DIY LTCC or similar system for LT1s

**vilefly** · 06-28-2018

The schematic suggests you are going ahead with a different arduino pro mini than I thought. But I realized you are going for a small footprint, and it looks pretty compact. This is what I will be using so I can modify for ion-sensing. The schematic will still work with it.
arduino-pro-mini-clone-atmega328-5v.jpg

Looks like you learned that the next generation of machinists suck. They forget to hone the valve guides after they are done cutting. I ran across this about 10 yrs ago, and was appalled that someone could not machine a small block chevy cylinder head properly. The worst part is that today's heads are more complex. I wonder how those jobs turned out. blech.

**spfautsch** · 06-28-2018

There's no arduino daughter board - this design is using the Atmega328P in a 28 pin dip package. I'll be ordering components from Digi-Key soon and if the boards all test out will have about 8 samples I'll be offering up here.

Competent machinists seem to be a dying breed seemingly because the vast majority of what they used to offer can usually be bought new from Chinese sources for less.

**spfautsch** · 07-28-2018

Circuit boards arrived from China yesterday. I'm nothing short of amazed that a board of this quality with gold plated solder pads, full mask and silk screening can be done for the neighborhood of $3 each in small quantities.

I'm tied up this weekend and probably next helping my mother move, but I was able to assemble one over the last two evenings. I wont be able to test fully for several days and / or weeks, but the initial power-up test proved successful. I fully expect to find at least one problem, but so far everything is looking good. I'll try to post a picture or two soon.

This leaves me needing a solution for a case. As much as I'm personally satisfied with potting them in silicone, I would really prefer some type of serviceable case so modifications can be made (there are three open outputs and one input). I've been stewing over some ideas for a 3d printed affair with o-ring sealing around the wiring penetrations and a lexan / acrylic lid (also with o-ring sealing).

How ever that pans out, I'll have some boards available around the end of August if anyone would like to come up with their own case in order to test.

**spfautsch** · 08-04-2018

Been working through a crash course in Blender 2.79 since last post. Hope to have a case design ready this weekend. Does anyone have a 3d printer they'd be willing to put in service? I've been wanting to buy a cheap Kossel type kit for several years but haven't had the funds. I could probably swing it now, but it would put me a few weeks behind with getting my cylinder head fixed.

What I think will work out is to make the case lid a piece of cut lexan that seals against a perimeter o-ring, a groove for which will be printed in the case. That is provided I can find an o-ring of the necessary size. To seal the wiring penetrations I was thinking of printing dimples in the case as drill locators, and the builder can drill as many holes as needed for their application. The holes will need to fit relatively tight to the wire insulation, and then can be sealed with a two part silicone. I'll try to illustrate graphically as soon as I can get the 3d model functional.

I believe the case may need to be epoxy coated for waterproofing and to smooth out printing granularity around the o-ring groove. I'd be grateful to hear any feedback from someone with actual 3d printing experience.

**vilefly** · 08-25-2018

Sorry for the late reply, I think I have my rostock max calibrated and upgraded now. That's what I've been doing when I found the post. It's a pretty big printer, so draft away. Just need the file in .STL format. By the way the free emachineshop.com software can export to this format as well. Blender is a monster that can do about anything, though.

I have a spool of white ABS set up. I was trying the popular PLA plastic, and was constantly having jams due to the filament extruder type that mine (like the mini-kossel) has. I now hate PLA plastic and went back to ABS, but now they offer a iron powder-PLA composite. One can print reluctor wheels, but in the end, it would decompose because PLA sucks. Wish they would mix iron with ABS, so we can make things with staying power. I recommend a delta-type printer only if you use abs plastic. The standard x-y cartisian printers with the extruder right there in the moving head can do PLA without jams.

**spfautsch** · 08-27-2018

Thanks for the info.

After a week of silence I lost patience and pulled the trigger on the mini kossel kit I'd been eyeing. I took the large box of parts with me on vacation last week and accomplished as much assembly as I could without experiencing the wrath of my wife.

Some of the design flaws I've encountered are staggering. The printed extruder mount "hardware" is probably the pinnacle of this stupidity. Let's mount something capable of melting plastic into a plastic that we printed with the same extruder hardware. That sounds like a good idea? And kapton tape is a suitable way to "mount" an ntc thermistor to a flat surface we want to monitor the temperature of closely.

If I can make it fit, I have some stainless thermocouple wire braid I'm planning to use to reinforce the teflon extruder tubing.

Once I have time to finish the incompletely milled parts and re-engineer the obscenely inadequate to make the machine functional I'll report back. I have two spools of "aluminum-look" BPA that I'm hoping will work suitably. I'm hoping there aren't a wealth of other pitfalls to discover in relation to how to print large flat bottom boxes without experiencing warpage.

**vilefly** · 08-28-2018

Well, damn. I should have posted something while I was upgrading my rostock max 3 weeks ago. All this headache could have been avoided. I got mine from www.seemecnc.com . Perhaps some olgling at their designs might give you a few ideas. Mine was version 1.0 in kit form. Set me back around $1000 bucks at the time 5 yrs ago. They are now up to version 3.2 with autoleveling and other junk, and I am struggling to keep up. Manual calibration can be tedious, but it becomes routine with time.

I am debating on creating my evil 352 engine. Basically, a .030" over 400 small block with a 327 large journal forged crank in place with bearing spacers (or extra thick bearings). It is the engine I've always wanted to build that suits me. Smokey Yunick had sworn by this engine where there are displacement limits racing. I am still on the ropes about deciding, though. I know the LT-1 intake would do nice things for it, heh.