A pair of ‘Tigres’

[Ramon WilsonParticipant @ramonwilson3]

Hi Guys, Given the interest in Jason's Firefly build and the engine in general thought you might like to see a couple of pics of the latest diesel engine project.

I haven't posted about them on here before having previously done so for the Nova, Racers and Etas – over kill in mind.

However if it's of interest there's a full build thread over on HMEM here –

**LINK**

As previously the cases have been machined from solid and bead blasted. The whole project took just over 8 weeks – as I think I mentioned before the nice thing about this type of project is the low part count and the quick return .

Good luck to whoever tackles one of these types of little engine – when it first fires you will certainly be rewarded

Regards – Ramon

[Ramon WilsonParticipant @ramonwilson3]

[David Clark 13Participant @davidclark13]

Hi Ramon

What about some articles for Model Engineer?

regards David

[JasonBModerator @jasonb]

I would strongly reccomend anyone thinking of building the Firefly or any other aero engine for that matter to read Ramons build over on HMEM, to see those crankcases being sculpted from solid is a joy to behold. Tells you just about all you need to know about making this type of engine..

Well except the annodising which you should have an article for David?

J

[Ramon WilsonParticipant @ramonwilson3]

Hi David, Thanks for the invitation however at this precise moment I need to take a short break though intend to begin something new I/C in the Autumn. Perhaps then? I will PM you on the details later

Jason's comment re anodising comes after being asked to cover it on the HMEM thread – which was declined saying that an article is in the offing – always assuming that's still the case?

Regards – Ramon

[dean clarke 2Participant @deanclarke2]

Hi ramon, very nice job on these as well mate, am wondering if i could possibly aquire a set of drawings for your loverly engines? also I can't seem to find that grayflex stuff for finishing over here, do they have a web site?

thanks

dean

the777eng@hotmail.com

[JasonBModerator @jasonb]

Its GaRRyflex not Greyflex made by Garryson.

Where is overhere? in the UK you can get it from J&L/MSC

J

[KWILParticipant @kwil]

Garryflex cheaper from Chronos and free delivery! Happy customer.

[Sub MandrelParticipant @submandrel]

Ramon,

When are you going to design one of your own?

neil

PS. I now have 8" of 2 1/2" alumium alloy ideal for sculpting engines So maybe Nova, or maybe something strange – a 4" scale version of the Suffolk. A bit stressful at the moment with three or four projects begging me to start them first, as soon as the shunter is lined out (edding pen came today)

[dean clarke 2Participant @deanclarke2]

hey sorry, over here is new zealand, and sorry for the incorrect name, yes garryflex the finishing compound rubber stuff. lol. wondering if that can be purchased online?

cheers

dean

[JasonBModerator @jasonb]

Try Google, heres a NZ supplier

Its the finest pink one you want

J

[Ramon WilsonParticipant @ramonwilson3]

Hi Dean, Thanks for the PM and your kind comments. I'll answer it here as others may be thinking the same.

Firstly though the Garryflex – looks like Jason has found you a NZ supplier but it may be viable to check ebay – there are lots of sellers and the prices vary considerably. They come in four grades and I use all of them when finishing cases though the coarsest and finest the least. Most used is the Blue and the Pale Brown – I think this is what Jason is refering to as Pink – the coarsest is classifed as Wine and is a definite pink in colour. The coarsest is however very useful in cleaning and abrading sheet surfaces prior to painting

Drawings – The Racer drawings were of course published in ME however the Tigre drawings are still not updated ( there were several mistakes!) along with the intention to redraw the Etas to include the Mk3 and Elite. Unfortunately thereby lies the nub – I am currently suffering from an old injury to my neck which is causing severe head aches and neck pain – sitting at the computer for any length of time quickly exacerbates this so when that will be I'm not able to say – I'm afraid I can't help at the moment but will let you know in due course. If Bill and Ian in Aus are reading this – I have not forgotten.

It would be nice to see pictures of your engines – why not post them on here as I'm sure they will be well received.

Neil, There was one in the offing – a 3.5cc – diesel or glow with varying bottom ends ie plain or BR but the reason above has put the dampers on – it's just too painful to sit here long enough to do drawings.

Regards – Ramon

[dean clarke 2Participant @deanclarke2]

hi again all, just wondering if anyone out there knows how i can fire up 8 glo plugs at once, any help with this puzzle would be greatly appreciated. i need a system that will glo all plugs well and simultainously.

thanks

dean

 

p.s. i will post some photos of my engines when i work out how and have taken some photos to upload.

Edited By dean clarke 2 on 15/10/2012 07:37:12

[TerrydParticipant @terryd72465]

Hi Dean,

Can't help with the glo plug problem, but to post images here there are two methods.

First, you can create an album (Click on 'My Photos' in the avatar box at the top of LH column). You can then upload images – jpegs only. They can then be inserted into posts by clicking on the 'camera ' icon above the text box when writing your post.

Secondly you can use a picture hosting site, upload your pictures to that then get the link and embed it into your post by using the 'image' icon next to the 'camera'. I have had problems in the past with the latter due to pictures changing their url when I have uploaded other images.

By the way, If you hover above the icons mentioned a description appears – as it does with all of them.

Best regards and looking forward to your pictures,

Terry

Edited By Terryd on 15/10/2012 08:01:57

[maurice bennieParticipant @mauricebennie99556]

Hi . Polishing pads 50 x50 mm packets of 9 different grades .The finest will leave a scatch

free surrface on acrylics. they can be washed off with water and used again

I get mine from " Axminster" tools .£8.00 per pack .Just a satisfied customer.

Love the motors ,I must try but live in awe of the ones who can make them.

Maurice

[Martin WParticipant @martinw]

Hi Dean

Without knowing exactly which glow plugs you are using and their characteristics it is difficult to give a definitive answer. However if they will work at about 2 volts then connect them in parallel and feed from a nominal 2 volt lead acid battery via a fairly heavy duty switch. Something like a 4 to 8 AH battery should be OK.

Cheers

Martin

Edited By Martin W on 15/10/2012 10:30:36

Edited By Martin W on 15/10/2012 10:53:12

[JasonBModerator @jasonb]

I would wire in all the glow plugs rather than trying to fit eight removable clips.

From a common "Distributor" take a live feed to the pin on each glow plug,( you can buy what look like spark plug caps to do this) and take one common neutral back from the engine. You will need a decent ampage to drive all the plugs, maybe a glow panel that gives 1.2V from a large 12V battery would be best.

Have a look at these bits from Just Engines, they do the plug caps

[Martin WParticipant @martinw]

Jason

The 'Glow Panels' are, I think, designed to feed just one glow plug. As Dean needs to run 8 simultaneously he will need something much more beefy. I have dug out some old glow plugs I had, from heli flying days, and their cold resistance looks to be about 0.2 ohms. This gives a cold current of about 10 amps per unit with the hot current being lower.

8 plugs running at 2v would require a whopping start/cold current of somewhere in the region of 80 amps which would fall back as they reach temperature. It might be better to break them down into separate smaller groups which while it does nothing for the total power requirement would would lower the current for each branch and make switching easier.

A quick test has given a current of 3 amps at 1.2 volts, nice orange glow, which would equate roughly to about 5 amps at 2 volts or 40 amps for 8 plugs in parallel for the plugs I have got.

If run from a 12v source, i.e. car battery, then the most efficient method would to use some form of switched mode supply or pulse width control system to regulate the feed to the plugs. A simple but crude solution would be to use a beefy hex-fet on a heat sync fed from a variable mark space oscillator and tune for optimum current. I would suggest something like a 555 Timer IC but Andrew would not approve as its very old hat.

Cheers

Martin

[JasonBModerator @jasonb]

Here is another solution though it would be better kept under the engine display stand, just one rechargable per plug.

**LINK**

[dean clarke 2Participant @deanclarke2]

hi all thanks for the info, i have 12 glo leads coming and 24x 6000mAh batteries, anyone got any idea as to how i go about charging all these batts?

going to make 4 banks of 6 batteries to cope with a couple of other projects underway as well as the v8 beast

thanks

dean

p.s. taking photos of engines at the mo will upload as soon as i can

[dean clarke 2Participant @deanclarke2]

here are a few of the engines i have made.

Edited By David Clark 1 on 16/11/2012 20:30:16

[dean clarke 2Participant @deanclarke2]

Edited By David Clark 1 on 16/11/2012 20:33:36

[dean clarke 2Participant @deanclarke2]

many thanks to all of you guys for the ignition ideas. i am still working out how to get a single setup for each bank of cylinders rather than 8 individual batteries.

thanks

dean

[JasonBModerator @jasonb]

That was an expensive way of doing it, rather than the removable glow clips I would have used the ones that stay wired in with just a small plug cap which I linked to earlier. That way if you just get the engine running and pull all the clips off and it dies you don't have to put all the clips back on.

It can also be wired with one positive wire to each plug and a common negative to the engine and the battery holder. You could wire a neat loom with just 4 wires and small plug caps or make glow plugs like old screwtop spark plugs as these ones on this Whittle have been.

 

Edited By JasonB on 01/11/2012 07:14:46

[dean clarke 2Participant @deanclarke2]

actually it wasn't that dear, but i hear what your saying. i have in fact got the leads you suggested already but am struggling to come up with a battery combo that will glo them all hot enough. thats why i went to individuall glo sets, having said that, i am now wiring the 2 sets of 12 nimh's into pairs in series and then into sets of 12 in parallel to get a better duration of glo time. you can see the engines first run on you tube if you search "777engman v8". thanks again for the help

dean

[Author]

Posts