Expert Multi Cylinder Glow Driver

[petertha]

I've been around RC a long time so reasonably familiar with plugs & starting. These el-cheapo clip-ons are essentially a NiMH cell direct connection, I don't think there is any other magic inside other than some have a mickey mouse meter in the end. There are much better driver units which not only regulate off of larger voltage lithium cells, but also sense plug resistance & adjust power on the fly, but they cost more. What I'd really like is to reverse engineer & have one dedicated per cylinder. Bottom line is the simple clip-ons work reasonably well. One cell per cylinder.

 

[petertha]

I've fallen way behind posting but at least building has continued to progress. The (heavily modified) O-ringed lifter bushings & pushrod tubes are finally done, so its more a bunch of fiddly things remaining to do now.

 

[mu38&Bg#]

Glow plugs, usually rated 1.2 or 1.5V, require about 1V to glow enough to start the engine. I measured .95V and 3.1A for an OS F plug. However, this voltage disregards voltage drop in the circuit. So often, people try using undersize, long leads, or high impedance batteries with glow drivers and have trouble due to voltage drop.

Running a single current regulated source to parallel plugs could prove expensive if a plug or connection fails. You want voltage regulation.

A couple years ago the RCD3007 driver was cheap and plentiful when I was looking to find something that would run off LiPo packs. It could be setup to run several units to drive multiple plugs. It seems RCEXL offers a similar but simpler product for 2-3S. Neither seems to have low voltage cutoff.

These were the best in the past 3-9 Cylinder Driver This one is ready to run a single LiPo Five Cylinder Glow Driver

 

[petertha]

Thanks for input @dieselpilot I actually forgot about the McDaniel unit.

 

[Vixen]

Most modern glow drivers, flight box starter and even my ancient 'Expert Multi' use Pulse Width Modulation (PWM) control. The full battery voltage is switched rapidly on and off at a controlled rate whch matches the glow plugs requirements. PWM control of glow plug current is far superior to any DC DC down converter.

The two multi cylinder glow drivers recommended by dieselpilot would be ideal for your engine. They are able to run off both Lipo and Nicad batteries. They both use a separate PWM control for each of the glow plugs.

Mike

 

[josodl1953]

I am considering the purchase of the German Rainbowtronic Glow Control unit for my Edwards, see Homepage . I do not know the technical details but is seems a good solution .

Jos

 

[petertha]

I am considering the purchase of the German Rainbowtronic Glow Control unit for my Edwards, see Homepage .

I was not aware of that system. Also lithium cell based. Sorry for sidetracking post @Vixen Has not really solved your original issue but at least some alternative options have come to light if circumstances so dictate.

https://rainbow-tronic.de/en/cartsearch/index.html

 

[Vixen]

I was not aware of that system. Also lithium cell based. Sorry for sidetracking post @Vixen Has not really solved your original issue but at least some alternative options have come to light if circumstances so dictate.

petertha,

That's not a problem. It's good to learn

In post #1 I stated my intention; "I'm trying to get my Seidel ST540 five cylinder radial engine back up and running with all the original equipment. It came fitted with an "Expert, Multi Cylinder Glow Driver".

Then back post #6, I said; "I discovered the Expert Multi was also sold under the World Engines badge and I have found a photo of the instruction leaflet. So all is well".

The Expert Multi connects to a 2.2volt battery pack which I will need to replace. The Expert Multi may?? be able to run off a higher voltage but it would be very expensive test, if it burned out.

Along the way, petertha has discussed other possible methods, none of which look very attractive. In the end it became obvious that the only way to go, was for him to buy a modern commercial five glow plug driver, which are now more flexible regarding the battery supply (as long as there is sufficient Ah capacity)

Mike

 

[Vixen]

I manged to charge some life back into my 20 year old, 25Ah Cyclon lead acid cell. I wired up the Expert Multi Cylinder Glow Driver and used a servo tester to switch on/off the current to the five glow plugs (OS Type F). Filled the tank with 10% synthetic oil/ methanol (no nitro!!!!!) and finger over the carb to draw the fuel through.

My Seidel ST540 fired up first first swing, coughed, cleared it's throat and settled down to a steady run.
I am running a 22 x 10 prop, which is way too big and too course a pitch for the little five cylinder radial; which limits the top RPMs. The manufacturer recommends a much smaller 19 x 8.(which I don't possess).

Without glow assistance the engine operates smoothly, with good pick-up between 1,100 and 3,600RPM.
With the glow assist the minimum RPM drops to a little over 500RPM.

Not bad for a twenty year old engine with an old tech 'Expert Multi' Glow Driver.

Mike

 

[petertha]

Nice, Mike! My auto charger has some conditioning algorithm that helps bring them back from the dead & it really does work over my older generation constant trickle chargers. Unfortunately it only has a nominal 12V & 6V switch setting. 2V would likely confuse it.

It looks like you are driving throttle with a servo tester (blue box with knob) & 4 cell type battery?

Did you make up your own clips for the glow plugs or was that part of the original harness? I'm looking for some good ideas in that regard for my engine since they will be more or less permanent for test stand purposes. Some of the shop made ones I've seen look more or less like a ~ 1mm thick medal spade with a hole & slit to grasp on the plug post.

 

[Vixen]

Hi petertha,

Yes it's a bit of a pain to add the throttle servo, tx and rx input for bench running, so I used that cheepo blue servo tester instead.
Have a look at the DIY multi cylinder glow driver at philsradial.blogspot.com. It uses an Aduino pro mini to control up to nine glow plugs. The glow power is controlled either by a pot, for bench running, or by the throttle servo channel. It runs off 3 Lipo cells (of which I have several).
He also shows how to use a blue crimp connector as a glow plug connector. you could also look at the Fastrax Fast52D remote connector, not tried them myself.
The Seidel came fitted with some spring loaded plug caps, but they have proved to be temperamental, so I am also looking for a good replacement.

Cheers

Mike

 

[petertha]

Thanks. Yes, Phil's build is in my collection of reference pics. I know on some glow engines, maybe similar to Seidel, the plugs are situated deeper in the head so necessitate the longer, cylindrical style connector to reach. But I think I can accommodate the lateral spade thing. And I even have some casting silicone to mold some kind of boot if I can figure out a way to marry the two.

http://philsradial.blogspot.com/2013/08/glowplug-clips.html