Casting or 3D print Ps4 truck master donation to combat zinc pest

Send me a picture

In one piece or with the sideframes off, or both?

Both the more info the better

Alan, did you get what you needed as an investigation start?

GRJ + How do I get with Harry Henning?

In the OGR Forum Scenery section, there's an interesting discussion right now about mold making and casting parts.  Casting the replacement sideframes might be a better solution for this problem than 3D design.

Dale

Casting does not require designing a 3D model for the truck as you can use an existing part to make the mold to replicate the truck.

So for complex shapes casting is a better approach.

I would like to see photos also for possible 3D printing.

above are pictures of my one good spare.

dimensions are approx 3.15 long by 0.700 high by 0.400 thick (not counting bronze bushing).

@NHVRYGray posted:

Alan, did you get what you needed as an investigation start?

GRJ + How do I get with Harry Henning?

I think we're in limbo right now.  The guy that was casting the GG1 sideframes hasn't done any for a year, and we're looking into 3D printing and a laser scanner.

A little fly in the ointment, you'll need some bearings pressed into the 3D prints for these.

Do you loose much detail when you use 3D laser scan?

Re Bearings:  If the original is crumbling you can reuse the bearings.  As far as 3D print, a method of picking up outside grail ground will also have to be devised, maybe phosphor bronze wire wipers.

Smooth On makes a silicone mold material that will withstand the heat of casting in pewter. I have not tried this so am not sure of the resolution of pewter but if I had to make these sideframes this how I would do it.

https://www.youtube.com/watch?v=D_BGMBmc7Pg

Good idea to reuse the bearings but new ones could be machined with oilite bronze.

I think a one part mold could work but the video shows how to make a two part mold.

Pete

Doesn't one have to compensate for material shrinkage by making an oversized master. And isn't the shrinkage casting material specific?  Earlier replies on the GG1 sideframe issue mentioned this.  How would resins be affected?

Jan

@NHVRYGray posted:

"I had two spare Ps4 tender trucks, now I have one.  One spare crumbled to pieces in the parts drawer. Now its trash (or maybe a scrap gon load)."

"Not only do the side frames need reproducing the bolster block does too,

I've go too many Ps4's to have then sidelined by zinc rot trucks.  And yes they are a hot part as I know I have had at least 3 go bad, not counting the bad one Lionel sent me as a parts order.

Any takers?  Who else needs trucks or just a spare or two."

Gray Lackey

On which Lionel production run is this occuring?

I really can't tell you as I have multiple Ps4's.  I do not have any Legacy engines though.

@Jan posted:

Doesn't one have to compensate for material shrinkage by making an oversized master. And isn't the shrinkage casting material specific?  Earlier replies on the GG1 sideframe issue mentioned this.  How would resins be affected?

Jan

Yes and yes.  There is shrinkage, and it is material specific.  Those were the lessons learned casting the GG1 sideframes.  The zinc ones looked great, but were about 1/4" too short, and obviously smaller in every other dimension.  The resin ones we ended up with held their size and worked very well.  But the specific material used for the casting has to be considered.

@NHVRYGray posted:

I really can't tell you as I have multiple Ps4's.  I do not have any Legacy engines though.

Which ones of yours have the Zinc Pest?

I have heard from Bob Turner who claims that CLW (Central locomotive works) has the “exact” tender truck side frame