Lionel Nuclear Reactor

I think I read somewhere that the accessory was great when it worked but tended to be problematic.

Dan,

Fellow Forum member @DKDKRD and I are probably among the few that have done a deep dive into this accessory. Please do a quick search in the Forum archives as there is much valuable insight on this great reactor.

I can tell you that when gears and belts and voltage are just right it is a wonder to behold.

Hopefully KD will add his insights as well.

John

Dan, It is cool and I encourage you to get into it a bit.  Mine had similar issues and it turned out to be a dry rotted rubber belt and I found it from one of the great part sellers on the forum.

go for it! 

Thanks John.  

While doing the search, I noticed there may have been more than one release of the reactor.  one is 6-24294 the other 6-14065.  I have the, 6-14065.

I couldn't find the exploded parts diagram.

Dan,

The 6-14065 is the one I have as well. All the guts are under the red roof building that also has the lever that controls manual and automatic arm operation.

There is a tiny black drive belt in there that I replaced. I got the replacement from an vintage record player supply house that matched the original specs. There is also a tensioning screw that presses on the belt so optimistically that might be all your unit needs is a tightening of that adjustment. Lastly, Northwest Shortline made an exact copy of the nylon drive gear that is prone to deterioration, so that is worth a look as well.

That's about all the detail I can remember. Hope it helps some...

KD ! Good to hear from you! I posted this above info, but you beat me to it!😁

John

Thanks KD. When I tore apart the first reactor I had purchased last year, I didn't take pictures.  Stupid me.  But the unit was beyond repair anyway.  This time, I will use the thing between my ears.  

Can someone tell me where I drop the U235 pellets in?

Chris S.

On the back of the silver dome is a chute.

Hello guys, here are a few images from my repair I did probably 8 years ago. I'm pretty sure I bought the part (gear) from chuck. The problem with mine was a visitor grabbed the arm and pulled, breaking the gear, but that was all the damage and mine has been flawless since purchased new.

Let me know if the pictures help of if you need additional angles.

Charlie

Mine has seen a lot of use. But I've noticed lately that there is a lot of "slop" or play in the arm motion. Is that a sign of a split gear?

Chris

LVHR

LEHIGHLINE, if the motor is engaged and the arm is jerky or hesitates = split worn gear. Slop in the arm when the lever is engaged indicates split gear also.

John

Oh, the joy! One more repair that I was not planning to do!  Does it make a difference if the gear is 9 or 10 teeth? I saw a previous post where a 9 tooth was used instead of a 10 tooth. I may as well install a new belt while I'm inside... One less problem for later.

Chris

LVHR

The gear I used  from Northwest Shortline on the recommendation of KD was a 10 tooth. Sounds like a 9 tooth worked out fine for Charlie. Engineering-wise I don't know why it matters. Obviously we're not dealing with super close tolerances here.

John

Another modification I did was to make the "as delivered" Reactor more closely match the catalog art. 

I used a high end decorative blue mettalic paint that is used in faux finishes. I think it changes the vibe of the dome considerably.

John

Hello again guys.

Just checked and it was April of 2011 that I did the repair as shown in the images above. While I wish I had the correct part at the time, I don't think I am going to open it up again since it is still working. Now, I don't use it every day, but I would safely say it gets activated a few times a month on average.

If it does break again, I will use the NWSL part as pointed out above.

And yes, if you are already at this stage of repair, might as well swap out the rubber drive belt which is easy to do.

Again, let me know if you need more images as I have plenty. I took progress shots during the disassembly so I had a shot at getting it back together.

Good luck.

Charlie

Charlie posted:

Hello again guys.

Just checked and it was April of 2011 that I did the repair as shown in the images above. While I wish I had the correct part at the time, I don't think I am going to open it up again since it is still working. Now, I don't use it every day, but I would safely say it gets activated a few times a month on average.

If it does break again, I will use the NWSL part as pointed out above.

And yes, if you are already at this stage of repair, might as well swap out the rubber drive belt which is easy to do.

Again, let me know if you need more images as I have plenty. I took progress shots during the disassembly so I had a shot at getting it back together.

Good luck.

Charlie

Charlie, thank you for your excellent photos.  They will go a long way toward helping me when I tackle the job.

Hi.....old post, new question. I have this accessory and it's one of my favorites. Years ago, I built a receiving car for it that vastly improves its usage and enjoyment.  Some photos and explanations on the old post.

https://ogrforum.com/...ear-reactor-question

The arm has always been flukey on this thing and last week it failed completely. I had it apart several times and couldn't identify the problem, but I suspected it was a stripped or split gear. Don't you just love these plastic gears? I was ready to give up and the unit was soon to be relegated to a paper weight or worse. But I found this posting on here and thought it was worth another try. I ordered the gear and the belt . The gear arrived yesterday, so I opened up the mechanism. The belt was fine (although, I will replace it when the new one arrives). The gear looked fine as well.......until I viewed it under magnification. Spotted a thin black line between two teeth. Sure enough, the gear was split completely and hanging loosely on the axle.

Before I install the belt when it arrives, I'd like to get answers to two questions I have. First....I was VERY hesitant to try and press the gear completely on the knurling. I don't want to split it again. I filed a bit of the knurling on the gear side and pressed it, but it doesn't cover the knurling completely and is not centered on the neighboring gear. I'm thinking it's fine this way. It won't come off easily the way it is. Your thoughts on this?

Secondly, I've been thinking about that arm and the reversing/clutch mechanism. After I reassemble, do I have to worry about the arm's starting position in the cycle (at the top or at the bottom)? Or will it be in its proper position on reassembly and will swing to the ends and reverse correctly?  I've got a sneaking suspicion this will be trouble. Again, your thoughts?

Thanks in advance,

Roger

Hello Roger, Wow! What a nice blast from the past... My best recollection is that the NWSL gear which was engineered and offered as an exact replacement for the Reactor and did not require any fiddling on shaft placement. I'm thinking if what you have now catches enough of the mating gear consistently, we'll then, good enough.

I do recall that, YES, starting position of the arm on reassembly is important. The bad news is that I don't recall exactly how I determined that position. Pretty sure I used the manual crank option to determine correct placement and arc then cranked down the assembly/ retaining screws accordingly.  Also recall that the belt tightness adjustment screw was of tremendous importance to fine tuning. Here's hoping🤞

John

Does anyone know if the NWSL gear is still available?  Where can I get a belt?

Thank you,

Richard

https://ogrforum.com/topic/62669288857487134

Here ya go...all the product info to order.

John

@ROGER1 posted:

Secondly, I've been thinking about that arm and the reversing/clutch mechanism. After I reassemble, do I have to worry about the arm's starting position in the cycle (at the top or at the bottom)? Or will it be in its proper position on reassembly and will swing to the ends and reverse correctly?  I've got a sneaking suspicion this will be trouble. Again, your thoughts?

Thanks in advance,

Roger

No, you do not have to worry about the arm position.  The arm shaft has two triggers mounted on the arm.  They trigger the micro switches to move the arm back and forth.  As long as the two triggers are between the micro switches. it will auto adjust.

Thanks, Joe. That's a hassle, I wasn't looking forward to.  As for the belt adjusting screw. What are the indicators that show bad adjustment?

Roger

@John Meyncke posted:

https://ogrforum.com/topic/62669288857487134

Here ya go...all the product info to order.

John

Thank you John

I wonder why your response didn't go directly to my email??

Hey Joe,

As I feared, I'm having trouble with the arm. The good news is......the unit works. The gear and the belt arrived a couple of days ago, and I did an install yesterday. I did not use the new belt. It was slightly longer than the OEM and being that the OEM looked in good shape, I put it back in. The bad new is, it doesn't reverse at the bottom. The first time I hooked it up this afternoon, it was worse. I did some adjustments and now it reverses at the top, moves to the bottom and bottoms out.....doesn't come back up. If I shut the arm switch to off on the controller and turn it back on again, the arm will come back up, reverses at the top and gets stuck again at the bottom. So, I seem to be missing something. When I look inside, I see one switch which the arm tab triggers, but I don't see another switch in there. ????     We're close, but no cigar yet. LOL

Also.....I've read about the adjusting screw for the belt. I thought I knew where it was, but that screw doesn't seem to do any adjusting. Since I'm using the OEM belt, I'm hoping it doesn't need adjusting, but I am curious about where that it.  

Thanks,

Roger

If I recall correctly, the adjustment screw, (silver) screws down onto the belt acting as a belt tensioner adjustment. It should be on top of the  black belt at or near the white nylon belt pulleys. Hope this helps,

John

Ok......now we're really close. Since last week, I've been wondering how this thing reverses with only one switch. I took it apart again and realized that the metal "lever"on the top micro switch was missing. So, I took the two switches out to try and find the part number to maybe find one at an online electrical parts site. I had been using my Vessel ratcheting screw driver to dismantle this and when I picked it up, I saw a glint.  The lever was stuck to the tip of the screwdriver. Awesome magnet in there. Took a look at the switch and realized that I could put the lever back in. Put it all back together and .....Bingo.....it works. However.....one last snag remains. It's not reversing when the arm hits my car with the pellet bins. Needs to dip lower. I raised up the base of the reactor and that worked, but it wasn't necessary previously. There must be a way to adjust the switches to compensate for the height. I'm thinking those tabs on the gear axle that contact the switch. I think I may be able to loosen the mounting screws on the one tab and adjust when it hits the switch lever. Must have been knocked off at some point when I took it apart or reassembled.   Am I onto something here?  So close, yet so far....

Roger

@ROGER1 posted:

There must be a way to adjust the switches to compensate for the height. I'm thinking those tabs on the gear axle that contact the switch. I think I may be able to loosen the mounting screws on the one tab and adjust when it hits the switch lever. Must have been knocked off at some point when I took it apart or reassembled.   Am I onto something here?  So close, yet so far....

Roger

Yup, that's how you would adjust it.  Lionel did not make provisions to adjust the arm.  Those tabs were factory set.   I have road bed under my track and I had to adjust the height of the reactor so it would go into the car the correct amount to pick up the load.

Joe,

Things are not going well with this. The arm keeps riding up over the damaged switch and jams. I tried putting shims under it, but as soon as I installed the arm, the leverage changes and it rides up and jams again. Getting frustrated. I did adjust the tabs to move up the contact time. Nothing worked. So......late last night , I ordered new switches from DigiKey. Found the part number on the side and ordered two (one hopefully is a spare). I'm also going to try and find a longer screw for the problematic tab (to prevent the ride-up). I think I can take this thing apart and back together in my sleep at this point. One reason why the ride up occurs (besides the leverage of the arm). is that the switch is mounted on plastic and when contact is made by the tab, the top of the switch actually moves rearward. I think my only options are the new switch and modding the tab to try and prevent that ride up.

Roger

@ROGER1 posted:

Things are not going well with this. The arm keeps riding up over the damaged switch and jams. I tried putting shims under it, but as soon as I installed the arm, the leverage changes and it rides up and jams again. Getting frustrated. I did adjust the tabs to move up the contact time. Nothing worked. So......late last night , I ordered new switches from DigiKey. Found the part number on the side and ordered two (one hopefully is a spare). I'm also going to try and find a longer screw for the problematic tab (to prevent the ride-up). I think I can take this thing apart and back together in my sleep at this point. One reason why the ride up occurs (besides the leverage of the arm). is that the switch is mounted on plastic and when contact is made by the tab, the top of the switch actually moves rearward. I think my only options are the new switch and modding the tab to try and prevent that ride up.

Even though I don't have one of these, I've been following the discussion with interest, because I'm tackling a somewhat similar project. In my case, though, I'm attempting to design and scratch build a working model of the fixed trunnion bascule bridge over Cambridge Creek in my hometown of Cambridge, MD, for the RFC train garden:

What the projects have in common IMHO is the physics of the animation -- in your case, in order to troubleshoot the problematic animation, and in mine, to figure out how to make it all work in the first place!

So far, I sourced a bunch of parts (geared motors, limit switches and direction switch) from overseas, and have breadboarded a test-of-concept configuration to make sure my "mental conception" might work in the real world:

After I take some measurements off the prototype today, my next step will be to mock up a model of the bridge works to see if my breadboarded animation is practical as planned. Hope your project succeeds in 'cracking the code' of your reactor in order to get it to work -- good luck, and I'll be following along with interest!

Just for future reference, the small plastic gear that fails in the reactors, pylons, control towers, etc... is the 102A gear...you can find several sources in China on ebay.   Seems the issue has been either the shaft is too large or the gear hole too small (take your pick) but the end result is that in time the gear splits.  Recommend using a small drill bit to open the new gear hole a fraction to help prevent future splits.  I've found that 2mm normally works good on the older accessories and 2.1mm works best on the newer ones (maybe thicker plating on the shaft?)

S/F Mike

Steve,

That looks like a very cool project!

@ROGER1 posted:

Steve,

That looks like a very cool project!

Thanks! Yeah, I just came back from measuring the bridge, and took a few more shots:

All the lift mechanisms (one set for each side of the lift section) will have to fit in the two boxy supports (one under the control station, the other just behind it in the photo). Also got a better idea how the prototype lift sections are attached, and are configured to both go up and down, *and* still present a drivable surface when down. Still, I predict the need for a lot o' fiddlin' . . .

1) Seems the issue has been either the shaft is too large or the gear hole too small (take your pick) but the end result is that in time the gear splits.

2)Recommend using a small drill bit to open the new gear hole a fraction to help prevent future splits.

1) Neither of those...  It's the material the gear is molded in...Nylon.  A "cost effective" choice (a.k.a., cheap!), but a poor one for longevity in many drive applications such as are the nature of our hobby's mechanisms.

Nylon is hygroscopic...affected by water.  It's qualities are subject to change based on ambient humidity and changes thereof.   In essence the part will 'grow' and 'shrink' with humidity change.  When the gear is already stressed with a press fit to the mating shaft...knurled or not...the part will crack over time at it's weakest point.  In this small gear case, the weakest point is usually at the gear root diameter.  The difference between the root diameter and the shaft diameter is the thinnest cross-section of the part...and the most 'stressed' area of the part.

Ergo, as the part strength fluctuates, a crack...and failure...will result.  Once the Nylon gear splits, its grip to the shaft is lost.  Using an adhesive...like CA...may restore the 'grip', but the gear tooth spacing at the split is disrupted, usually resulting in a 'clicking' sound and/or binding 'hiccup' in the rotation.

Replacing the gear is the solution.  Replacing the original Nylon gear with one of a non-hygroscopic material is the best solution.  For example, NorthWest Shortline (NWSL) would typically offer replacements in brass and/or Delrin (acetal resin)for a Nylon gear such as in this mechanism.   Replacing the split gear with another Nylon (usually white) gear is typically a recipe for repeat failure.

2) Reducing the amount of press fit by reaming the gear I.D. will perhaps extend the time-to-failure for this Nylon gear application.  However, and again, depending on ambient humidity levels/changes, ultimate split/failure is very likely.  The weakest area in the design is still the weakest area.

FWIW...

KD

Unless i missed it, nobody in this thread had a video of the reactor in action and had never seen one, but found one in a 2014 post that still works:

https://www.youtube.com/watch?v=tAG4mLaw62I

Just wish it continued on to where the pellets get put back in the car.

Well, I think I've had it with this repair project. I never give up easily, but I've literally worked on it for a week. I replaced the gear, tonite replaced the belt. I replaced a broken micro switch. Thought that would do it when those switches arrived today. Installed it, powered up.....nothing.....dead. Then I found a brown wire coming up from underneath....connected to nothing. To access it, I was maneuvering the motor housing and the gray wire popped off. Took quite awhile to figure out what they connected to. Finally discovered the slots in the circuit board. Rewired it, put it back together. The motor ran and reversed when I turned the axle with the contact tabs. Thought I had it. Put it back together and the motor worked but the gears mostly didn't turn. Problem with the belt. Replaced it with the new one. No different. Adjusted the belt tensioner. No different. If anything it worked worse. I'm out of ideas and patience. Thanks for all who offered advice, but I'm either going to throw it out or.....use it on manual (only because I put alot of work into the receiving car).

It's a toy and it's got plastic gears. Bad combination.

Roger