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MX5 Fun Car

So the MX5 is the first turbo install I have done where its not factory replacement or completely and entirely compromised by packaging, and i generally have a reasonable amount of time on my hands to get little things sorted (yay for no race schedule).

On all the previous cars (even the factory stuff) the water ports have been relatively horizontal, and I have followed suit for other turbo conversions.

However, reading this Garrett whitepaper (mirrored on GCG) [url]https://gcg.com.au/component/rsticketspro/view-article/18-water-cooled-turbos-they-need-water[/url]
they suggest a 20° clock with the inlet down and the outlet up. But also recommend an uphill pipe from the outlet to somewhere else in the engine to enable thermal siphoning after shutdown.

[img]http://gcg.com.au/images/water_p7.jpg[/img]

On the MX5 this is a problem, as the high pressure inlet sources for the turbo are all in the head, and higher than the turbo. Conversely, all the return locations are low in the block or the mixer.

Originally i was planning on just running the high pressure side out of the thermostat spacer at the back of the head, where the heater core comes out. Or as another guy down here has done, inline with the heater core:

[img]https://i.imgur.com/w2TPhkc.jpg[/img]

But that puts the inlet side at 20° elevated, rather than on a decline, and from this graph is more than somewhat undesirable:

[img]http://gcg.com.au/images/water_p8.jpg[/img]

How much am I overthinking this? Just put it in horizontal and leave it be?

Started working out a place for the intercooler and oil cooler, and I think it will end up with them stacked in front of the radiator. A little less than ideal, but nowhere else really works for packaging.

Used it as an opportunity to practice more on the TIG:

[img]http://images.plebeians.net/_data/i/upload/2019/05/25/20190525005709-fa133f9e-xl.jpg[/img]

Made up a long bracket to go between the upper AC mounting holes:

[img]http://images.plebeians.net/_data/i/upload/2019/05/25/20190525005735-bbdc22b3-xl.jpg[/img]

FG intercooler fits well in there now:

[img]http://images.plebeians.net/_data/i/upload/2019/05/25/20190525005727-68707ef2-xl.jpg[/img]

Although im still considering getting a shorter and wider core to mount in the air stream some more. Perhaps something like this at 500x230mm:

[img]https://i.ebayimg.com/images/g/vy0AAOSwFeNcw8Dj/s-l1600.jpg[/img]

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MX5 Fun Car

Typical that just after I pick up the block i come down sick and am out of action for a week or so. Crawled out of bed today and was feeling a touch better, so started pottering around building the engine.

First up was doing all the calcs for the piston/rod/pin combos:

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050531-3e3b1bd9-xl.jpg[/img]

Then file fit all the rings, which mercifully didnt need much more than a touch on the linisher.

Add one set of ACL race bearings:

[img]http://images.plebeians.net/_data/i/upload/2019/05/23/20190523050523-b9f234c1-xl.jpg[/img]

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050514-b652dd86-xl.jpg[/img]

Add rings and spin them all around to different parts of the piston, and compress:

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050504-3274377c-xl.jpg[/img]

Insert into block:

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050359-8b808809-xl.jpg[/img]

Check bearing clearances with Plastigage… then find out that your plastigage has gone hard, and go buy ACL Flexigauge. Check bearing clearances with Flexigauge:

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050409-f0e42e62-xl.jpg[/img]

Rinse and repeat 4 times while fielding calls from OS and small children, and you get this:

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050431-d1a2741e-xl.jpg[/img]

[img]http://images.plebeians.net/_data/i/upload/2019/05/23/20190523050456-2a51c8a3-xl.jpg[/img]

Subsequently realise that you cant remember aligning the rings on piston 2, and so remove that to check… thankfully i had actually done it.

CSH time: When i was in high school a kid a couple of grades above got a Datto 1200 for his birthday and proceeded to do it up, so that he could drive it to the Year 12 formal. When it came down to the wire he started it up and it was spewing smoke out the exhaust. Nevertheless he drove it to school proudly.
What went wrong? Well he was a little bit OCD with the car, and so lined up all of the piston ring gaps on the pistons…. :knock:
Taught me that you shouldnt line up piston ring gaps, even before i had built an engine.

Anyway, now waiting for replacement valve springs to come for the head, and then I should be able to screw that together and start thinking about closing up the engine.

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VORON Raspberry Pi Case

Had a couple of hiccups with the 24v PSU burning out the crappy SSR, so that needs to be replaced. Printer is working well though, but can only print PLA as the heated bed cant get hot enough without the SSR failing at higher amperages.

In lieu though i decided i needed to learn Fusion 360 rather than using old AutoCad 2d and Blender stuff. So i knocked up a Raspberry Pi case for the printer. Here is the timelapse of the build:

Now i just need to wait for some bits to build a custom FET driver for the heated bed, rather than having to use another black box SSR that may fail. See this thread for more details on that: [URL]http://forums.overclockers.com.au/showthread.php?t=1195177[/URL]

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VORON Update

Didnt have much time over the weekend, but got it mostly running:https://www.instagram.com/p/BE3gCwpEp7v/
My Geetech fan extender seems to be not playing nicely and has a short on the board, so i have lost the servo pins on my RAMPS. So the fans are manually controlled for now. Im using the 18mm bodied sensor as I dont have the 12mm yet, and it requires some funky config as the extra depth pushes it off the build plate when sensing.
Oh and i accidentally swapped the Ext0 and Ext1 heaters, so its a bit squiffy there, but not terribly hard to fix. 
Now i just need to wait for a new RAMPS board so i can get the servo/fans running again, and I have to tidy up the RAMPS box, as its a bit messy in there.
Oh and i have somehow lost a mounting bracket for a NEMA17, so i cant mount up the second extruder yet. 🙁

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VORON Part 3: Wiring

Did most of the electrical today, and brewed my traditional ANZAC day beer in between.
All pretty much ready to go, except that the Arduino blew up, so time to get a new one.
What i forgot to mention in the video is that the RAMPS box im using has a hole cut out of the top to allow for the extruder carriage wiring to drop in the top there, makes for a cleaner wiring path IMHO.
Now to wait for the bits from eBay which will hopefully all be waiting when i get home.

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VORON Frame

I built my cube today as well, after having to modify the bolts to hold it together because the OpenBuilds cubes were machined fairly poorly.
[IMG]http://gallery2.plebeians.net/d/38006-2/20160422-163309-iPhone.JPG[/IMG]

Still its together and as square as reasonably possible:
[IMG]http://gallery2.plebeians.net/d/38001-2/20160422-163219-iPhone.JPG[/IMG]

In lieu of the next video here is a parts glory shot. Stupid GoPro decided to blink as if it was recording but record about 15s and then stop.
See if you can spot the missing parts…

[IMG]http://gallery2.plebeians.net/d/38011-2/P1010005.JPG[/IMG]

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VORON MIC6 Bed Plate

Also in the box of bits from the US was my MIC6 build plate that i got from a US supplier because chasing suppliers here in Aus was a pain in the butt: “oh you want 6061 plate”…

Anyway tonight i had an hour or so free after coming home from a meeting and decided to see if a plan that i have had in the back of my head would come to fruition.
[IMG]http://gallery2.plebeians.net/d/37991-2/20160421-232002-iPhone.JPG[/IMG]

The recommended heater for the VORON is a stick on silicone rubber heater mat in AC voltages, which is then fed through an AC SSR to be controlled by the RAMPS. Now i dont mind AC stuff, but mixing AC and DC on a 3d printer just annoyed me slightly. Plus the silicone heater mats dont tend to work particularly well unless you spend a motza on them. I had this MK3 heated bed lying around as it had a damaged ear from shipping and so couldnt be leveled properly on my Prusa.

So i decided i would try using a standard MK3 heated bed as the heater for the VORON. Thats the standard 230mm MIC6 bed underneath with four tapped M3 holes in it to mount the bed to. Also planning on using either a sheet of 3M mounting tape (same as the PEI stuff) to add adhesion, or a thin smear of silver thermal adhesive to remove some of the stress from the bolts and also to increase thermal conduction.

There is a bolt missing from the damaged corner of the bed, but I’m planning on cutting the broken piece of metal out and attaching the bed to that corner as well using a wider custom washer.

Will see how it goes. But hoping it will be a viable alternative. Also if the threads fail in the aluminium plate i was thinking of drilling through and using neatly countersunk M3 taper head bolts under the PEI to bolt the heated bed on. Its also touch and go for the spring mounts, but should be able to squeeze them in. For a bigger bed size it would be a cake walk.

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VORON 3D Printer Part 1

For a little while now i have been gearing up to replace my Prusa i3 with another printer that will be stored indoors. One of the big factors is WAF along with the safety for little hands being near it.

After deciding on a CoreXY build i couldnt settle on the specific design, until a few weeks ago when russiancatfood/mzbot released the VORON to the public. I quickly settled on that for a variety of reasons, not least of which is the ease of enclosure and general minimalistic beauty of the build. This weekend im planning on building it from go to whoa, and here is the thread for documenting it.

In the past I have put up extensive build threads on various forums, usually for race cars (such as the one you can see in the corner of the frame here). But for the VORON I thought i would do something different given that its not so much an engineering and design challenge, but just a build thread.


Thats the first part of the build done. Just waiting on a parcel with the corner cubes and i can put the frame together. The other stages will be2. Mechanical3. Electrical4. Finishing touches

Planning on a couple of little mods to the design, but they will come later.
Also sorely missing my lathe and mill at this point. In the past i would have fed that 20mm T-slot in through the headstock and into a 4 jaw chuck, and simply parted it off on the lathe using a cutting disc mount. Sadly all that equipment is 800km away in a storage shed 🙁

More on the VORON can be found here: https://github.com/mzbotreprap/VORON

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Welcome to the Garage

For about two decades now I have been tinkering on random things in various ‘garage’ spaces to keep myself sane. Starting out with computers and case modding, and then moving to cars, bikes, microcontrollers, and now 3D printers, it has been a rather long journey.

Lots of this journey has been documented on various forums over the years, but with the forum platform now going the way of the dodo I thought it was high time to migrate a bunch of build threads and other garage threads over to a blog.

Occasionally in these builds there will references to other threads or to people from the forums, and it may not make entire sense. But that is a price I’m willing to pay for not having to rewrite everything from scratch.

Here goes then, an attempt to collate all the random garage stuff I have done in the past 20 years.