Alan Bond's Marine Engine Sound Unit (petrol version)

This is a general purpose engine sound module that can produce a variety of different engine sounds. At present it comes in petrol, diesel and steam variants.

Whilst a synthesized engine sound can never compete with recordings of the real thing, nevertheless I think I have captured the 'spirit' of various engine sounds.In all cases the hardware module remains the same and the type of engine sound and it's character are varied by firmware (ie the fitted software) alone.

The hardware is based on PICAXE chips and all units may be built 'as is' using the released software or, the more adventurous of you can experiment by tweaking the values in the code to change the exhaust pulse (or steam hiss) character of each cylinder, the tickover speed, the rev range, the idle time-out period, inhibit or modify the "starter" and the engine run-down to stop etc. The code has been specifically written to make such experimentation easy and has been commented accordingly.

For the purposes of this video the engine idle timeout period, normally one minute, has been reduced to a few seconds. Again for the confused amongst you, I am not using the throttle channel in this video as it is a ratchet type and rather 'notchy' which spoils my 'smooth as silk' throttle response.

A full article is present on the club website
http://www.srcmbc.org.uk/ht_afb_sound-units_marine-engine.php or see the unit running in a boat
http://www.youtube.com/watch?v=L31bVTn-Xg4&feature=channel_page

A kit of parts (or made up kits) are available from Technobots
http://www.technobots.co.uk/acatalog/Marine_Engine_Sound_Unit_Kit.html at a very modest cost. I don't get a penny out of this, I'm merely putting something back into the collective 'pot' from which I've drawn since taking up boat modelling (Autumn 07)

Category:

Science & Technology

Tags:

• boat
• effect
• engine
• model
• petrol
• picaxe
• sound
• unit

[srcmbc]

@MrRCflying the max RPM can only be increased by re-programming the chip and also the neutral and span of the rc interface would need to be re-programmed to match the forward only speed controller used on a plane. The new progranmmable unit just recently launched can be user set to accomodate forward only controllers and the max RPM can be adjusted, though not as to be as fast as I imagine you would like for your application. I can try setting the max RPM much higher and mail you a sound file

[srcmbc]

@tpvalley - You are not the first by far to make that observation! This is synthesized sound so stark realism is not what this 'fun' unit is about. The other sound set for this unit is rather 'thuddy' so I christened that one 'diesel' and this brighter sharper sound as 'petrol'. With hindsight, it would have been better to call them 'type1' and 'type2' or similar I guess. No such problems with the steam variant though!

[salem42salem42]

have you got one for an aircraft , like say a radial engine , you sell ???

[srcmbc]

@salem42salem42 - sorry no, the algorithm I'm using to create the sound isn't really suitable for those kind of engines

[ransepans]

This Unit sounds great! I never heard such a realistic engine sound. Is it possible to get the software for experimenting?

[srcmbc]

@ransepans - this unit has now been upgraded into a commercially available item. To protect the investment made by Technobots in designing a PCB, productionising it, tooling the case etc the source code is no longer available I'm afraid. (Find link to Technobots in the drop-down info panel immediately below the video window)

[MrRCflying]

Hi, I am interested in one of these units to try on an RC plane. I know they are not made for that, but I would like to try. Is there a way to increase the max RPM of the sound? Which unit would be the best, the Petrol sounds the best, but would the programable one be better? If it works out, it might open up a whole new market for you. The ones made for planes are WAY too expensive in my book.

[fatgirlfister]

where can you buy this?

[tpvalley]

@srcmbc

this sounds like the diesel not the petrol!

Apart from some very tired petrol engines of course!