llynrice
1st Class Member
Cornwall, Vermont
Foreman
Posts:182
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 | | 04/22/2008 1:47 PM |
| 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 | |
Llyn Rice
Cornwall, Vermont
Vermont Scenic Railway | |
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weaverc
1st Class Member
Lexington Virginia
Foreman
Posts:326
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| | 04/22/2008 2:03 PM |
| Llyn,
Thanks for the excellent photos and a very clear explanation. | |
Carl Weaver
SA#138
Big Bear Steam Railway
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Skip
Ontario, Canada
Foreman
Posts:172
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| | 04/22/2008 2:39 PM |
| | 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... | |
Paul
Greensville-Crook's Hollow Railway Company
building the finest mongrel short line in S. Ont.
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Shay Gear Head
Easley, South Carolina
Foreman
Posts:104
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| | 04/22/2008 2:42 PM |
| | 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. | |
Bruce Gathman, President
Eldorado Timber & Mining Company
Tall Trees - Deep Shafts
Recreating the past with live steam Shay locomotives and lots of log cars. | |
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rbednarik
1st Class Member
Mt. Holly, NJ
Foreman
Posts:248
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| | 04/22/2008 4:30 PM |
| 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. | |
-ryan
SA #1361 | |
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Larry Green
1st Class Member
Vermont
Foreman
Posts:136
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| | 04/22/2008 4:38 PM |
| 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
1st Class Member
Cornwall, Vermont
Foreman
Posts:182
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| | 04/25/2008 6:26 PM |
| 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 | |
Llyn Rice
Cornwall, Vermont
Vermont Scenic Railway | |
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steam8hack
Brakeman
Posts:48
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| | 04/25/2008 10:01 PM |
| 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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