Blunami'd MTH PRR H10

@Weener Dog posted:

Norm, just finished watching your video on the Blunami install, fantastic video as always.   Do you think the day will ever come when manufacturers standardize to something such as Blunami or possibly sell locomotives with the option of not having their control boards automatically installed?   Dwayne

It is highly unlikely that the likes of Lionel or MTH (or even Atlas for that matter) will ever standardize on a mainstream DCC / sound control system for 3-Rail or even sell a model without control boards factory installed.  Even Atlas switched from using the superior ESU Loksound DCC decoders on their 2-Rail models to use MTH DCS/DCC once Atlas acquired some of the MTH tooling. 

What you have to understand is that the manufacturers are not supplying the electronics just for our benefit.  Electronics are a nice little profit center for these manufactures.  However, if you start supplying a 3rd party electronics system or none at all, there is very little excess profit (if any) versus driving the customer to adapt their entire proprietary electronics ecosystem.  Obviously, the manufacturers want to supply a product that that they believe meets customer expectations, however, their electronics offerings are not their primary product, just a nice little niche add-on profit generator.  Their primary product is the model itself whereas the products from the mainstream DCC electronics suppliers are the primary product and is usually superior to the niche proprietary manufacturer systems.  Lionel and MTH both have proprietary electronic designs, so there is a far greater incentive to inhibit incursion of the mainstream electronics DCC products versus trying to make it easy for you to adopt a command control ecosystem that is not one of theirs.

The HO modelers have it just the opposite.  They started with 3rd party DCC as their mainstream electronics control/sound system, so they will never go to a proprietary control/sound system that is less than optimal.

For now, DCC in the 3-Rail world will remain just a small cult-like following and since DIY conversion is pretty involved, aside from the current MTH DCS 3.0 w/ DCC it is likely that the big 3-Rail manufacturer's proprietary electronics offerings are pretty entrenched for some time to come.

Scott

While HO DCC was originally third party, it did not start out standardized. There were multiple incompatible systems. The NMRA reviewed all the different systems and standardized on the waveform that command stations use to communicate with locomotives. They chose the waveform used by the Lenz system. Vendors were free to innovate regarding command stations, decoders, handheld controllers, but all would be interchangeable because all would use the same communication standard through the track to the locomotive. Existing vendors except Lenz had to reengineer their products to meet the NMRA standard.

Wow! that IS very impressive. Thank you Norm for the instructional video. It seems easier to install than DCS or TMCC. What I really like about it is the clean crisp sounds and the superb motor control.

@Scott Kay posted:

For now, DCC in the 3-Rail world will remain just a small cult-like following and since DIY conversion is pretty involved, aside from the current MTH DCS 3.0 w/ DCC it is likely that the big 3-Rail manufacturer's proprietary electronics offerings are pretty entrenched for some time to come.

Scott

Two things Scott. Scott Mann indicated he has maybe a 5 year supply of ERR parts. Neither He nor Atlas might have a choice other than DCC or DCS when that option is exhausted.

Blunami is no more difficult to install than ERR and actually simpler than PS3. Strip 6 wires and insert them in screw terminals. 4 more wires for lights.

Pete

I think it’s the easiest aftermarket command control you can install. No chuff switch needed for steam exhaust and no motor encoder needed for cruise feedback. Keep in mind I am not running electrocouplers nor smoke. The small board size is great too, it can probably fit in just about anything. I was sort of concerned about heat sinking for the motor FETs but have yet to see any issue. The sound selection is just wild to me after all these years of hunting for vintage TMCC RS4 audio boards for my projects.

Now if ESU LOK sound would add bluetooth to their O scale decoder that would solve the smoke and electro couplers ,problem as they have provisions for high current outputs for smoke and couplers.

Electrocouplers are not a problem for Blunami, I added to them to my Williams Scale 44Ton conversion (see my posts). Gerbers have been posted on this site for having electrocoupler boards made, they’re very inexpensive. I found populating these boards very easy and I’m an electronics neophyte. Operating the couplers with the app is easy too.

@Engineer-Joe posted

Amazing job @Norm Charbonneau.

If they add smoke control, or at least a chuff output or maybe an input to be able to use @gunrunnerjohn's chuff generator and superchuffer, I'm all in.

@rplst8 posted:

Amazing job @Norm Charbonneau.

If they add smoke control, or at least a chuff output or maybe an input to be able to use @gunrunnerjohn's chuff generator and superchuffer, I'm all in.

A relay will allow you to turn on a smoke unit. The ones I use draw 30ma and can carry two amps and cost a buck. Johns chuff switch will turn the fan on 4 times a rev but having it synched with chuff is luck. It will be different every time you initiate the app, sometimes very close other times way off.

Pete

A quick question to the guys who have already installed this system. Obviously from Norm's video we know that the Blunami has excellent motor control on a steam locomotive with a single motor but has anyone ever used it on a dual motor diesel? How was the motor control at slow speeds to medium speeds?

What 10 pin tethers (male & female) are available for trailing units... whether Diesel or Steam?

Just wanted to say "THANK YOU" to those who posted the link to, as well as the actual, YouTube video produced by Norm.

Chuck

@Dennis-LaRock posted:

What 10 pin tethers (male & female) are available for trailing units... whether Diesel or Steam?

I use the MTH 10-wire tethers.

Good to have options for locos that have failed original electronics or never had them in the first place.  I think the future of command control in O gauge three rail is clear for the next few years, but as mentioned, the longer term is uncertain.  Lionel had to outsource the software for their new system to control all their command equipped locos. It's not clear that Atlas (or MTH) have the personnel or resources, or the interest in further development of DCS.  So one can indeed see a scenario where Lionel and Atlas contract with Soundtraxx to develop a system that addresses newer locos and is backward compatible with TMCC/DCS/LionChief/Legacy.

Motor control is smoother and slower than anything you’ll get from existing systems. My 44Ton will smoothly crawl at 12” in two (2) minutes. I am using the optional capacitor to guarantee continuous voltage.

@Hudson J1e posted:

A quick question to the guys who have already installed this system. Obviously from Norm's video we know that the Blunami has excellent motor control on a steam locomotive with a single motor but has anyone ever used it on a dual motor diesel? How was the motor control at slow speeds to medium speeds?

Here's two videos of my Weaver dual motor U25B with Blunami.

Speed step 1:

Speed step 2:

This is Blunami out of the box with no playing around with the speed settings or any special features.

~Chris

My contribution to the Blunami conversion effort...

I bought some of the cheapo LM2596 AC-DC voltage regulator boards from Amazon to see if they could cut the mustard in a Blunami conversion.  This is the device listed as an "AC/DC to DC step down converter" and rated for 2.2A.  The board PCB for the module is ~1 3/4" long x 7/8" wide and has the pin-through hole LM2596 regulator in a TO-220 package that is vertically mounted and attached to a relatively small heatsink.  The heatsink is cast aluminum and ~1/16" wider and 1/16" taller than the LM2596 chip, and about 1/4" thick.

1. The regulator board was connected to an isolated variac with the output voltage set to 18VAC.
2. An electronic DC load was connected to the output of the regulator and remote voltage sensing was connected right at the output of the regulator.
3. The electronic load current was set to 2A constant current.
4. The LM2596 chip and output inductor were both thermocoupled to monitor the temperature.

After allowing the regulator to run for 3 minutes, I turned off the electronic load because:

1. The LM2596 chip reached 130C (266F).  This is within 20C of the absolute max in the datasheet.  Interestingly the datasheet for the LM2596 part shows a rating of 3A.  But that is with a large PCB that has generous copper planes and a 7020 heatink that is 1.3"W x 1.45"H x 0.5"D.  The 7020 heatsink is much larger than the heatsink included on the regulator module.
2. The output inductor reached 90C (194F).  I believe the inductor is rated for 100C.  Now, if the output inductor on a switching regulator becomes too hot, it no longer looks like an inductor.  Instead it looks like a very small resistance.  That's bad news for the output stage FETs in the LM2596.  They aren't designed to handle the high currents associated with a small output resistor instead of an inductor.

Overall, I'm not sure if the hot inductor caused the LM2596 chip to heat up or if the LM2596 chip caused the inductor to heat up.  Either way, I don't want something that hot to be inside my plastic shell diesel.  So, if your going to do a conversion and want to use one of those cheap regulators from the web, be sure to run the loco for a while at high current and check the temps of the regulator.

For my conversion, I'll be following the same method that Norm used.  That is, mount a full bridge rectifier to the loco's metal chassis and use a large filter capacitor on the output.  Also, oversizing the rectifier to one that has a large metal surface will help pull the heat out quicker.  And picking one with a low forward voltage drop will reduce the heat dissipated.  Lastly, I'll be putting a TVS on the AC input.

@Crazy Train posted:

My contribution to the Blunami conversion effort...

I bought some of the cheapo LM2596 AC-DC voltage regulator boards from Amazon to see if they could cut the mustard in a Blunami conversion.  This is the device listed as an "AC/DC to DC step down converter" and rated for 2.2A.  

Overall, I'm not sure if the hot inductor caused the LM2596 chip to heat up or if the LM2596 chip caused the inductor to heat up.  Either way, I don't want something that hot to be inside my plastic shell diesel.  So, if your going to do a conversion and want to use one of those cheap regulators from the web, be sure to run the loco for a while at high current and check the temps of the regulator.

For my conversion, I'll be following the same method that Norm used.  That is, mount a full bridge rectifier to the loco's metal chassis and use a large filter capacitor on the output.  Also, oversizing the rectifier to one that has a large metal surface will help pull the heat out quicker.  And picking one with a low forward voltage drop will reduce the heat dissipated.  Lastly, I'll be putting a TVS on the AC input.

There are a lot of inexpensive buck regulators out there. Not all overheat. A 5 amp unit from Amazon can be had for 4 bucks and easily handles a 4408 Blunami. 2-3 amp Buck regulators suitable for 2200s that don’t overheat will cost more. Pololu has some that cost about 15 bucks but are very small, less than 1” square, where space is at a premium.

Pete

There’s really no reason to overcomplicate it. I used a bridge rectifier and a 470uF cap because that’s what I had on hand but a 1000uF cap will give a little less ripple at higher loads. I bought some $3 buck converters with the idea that I could dial in 18VDC at the board but didn’t end up using one. The H10 is still running like a champ. It’s almost addicting to play with since it runs so well and I have another Blunami board on the way.

I wouldn’t recommend a linear regulator for this sort of thing. Their best use is for lighting circuits imo.

@Hudson J1e posted:

A quick question to the guys who have already installed this system. Obviously from Norm's video we know that the Blunami has excellent motor control on a steam locomotive with a single motor but has anyone ever used it on a dual motor diesel? How was the motor control at slow speeds to medium speeds?

Both my Blue Shark and Blue Geep have dual Mabuchi RS-385 motors and run just fine, controlled by the Blunami 4408 board.  Good slow speed operation, good cruise, smooth speed control up/down.

@KarlDL posted:

Both my Blue Shark and Blue Geep have dual Mabuchi RS-385 motors and run just fine, controlled by the Blunami 4408 board.  Good slow speed operation, good cruise, smooth speed control up/down.

Thank you Karl! I appreciate the information.

Really awesome. One of these days I'll stumble upon a donor. I have a Railking SD70MAC with bad electronics but it is not worthy. Need a scale/detailed model...

Norm, does the steam board have the alternate whistle feature? On the diesel board you can enable alternate horn. You can have 2 different horns programmed. Switching between them by using short horn button on the main screen in the app. Use long horn to blow the horn.

Thanks

It does but I have yet to use it.

I did get around to setting up the automatic forward and reverse whistles with the CV function mapping. Pretty cool! This engine continues to run very well and I’m looking forward to another install.

I have used the Blunami in G gauge DC engines with great sucess , looks like i am going to have to work on something for the O gauge items, I really do like the blunami , Thanks everyone.

Could someone put up a schematic and parts list/Specs for the Bridge Rectifier and Filter Capacitor changing the AC to DC for use with the Blunami board. and i wonder how much loss , what do you typically set your input/track voltage at ?

Jim, this is all I really did:

I used a 10amp rectifier and a 1000uF cap in this pic. In the H10 I have a 470uF cap and I soldered it directly across the rectifier to save some space. I plan on using a 1000uF cap for my next install. With a higher value cap should be less AC ripple at higher current loads but I haven't had any issues with the 470uF in the H10. I run my track at 18VAC (unloaded) and Blunami is showing me 25.7VDC. I did some real world measurements in my vid. These common components are easy to get from Amazon or eBay.

I talked about considerations for using a buck-boost to dial in a constant voltage at the Blunami input. The main benefit of that would be in a situation where I might run on a layout with a track voltage that might be plus/minus a few volts off from 18VAC. I honestly don't know of anyplace I'd encounter that so I didn't put one in. The extra component would take up precious space in a small engine. The Blunami board can hang at 27VDC according to their documentation.

Thanks Norm great answer,