# K28 suspension mods



## llynrice (Jan 2, 2008)

When I first received my K28, I discovered that the main axel journal blocks had essentially no travel. The suspension was, effectively, solid. Rick Richardson of the New Jersey Live Steamers told me that the stop bars which retain the bronze journal blocks from sliding out of their slots in the frames are the culprits. The first photo shows a stop bar in place below the bronze journal block. 








The stop bar is stamped from brass sheet stock and there is a tab bent over along the top edge as shown in the photo below. It is this tab which limits how far the journals can slide down and having the tab on top permits essentially no travel. So, the obvious first step is to turn the stop bars upside down so that the tabs are on the bottom. In order for the journals to be able to slide down behind the stop bars, the stop bars have to be spaced out from the frame. The srews which hold the stop bars are M2.0 x 4mm long metric flat head. At the hardware store, I found some 2mm washers and some M2.0 x 6mm long screws. I put two washers between the stop bar ends and the frame and used the longer screws. That allowed the journals to just slide behind the stop bars except for one journal where I had to use three washers at each end. This gave the suspension plenty of travel. 








I noted that the loco stood about 3/32" higher (no big deal) and that there was a bit of space between the stop tab and the bottom of the bronze journal even when the springs were fully extended. So, I decided to add shims to the stop tabs in order to permit full travel while taking out any slack. I soldered bits of 3/32" dia. wire in place as shown in the photo below. This left ample travel and the loco is now more flexible. 








One disclaimer: I live in Vermont where deep winter snow prevents winter running and I bought my loco in the middle of winter and did not have an opportunity to run it as delivered. So, I cannot say how bad the rigid suspension may have been. It just did not make sense to me to leave a sprung suspension locked up nearly solid. 
I have run the loco on my home layout which is mostly thawed out from the winter. My K28 did manage to point out three bad spots in the track which were easily fixed. Once those bad spots were corrected, the loco ran just fine even though most of the track still needs to be inspected and adjusted before the major summer running season. 
The loco is heavy and the springs are fairly stiff. In time, I might consider softening the suspension a bit (take out one of three srpings over each journal block). 
Llyn


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## weaverc (Jan 2, 2008)

Llyn, 
Thanks for the excellent photos and a very clear explanation.


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## Skip (Jan 2, 2008)

As we discussed previously, the Mogul suffers from exactly the same problem. Now to find some 2x4 metric bolts and washers. Them's pretty rare hereabouts...


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## Shay Gear Head (Jan 3, 2008)

How many miles did you drive to get the metric standard bolts needed? I thought that metric was the standard in Canada! Woops - here goes another can of worms again. Glad the US has had a metric standard for over ??? years, too.


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## rbednarik (Jan 2, 2008)

Guys, 
For metric fasteners, http://www.microfasteners.com/ has a pretty wide selection of stuff. I use their SS parts religiously when doing kits and re-builds, so far, no complaints. You get the odd slug or two, but for the price it is hard to beat.


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## Larry Green (Jan 2, 2008)

Bruce, the local hardware stores here have those racks of cardboard trays with a little bit of everything, including a very good assortment of metric fasteners, even stainless. I learned about the good selection of metric stuff when I needed some cap screws for a project on my Honda. 
For buying in quantity, I use McMaster-Carr or other known suppliers, but when only a few pieces are needed, it's off to the local hardware store. 

Larry


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## llynrice (Jan 2, 2008)

I tried my K28 on Larry Green's bench layout which had settled some over the winter. That variability plus the fact that track trays tended to flex a bit under the loco's weight caused it to derail several times. When I looked my loco over after the first try on his layout, I realized that, while I had increased the suspension travel, it was still very stiff and that I had to push down on the loco quite firmly to get the suspension to move. There are three coil springs at the top of each bronze jouranal block; so, I popped out the center spring (easy to do) in all eight locations. Today I ran the train on Larry's layout again and it tracked perfectly for an hour without any side trips onto the ties. Giving the suspension more travel AND reducing the stiffness seems to have been the majic combination for this loco. Looks as if I can stop tinkering with the suspension now and enjoy running. 

Llyn


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## steam8hack (Feb 11, 2008)

llyn: 
Understand some have found the springs are not the same throughout as the weight is not evenly distributed so might need more/less springs or turns per spring, per wheel to compensate, depending. K-27 needs some compensation was mentioned in an old thread.


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## rrdude (Feb 21, 2008)

After searching all over town, someone suggested I try an ACE store up the road a bit. They had a great selection of metric and American nuts, bolts & washers. (Remember you'll need 16 bolts. First time in I only got 8. . .) 

I just got my K-28 the other day. I have already removed the center spring on each journal, turned the caps upside down (per above) and softened the springs on the pony and trailing trucks. Now to get out and do a few mods to the track. That's a BIG engine! I have a section of track in a cut (A concrete mountain) that is too narrow for the K, I guess I'll have my men go out and blast it a bit wider. (If only it was going to be that easy. . .)


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## chuck n (Jan 2, 2008)

I had the same problem with my electric K-28. It took over two years to get it it go around my track once without derailing. I kept thinking that it was my track until I mentioned it to someone who said that it was the suspension. I did the opposite of what you did. I left the center spring and removed the two outside springs. This solved the problem. It now runs without any problems. I didn't need to adjust the slide stops. 

Chuck N


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## jfrank (Jan 2, 2008)

I have never done anything to mine and it tracks perfectly. In fact better than any of my other locomotives. Maybe you guys need to check your track first. hehe. But thanks for the ideas. The suspension is pretty stiff.


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## llynrice (Jan 2, 2008)

Hi John, 
Glad to hear that your K28 has always tracked well. It appears that, even though they are very fine models, they can be somewhat variable and you got a good one. I've lived with mine long enough and have used it on enough different tracks that I am confident that the suspension modification was necessary.

Though this has nothing to do with the K28 suspension, there is one class of track defect which derails my K28. The defective aspect of track work which I have found to be crucial is the joints -- especially in code 332 track. Even though I use split jaw clamps which secure the joints very solidly, the rail ends seem to vary a bit and the railhead and inside face transitions from one rail length to the next are not always smooth. When my K28 spots a small joint mis-match, the pony truck wheel climbs right up and out and the loco ends up on the ties. Now, when I make a new joint or take apart and reassemble one, I use a mill smooth (as opposed to mill *******) file to blend the rail heads and inside faces across the joints. With the joints thus dressed, my K28 runs perfectly. I should also point out that I'm a sparkie as well and have run many locos (both my own and other modelers) on my layout without climbing over and derailing on the joints. It seems to be a fussiness reserved to my K28.

Larry Green's layout is made up of Llagas Creek code 250 aluminum rail and I've had very little problem with picking joints on his layout. I'm guessing that the more popular code 332 brass rails must be more variable.

Llyn


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## jfrank (Jan 2, 2008)

Hi Llyn. Obviously I was just adding a little humor. I really appreciate these little helpful bits that people post on here. That is what makes this site so useful. I use the Llagas creek track screwed down to Mainline Enterprises PVC roadbed. But even that requires maintenance to keep it level and kink free. Your comment about the lead pony truck is common for all Accucraft engines. My all time worst one is the C21 followed closely by the C19. I worked on the C21 for a long time before I could get it to track correctly and I still don't really trust it. Oddly, the K28 worked ok from the start. What I have found works best for most of these Accucraft engines is to cut off the spring on the lead truck to make it softer and then add lead weights to the truck frame. Also, the lead truck often does not drop down far enough and you have to shim the screw that holds it to get more up and down play. On the K27 I also had to cut the trailing truck spring. Most of the springs they use are just too stiff.


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## weaverc (Jan 2, 2008)

John,
On my C-21 leading truck and my K-27 trailing truck, I found that the wheels were too far out of gauge and riding up on switch frogs and bad track joints. After gauging them properly, I had no more off track incidents.


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## llynrice (Jan 2, 2008)

About the time I finished writing my previous posting, it occured to me that I should check the gauge. This I will do in the next few days. 

As a follow-up about weighting the pony truck, I have a coil of roofers' lead flashing. I cut a strip of this and rolled it around the axel. It proved to be a quick and simple solution. 
I really love my K28 and run it a lot. And it's a first rate track tester. If it doesn't derail, the track is in really good shape. Happily, it runs on my layout and Larry Green's layout with very few mishaps.


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## jfrank (Jan 2, 2008)

Carl, the first thing I check on anything new from any manufacturer is the wheel gauge. I had one accucraft engine with front wheel gauge problems, the C19. The only Accucraft rolling stock I had any problems with were the San Juan cars. However, Bachman stuff is always out of gauge. So is Aristocraft, but I don't have any of it thank goodness. And, just for the record, I have had to fix some of my friends Asters that were out of gauge(just the lead trucks).


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