G Scale Model Train Forum banner
1 - 20 of 76 Posts

·
Premium Member
Joined
·
2,268 Posts
Discussion Starter · #1 ·
Well since after 2 hours of running I loosened the one crosshead pin enough to bend the rod I had to tear it down to replace the bolts and straighten the rod back. Here is the new bolts I turned without the nuts that are on order.





Sonce I knew there was a clicking sound coming from all the bushings I decided to measure all of them, they are all about .010-.013 difference from the crank pins. That means a lot of slop and within just a few hours you will have siginifiant wear on the crank pins as I do.

Here is the amount of clearance that is on my bushings.



As you can see from the light reflection there is a defined ridge already worn into the crank pins from the main rods. So far after 2 hours of run time I have a .005 groove worn into the pin. After another 10 runs at the current wear rate it would be at about .0125 At 20 runs at about a .025 groove. At this point the threads from the retaining bolt will start to show on the outside. Now this wear is only on 180 degrees of the pin to the pin will continue to oval itself out, along with the bushing already ovaled out on mine.





According to Accucraft my loco is the only one with these issues as no one else had checked or called. I inspected 2 other 2nd run 4-4-0's and both of them are the same as mine. Neither of the 2 people had run the locos more than once so far and the bushings were just as bad. Accucraft seems not to want to change the design of these bushings since they do not get any complaints. I have noticied that on my older Accucraft locos the bushings and rods were still very tight. The newer design locos seems to all have oversized holes for the crank pins as on the C19 or Cabfoward where some people already made new bushings or installed roller bearings. If anyone else has the same issues please voice it as no one is being heard on the issues out there untilafter the parts are going to be long gone. As it is already they have no replacement parts 4-4-0 until they get enough requests for a part. Almost 260 were built and all were shipped but I think 1 or 2 units.

(resized to max 640 pixel width, SteveC mod.)
 

·
Premium Member
Joined
·
2,268 Posts
Discussion Starter · #2 ·
Sorry about the photo size I cant get to my FTP site to change them right now. 600x800 is not that large and the file size is small anyway

From Peter Bunce - moderator - I have asked Jason if he can reduce the size of his photos - from the above I think that is the case, and it will be done as soon as his FTP decides to play ball.
 

·
Premium Member
Joined
·
501 Posts
Jay,
If you are able to do so, it would be a good idea to inspect a new out of the box engine prior to running. Photograph, document ect the condition of the bearings prior and after 2 or so hours running. This would give you a solid base line on the problem. The problem could also be a issue of correct quarting of the dirvers and that is why the larger side rod holes. The early C-16's had this issue. I have replaced totally egged out bearings on at least three C-16's for folks.
Noel
 

·
Premium Member
Joined
·
3,378 Posts
Jay
Of the 4 I know about it's been 50% with enlarged bearing, loose fits and cross head problems. Even higher percentage of running gear problems with the AC-11. As per the AC-11 it was been documented to Accucraft.
 

·
Premium Member
Joined
·
2,268 Posts
Discussion Starter · #5 ·
Noel - I dont know of any other locos that have not been run except Alan Redeker and he is away on business for a while and has not had any chance to even open it yet unless he did over the 4th of July.
What were you using to check the quartering of the drivers? Did you make up a jig for it?
 

·
Premium Member
Joined
·
501 Posts
Jay,
Made my own jig out of angle brackets and 3/8ths inch nuts and bolts. I either found how to do it in a STIG article or on this site many moons ago. I will try to take some pics and send to you.
Noel
 

·
Premium Member
Joined
·
118 Posts
I plan to make new bushings for mine, as they are very sloppy as well. I put roller bearings on my C-19, and I was able to fine tune the timing after that. It was sloppy as well right out of the box.
 

·
Premium Member
Joined
·
49 Posts
Jay,

I just checked my engine, unpacked but has not been run yet. Pins are all loose and look like yours in the photo's.

Looks like it will need a BB retrofit if someone can find the right size and will need the cross head work also.

Jon
 

·
Premium Member
Joined
·
501 Posts
Jon,
Before you run it call Cliff and tell him. This is NOT good. Glad this is all coming out but not for you guys to have to deal with. I was planning to give Royce a call but now will wait. Seems that a rethink is iin order here. Perhaps even an price discount....heheheheh.
Noel
 

·
Premium Member
Joined
·
2,268 Posts
Discussion Starter · #10 ·
Dont worry Jon - There are no replacements though and our only option is that Norm fixes them on the East coast and Dave fixes them on the West coast. That was Cliff's answer to me. He is at the show this week so it will be a week before you get a response from him.

Do you have a dial caliper that you can measure the shaft dia on all the pins and the bushing hole in the rods? Using the cheap Harbor Freight digital Calipers will give you false measurements. I have tried using them a few occasions and then checking again with the good set of calipers (Starrett) and a Micrometer it was off by almost .005" Not good then I was trying to thread a fine thread for an adapter.

I think bushings will be sufficient so long as the tolerances are correct.
 

·
Registered
Joined
·
308 Posts
I think the rapid early wear is more the result of a poor surface finish. on the pins..its asturned and certainly not polished..

it may settle once the thrust area is polished by the bush.. but if you want to make nerw bushes try a floating bush,not press fitted in the rods but aclose running fit with acouple of cross holes to allow oil into both sides..quite good method in guage 1 sizes.
 

·
Premium Member
Joined
·
3,378 Posts
Jon
We have a good source for BB as we are replacing GS4, AC-11 bearing with this upgrade. I will send the name to you.
 

·
Premium Member
Joined
·
32 Posts
I have been thinking of Buying one of these locos, But if they have issues out of the box ,will Accucraft stand behind them and offer a fix or maybe pay for the fix?
 

·
Premium Member
Joined
·
49 Posts
Charles thanks. Look forward to the info.

Jay, are you going to make me a few cross head bolks? I am sure we can work something out.

Accucraft is usually good about standing by their product, I have a half dozen of their engines. I like to tinker,so I'll make the fixes rather than send it off to get it done. Cliff will make things right if you need to go that route. If you want to make improvements yourself, there is plenty of help here.
 

·
Premium Member
Joined
·
3,378 Posts
Jon
As per Groucho, "say the magic word...." well, you said it; improvement. Most of us are like your situation. Instead of sending back for a stock replacement part would rather fix it with an improved part. That isn't to say that Accucraft will not deal with the problem as per their statement of satisfying the customer...
 

·
Premium Member
Joined
·
2,268 Posts
Discussion Starter · #16 ·
Jon I guess I will be adding you to the list I already have going. The first set took 2.5 hours with screwing around, probally about an hour per set or so if Im really moving. These friggin things are tiny on a 10" lathe. Thank god for collet setups. Jon I need to know that the dia of the hole is on your crosshead and main rod. Both of mine were two different sizes and #99 and a #98 drill bit I think. Could be wear too though as my pins were already loose. I had turned my pins to fit both holes tight except for the .001 clearance I left on the shoulder for the Main Rod. Again both main rods had 2 different sizes.
 

·
Registered
Joined
·
33 Posts
Hi all.
I think that this problem is more wide spread then we think.
All of my Accucraft rod engines ( C-21, Mogul, Ida, Ruby and even my new C-19) are experiencing the same problem.
I have the Mogul on the bench now so it is the one that the measurement are coming from.

First off for clarity, I’m numbering the drivers 1 through 3 starting from the front and working to the rear. So driver #1 is the set just behind the pony truck.

Driver #3 has the least amount of slop with about 0.008" TOTAL clearance. Drivers #2 & #1 have the most with about 0.022" to 0.019" respectively. Both sides show equal amount of wear. I can easily stick a #76 drill bit in the gap between the bushing and crank pin on #2 driver.
This yields CENTER clearances of... #3 about 0.004", #2 about 0.011" and driver #1 with about 0.009".
Just for comparison, you car engine, rod bearings have around 0.005" to 0.010" of TOTAL clearance.

On the Mogul, I don’t show the wear on the crank pin that Jason shows. But the rod bushings are definitely worn.
This engine has never ran right, regardless how well tuned. I always blamed it on internal steam leaks in the valves. But I’m now wondering if has more to due with quartering problems due to the excess clearances.
The engine does have some time on it, about 30 hours. It has also been very well oiled..

The new C-19 has about 5 hours on her, and without taking anything apart, there is definitely excess clearance also. You can see it just by grabbing a hold of the rods and moving them without moving the drivers.

I don’t know what material Accucraft is using for their bushing, but it looks like just plain old brass. What ever they are using, it is obvious that it is not working out very well!

Maybe we need to start looking for someone with access to a small lathe, to turn out some replacement bushings out of Oil Lite Bronze. Even if they are installed on to bad crank pins, they would be better than what we have now.
But that would lead to the next problem. How does the average Joe replace them with nothing more than a $30 drill press, some dull drill bits and a sledge hammer!?!?

Doug Bronson
 

·
Premium Member
Joined
·
32 Posts
Doug I think you are correct about the Bushing Material, I to think its Soft Brass, and maybe the pins should have been hardened.

I am NOT BASHING Accurate, but if I am to pay $1800.00 dollars for one of these Locos which I am still very likely to do, I would like it to run more than Two Hours before it needs to be torn down and rebuilt. I also like to tinker and am not opposed to fixing the problem myself, and I do have the machinery to make the fix, it just concerns me that it needed to be done after what seems to be the first trip to the filling station.

All in all I don’t think you can find a better Loco for the money! I currently have a K-27 with NO Problems.
In any case their will probably be one of these in my Hands very soon, and I’ll just hope for the best, and I guess this is the Nature of the Beast.

Why was Steam replaced with Diesel?
Who cares, I like Steam!
 

·
Premium Member
Joined
·
118 Posts
Doug, getting rid of this slop will help with timing issues. If you add the slop from the main rod, and all connecting rod bushings between the actual pistons that are pushing them (and look to see which one has the eccentrics that are pushing the valves), It is quite a bit of slop. This amount of slop is relative to the accuracy in timing that you are able to achive. I use bronze when replacing bushings, and in the C-19s case, ball bearings. The siderod/ mainrod width on the 4-4-0 is only 7.9 to 8mm. So the bearings I found that worked on the c-19 would not work on the 4-4-0. The outside dimension on the Ball bearings that I found are 7mm with 4mm inside. Not enough meat on the siderods to ream the bushing holes out to accept 7mm bearings.
 

·
Premium Member
Joined
·
49 Posts
So it looks like we either need bigger side rods that will accept a BB, find smaller BB that would require the crank pins to be a smaller diameter to allow for a BB or just get better bushing material. Thoughts?

Looks like you have about a 6mm outer diam for the bushing with a 4mm inner for the crank pin.

Jon
 
1 - 20 of 76 Posts
Top