington pn TRA-815. Also available at bearing distributors in most cities.

 

[Walkalong]

When tightened down properly, the shell plate, washer, bolt, and drive hub are all moving together. The place for a bearing would be between "A" and "B" on the drawing I made, but then you would have to turn some metal off to make room for one. I polished things in the appropriate places and it is very smooth.

The little jolt you get is the assembly jumping a hair when the ball bearing drops into the detent in the sub plate. No matter how smooth the trip is getting there, it will still jerk a tiny bit when doing that.

 

[nofishbob]

I am unclear on why a thrust bearing will help with the spillage problem.

If anything, I would expect the thrust bearing to reduce friction and thereby let the shellplate accelerate more rapidly.

I have not experienced spillage because I am using loads that do not end up with the powder near the top of the case.

Putting something like a friction washer or drag disc from a fishing reel might offer some damping of the motion, but may require a lot of trial and error to get the resistance just right.

Bob

 

[Walkalong]

Putting something like a friction washer or drag disc from a fishing reel might offer some damping of the motion,

Like letting your finger drag on it a little. Works great, but that is a great idea, which should work.

I do have some loads with powder near the top that wants to jump out sometimes. Just a few kernels, but why go to the trouble to use a good measure and then toss out a few kernels here and there from every third case or so.

 

[floydster]

I don't see where a thrust bearing would do any good as evrything moves together--- I'm lost.

 

[mongoose33]

You're right--I was thinking that the bolt moved separately, and it doesn't.

And Walkalong is right--it would have to be underneath, but you can't get it there without making a mod.

I bought some sticky grease--going to see if that will help slow down the detent balls a bit.

 

[Roccobro]

I get a little spillage on the tiny calibers. I just might try putting some clay in the detent holes to lessen the movement.

Justin

 

[floydster]

How bout peanut butter?

 

[UltimateReloader]

I'll 2nd the "Ridgid mount" approach (lessening vibration). Since I've built a steel pedestal, my presses just generally work better. You can feel the priming portion of the stroke better (less raised primers) and have a more positive "ram at the top of stroke" feeling as well.

You can see the pedestal I built in these videos:
http://ultimatereloader.com/?p=453
http://ultimatereloader.com/?p=103

 

[showmebob]

I've helped that problem out by using a very thick silicone brake lube grease (Ford) on the detent ball recessions. It works great for a while but then you need to regrease.

 

[Robert Palermo /Penn Bullets]

I have been following this thread with some intrest. Haven't had the time to try this with the 650 Dillions yet. However, the thought occured to me that a way to add some resitance to the shell plate might be by way of a Bellville disc spring washer also available from McMaster Carr. that way you could apply a certain amount of tension to the plate to keep it from snapping. I'd try it except I am just a bit too busy right now to give it a whirl.