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Anyone have experience with doing a can motor upgrade on the Max Gray K5? Is there a particular Pittman motor I should be looking for? Were the ever any CV shafts that fit or is it a custom deal? This is my first project of this type so I'm trying to learn from the experts in this area before diving in.

Thanks

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The 94xx and the 92xx is the same motor except for the location of the wires.  The 9 indicates the diameter and the 3rd position x indicates the magnet and the fourth position x indicates the length of the motor.

A 9x33 or a 9x34 would be the appropriate motor.  The 9x33 is more than sufficient for a pacific.  Sometimes the 9x34 is too long to fit.

Ed

A 9433 will fit. I did a Max Gray K5 many moons ago for one of my dad’s clients…..a fella in Midolothian Va,…….the slightly shorter 9433 will give you the wiggle room as the bottom of the firebox detail gets a little tight,…..in fact, mark your chassis with a sharpie right where the firebox detail ends, and you’ll know where the “ do not cross” line is….the gear box in that model has a 4mm worm shaft, so same as the Pittman. RC car driveshafts are available in multiple lengths, and end bores, ….4mm end bores is an option. Pictured below: KTM Westside J3a with RC car CV type shaft. You can find me via profile for a link…

Pat IMG_7704

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@harmonyards posted:

A 9433 will fit. I did a Max Gray K5 many moons ago for one of my dad’s clients…..a fella in Midolothian Va,…….the slightly shorter 9433 will give you the wiggle room as the bottom of the firebox detail gets a little tight,…..in fact, mark your chassis with a sharpie right where the firebox detail ends, and you’ll know where the “ do not cross” line is….the gear box in that model has a 4mm worm shaft, so same as the Pittman. RC car driveshafts are available in multiple lengths, and end bores, ….4mm end bores is an option. Pictured below: KTM Westside J3a with RC car CV type shaft. You can find me via profile for a link…

Pat IMG_7704

Thank you, Pat. That is very helpful. Exactly what I was looking for.

The nice thing about Max Gray and USH steam engines is they were built like tanks.

The MG engines did not have the nice lost wax castings that later USH and Westside did, but you can add them. As far as the drive goes , the early MG axles were 1/4 or .250 in. The later USH were metric, so if you want to change the gearbox to a USH box you also need a metric bearings and axles. The hardest part is quartering. I hope this helps, I don't claim to be an expert , but I just wanted share this.

The nice thing about Max Gray and USH steam engines is they were built like tanks.

The MG engines did not have the nice lost wax castings that later USH and Westside did, but you can add them. As far as the drive goes , the early MG axles were 1/4 or .250 in. The later USH were metric, so if you want to change the gearbox to a USH box you also need a metric bearings and axles. The hardest part is quartering. I hope this helps, I don't claim to be an expert , but I just wanted share this.

The early MG axles will take the KTM gear box, the bearings & gear can be bored to accept the 1/4” axle,….however, it was always hard to find separate sale KTM gearboxes except on the secondary market,….in the case of the K5, I do remember swapping out the gear box on the example I worked on, ….more than likely I used a NWSL, as at the time, they were plenty available….now not so much….

Pat

@harmonyards posted:

The early MG axles will take the KTM gear box, the bearings & gear can be bored to accept the 1/4” axle,….however, it was always hard to find separate sale KTM gearboxes except on the secondary market,….in the case of the K5, I do remember swapping out the gear box on the example I worked on, ….more than likely I used a NWSL, as at the time, they were plenty available….now not so much….

Pat

So this is not filling me with an abundance of confidence... Hope I didn't bite off more than I can chew.

I recently acquired a nice US Hobbies Santa Fe 4-8-4 (numbered 3780) which has been upgraded with a can motor, LED headlight, wireless drawbar, and NWSL wheel sets for the pilot, trailing truck, and tender trucks. I had to fabricate new handrails leading from the boiler walkway down to front deck and paint them, because the old ones had been lost somehow. The engine runs very smoothly with its can motor and original USH gearbox with new grease and lubrication all around.

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