134 replies to this topic

[Bigfella237]

I noticed that SolidWorks has different file extensions for a part or an assembly and you can't open an assembly unless you have all the parts, but this free software just has the one file extension.

 

Regardless, yes I'm creating all the parts separately and storing each separately both as a 2D sketch and a 3D model, then I just import them all into one common model that you see above.

 

The drawback with this is that if I need to change something, I have to remember to go back and make the changes in the original file and then re-import that part back into the assembly, whereas I assume SolidWorks lets you modify the part within the assembly and automatically updates the individual part, but this software is free and SolidWorks cost thousands of dollars so I'm not complaining!

 

EDIT: My TV needs a zoom function, I'm watch the V8 Supertaxis do pit stops but I can't quite see their disc rotors? :(

Edited by Bigfella237, 12 July 2015 - 04:38 PM.

[Bigfella237]

Yeah I should have drawn the vanes separately but I didn't, would've been a lot easier to extrude the three parts and merge them than the way I did it but I'm still learning... Proper Planning Prevents Piss Poor Performance

[Sven]

Yes. There are lots of ways to do the same thing. For me, I find I model, the same way I would construct the timber pattern.

[Bigfella237]

Last couple of bits added...

 

 Floater Assy 7.JPG   53.66K   0 downloads

 

...and finally all assembled...

 

 Floater Assy 8.JPG   58.93K   0 downloads

 

I (thankfully) was able to cheat and downloaded the caliper off GrabCAD, it wasn't even close to full scale but seems to have up-scaled well enough, it's not the correct one from the kit either but you get that.

 

I couldn't be bothered CADing disc pads or nuts, bolts & spacers etc., same for the springs, adjuster and so on for the handbrake, although I would like to re-design the little lever when the time comes. At the moment their setup has the cables pulling from the front but I'd rather it pulled from the direction of the diff centre so the cables can run along the top of the axle tubes and into the car with the (centred) top trailing arm (much tidier / more hidden that way), should be an easy job, just have to make sure the cable travel vs leverage is correct.

 

I'm just gonna have a quick look at this disc backing plate / air scoop idea then it's back to the diff housing and rear suspension, that's unless I get side-tracked doing wheel rims in the meantime!

 

[Bigfella237]

In the interests of keeping it simple, something like this...

 

 Backing Plate 01.JPG   60.13K   0 downloads

 

...but I'm undecided whether to have it down low in the air flow where it can pick up stones and crap, or up higher where there won't be as much wind?

 

If I moved it up too far I'd need to consider that it might hit the chassis on full squat too, although it could be shortened to fit within the same profile as the caliper I guess?

 

I'll keep playing...

 

[Bigfella237]

I remember that little scoop on Hilux front discs, they were a plastic scoop riveted to the metal backing plate IIRC?

 

Yep, found a photo on google...

 

 Hilux backing plate_sml.jpg   44.12K   0 downloads

 

...but Landcruisers didn't have them. Why? Because early Hilux had solid front rotors and Cruisers had ventilated.

 

[Bigfella237]

Does the free software you're using have a library for this like bolts and washers?

 

Bearings you can get from the website of the manufacture, FAG bearings or NSK are pretty good

 

I think you're right Joshua, thanks for that, I dismissed that screen originally because it had all kinds of weird robot parts and the like but I'll go back and have a look.

 

I have been to NSK's website and I think it's an absolutely brilliant idea to make CAD models of your products available (unless they're easily reproducible that is), unfortunately I don't know the part number of the bearing Strange is using so I couldn't narrow down the selection, I should just pick one that looks close (I know the ID is 2" anyway) and throw it in but I've been busy elsewhere!

 

Version 2.0 of my scoop is like V1 with a slightly hipper rap...

 

 Backing Plate 02.JPG   55.66K   0 downloads

 

...but this one has to bolt on because it covers the handbrake adjuster hole.

 

Although, after seeing the Hilux plate again, I do like the idea of louvres instead of a grille, just have to figure out how to draw them in CAD? And I also like the thought of making the scoop piece out of plastic or maybe composite so that if it ever does happen to get snagged on something it can simply bend or break away instead of bending everything its mounted to.

 

I was thinking about some kind of ducting for the front brakes but that's a whole other story because I want to redesign the fiberglass A9X air ducts to funnel into a flexible hose, but I also want to incorporate an oil cooler within each one. I know that would pre-heat the air being fed to the brakes somewhat but oil temp will still be significantly lower than brake temp and it's a neat way to hide the oil coolers!

 

But on the rear I don't really know where you'd duct air from? I've seen ducting cable-tied to trailing arms but that looks untidy and wouldn't be too much different to the above design.

 

In the end, I don't know if rear brakes even need that much cooling, especially being 13" ventilated rotors as above, I just thought I'd toy with the idea but want to keep it neat and tidy, not looking like a full-on race car.

[Bigfella237]

As Tim The Tool Man Taylor would say "Ogh Ogh Ogh", Version 3.0...

 

 Backing Plate 03.JPG   91.92K   0 downloads

 

I think I kinda prefer the look of V2 myself but bigger has gotta be better when it comes to cooling.

 

This reminds me of something I've seen before, but it may just be the louvres, which BTW, really suck to draw in CAD!

 

[Bigfella237]

Damn I'm getting tired of drawing this diff housing, this is V3...

 

EDIT: DOH! Hit the post button instead of "More Options", I've been awake too long I think!

 

 9'' Diff Housing 01.JPG   32.93K   0 downloads

 

 9'' Diff Housing 03.JPG   33.1K   0 downloads

 

V1 (pictured earlier in this thread) was really scrappy and I've learned a few things since then, don't even ask about V2, drew the whole bloody thing up and then realised I was working off the wrong set of dimensions! Errgghhh...

 

Onto the third and hopefully final version, oh well, I got to refine all the dimensions a little too, shaved off half an inch from the total depth and finalised the axle tube lengths (keeping the same width as a standard SS diff).

 

Drew up a 2D sketch for the plate needed, that entire back section (with the exception of the four internal baffles) is one piece, 18 folded edges and only 4 welded seams (not counting the front plate or axle tubes)

 

Anyhow, better resubmit before my damn edit time runs out again!

 

EDIT 2:

 

BTW, I figured out the volume calculator and the sheet metal section only holds just over 5 litres total (chock-o-block full) so maybe a third of that will be the oil capacity? I still need to figure out exactly where the oil level should be (and don't say "the filler plug" because that's what I'm trying to add).

Edited by Bigfella237, 15 July 2015 - 11:04 PM.

[Bigfella237]

Downloaded an inner axle tube oil seal off the SKF website, pretty crappy looking actually, not sure how well it would seal not being round? I'd guess that it's a computer generated CAD model, should'a just drawn one myself but couldn't be bothered.

 

Anyway, I thought I'd whip up an alloy collar that clamps into the axle tube behind the seal, not sure if it's really needed but would assist in not pushing the seal out when fitting the axles at least and it should weigh bugger all.

 

 Axle seal and collar 01.JPG   42.83K   0 downloads

 

Although it somehow ended up looking more like the nozzle off a rocket motor than an alloy collar.

 

 Axle seal and collar 02.JPG   35.75K   0 downloads

 

[Bigfella237]

P.S. Their wheel bearings aren't any better...

 

 Hub with Bearings and Seal 01.JPG   43.32K   0 downloads

 

...but I was thinking that this might be deliberate to prevent people using SKF's own CAD drawings to machine up parts?

 

[Bigfella237]

Just finishing up some bits 'n pieces with the front plate of the diff housing and getting some practice in with making hoses & piping too...

 

 9'' Carrier in Front Plate 02.JPG   66.39K   0 downloads

 

Those hoses above will change once I figure out where the upper trailing arm mount goes so they're not the finished product, I really just threw them in for aesthetics.

 

Figured out where the oil level should be and made a filler plug with a sight glass, I was tempted to use an elongated sight glass so you can actually see where the level is rather than just whether it's full, but I'd be worried about a rock hitting it and letting all the oil drain out of the diff, do they make bullet-proof ones?

 

Also made a rough attempt at a temp sender but I've been looking around online for a combined temp and level sensor, found a few although nothing that really takes my fancy, I'd like both features but not separately. I made all four holes ¾" NPT anyway so pretty sure I should have room to adapt something later.

 

I'm still unsure if I need a separate sender to trigger the pump/cooler as well, I might be able to use the same one for pump and gauge if I can find a suitable controller, although that would give me adjustability it's just one more thing to go wrong so I might still need to rearrange the layout yet?

 

Made a neat looking little copper pipe to dump oil returning from the cooler onto the pinion, still undecided whether that's the best place for it and I'm open to suggestions? I think the absolute best place would be tapped into the snout of the case to positively oil the front pinion bearing, but I'm trying to stay away from modifying the case and just keep everything in the housing.

 

 9'' Carrier in Front Plate 03.JPG   70.77K   0 downloads

 

I think I'd need to incorporate a one-way check valve in the system somewhere too, maybe in the pickup down the bottom, to stop all the oil draining back out of the plumbing and overfilling the diff.

 

The lower fitting could double as a drain plug but wouldn't ever get used, heaps easier just to disconnect a hose off the cooler and used the pump to do oil changes.

 

Nearly suspension time, following Heath's other thread with interest...

[Heath]

Since I started the thread I should probably contribute something. 

 

Drew up some front crossmember spacers with an eccentric/offset on the spigot. Gonna get them NC machined in 30mm alloy plate, the rest of the bits I'll make on manual machines.

 

Edited by Heath, 17 July 2015 - 10:05 PM.

[Bigfella237]

I've been thinking more about Jeff's suggestion to have those eccentric spigots removable so different offsets could be fitted...

 

 k-member eccentrics.JPG   19.16K   0 downloads

 

...but I think you'd have to have them hex-shaped or at least add a flat side to stop them turning? Otherwise the whole k-member could slowly work its way sideways.

 

Hey Heath, while you have the verniers out, any chance you can measure up the holes in the top of the chassis rails for me?

 

I'd like to CAD a set of alloy bungs but not sure how to retain them. I see some have o-rings but not sure how long they'd stay put? Can't really attach them to the k-member bolts either, maybe some kind of twist 'n lock system?

[Bigfella237]

Well whadda ya know, this software does do mirroring (I blame the operator myself)...

 

 Backing Plate Ducts.JPG   27.8K   0 downloads

 

Seeing as you've confessed to being "the man" when it comes to 3D printers Heath, and as I've never even seen one let alone printed anything, what is the material things are printed with?

 

Is it a soft plastic, or rubber, or some kind of wax, or is it something more durable?

 

Why I'm asking is, if I got these ducts printed, could they be used straight off the printer or would I have to then take a mold off the print and lay one up out of composite or similar?

[Bigfella237]

Pouring on the style now...

 

 9'' Diff Housing 04.JPG   42.18K   0 downloads

 

I only really guessed the height of the Watts Link pivots (I know they're separated by 5" vertically same as the bell crank, I just don't know where the rear RC will actually be yet) but from looking at a few photos it would be close enough for now. I considered adding a third tube to brace that upper Watts Link pivot (on the right) but I really don't think it needs it?

 

BTW, those tubes are the same diameter as the trailing arms will be made from, 1-3/4" OD 120 thou wall chrome moly with the biggest rod ends I could find. all super heavy duty rock-crawling gear!

 

Which reminds me, I was watching Monster Jam before and the diffs in those trucks look almost identical in design to the above (just a lot beefier), I swear I never looked at them before I designed this, honest.

 

The only thing I still need to add are the pushrod mounts for the remote transverse coilovers but I need to look at rim widths & offsets first to see how far out I can get them? I may be able to go higher with the upper trailing arm mount too but I need to somehow model a Torana rear chassis clip first so I can work out where the coilovers are going and how far up through the floor everything can travel?

 

The only drawback so far is that my brake disc vent is a little too tight so back to the drawing board for version 4 of that, I've got some other ideas I want to try anyway now...

 

 9'' Diff Housing 05.JPG   32.76K   0 downloads

 

[Heath]

Seeing as you've confessed to being "the man" when it comes to 3D printers Heath, and as I've never even seen one let alone printed anything, what is the material things are printed with?

 

Is it a soft plastic, or rubber, or some kind of wax, or is it something more durable?

 

Why I'm asking is, if I got these ducts printed, could they be used straight off the printer or would I have to then take a mold off the print and lay one up out of composite or similar?

There are a range of printing technologies with different types of media, but the only one you'd really be considering for parts on your car (taking into account cost & part longevity, mechanical performance etc.) would be those done on an 'FDM' style machine, so the parts would be rigid thermoplastic and yeah for a part like that vent you could print it on a decent professional machine in ABS; that would be durable enough for your average Torana, but probably wouldn't put it on a fourbie crossing the outback and throwing up thousands of stones. At the same token, without having a machine yourself, there would be other ways to make a component like that duct that wouldn't be that hard, either.

[Bigfella237]

One more piece of the puzzle (and a part I've been wanting to do for a while now)...

 

 9'' Diff Housing 06.JPG   52.54K   0 downloads

 

Not sure if the dimensions are correct, I think the width across the top is a little narrow compared to shop-bought kits but everything else should be okay?

 

The bell crank is 5" between rod-end centres and has 6" of total vertical adjustment, as best I can find on the net that's how most kits are? And the whole thing is designed to bolt to a 50x50 square tube.

 

Unfortunately I need to go back and remake the diff mounts now as they don't quite stick out enough, but I might wait and see if the spring mounts can be incorporated as well. Doesn't matter too much anyway, it's a lot easier to fix something like that in CAD than IRL!

 

Apart from tidying up a few little bits, I don't think I can go much further now until I can find a bare Torana shell to measure up the chassis rails on?

 

[Bigfella237]

Hmm, didn't realise how big the tyres were until now (everything to scale)...

 

 9'' Diff Housing 07.JPG   47.57K   0 downloads

 

Rear track width and lower trailing arm mounts look about right but my suggested range for the rear RC is 6.5" - 12.5" AGL and I'm a tad over two inches too high so I'll have to drop the entire Watts Link assy down, which means relocating the diff mounts too if I want to have the links level in the centre of the adjustment.

 

Oh well, I had to adjust them anyway and that means I get to lower the LCA mounting points some more as well, so long as I still have at least 100mm ground clearance but I've got 180mm at the moment so still a bit of wiggle room left.

 

Overall width from the outside of one tyre to the outside of the other is 70.2" (1783.6mm), suppose I'd better try and figure out whether that's gonna fit under a set of flares too, although there's no law against widening flares (so long as I stay under 2.5m of course)!

 

[76lxhatch]

Why do you want to drop the roll centre so low, will you be redesigning the front end to match? If your roll centre is 6.5" above ground and the bell crank is 2.5" radius then surely by the time you account for the extra bulk there is no way you'll have 100mm clearance?

What rolling diameter do you have there, looks reasonably large?

[Bigfella237]

Why do you want to drop the roll centre so low, will you be redesigning the front end to match? If your roll centre is 6.5" above ground and the bell crank is 2.5" radius then surely by the time you account for the extra bulk there is no way you'll have 100mm clearance?

What rolling diameter do you have there, looks reasonably large?

 

For the time being I'm basing everything on a rear tyre size of 315/35R17 (12.4" wide, 4.34" sidewall height, 25.68" diameter), based on the biggest Khumo KU36 they make...

 

 Kumho KU36 sml.jpg   27.25K   0 downloads

 

(The tyre pictured is not the same exact size, just a generic picture)

 

I actually wanted something more like a 345 but I'm trying to stick with 17" rims and the range is somewhat limited in street/sport.

 

Anyway, I must confess I haven't gone to the trouble of working out all the correct front & rear ICs & RCs yet, I was working off Ron Sutton's "suggested ranges" as follows:

 

As a rule of thumb, starting point for roll centers, I'd suggest ...

Conventional High Roll Angle Set-ups:
Autocross: Front RC 1"-3" & Rear RC 9"-12"
Road Courses: Front RC 2"-4" & Rear RC 10"-14"
Suggested Rear RC Range: 8.5"-14.5"

Moderate Mid Roll Angle Set-ups:
Autocross: Front RC .5"-1.75" & Rear RC 7"-10"
Road Courses: Front RC 1.25"-2.5" & Rear RC 9"-12"
Suggested Rear RC Range: 6.5"-12.5"

Modern Low Roll Angle Conventional Set-ups:
Autocross: Front RC 0-.5" & Rear RC 5-8"
Road Courses: Front RC .5-1.5" & Rear RC 8"-10""
Suggested Rear RC Range: 4.5"-10.5"

The starting points & ranges above are assuming a solid axle rear end with no camber, toe or significant rear steer.

 

I took a guess at the "Moderate" setup but if we take the figures for the "High Roll Angle" setup then what I have now is actually spot on.

 

Any thoughts on where the rear RC should actually be for a Torana (and yes I know that's like asking "what rims fit my car" but at least a range would get me close)?

 

[76lxhatch]

Tyre is nowhere near as tall as I thought it was, around the 26" mark seems to work OK.

As I mentioned I believe ground clearance would be an issue if you dropped the watts link centre height to 6.5". Beyond that though my thoughts would be to not get too carried away with lowering the roll centre excessively in a mild modification scenario. Although the factory roll centre is too high, the car as a package can be made to work well enough and moving drastically away from that can introduce as many problems as it solves. I think its fair to say it would overall fit into the high roll angle setup.

If we're talking major changes and revising the front end as well, then its clean sheet time and none of this applies, but then you've got a massive amount of research, development and testing work in front of you!

[Bigfella237]

 ~ you've got a massive amount of research, development and testing work in front of you!

 

Tell me about it! My goal at this stage is just to get everything 'roughly' in the right place and build-in enough adjustment to allow for fine-tuning later.

 

But as is evident, aesthetics are high on my list of priorities too, for example those nice rounded diff mounts will probably weigh a touch more than a plain ugly bracket would, but for me it's worth the difference. What I'm trying to do is design the strength into the structure rather than the material, if I can use 3mm plate instead of 5mm I've saved 40% of the weight straight away therefore I can use 40% more surface area to add strength. Triangles and circles are stronger than squares and rectangles!

 

As for those tyres, I agree they look disproportionate to everything else but I've measured, re-measured and re-re-measured half a dozen times already and it keeps telling me they're correct.

 

I must admit though that I've been caught out before by this software (usually after staring at the monitor for too many hours), when creating circles it asks for the diameter but for cylinders it wants the radius, a little annoying but what do you want for free!