gregh
electronics, computers and scratchbuilding
This is my story of how I took two Hartland Mack locos like these…
….and finished up with this…
I have previously used Aristcraft motor blocks for my scratchbuilding. But with their unavailability, I decided to try using the Hartland Mack blocks.
These locos sell for 50USD in the States, so I got my daughter to bring me 3 when she visited.
I had already converted a Mack to simple battery for grandson Eddie, but without RC. But now that he's 6, he wanted full RC. I decided it would be a too much of a squeeze to get the batteries, RC and sound gear and a speaker into a standard Mack, so we decided he would get a 'double loco'. One of the 'locos' is just a dummy and carries the batteries only. The powered loco has the RC, motor control, sound and speaker. He requested the blue/green colour scheme.
The internet provided info on how to dismantle the locos. They very much click apart and you finish up with these parts..
The motor block top and bottom can be removed easily, so as I'm using battery power, I removed the pickups from the wheels and just brought the motor wires out.
(The motor block must be removed to get at the screws that hold the cab on, otherwise I probably could have done this with the motor in place.)
While I had the motor off, I painted the wheels flat black.
I retained the very chunky bogie side plates (if that's the term).
I did try changing the simulated coil springs to leaf type on on side, but decided it was too much work for little reward. So the other 3 sides retain the coil springs.
For the 2nd loco I built a 'wheel block' from wood and used plastic wheels. These wheels are smaller diameter than the Mack, but the beauty of the chunky side plates is that you can't see the wheels.
(That also gives me a spare motor block for future builds.)
The cabs were reused without change except for replacing the frosted glass with clear windows.
I made the 'hoods' from styrene and some louvre material I had on hand.
The rear compartments are also styrene. The 3” speaker is glued on the back wall behind a large section of louvres.
I used a Hobbyking 2.4 GHz receiver. I built my own motor speed controller using a Picaxe 08M2 to decode the Rx speed and direction outputs, and used a relay for reversing. Another picaxe provides the diesel sound into an LM380 amplifier.
I scattered as much lead around as I could fit in to bring the weight up to 1300g. (The original Mack weighs 1000g)
In the dummy loco, I used 8, AA size, 2500 mAh NiMH cells of the low self discharge type, from Hobbyking. These are soldered together, 3 cells under the front hood and 5 at the back to distribute the weight.
A 3 wire servo type plug/socket connects the 2 locos. (3rd wire is reverse headlight.). That brought it's (dead)weight up to 700g.
A quick paint and some yellow lining and it was done. It's not a model finished to a high degree, just something for Eddie to play with. I doubt if there is any prototype.
Here's a link to the video of it's first test run.
https://youtu.be/uhDgfSdkVdI
….and finished up with this…
I have previously used Aristcraft motor blocks for my scratchbuilding. But with their unavailability, I decided to try using the Hartland Mack blocks.
These locos sell for 50USD in the States, so I got my daughter to bring me 3 when she visited.
I had already converted a Mack to simple battery for grandson Eddie, but without RC. But now that he's 6, he wanted full RC. I decided it would be a too much of a squeeze to get the batteries, RC and sound gear and a speaker into a standard Mack, so we decided he would get a 'double loco'. One of the 'locos' is just a dummy and carries the batteries only. The powered loco has the RC, motor control, sound and speaker. He requested the blue/green colour scheme.
The internet provided info on how to dismantle the locos. They very much click apart and you finish up with these parts..
The motor block top and bottom can be removed easily, so as I'm using battery power, I removed the pickups from the wheels and just brought the motor wires out.
(The motor block must be removed to get at the screws that hold the cab on, otherwise I probably could have done this with the motor in place.)
While I had the motor off, I painted the wheels flat black.
I retained the very chunky bogie side plates (if that's the term).
I did try changing the simulated coil springs to leaf type on on side, but decided it was too much work for little reward. So the other 3 sides retain the coil springs.
For the 2nd loco I built a 'wheel block' from wood and used plastic wheels. These wheels are smaller diameter than the Mack, but the beauty of the chunky side plates is that you can't see the wheels.
(That also gives me a spare motor block for future builds.)
The cabs were reused without change except for replacing the frosted glass with clear windows.
I made the 'hoods' from styrene and some louvre material I had on hand.
The rear compartments are also styrene. The 3” speaker is glued on the back wall behind a large section of louvres.
I used a Hobbyking 2.4 GHz receiver. I built my own motor speed controller using a Picaxe 08M2 to decode the Rx speed and direction outputs, and used a relay for reversing. Another picaxe provides the diesel sound into an LM380 amplifier.
I scattered as much lead around as I could fit in to bring the weight up to 1300g. (The original Mack weighs 1000g)
In the dummy loco, I used 8, AA size, 2500 mAh NiMH cells of the low self discharge type, from Hobbyking. These are soldered together, 3 cells under the front hood and 5 at the back to distribute the weight.
A 3 wire servo type plug/socket connects the 2 locos. (3rd wire is reverse headlight.). That brought it's (dead)weight up to 700g.
A quick paint and some yellow lining and it was done. It's not a model finished to a high degree, just something for Eddie to play with. I doubt if there is any prototype.
Here's a link to the video of it's first test run.
https://youtu.be/uhDgfSdkVdI
