Weaver - my first attempt.

Hi Max.

I'm not getting involved in your rebuild as I don't use sound or any fancy gimmicks for me it's all DC all the way but that's me and I never knock anyone else for living in the present!

I have been involved in O Scale for many years getting close to 30 years maybe, who's counting, and I am a bumbling modeller who gets by on my average skills.

I have many Weaver and Red caboose diesels some run great some don't for the operation day I don't like hassles so I run a fleet of six Atlas SW diesels and never have a problem.

Anyway enough self praise that's not what I am writing about.

Loco Rollers: This is what I use they are from Mustard Models in England I go every year to England and always go to Telford for the O gauge show which is the biggest same Gauge show in Europe so I'm told not much USA items but plenty of tools and stuff like this.

Maybe you should ask an old O scale bloke sitting down in his workshop at the end of the earth before buying equipment in the future I can give you O SCALE advice but's that's all, I am not an expert and I am not a dealer just an old man playing with his trains.

Nev.

Hi Roo

I'm not fussed about the rollers.  It's good to support our sponsors at the top of the page.

I've got an Atlas SDP-35, which has no running problems.  I fitted a new L Select to it and it seems to have a fault as it's showing a short circuit.

Bryan from SBS4DCC is sending me a replacement which should be here next week.

One step forward and one step back - at least it's not two steps back.  

OK, Max.

You obviously know what your doing, I will let you get on with your work and leave you alone.

Best of luck with your endeavors.

Roo.

know what your doing I leave you to it mate.

good luck.

Roo.

Hi again, Kelly.

To deal first with the motor whine . . . I've been running the loco - first on DC, then on DCC with developing drive trains.  Even with the P&D tower, it wasn't there.  I can't tell for sure; maybe the changed gear ratio has something to do with it.  I really have no idea, but the motor is fine.

Here is a shot of the tower as assembled . . .

As you can see, it's a perfect fit.  There's even a small gap at the left hand end of the slot between the pin and the end.  Couldn't be better.

I could shim the gear a bit to move it more directly above the bottom sprocket.  I could also add a few more links into the chain, which will allow me to raise the tower so that the tail shaft is perfectly level.  Fine tuning really, but it might help to chase down the whine.

Once I've received my rollers, I should be able to home in on the rattle at the bottom.

It's all part of the tapestry.  Who knows - we might even find some pointers for those tackling Weaver GP 38's in the future.

Cheers

I'm finding these posts most interesting, as I too have just purchased a Weaver "38" online.

Have yet to receive it, and hope it will not have any of these issues, but if it does, I'll have some good info with which to address them, thanks to this thread...

Mark in Oregon

Hi Max,

Great work - man that kit is nice! I am now fully motivated togetstuck into mine as soon as I get back. I would say at first glance that the chain does look a little angled coming off the top sprocket so worth a tweak to get them 100% aligned. At least top and bottom tower shafts are parallel now! I doubt if there's enough offset through the UJs to be adding much noise. 

I have been thinking about that "bucket of bolts" rattle that's in your video, and was leaning towards a busted motor as Kelly suggested, but that seems highly unlikely now you have brand new BB Pittman, as you say.

There are only 2 things left I have seen on some of mine that can cause uneven load: The Delrin slider section of the motor drive shaft not being free to slide forwards and backwards from the centred no-load position, and the square-section brass slider driveshaft between the trucks being bent or unable to slide freely. I keep the Delrin dry (file and smooth it if required),  but lube the brass. But tbh I highly doubt either of those would cause a rattle like in the middle of your video.

Anyway, keep up the good work and look forward to seeing what you find. It will be worth it!  

Pete

Thanks, Pete.  Nothing's ever wasted in this hobby. 

I think that I will go back and fine tune the whole thing, just to satisfy myself; while I'm waiting for the rollers.

It all turns very smoothly by hand - both from the top and the bottom shafts, but we all know how things can change once we begin to drive them.

How was Europe?

Thank you for the pictures, I have a few questions and comments.

1) Does the GP38 come with the flywheel show?

2) FYI the small gear is only pushed onto the splines of the shaft about 1/8". It can be pushed onto the splines further if you need to move the chain closer to the tower. This can be done simply by tightening the shaft nut, it won't damage the bearings. Make sure you back the nut off after you do this to prevent binding the tower bearings.

3) My GP9 was a bad runner and I stripped the entire drive train down and found an extra shim inside the lower gear box that was causing binding.

4) Per the instruction in my kit I use locktite and only hand tighten the two lower gear box screws/nuts. Any tighter and the loco started to run bad again.

5) I had flashing inside the brass tube that connected the two lower gear box's. One was also bent a little. I cut new tubes. Make sure the tubes are not to long and pushing against the large lower gear or it will bind.

Hi Kelly

I'm not sure what you mean by a flywheel show.  The motor and flywheel assembly is exactly the same size as the one I removed.

I'm confident that I can line everything up.

I guess it will just be a process of "blueprinting" to use a motor racing term, every component to get them fitting properly.

I can easily turn the drive train with my fingers on both the lower and upper shafts, so I suspect that the spurious whine and rattling is some kind of referred vibration or suchlike.

 I haven't glued any of the screws as yet, until make sure that I haven't over tightened them.

Like I say, I'm going to retrace my steps until I find it.

Cheers

Sorry typo,

Did the GP38 come with the flywheel shown in the picture? Just wondering if the flywheel was available from another source because a few people have asked my to make them but I don't have a CNC lathe.

Ha ha.  Now it makes sense. 

Yes.  I prised the flywheel off and pressed it on to Pat's motor, which had no flywheel.

Flywheel are offered by NWSL.

the just fit perfect to Pittman shaft.

Thank you for the updates this is a great topic, with a lot of great solutions.

I fixed all my weaver using NWSL and P&D products.

Now I have to give a try to finescale tower upgrade.

Andre.

I had a number of flywheel equipped locomotives that had vibration/noise issues at high RPM.  Holding the motors in my hand and revving them up I could feel the vibration - even though I could see that the flywheels were running true.  I discovered that the flywheels were fixed on the motor shaft with steel set screws recessed deep inside the brass flywheel - consequently the flywheels were inherently out of balance.  My fix was to re-bore and tap the flywheels for long brass set screws with heads cut flush with the outer face of the flywheel. This eliminated the out of balance condition - flywheel induced vibration gone!

Ed Rappe

Thanks, Ed.

Fortunately this model has a solid flywheel, so I'm saved from that.  The whine wasn't there before I fitted the tower mod, so that's another bonus.

I goes to show that we need to look properly for these vibration sources.

Flywheels are redundant with DCC, but we need the physical connector to the shaft, so we're stuck with them.

I've done some further work on the tower while I'm waiting for the rollers.

I've trimmed a further 2 mm off the end of the shaft to make sure that Pete's suggestion is covered.  The gap in the shaft slider is now quite large.

I shimmed the sprocket with a brass 3 mm washer, which brought it in line with the bottom sprocket.

I added one link to the chain, which raised the top axle to be perfectly in line with the drive shaft.  I'm not sure what the ideal tension is for the chain, but I guessed that about one chain width deflection midway between the sprockets could be OK.

Anyway, the whine is gone - together with most of the rattle.

What is left of the rattle seems to be coming from the bottom somewhere, but as I say I'll be able to tell more when I use the rollers.

You can also see an ugly burn mark on the chassis, where I made clearance for the chain, as it hits the chassis cross member on full lock.  I used my soldering iron, but I'll clean it up later if I have to take it apart again.

Clearly Weaver made the frames to suit the loco they were modelling, so they are all different.  The mods have turned out to be worth the effort, but they need a bit of tweaking to get them to 100%

Excellent work Max! Looking at this latest picture and from your comments it sounds like you nailed all the "upper drive train" issues. Now that you have the upper drive train running faster than the lower, that should help you isolate the source in the lower on the rollers. 

I was so glad to read "The mods have turned out to be worth the effort, but they need a bit of tweaking to get them to 100%"  

I am still in EU - Madrid this week, a lovely city, and I'll be back next week. I am even more keen to get these tower upgrades kits installed now. Thanks for letting me live vicariously through your emotional roller coaster! 

Looking forward to the next video clip...

Pete

Oops, meant to say that usually the UJ yoke will press fit onto the Pittman shaft the same way it does on the flywheel. So you likely could remove it if you wanted, That big flywheel on my F7 (no idea who made it) is actually hollowed out and the UJ fits onto the end of the motor shaft deep inside. That said, 2 of my original Weaver drives had split yokes. Not that surprising I guess. 

Thanks, Pete.

I might wait until I get it completely done before I make another movie.

The flywheel has the UJ yoke pressed into it on the GP-38, so I didn't bother trying to take the flywheel out of the line.  With hindsight, it could have been a good move - given the problems Ed had with his flywheel being out of balance.

Anyway, enjoy Europe.  Are you on holiday or working?

Cheers

Max, my guess is the solid press-on flywheel is good. I have a couple and they don't vibrate running just the motor on the bench. It's the grub screw ones that can prove troublesome if the grub screws aren't arranged in exactly opposing pairs. Ed Rappe's elegant solution fixes that problem for sure! 

OK on the video - it'll be worth the wait. I'm guessing the difference will be stunning.

My trip is business, sadly.  I'm in the waste-to-energy sector so I tend to travel to interesting cities and then have to go straight to visit the landfill. That "landfill aroma" is surprisingly consistent around the world...       Luckily our Spanish partner knows the value of siesta so its not all bad!

Pete