The Wonder engine

[cabbage]

Last year I bought a printed kit from ALD models. It is a great model of the "Janus" double engined industrial locomotive. So emboldened by the kit I sat down and unearthed my PDH book on experimental locos. In here are the lists of parts and dimensions of things that I would have to get or make. Some of the suppliers no longer exist but that is life!

The loco that I chose to print is "the other" LMS diesel electric, the LMS 10,800. This became the fore runner for classes 15 and 16. By the end of this week I hope that two bodyshells will be completed. Tje SCAD files are in the G3WIKI. The side panels may be mixed and matched to produce any sort of diesel loco -thus giving truth to the Italian "train spotters" jibe of "wardrobes on wheels"!












check my display resolution

[cabbage]

Only the cab rooves of the two printed locos need to be done and construction will commence today. To print the two locos bodies I used less than a reel of PLA so without weighing the £12 reel I can say that each body print was less than £6 each. NOTE: the prints are cheap - the printer was not!

One of the locos will be for me and the other for my "Apprentice". Both will be in BR Diesel Green - but mine will look more "steam era" with oil lamps (white metal) which are *genuine* Basset Lowke parts!!! (I love Ebay).

I have decided to give it a  "MylocoSound" card and will use it with an isobaric speaker arrangement. Since the card powers 8ohm - this means two 16ohm speakers in parallel.  In the Red 5 I used them in a magnet to magnet configuration in the tender. Here I think(!) There is room for a magnet in cone configuration as in the classic Linn DMS/PMS or Sara speakers. Since the correct engine  sound is not on the card, I was told to choose the large Sulzer and increase the tickover speed.

As yet the motor choice is unknown... There is a nice geared motor that I used for the ALD Janus - but mounting is a little awkward...

Anyway today it is out with the UHU and the CA.

Regards

Ralph

[cabbage]

The afternoons work.

The body is glued together and the frame "getting there".

[cabbage]

The cab roof has been programmed and is now printing. This will take about six hours and there have to be two of them... I did debate on wether to design and programme the bogie sides, vacuum brake and battery boxes but instead I ordered them from Kippo. (Yes I know I am lazy).

After discussion on Sunday afternoon we decided that we would both use a 4.5Ah 12V SLA. This will sit between the bogies giving a good centre of mass. The 50mm dia wheel blanks have yet to be ordered, but that os not really a problem. As is my wont I have one motor per axle this will mean designing a motor clamp to be printed. I am planning on using the SME motor that is small and rugged. This will be fitted with a 12tmod1 spur to a 45tmod1 bull gear. Power fr the battery will be around 120Watts - so the Viper10 or Viper15 ESC would be a good fit, there will be a heat sink bonded to the back and a 40mm fan blowing through the roof. The R/C is going to be deltang rx102 (while they are still available!)

The steel angle for the framework/chassis is going to be 16mm sq x 3mm black rolled. It is cheap, drills and taps easily, and brazes neatly.

I am going to look through the sprues of "dress up" parts to get the rivits, nut ends etc that inhabit the bottom of the " will be useful someday " draw!!!

Regards

Ralph

[cabbage]

The "someday draw" had in it a pair of 16ohm speakers that I plan to use to provide the sound of the loco through. I am a fan of the "orange" brand of guitar amplifiers and even before they supplied isobaric speakers I was deeply in love with the Linn Isobarik DMS...

Hence an isobaric speaker system for the loco. These are 50x75mm ellipticals and will be mounted in a magnet in cone manner. The three methods are magnet in cone, cone to cone and magnet to magnet. However the most importand thing is that the isobaric chamber, (the sealed volume between the speakers), be as small as possible
This makes the coupling between the two speakers as rigid as possible.





What are the advantages of an isobaric system other than to increase the income of the vendor(!) Well they can produce a deeper note than would be normally possible with that speaker and they are "faster" sounding.

Now back to Openscad to write the chamber program.

Regards

Ralph

[cabbage]

Things are now being trial fitted to the bodywork... As we all know, that despite careful planning and measurement that Part A will never fit into Part B - no matter how you try!!!

The shot shows the SLA battery and lower of the two isobaric speakers and the speed controller. The sound card will be lodged under the motor roof and the smoke generator housed on the RHS of the SLA.





The next step will be to design the "control panel" for the loco. This will have the two main power switches, the fuses and the DPDT that is the battery isolator. Yes this environment is great for black wite corrosion...

Regards

Ralph

[cabbage]

The shot shows the halfway point of the isobaric installation. The lower speaker has been sealed to the base board and the isobaric chamber about to be sealed behind it. Then the infinate baffle chamber will be installed and sealed above the the upper speaker.

Both speakers operate in push push mode so the polarities of them are the same. Each speaker is 16 Ohms thus the load on the sound card is 8 Ohms as they are wired in parallel.

I will have ask about the absolute volume of the system...





Regards

Ralph

[cabbage]

One of the great things about printing is that you can make another...





(Mine is the one on the left).

Regards

Ralph

[cabbage]

Well as the saying goes " it might not be pretty -but..."
This is the start of closing off the back panel of the infinate baffle for the upper speaker. Putting 6V across the wires delivers a "cluck".

The steel angle for the two sets of frames has been ordered and the four "lazy Susan" ball race bearings have been ordered





Regards

Ralph

[cabbage]

Ok we have reached the part of the build where  I disengage "George" and engage my brain... The motors I normally use are made by SME of Italy, these are robust little gems and have enormous torque for their size!!! The single stage gearbox is 12/90 and is MOD0.5 tooth. This gives a ratio of 8.5:1 which is the same as the "Peak" loco, but the Peak has two motors per axle, (yes TWELVE motors). As with the Peak I will bolt the bull gear directly to the drive wheel. With this motor it is the only way to avoid axle slip...

The bogie frame plates design is the next thing on the list
I plan to print the motor "girdle" as I did with the 2-NOL. My Son complained bitterly at the squeaking sound as the motor was slid into its girdle and then three grub screws anchored it.

The steel angle (3x13x13) should arrive Friday and so Sunday it will be out with the hacksaw. I plan to rivit angles to hold the ends to the buffer beams and then braze the joints solid as I did with the 2-NOL.

Pass the Ginger Nuts...

Regards

Ralph

[John Branch]

Ralph,
Are the motors you mention those that are for sale at £1 for 4 on ebay and called FC-170?  If so, is the fitted brass gear MOD .5?

I do love a man who uses 13x13 steel angle to keep the buffer beams apart.

John

[cabbage]

Ok so it ahould have read 13x13x3mm. What is a missing mm between friends? The simple rectangular frame will have the "lazy susan" bearings between them as its only job is to act as transfer during motion and hold the model straight!!!

Yes the motor is the SME fc170. This is one of my three "go to" motors. The others being the Canon ( which powers the 2-NOLs) and the Johnson (which powers the NER EE1, maude, the davidson and few others!) They all function well at 12Volts, although the Canon really needs 18Volts if used in parallel.

But I bought rather more than four SMEs and the discount rather larger!!!

I don't know what the mod or dp the brass gear is. I normally take them off and fit a mod1 or mod0.5 spur. This gives me something I can easily work from. A simple tube adaptor gives the 2.3mm shaft to 4mm gear that this requires.

But, I think I have enough to last me...

Regards

Ralph

[cabbage]

Parts arrive via the beleaguered postman, who has to suffer the amall packets for me and my Son... BUT the steel angle for the rectangular chassis frame has arrived as have the castings for the bogie sides vacuum cylinders and battery boxes. The battery box castings will disguise the SLA between them!

Yesterday I had a quick doodle as to how the steel bogie sides should look. Now that I have the casting to look at my only option is to start again with precise dimensions. They will be a compensated design with a wire "torsion bar" .  The port side of each bogie plate will house the motor and gearbox with the "torsion bar" set to force the port side down.

Regards

Ralph

[cabbage]

The bogie plate designs have been uploaded to MEL and since there are going to be two models (made here) I will require eight plates. The dress up bogie sides with the vacuum chambers and battery packs have arrived from Kippo. The mod0.5 gears for the motors and wheels , although possibly I should have used mod0.7 as the teeth will not clog as much. I now have a few smoke units to blow smoke thrpugh the exhaust vents. I have not used one of these before and all that I do know is that it runs on 6Volts!

At the moment I am gap filling and will  grey primer it before applying green undercoat amd BR diesel green.

Regards

Ralph

[cabbage]

The first Wonder Engine is about to have its public debut on Saturday. It did have a runaround on the CB track at the AGM but now the final parts have been printed and apart from transfers and plates - it is complete.

The second one is near rolling model stage. This one will be mine and different in barious ways from the first one.

Regards

Ralph