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Rorty DeDion axle assembly drawings.
Rorty - 21/10/05 at 09:02 AM

As requested, here's my take on the Locost De Dion axle (thanks go to flak monkey for hosting it).
No warranty is given or implied as to the design's suitability for any purpose. It is as yet unproven in a Locost, but is freely offered for educational and comparative purposes.
If you decide to have a go at constructing this interpretation and injure yourself or cause some damage, then you're an idiot and there's nobody to blame but yourself.
ADDENDUM In drawing # 08 the material spec states 4140 or EN24T steel. It should read 4340 or EN24T steel.
RortyDeDionAxleAssembly

[Edited on 28/10/05 by Rorty]

zzrpowerd-locost - 21/10/05 at 09:10 AM

does this fit straight into the book chassis?

CommanderAce - 21/10/05 at 10:39 AM

Excellent! Cheers bud, just what I was after!

ned - 21/10/05 at 11:24 AM

a good looking set of drawings, but i do wonder why you bothered rorty? these plans (in essence) have been around yonks, are on the locost cd and the locost7.info site iirc

Ned.

David Jenkins - 21/10/05 at 11:33 AM

Well Ned, I haven't seen either of those sources so I'm very grateful for Rorty's efforts!

Rorty - I have a question - on your drawing you call one part the 'Watts Linkage', but it looks like a panhard rod to me. Or is that my ignorance showing?

David

ned - 21/10/05 at 11:41 AM

ok well i can't find the stuff on the locost7.info site, but i'm sure i've seen it online somewhere.

i have the locost cd so can post the pics if it'd help anyone.

Ned.

MikeR - 21/10/05 at 11:44 AM

Ned seeing as you have access to three sets of plans now, what are the differences between the plans? Are they all pretty much identical? do they all use the same thickness steel?

Is there scope for a best of breed here?

(Rorty, i'd also like to add my thanks, this is the first time i've seen proper plans. I keep thinking about de-dion and you might have pushed me over the edge!)

ned - 21/10/05 at 11:50 AM

happy to admit my mistakes.

rorty's is more similar to the gts dedion as its 2 straigh pieces joined in the middle, the locost cd version is a bent tube.

pics now uploaded to my photo archive from the locost cdrom :
http://www.locostbuilders.co.uk/photos.php?action=gal&user=ned&folder=dedion
but they have been posted before as they're in someone else's archive already as the system renamed some with a '2' at the front to signify that name already exists in the uploads folder on the server.

I'm sure Rorty's input is and will be appreciated and is a better engineering drawing than the sketches with dimensions linked above.

Ned.

Triton - 21/10/05 at 11:51 AM

Certain parts look like the one i did for the GTS....but then nowt is really new on cars anyway just done differently

Good set of plans though Rorty, i like your English Wheel stuff on your webby too....pat on the back there

Surrey Dave - 21/10/05 at 12:28 PM

My Acrobat wont open it , says it cannot decrypt, any ideas?

[Edited on 21/10/05 by Surrey Dave]

David Jenkins - 21/10/05 at 12:33 PM

It opens OK with Adobe Acrobat 7.0.5 for me.

Maybe you need an upgrade?

David

BKLOCO - 21/10/05 at 12:42 PM

Cheers Rorty.
I was going to make myself some caliper brackets.
Your drawing will save me a lot of measuring and designing.

Just as a point, there are a few dimensions missing off the drawings, although with a little common sense it's not difficult to work them out or best guess them.

Rorty - 21/10/05 at 01:16 PM

quote:
Originally posted by zzrpowerd-locost
does this fit straight into the book chassis?

Yes, it's designed around The Book's chassis dimensions.

quote:
Originally posted by ned
a good looking set of drawings, but i do wonder why you bothered rorty? these plans (in essence) have been around yonks, are on the locost cd and the locost7.info site iirc
Ned.

I drew up a complete De Dion Locost when I first joined this forum, thinking it might be fun to build one (but that's the only lot of drawings at the moment with dimensions and notations).
I don't claim to break any new ground with any of it. It's all been around for decades, I just interpreted it my way and drew it all up. Much of it is common to other projects I've been involved in and I just applied it to a Locost chassis.
I can say in all honesty I have not seen the Locost CD, nor knowingly copied anyone else' drawings with the exception of the basic dimensions of the chassis. I think I may even have done my De Dion drawings before I was aware of the GTS example.

quote:
Originally posted by David Jenkins
Rorty - I have a question - on your drawing you call one part the 'Watts Linkage', but it looks like a panhard rod to me. Or is that my ignorance showing?
David

You're quite right, I did call the Panhard rod (or bits of it) a Watts linkage or something. I was in hospital recuperating after major surgery when I threw that lot together and I was seemingly still under sedation. I opened my laptop one day recently, not having used it since being in hospital, and there were all the drawings. I have no recollection of finishing them!
I only looked at them briefly (and admittedly didn't pick up on the Watts bit of it), but someone asked for De Dion drawings the other day which spurred me to stick the drawings in a PDF file, and there you have it.

quote:
Originally posted by BKLOCO
Just as a point, there are a few dimensions missing off the drawings, although with a little common sense it's not difficult to work them out or best guess them.

I didn't think there would be this much interest in the drawings, but seeing there is, I may look at them again and touch them up. If you let me know which dimensions you are after, I'll make a note and revisit it when I have some time.


Anyone can take it or leave it as they wish.

Alez - 21/10/05 at 01:16 PM

"Due to their propensity to sue anything with a pulse, Americans are explicitly requested not to attempt to construct this assembly either in part or in whole."

MikeRJ - 21/10/05 at 01:32 PM

Does the "hub bucket" not need cut outs for the bearing carrier bolts? It looks a bit tight in the drawing, and I think the GTS axle required cut outs.

Rorty - 21/10/05 at 01:57 PM

quote:
Originally posted by MikeRJ
Does the "hub bucket" not need cut outs for the bearing carrier bolts? It looks a bit tight in the drawing, and I think the GTS axle required cut outs.

Only if the screws are too long and poke right through.
IIRC, I drew it so that a 25mm (or was it 30mm?) screws would run to the end of the threaded hole only. Threads sticking out the back of the plate don't add to the overall strength or retention.
Actually, I would insert some old dud screws into the holes before welding the plate to the bucket so you don't get any spatter buggering up the threads.

Rorty - 21/10/05 at 02:04 PM

quote:
Originally posted by ned
rorty's is more similar to the gts dedion as its 2 straigh pieces joined in the middle, the locost cd version is a bent tube.
Ned.

I meant to add earlier, the tube in my drawing is bent and not two pieces. A proper tube bender isn't even necessary; heat from a torch and some grunt would bend the tube sufficiently. It's only a shallow angle.
Cutting and shutting the tube would be a waste of time IMHO.

MikeR - 21/10/05 at 04:00 PM

ok, i've no engineering background so please ignore the ignorance.........

what made you pick the steel thicknesses you've done? Just thinking that some of them seem majorly heavy duty compared to what we're using on the locost chassis.

zzrpowerd-locost - 21/10/05 at 07:54 PM

quote:
--------------------------------------------------------------------------------
Originally posted by zzrpowerd-locost
does this fit straight into the book chassis?
--------------------------------------------------------------------------------


Yes, it's designed around The Book's chassis dimensions.


So if i built the book chassis this would fit straight in? The Gts de dion drawings show the bottom chassis rails flat instead of angled

Mansfield - 21/10/05 at 09:14 PM

Hats off to Rorty.

Seems to me that all these threads start with questions, and its damn nice to see someone start a thread with a solution.

David

MikeR - 21/10/05 at 11:00 PM

solution, solution ......... its just just made me question my whole axle decision 5 years into my build. I don't call that a solution, i call it bloody annoying & another 2 year delay.



Whats that quote again, its not the destination, its how you get there!

Rorty - 21/10/05 at 11:24 PM

quote:
Originally posted by zzrpowerd-locost
quote:
--------------------------------------------------------------------------------
Originally posted by zzrpowerd-locost
does this fit straight into the book chassis?
--------------------------------------------------------------------------------


Yes, it's designed around The Book's chassis dimensions.


So if i built the book chassis this would fit straight in? The Gts de dion drawings show the bottom chassis rails flat instead of angled

AFAIK, this will fit straight into a Book chassis, but I can't put my hand on my heart and swear to it, because I've never built a Locost.
According to the chassis dimensions I've gleaned, this will work. If the chassis dimensions everyone is using don't work, then this won't either.

Rorty - 22/10/05 at 12:37 AM

quote:
Originally posted by MikeR
ok, i've no engineering background so please ignore the ignorance.........

what made you pick the steel thicknesses you've done? Just thinking that some of them seem majorly heavy duty compared to what we're using on the locost chassis.

Admittedly, a lot of the stuff is on the "stout" side, but I specced it for a reason. I put this document together for the average home-based builder taking into account all the levels of skill. It's much easier for the novice to weld thicker material because they can get more heat into the material and accomplish better welds accordingly.
If I were to ever build one of these cars, it would be for the track only and I would use lesser thicknesses of steel (probably choose 4130 steel and go really light weight).
Take the calliper bracket for example, personally, I would make it out of 3mm 4130 steel and TIG the appropriate length of bosses into the mounting holes.
Likewise, I would make the axle brackets and Panhard brackets etc, out of 2.1mm 4130 and TIG bolster washers into the bolt holes.
If you're an accomplished fabricator then you could easily reduce the thickness of the brackets etc., but then if you were an accomplished fabricator, you'd take one look at these drawings and conclude that for yourself!
If you follow the drawings to a T, you will have an easily constructed and strong set-up but if you are well versed in car constructing, then I would only expect you to use the dimensions to build your own version.

sgraber - 22/10/05 at 05:35 AM

Bob (Rorty), you're a good guy. Everybody is usually just sucking the information out of this place. You are one of few that is constantly refreshing it with consistent quality info. Thanks.


At first when I read this part of your pdf I was a bit miffed...

quote:
"Due to their propensity to sue anything with a pulse, Americans are explicitly requested not to attempt to construct this assembly either in part or in whole."


You mean in 'other' countries people take responsibility for their own actions?

Will you make an exception for me? I promise not to sue since I am apparently one of the few Americans that am willing to take responsibility for my own actions...

Rorty - 22/10/05 at 12:32 PM

quote:
Originally posted by sgraber
Bob (Rorty), you're a good guy. Everybody is usually just sucking the information out of this place. You are one of few that is constantly refreshing it with consistent quality info. Thanks.


At first when I read this part of your pdf I was a bit miffed...

quote:
"Due to their propensity to sue anything with a pulse, Americans are explicitly requested not to attempt to construct this assembly either in part or in whole."


You mean in 'other' countries people take responsibility for their own actions?

Will you make an exception for me? I promise not to sue since I am apparently one of the few Americans that am willing to take responsibility for my own actions...

Steve,
thanks for the kind words (check your PayPal account).
You're such a part of this comunity that I just think of you as a Brit anyway, so of course the rider doesn't apply to you.
I'm sure you've come across the sort of people that rider's aimed at though.
I had a run-in with an over protective US parent over some of my buggy plans apparently being unsuitable for their 17 year old!

Rorty - 22/10/05 at 12:39 PM

I amended the PDF file so the Panhard bits are now correctly refered to as Panhard bits (funnily enough) and not Watts bits as originally.
I don't know what my brain was doing at the time!
I've also specced the size of the hub retaining bolts.

MikeRJ - 23/10/05 at 03:53 PM

quote:
Originally posted by sgraber
You mean in 'other' countries people take responsibility for their own actions?


Well, that used to be the case in the UK, but the governemnt aren't too keen on personal responsibility, hence the explosion in the number of blood sucking, insurance claims services. "Where there's blame, there's a claim"

Just to add something relevant to the thread:

Rorty, I bought a GTS de-dion axle because one of my worries was getting the bearing carrier mounting plates perfectly parallel and exactly in-line. For those contemplating building this, do you have any cunning tips, or is it a case of measure twice, cut once, throw it away and have another go?

britishtrident - 23/10/05 at 04:00 PM

Very Impressive -- neat -- cool -- hot -- sweet --- and and other adjective that means you diid a good job.

Rorty - 24/10/05 at 04:57 AM

quote:
Originally posted by MikeRJ
Rorty, I bought a GTS de-dion axle because one of my worries was getting the bearing carrier mounting plates perfectly parallel and exactly in-line. For those contemplating building this, do you have any cunning tips, or is it a case of measure twice, cut once, throw it away and have another go?

I contemplated writing a full manual to accompany the drawings, but thought most people would follow it all OK. Adding complete descriptive text usually requires further drawings of jigs etc. and I got to the point where I began to think less charitable thoughts!
I did wonder though how long it would be until someone asked about aligning the De Dion tube and hub plates.

There's nothing complicated about setting the tube and plates up and there are several ways I've done it previously.
1. An expensive option, though the most accurate way I did it (for four identical axles) was to cut the toe-in angles onto the ends of a length of 125mm x 125 mm x 6mm SHS. I then tack-welded some pre-drilled and tapped flanges on the ends of the RHS and then finally machined the faces of the flanges accurately after the welds had cooled.
It was then a simple job of bolting each set of hub plates to the beam and cutting and welding in the De Dion tubes.
2. Basically the same as above, but without the expensive machining. I tacked a couple of spare hub plates to a steel beam (the side of my chassis stand). Before welding the second plate to the beam though, I clamped a length of angle iron to each plate and measured the ends, much as in setting the toe on the front of a car, then welded them solid.
Then as in the previous suggestion above, the actual hub plates were bolted to the ones welded to the beam and the De Dion tube added.

The actual toe angle depends really on whether you anticipate spirited or leisurely driving.
For a Locost, I would probably aim for ½°-1° total toe-in.

Rorty - 24/10/05 at 05:01 AM

quote:
Originally posted by britishtrident
Very Impressive -- neat -- cool -- hot -- sweet --- and and other adjective that means you diid a good job.

Those are indeed (many) kind superlatives, and, coming from you, are much appreciated.

Steve Hnz - 26/10/05 at 11:30 AM

Rorty, Thats a really neat bit of design work & will save me a heap of work on my effort. Many thanks for your efforts.
A couple of queries if I may?
I'm assuming that the trailing arm mounts are designed for book length arms which from memory are about 304mm ( 12" ) ?
Yor panhard mount on the tube, which you describe as being made from 4140(?), is this one piece?, & is the seperate piece shown, like a washer with one conical side, is that the safety washer? Thats what I've taken it as, sorry if this sounds thick.
Thanks, Cheers Steve.

Neville Jones - 26/10/05 at 02:17 PM

How many people on here know what 4130 and 4140 are? How difficult is it to get?

And do they know it has to be welded very carefully with special filler material? I had to search the inet to find out.

Ordinary mild steel is what the book specifies, is this good enough?

I've got plenty of stainless to hand, use it in the salt, can I use that?

Sorry for the Q's

Nev.

NS Dev - 26/10/05 at 05:16 PM

Why would you want to use 4130 or 4140.

You DEFINITELY don't want 4140, it is a tool steel!

4130 would be nice but as you say needs careful welding and to make any advantage out of it you will need very thin section tubing, which will be a) very tricky to get hold of and b) very expensive.

cheers

NS (engineer in an alloy steel tubemaking plant!!)

Neville Jones - 27/10/05 at 03:21 PM

I am a bit confused by this now. Rorty said a few posts back that he preferred 4130 and somewhere mentioned 4140.

So what do I use? We have plenty of 316 and 306 stainless in the shed, is this ok?

Nev.

Rorty - 28/10/05 at 04:22 AM

quote:
Originally posted by Steve Hnz
Rorty, Thats a really neat bit of design work & will save me a heap of work on my effort. Many thanks for your efforts.
A couple of queries if I may?
I'm assuming that the trailing arm mounts are designed for book length arms which from memory are about 304mm ( 12" ) ?
Yor panhard mount on the tube, which you describe as being made from 4140(?), is this one piece?, & is the seperate piece shown, like a washer with one conical side, is that the safety washer? Thats what I've taken it as, sorry if this sounds thick.
Thanks, Cheers Steve.

Steve,
if you download the PDF file and look at drawing # 08, you'll see the mount is one piece and the safety washer is another separate item. Actually, that spec should read 4340 and not 4140. I'll fix that.
The safety washer is there in case the bearing ever pulls out of the rod end, in which case the washer prevents the rod end's body from becoming completely detached from the mount.
In the rare event it happens, you'll hear a thump and the car will become a bit loose, but it will allow you to pull over safely.

Rorty - 28/10/05 at 04:24 AM

quote:
Originally posted by Neville Jones
How many people on here know what 4130 and 4140 are? How difficult is it to get?

And do they know it has to be welded very carefully with special filler material? I had to search the inet to find out.

Ordinary mild steel is what the book specifies, is this good enough?

I've got plenty of stainless to hand, use it in the salt, can I use that?

Sorry for the Q's

Nev.

4130 and 4140 are SAE alloy steels, but they're imported into Britain and here too. Actually, that should be 4340 and not 4140 (though you could use 4140 if you had a lump of it).
You may have more luck obtaining EN24T in the UK though, as that is the Euro equivalents.

Rorty - 28/10/05 at 04:27 AM

quote:
Originally posted by NS Dev
Why would you want to use 4130 or 4140.

You DEFINITELY don't want 4140, it is a tool steel!

4130 would be nice but as you say needs careful welding and to make any advantage out of it you will need very thin section tubing, which will be a) very tricky to get hold of and b) very expensive.

cheers

NS (engineer in an alloy steel tubemaking plant!!)

My mistake; it should have read 4340. Even so, 4140 does get used for high strength welded fasteners on some race cars etc. though I use it mostly for making axles.

Steve Hnz - 29/10/05 at 08:37 AM

Thanks Rorty, I've got that now, I'm Ok with the rest ( I hope), off to look for someone with a lump of 4340
Cheers, Steve.

flying_coffin - 12/8/06 at 07:47 PM

Sorry if this is a dumb question and sorry to drag up this tread again...

However, just to satisfy my mind, are the drive shafts from the Sierra standard lenght or have they been modified in any way.

cymtriks - 22/8/06 at 10:26 PM

A four inch Deon tube in 14 gauge is fairly hefty.

Caterham used a 2.5 inch tube (I don't know the gauge) and the LaBala project uses 3 inch 16 gauge.

I reckon a 2.5 inch tube in 14 gauge would be man enough or 3 inch in 14 gauge to allow some leeway in welding skill.

Surely four inch would hold up a monster truck?!?!?!?