AML GP60 Prototypes

Prototype review:

I participated in some review of a first prototype. In my opinion there was not enough thinking on the robustness of the mechanical design and the electrical issues.

No offense to Accucraft, but this has been an issue with the brand forever, initially I was told the brand was "museum quality" in detail but not good runners.

In retrospect these issues have carried forward to the manufactured product.

 

Prototype issues:

Observations:

1. logo and stripes below the grill on long hood not level (surely will be corrected)

2. motor block looks virtual clone of USAT design, but no suspension.

3. axle bushings look silvery, not brass, can you determine metal? - final will be bronze

4. power pickup internal wipers (look like spring bronze wire), possible weak point, short circuits will remove temper from this and it will lose contact.

5. where is the insulator in the wheelset, it must be in the center worm gear.

6. The worm gear looks strange, like there is a brass plate embedded into the sides of it

7. the worm appears metal

8. further inspection appears that one half axle is splined to set gauge, other side is fixed to the gear

9. the closeup of the wheel makes be believe sintered, also there are mold marks at right angles to the lines you would have seen if CNC machined solid steel - production wheels will be blackened SS wheels,

10. but looking at the face of the wheel, it looks like machine marks, but those could be from the mold.

11. the internal use of rods to distribute power is another clone of the USAT design

12. note the adjustment of the wheel gauge appears to yield non-symmetrical spacing of wheel to gear 13. wheels scale to 38.7"

14. flange depth looks ok

 

Comments to Accucraft:

Mechanical:

need ball bearings, the internal bushings take all the loco weight in this design, not true with USATdesign, this loco is 11 pounds

Specifically, on USAT, the model supports the chassis through the axle tips in the sideframes, thus very little force on axle bearings in the motor blocks. This design supports the

need polyfuses to protect whisker power pickups on axles

 

The model:

 

The chassis is a long piece of metal down the center

 

Mechanics:

The motor blocks are very similar to USAT, but do not passs the weight through the axle tips.

 

Electronics:

There was nothing to see, and the result in the product is a mess.

 

Weather Underground PWS KCACARLS78