Mods to drawbar for swap? B-Man Connie + MP Vandy

[SandyEggoJake]

OK.  So I finally scored a small horde of N Scale MP Vandy's for swaps to a B-mann Spectrum connie fleet. 

To those of you who have made this swap, what DRAWBAR / TENDER mods did you make and are you happy with the running performance of such? 

My current plan is to retain the B-man bar as I like the ease of attachment to the loco.   Eventually I'll be swapping to the B-man trucks for lower friction, all wheel pickup, and up hard wiring each to the tender body instead of using the bronze rub tabs).

As those with experience in this swap recall, the stock MP drawbar attaches by slipping a loop over a pin inside the tender chassis, coming up from the floor.  But the B-man drawbar is attached under its tender chassis, riding above its truck on a collar, both held in place via the bolster screw. 

I've dry fitted the B-man bar to the underside of the MPVT (the "B-man way", in this case using either truck and the MP bolster screw w/o MP axel wipers) and that method seems to reach ... barely ... yet unacceptably deforms the bar down and would seem to require generous scrapping to the bar, tender front and underside to give needed clearance.   But still might not yield ideal close coupling and have less than ideal turning friction and slop on the truck screw.

Attaching the B-man bar in the "MP way" (to the pin coming up from the MP tender chassis floor inside) seems to work much better.  But there is even more slop on the pin and not close coupling at all.  Also the bar seems bent down, but here it is from the tension on the B-mann bar connector spring wires pressing against the inside slopped walls of the MP tender cylinder sides and riding up them. 

To correct this, I'm thinking I could move the tender's pin back (about 2 mm?) to improve coupling.  And to remove the slop, I could either make the new pin of a larger diameter of the drawbar hole, or use an off-center collar that fit over the pin and yet inside the drawbar hole.  This latter method would seem to also yield an method to adjust coupling later - just change the collar or even turn it 180 degrees. 

To reduce the bar deforation, I could bend the spring wires together so they have less tension and thus do not ride up the sides forcing the front of the bar down.  But I wouldn't over do it as these springs act to keep the bar centered on tender's pin.  So I'm thinking I could fashion a "keeper" out of styrene or 3DP that fits over both the tender's pin and bar's connector springs inside the tender and using tension fit only with the top of this box, holds the springs down and horizontal, thus keeping the bar flat.   

Eventually, my plan is to also install some other operating components as well as DCC & sound in each (looking at the LokSound Micro and speaker installed in the tender,  but holding off to see what MP is putting in their forth coming release of the Mike+vandy).

Suggests most welcome!  Eventually, I'll do a write up and give the credit where do.

[victor miranda]

I am a bit worn out just reading all that.

MP vandy tender...  I assume you won the lot on e-bay.
good price as I recall

that tender is fairly hard to get all wheel pick-up installed.

the rest is fairly simple
hard wire the two together after you make a drawbar

I think you may want to glue up a few layers of styrene on the tender side if you want
a level drawbar

I'd consider if I can get the drawbar attached to the front truck bolster.

not an easy set of tasks in front of you.

victor

[SandyEggoJake]

Ha!  Thanks Victor. 

I did.  But also picked up a few others at the NSE convention, for a total of 10.   A few more than my current need, for sure.  But when I called MRC a while back they didn't know if they would have any vandy tender parts with the upcoming release or if the tender only sku would be ever be offered again. 

My plan to create all wheel pickup is to use the B-mann tender trucks as I've seen others do.  I'll either PE new axle point contact strips or bend the bronze tabs of the existing ones down 90 degrees towards their bolster pin and solder wire on each to make the connection via new pass holes in the bottom of the MP tender floor.  Holes that I hope will double as sound vents.   (It will be interesting to see how MRC adds sound and all wheel pickup to their new release of the vandy, as has been reported).   

I've not considered making a new drawbar from scratch - mostly as this swap yields two stock bars that can be modified already.

Have you made a decent runner of this MP vandy tender that has a drawbar attached to the tender's front truck bolster instead of its stock tender side drawbar pin?   

[RRRover]

I used sheet brass strip and made a new drawbar by bending and drilling to make it work. Used Bachmann trucks and super flex wire soldered to the truck axle-end pickups (the little tab that sticks up and makes contact with the onboard contact plates on a Bachmann tender). A simple drilled oblong hole on each side above the contacts suffices for routing the wires into the tender. You'll need to set up a small terminal strip to tie everything together with the pickup wires from the loco, and then route the wires to your decoder within the tender. You'll end up with six wires between the loco and tender - 2 for motor, 2 for track pickups, 2 for headlight (if you use a magnet-wired SMD LED headlight those will be your smallest diameter wires). I'd like to wire up the marker lamps, but...

[victor miranda]

for an article I had planned.
ETA this is about three years old...

there are some aspects I'd do differently now

it is one way to get this job done

this is a MP vandy tender and the trucks that came with it
I used .008 ph-bnz and Kato caboose wheelsets

the weights were custom made by me

I recall spending a lot of time shaving thickness off the strips in the tender
to allow it to settle onto the tender trucks.
I wanted all the tender weight on the pick-up strips


look at the photos most if the information you need is there

[SandyEggoJake]

Thanks again.  Victor, might you have pics of the front and/or truckless bottom of the tender showing the drawbar end?  The last two pics both show only the trailing end, with a removed coupler box.  And by the first pic, from what I can make out, it seems in this case you used the stock MP drawbar lashed to a what looks like an MP Light Mike?  So perhaps in this instance, did you make significant drawbar mods?

On your solution for all wheel pickup in the MP vandy, as you say, that does seem to be a "fairly hard" way to do it.  But more at issue is I suspect the size of the internal structures may preclude many of the tender located DCC+ sound options I'm considering.  Last night I did the all wheel pickup using a B-mann truck swap method I described - quite similar to that suggested by RRRover.  It's now a notably much freer runner and in a brief tour of the test track ran flawlessly when lashed to the stock MP Mike using the stock drawbar. 

So my focus now remains on options for a drawbar mods to enable the lash to the B-mann connie.

[victor miranda]

yer welcome.

[SandyEggoJake]

I got a PM with yet another option on this lash.

To summarize:

 option 1:  mod  tender end of B-mann bar and mod MP tender bolster screw collar plus scrap tender for clearance (lash similar to stock B-mann way)
 option 2:  mod tender end of B-mann bar and mod MP tender drawbar pin (tender end of lash similar to stock MP way)
 option 3:  use mod bar made of loco end of the B-mann bar affixed to the tender end of the MP bar (both ends lashed in their stock configurations)
 option 4:  mod tender end of B-mann bar by affixing to leading truck
 option 5: scratch build new bar, and lash via option 1, 2 or 4.

decisions, decisions....