Hello, Troops:
I've got an old Blue Box F7B dummy that needs some updated trucks. With some further body detailing, it's likely to be latched from time to time to some much nicer Genesis and upgraded Stewart/Kato F units. The current visual disparity in the truck details with the Blombergs on those newer locos is rather glaring.
The B unit will remain a dummy as all the others are powered and I'd like to throw my time and money elsewhere. Other than grabs, lift rings and whiskered Kadees it won't get anything else. No electricals to worry about so I won't need any pickups on the new trucks. It would be nice to be able to employ the existing pivots that are on the cast chassis but I'm prepared to remove them, then drill and tap replacement mounting holes as necessary. I'm looking for black plastic/delrin and metal wheels if something like that is avaiable. Got any suggestions?
Thanks!
John
The old Walthers diesel dress-up kit contained parts for one F7A and one F7B. The B parts were grabs and porthole windows.
It takes an iron man to play with a toy iron horse.
Do the trucks on that thing have existing plastic side frames, or are they the cast metal type?
If you do train shows you can probably find an unpowered or broken A unit pretty cheaply and remove the trucks and gearing for use in you B unit.
I'm not an expert on it, but my understanding is that the Athearn two-axle plastic locomotive trucks on their F-units and GPs have always been considered very good reproductions of EMD Blomberg trucks. Many folks change the wheelsets out, but the truck sideframes should be good. You might need to ream out the opening for the axles a touch to make them roll better.
I just looked at mine. Mine are plastic, but it's a one piece casting, and I think the older metal trucks were the same.
The OP will have to find the truck of his liking, and figure out how he can mount it to the frame.
The frame will accept the powered trucks, you could take the gears out of a power truck, to eliminate some drag, and install that, the same way a powered unit goes together, then you'd have the option of removing just the side frames, and replace them with what you want, or a more detailed version of what's there.
Mike.
My You Tube
The existing trucks for this Athearn BB are the old cast (white?) metal jobs. In two halves, screwed together with a couple of round head 2-56s at the bolster pivot point. Detail reflects that kind of casting, with a fair amount of flash in or totally covering some of the openings. Wheels are plastic with metal axles.
I'll get a picture up - after I get back from a trip to the dump. Too many mundane things interrupting the hobby!
I would say the trucks only need replacing if the side frames are the old metal ones. Replace with the plastic side frame version - those plastic Blomberg-B's were some of the best ever done.
Rio Grande. The Action Road - Focus 1977-1983
AttuvianThe existing trucks for this Athearn BB are the old cast (white?) metal jobs. In two halves, screwed together with a couple of round head 2-56s at the bolster pivot point. Detail reflects that kind of casting, with a fair amount of flash in or totally covering some of the openings. Wheels are plastic with metal axles.
OK, well, you won't find plastic trucks that are contructed the same way, with 2 pieces bolted together.
As I mentioned, the later plastic version is all one piece, but I'm sure the detailing is much better.
mbinsewi Attuvian The existing trucks for this Athearn BB are the old cast (white?) metal jobs. In two halves, screwed together with a couple of round head 2-56s at the bolster pivot point. Detail reflects that kind of casting, with a fair amount of flash in or totally covering some of the openings. Wheels are plastic with metal axles. OK, well, you won't find plastic trucks that are contructed the same way, with 2 pieces bolted together. As I mentioned, the later plastic version is all one piece, but I'm sure the detailing is much better. Mike.
Attuvian; You mention you would be willing to alter the mounting bolster on the F-7 frame if needed. If so, Kato's Blombergs are good looking trucks with separately applied swing hanger and brake cylinders. They mount differently than Athearn. They don't mount at the center of the truck, but are offset a bit. At worst you might need to make new bolsters from brass strip and attach to the frame. Under that wide body that would be hidden with no interference.
The reason I offer this suggestion, if you're willing to go to the effort, is that I can send you a pair of them that have had their gears removed for other projects. They'll be fine for dummy use and do have metal wheels. PM me your address if interested.
You can see what they look like if you go on ebay and look for Kato Blomberg trucks HO.
Dan
LION uses the -unit trucks on the B-units of him. Remove the gears and they work better than the provided B-Unit trucks.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Southgate Attuvian; You mention you would be willing to alter the mounting bolster on the F-7 frame if needed. If so, Kato's Blombergs are good looking trucks with separately applied swing hanger and brake cylinders. They mount differently than Athearn. They don't mount at the center of the truck, but are offset a bit. At worst you might need to make new bolsters from brass strip and attach to the frame. Under that wide body that would be hidden with no interference. The reason I offer this suggestion, if you're willing to go to the effort, is that I can send you a pair of them that have had their gears removed for other projects. They'll be fine for dummy use and do have metal wheels. PM me your address if interested. Dan
John, I'd be interested in knowing how much of a difference there is between the Kato and the Athearn trucks, as far as the location of the pin from the frame to the truck, and what modifications you did to the frame.
Thanks,
riogrande5761 I would say the trucks only need replacing if the side frames are the old metal ones. Replace with the plastic side frame version - those plastic Blomberg-B's were some of the best ever done.
Jim,While correct on the metal side frames the can be replace with the newer trucks..Athearn still list those Blomberg-B's trucks with the modern frames.
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
mbinsewi John, I'd be interested in knowing how much of a difference there is between the Kato and the Athearn trucks, as far as the location of the pin from the frame to the truck, and what modifications you did to the frame. Thanks, Mike.
Mike, here's a side by side comparison of a later BB Athearn truck on the right, with the Kato on the left. The trucks on John's old locomotive are different from this Athearn truck, so it's not a direct comparison to his.
Note that the Kato truck's pivot is off center, I'd say about 3/16 of an inch. It has a nub that would snap into a hole on the frame, held in place by those protrusions on the worm gear cover. The bolster height is close to the same.
John found he had some Athearn BB Blombergs with plastic sideframes, and is going to try to use them, as per our last PM contact. Maybe he'll post progress here? Dan
Southgate The trucks on John's old locomotive are different from this Athearn truck, so it's not a direct comparison to his.
Thanks Dan.
I have the plastic version of what John has, and I was going to offer him a set of those, but there still a one piece casting, only in plastic and not the old metal.
Using the trucks that he is, would be the best way to go. He could add metal wheels to that if he wanted to.
The Kato truck pictured is from a Con Cor / Kato MP15. The Stewart / F unit trucks are a perfect fit for the Athearn F frame. I would use a pair of those.
Chuck - Modeling in HO scale and anything narrow gauge
OK, guys, thanks for keeping this thread alive. Southgate notes that I launched the little project yesterday, I remembered that I had an old Athearn GP9 in storage that was a functional dummy as the motor had been removed. Its power trucks have plastic Blombergs. I hauled it out and first checked to see if the two chassis were the same length and I could adapt the Geep's to take the B unit shell. That would have been simpler but no dice, it was too long. Sorry for this "teaser": I'll be out of circulation on the forum for at least the next six hours. I'll get back later today with the story (and photos) of how this developed.
John.
I would think that you could take the truck from the GP and use it in the Fb.
mbinsewi I would think that you could take the truck from the GP and use it in the Fb. Mike.
I've got a set of the plastic trucks, from a "dummy" (I hate using that word) F7. They are one piece, and they clip over the same bar on the frame that the power trucks fit on to.
It's just that they are one piece, hanger and cylinders are molded on.
If you can use them, I'll send them to you.
I'll get a picture up.
EDIT: Pictures:
I have this, which is a one piece plastic casting,
OR, I found these while getting the first one out, these will fit right on your b unit, they have seperately applied hanger and cylinders, you can also add metal wheels to these, if you want.
You'll need the axles and the little brass bearing blocks for using metal wheels.
I have an FA & FB sitting on my bench, and these match.
Let me know if your interested. No charge, I have plenty more.
mbinsewi I've got a set of the plastic trucks, from a "dummy" (I hate using that word) F7. They are one piece, and they clip over the same bar on the frame that the power trucks fit on to. It's just that they are one piece, hanger and cylinders are molded on. If you can use them, I'll send them to you. I'll get a picture up. Mike. EDIT: Pictures: I have this, which is a one piece plastic casting, OR, I found these while getting the first one out, these will fit right on your b unit, they have seperately applied hanger and cylinders, you can also add metal wheels to these, if you want. You'll need the axles and the little brass bearing blocks for using metal wheels. I have an FA & FB sitting on my bench, and these match. Let me know if your interested. No charge, I have plenty more. Mike.
Mike,
Very gracious of you but I shall pass. I have two pair of the ones in your second picture. One pair from my excess motor- and gear-less Geep (note how I avoided use of the "D" word?), and a pair from the one that I bought yesterday out of the junk pile at one of my LHSs - before I remembered my own. It is this kind that I'll be using. And I won't have to wait for anything in the mail!
I've remeasured everything and I will avoid the dropstep/cylinder issue by moving the king posts 2mm toward the chassis ends. That will fix the major swing restriction and enable me to match up the wheelbase with the Stewart/Kato B unit. In the process I will also be able to take out the last excess milimeter that currently causes the unit to ride that much higher than my other Fs.
Off to Home Depot to pick up a piece of aluminum bar stock to adjust the king posts.
BTW, in you box of old goodies do you have any porthole inserts for old Athearn BB F7Bs?
I guess I'm not getting the swing issue. OK, well good luck, and nope, no window inserts. Some place around here I have a couple sets of the Walthers Diesel dress up kits. I think they came with the inserts. You can still get those kits.
mbinsewi I guess I'm not getting the swing issue. Mike.
I guess I'm not getting the swing issue.
Sent you a PM John.
Thanks, Mike. Replied.
Friends,
The first issue was creating new mounts to this old chassis frame. The old king posts were rather fat castings that retained the old trucks by means of short rubber sleeves. The diameter of the post was far larger than the hole in the proposed Athearn truck bolster as seen below:
Away with the old posts, and replace them with 4-40 machine screws (which required that I bore out the bolster holes a tad):
Arrggh – this is where my mind can hear guys start shouting: “Dude, just buy a newer B dummy somewhere and be done with it!” Sorry, guys, now I’ve been bit by the fix-it bug. And we know there’s only one cure for that – DIY. Not only do I need to elevate the base of the new king post screw to accommodate the higher truck, I need to move the pivot point toward the end of the frame by 4 mm. How to do this? Hmm, look at that channel along the length of the upper portion of the old frame. Why, it measures almost exactly an inch wide. I’ll bet Home Depot has a thin stick of 1” aluminum bar stock that can be used. And they do, it’s 1 x 1/8 x 36. I lop off two 1 3/8” lengths, center a point 3 mm in from the end edge of each and drill and tap for that 4-40 screw that serves as the new king post. Now I can position these two plates so that the new post screws are 107 mm apart, rather than the 99 mm between the original posts. [Note: yeah, I’ve mixed metric and English systems here. Just think of me as being momentarily beset by inclusiveness.] Let’s see, gotta add a 4-40 nut to act as a new post shoulder (better than washers, which will fall off in any assembly/disassembly process). And also file away the old post locations from the chassis frame to allow for swing of the lower shoulder of the Athearn gear housings:
Can’t have the trucks falling away every time I pick it up. And it’s too much of a hassle securing the trucks to their posts from underneath by means of a nut. Well, let’s at least remove the fingers, which are now both an impediment and useless. Maybe something else will present itself:
Well now, look at this! There’s a little slot or gap underneath the top of the gear tower retainer clip:
Hey, I think I have a bar of brass stock may fit in there from which I can make a retainer bar. It will extend over the king post screw head to do the job of those discarded “fingers”. Yup, here it is, a length of scrap that is 1/4 x 1/64 - and it fits exactly! Lop off a couple of 1 1/16 inch lengths and also a couple of quarter inchers, the latter to serve as pads filling the gap above the tops of the screw heads.
CA the pads on one end of the retainer bars (to keep them from sliding back into the tower clip during operations), then drill and tap for a 2-56 screw on the other end (to keep it from slipping the other direction). Pop the trucks onto their posts and install the retainer bars in the gear tower clips.
Much better looking than those old trucks, I’d venture:
For final touches, add some grabs and glazing, paint the fuel tanks, attach the shell to the chassis, and you’re good to go.
In support of truth in advertising, I must mention that the coupler height for my project needed adjustment. I think that would have been necessary regardless of all the modifications to other parts of the chassis. Not a big deal as I will nab and install a pair of Kadees with underset shanks.
Sorry for the extended presentation, folks, but I don’t have a blog on which to post it. You may not have an identical issue calling out from your workbench, but perhaps there are a takeaway or two that you can employ elsewhere. It was a good exercise of the noggin and some basic skills. And I didn’t have to send off for anything, new or old. I hate paying postage and then waiting – and waiting....
Please advise with any suggestions for improvement – and thanks for exercising your attention span.
Lookin' good, John. I'd suggest after all that work, paint the trucks a flat gray to bring out the detail, as it gets lost in the dark black plastic. Maybe a little weathering too.
(I meant to send this days ago, didn't click submit) Dan