3D printed Synchros?

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Grendle
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3D printed Synchros?

Post by Grendle »

I'm about to start trying to hunt down synchros by seeing if any DFW transmission shops or Toyota specialists can source any NOS shelf parts. If I come across what I need, I got to thinking that it should be possible to 3d print replacements as long as an unused example can be found and brass 3d printing is possible. A quick google search suggests it is. Anyone with more insight into that than me have thought on the viability?
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NWMO
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Re: 3D printed Synchros?

Post by NWMO »

Grendle,

Interesting thought and there are still some NOS out there if you’re patient.

Chris
Psalm 37:4 "Delight yourself in the Lord and he will give you the desires of your heart"

In remembrance of my friend ARCHINSTL:

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Petros
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Re: 3D printed Synchros?

Post by Petros »

Robert Walker (Xirdneh on the form) looked into having some syncros made in a short run custom machine shop. as $26 each, but that adds up to a lot for all 5 syncros. there is a thread on the topic.

we speculated that we would only need to make new sycros for 1st, 2nd and 3rd gear, and perhaps pay a bit more to have only 20 of each made. but so far there are some of the syncros that keep showing up on various supply websites when old inventory gets discovered. I think I have one set of "New, In Box" sycros I have been saving for a future build.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
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Grendle
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Re: 3D printed Synchros?

Post by Grendle »

Good to know. I think if I come across a NOS set I'll look into the 3d printing option. So far I've had little luck with Dallas machine shops when NLA parts for my van need replacing, but I could definitely live with paying a good machinist a bit extra if it meant keeping my car alive. Especially considering the asking price and rarity of spare transmissions.
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SirFoxx
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Re: 3D printed Synchros?

Post by SirFoxx »

When I worked at a machine shop that specialized in gears, i had them quote me on a new input shaft. costs alone, labor excluded was 180. Out the door pricing was ~600 per shaft :/
1988 DLX 4wd Tercel Wagon w/ weber (RIP)
1985 4wd Tercel SR5 (RIP)
1986 Base 2dr Hatch (RIP / PARTS)
1986 DLX 4wd Tercel Wagon with ???
1985 DLX 2dr Tercel Hatch w/manual swap
1981 2dr Toyota Tercel w/7age (RIP)
1981 3dr hatch Toyota Tercel w/Turbo 4AGE
1981 3dr hatch Toyota Tercel SR-5
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eightyfive4WD
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Re: 3D printed Synchros?

Post by eightyfive4WD »

On the topic of 3D printed synchros, I think it would be a wonderful solution to a problem for many.
My concern however is that the type of plastic used by most 3D printers would not be durable enough.
PLA & ABS tend to be relatively brittle, and I don't know how they would hold up to the heat and exposure to gear oil. Further concern is in the fatigue stresses seen on high cycle parts such as gears.
I'm certainly not trying to say it cannot be done, but based on my limited materials science knowledge, I am not immediately hopeful.

P.S. After re-reading your post, and seeing that you intended this to be about brass 3D printing, I think that would certainly work. There are websites which offer 3D printing for metal parts, such as https://www.xometry.com/. Have not used any of them, but I know other companies such as SendCutSend do not charge absurd prices & usually offer quick turnaround times.

You would have to create your own files to send to the printing company, so essentially you'd just need a spare transmission for proper synchro dimensions, as you mentioned. But that may just be the answer to your problem. I have no specific experience in 3D metal printing to offer but hopefully someone else here can chime in!
1985 Toyota Tercel DLX 4WD 5 spd wagon (manual swapped, daily driver)
2007 Toyota Tacoma TRD 4WD access cab long bed (road trip/adventure-mobile)
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eightyfive4WD
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Re: 3D printed Synchros?

Post by eightyfive4WD »

Another interesting point, as Petros & Chris pointed out, is that 3D printing synchros may not require a spare transmission necessarily. If there are access to unused parts that can be used for dimensions, this would be easiest.

The great thing about this type of 3D printing & design technology is that it really is accessible to most people now. Fusion360 is a free to use CAD software, and there are free apps for iPhones (and I assume other smartphones?) which allow you to 3D scan objects to aid in dimensioning. The 3D scanning is not a requirement but may make this process a bit easier.

I have been meaning to download one of these 3D scanning apps to aid in my design of an ash tray cupholder for the Tercel. Not exactly as high-pri of a design project as synchro gears but I think it would be fun nonetheless
1985 Toyota Tercel DLX 4WD 5 spd wagon (manual swapped, daily driver)
2007 Toyota Tacoma TRD 4WD access cab long bed (road trip/adventure-mobile)
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Petros
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Re: 3D printed Synchros?

Post by Petros »

I have a set of brand new sycros, bought some years ago from some parts warehouse clearnace. I do not think I have the whole set, but at least two, or three of them. I have been saving them for if I ever want to rebuild a Tercel4wd trans. if you want to borrow them for taking measurments from we might work something out. I will want them back of course.

there are several issues I can see with printed metal syncros: the fit tolerance is very exactly, too large it will not work, and too tight it will not act as a synro. So I would think the smooth printer surface of the friction cone part of the ring would have to get final machined to the exact correction size. the other is the durability of the metal, consider you would want it work for 150-200k plus miles, I would think that a metal printed into the shape would have different properties than the original brass alloy stock used to make the factory syncros, and who knows if htey were using some special alloy metal mix to improve performance. Installing a set of experimental new printed syncros might work fine, but it is a big job to overhaul it, and they may disintegrate after only a few months of driving. Adding to that risk, when the experimental printed syncro breaks apart, it is possible it could trash the rest of your transmission. you not only risk the expense of fabricating new tech printed syncros, that may nor many not work as intended, but you also risk the effort and costs of a complete trans rebuild effort, as well as risking a whole working transmission as well.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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eightyfive4WD
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Re: 3D printed Synchros?

Post by eightyfive4WD »

Hello Tercel freaks,

I wanted to return to this topic once more with some information I gathered during a manufacturing process course at Arizona State. I took a materials science/manufacturing tech elective and additive manufacturing was one of our discussed topics. The professor mentioned that in the case of metal additive manufacturing, specific metal density/porosity can be achieved, so as to allow for a certain level of oil saturation within the components themselves. In the application of gears or synchros, I believe additive manufactured metal parts could be a great choice.
1985 Toyota Tercel DLX 4WD 5 spd wagon (manual swapped, daily driver)
2007 Toyota Tacoma TRD 4WD access cab long bed (road trip/adventure-mobile)
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Re: 3D printed Synchros?

Post by xirdneh »

The place i found was in india. I sent them a used sample. The cost per synchro was very reasonable but you had to order several hundred to make it worth it to them. Something like 900 bucks worth of them.
Love those Tercell 4x4 wagons but they sure suffer from road noise.
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NWMO
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Re: 3D printed Synchros?

Post by NWMO »

Hey all,

Peter indicated 5 synchros, so my “kit” did not include the 5th gear synchro. Two larger and two slightly smaller, both twins as far as I can tell for 1-4 and reverse? I am including a pic of the “missing” 5th gear synchro (the smallest of the 5) from a parts tranny that lost 5th gear.
10655743-8601-40C2-B6DE-A2E8341E5E73.jpeg
CC05EC51-CCCE-4EC3-B906-705EC8570466.jpeg
AAD74989-06BC-477A-B89F-A4E1F775BE7F.jpeg
1785C1D6-AD17-4C76-81ED-6981B31067FD.jpeg
If these are “twins” as they appear to be, you would only need 3 for “mapping” purposes.

I also have the half dozen or so paper gaskets. I would think those would be pretty easy. I just used form-a-gasket on the Rusty Frog, but the tranny weeps a little.

Chris
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Psalm 37:4 "Delight yourself in the Lord and he will give you the desires of your heart"

In remembrance of my friend ARCHINSTL:

T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"

"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
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SirFoxx
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Re: 3D printed Synchros?

Post by SirFoxx »

NWMO wrote: Thu Jan 05, 2023 9:46 am Hey all,

Peter indicated 5 synchros, so my “kit” did not include the 5th gear synchro. Two larger and two slightly smaller, both twins as far as I can tell for 1-4 and reverse? I am including a pic of the “missing” 5th gear synchro (the smallest of the 5) from a parts tranny that lost 5th gear.

10655743-8601-40C2-B6DE-A2E8341E5E73.jpegCC05EC51-CCCE-4EC3-B906-705EC8570466.jpegAAD74989-06BC-477A-B89F-A4E1F775BE7F.jpeg1785C1D6-AD17-4C76-81ED-6981B31067FD.jpeg

If these are “twins” as they appear to be, you would only need 3 for “mapping” purposes.

I also have the half dozen or so paper gaskets. I would think those would be pretty easy. I just used form-a-gasket on the Rusty Frog, but the tranny weeps a little.

Chris
reverse has no syncro. thats why it grinds super loud if you dont hold the clutch pedal long enough before shifting.
1988 DLX 4wd Tercel Wagon w/ weber (RIP)
1985 4wd Tercel SR5 (RIP)
1986 Base 2dr Hatch (RIP / PARTS)
1986 DLX 4wd Tercel Wagon with ???
1985 DLX 2dr Tercel Hatch w/manual swap
1981 2dr Toyota Tercel w/7age (RIP)
1981 3dr hatch Toyota Tercel w/Turbo 4AGE
1981 3dr hatch Toyota Tercel SR-5
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NWMO
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Re: 3D printed Synchros?

Post by NWMO »

Thanks Keegan, I wondered about reverse. Is the granny low the same? no synchro?

Chris
Psalm 37:4 "Delight yourself in the Lord and he will give you the desires of your heart"

In remembrance of my friend ARCHINSTL:

T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"

"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
xirdneh
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Re: 3D printed Synchros?

Post by xirdneh »

1st/2nd have same size synchros (largest dia)
3rd/4th have same size synchros. (Mid size dia)
5th/granny have same size synchros (smallest dia),

I have quite a few very good used small ones if anyone needs one
I have some used large and mid but they are worn but usable (better than nothing)
Love those Tercell 4x4 wagons but they sure suffer from road noise.
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NWMO
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Re: 3D printed Synchros?

Post by NWMO »

Thank you very much Robert! Are all three pairs twins?

Chris
Psalm 37:4 "Delight yourself in the Lord and he will give you the desires of your heart"

In remembrance of my friend ARCHINSTL:

T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"

"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
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