GT2 vs 2GT belts/pulleys??

Hello!

Recently i've seen many 2GT belts on ebay and alixpress. Then found 2GT belts and pulley from GATES
on e3d site
[e3d-online.com]

It seems like profiles for 2GT is a little different from GT2, but i am not sure.

Maybe someone already dug this issue and have an answer how different or similar GT2 and 2GT.

Lots of places get really sloppy with their part designations. The GT refers to the tooth profile, and the number after it refers to which generation of the tooth profile. The original profile
was designated GT, then GT2 and the newest is GT3. The number in front usually refers to to the pitch of the belt in mm. But because of the confusing terminology, most industrial supply companies will explicitly state "2mm pitch GT3 belt", or whatever. Almost anything being sold by 3D printer suppliers is going to be 2mm pitch, and mostly the GT2 profile (I think the original GT might be completely obsolete at this point.) As for GT2 vs GT3, the pulleys are actually identical, but the GT3 belts have a slightly higher load rating.

The more important factor, hardly ever mentioned, is the belt stiffness. I've noticed that the belts from premium manufacturers (like Gates) are significantly stiffer than random Chinese belts. Also, MXL belts (which have nearly the same pitch as 2mm pitch belts) are stiffer than the GT series belts. In theory MXL belts have more backlash than GT belts, but I'll take the miniscule backlash of the MXL belts over the reduced stiffness of the GT belts.

And yes, this topic probably has been covered elsewhere so you might want to search around for more insights.

From what you say the correct way to name a belt would be 2GT2 - 2mm pitch GT profile 2nd generation belt.
Yes, profiles for GT2 and Gt3 are the same, i have read the misumi and gates notes on that.
Profile for original GT is different.
However, E3D in its blog specified that profiles for their 2GT belts and GT2 belts are different. How different - no info.
So, either 2GT is really GT1 - 1st generation - belt profile. OR 2GT is really a different thing.

Timing belt nomenclature is an absolute disaster. Misumi has a table here that might help: [blog.misumiusa.com]

You can also browse Gates part numbers to get a better idea of their various parts. I suspect that the cheap components are the Asian circular profile and not a Gates curvilinear, but to test it you would probably need to scan a genuine and off-brand pulley at high resolution and compare.

imagine my disappointment when i ordered 2 gt but only received one...clever ebay listing.

As seen from the table the number in front is not pitch. 2GT belts can be 2,3,5,8mm pitch. So, nobody knows what this number actually means.

But 2GT belts are circular H -type, and curvilinear Gt2 type are named MR2.

Arghhh. God, help us all.

It says " MR is a curvilinear profile and is compatible with PowerGrip® GT® 3 from Gates. MR is GT® and vice versa GT® is MR."

However, from the text 2GT/3GT are not GT2/3 profiles. They atre CIRCULAR.
Gt2 and GT3 profiles are the same- curvilinear.

Now, it seem like 2GT belt from e3D are cicular profile.

if you want more confusion look at this aliexpress listing:

[aliexpress.com]

It says that it is Gt2 2GT belt. I asked the seller what kind of belt is it: gt2 or 2gt and he replied that ti is the same thing.
Look at the picture in the description: it states 2GT and shows circular profile.
But the title about picture again says "GT2 Open timing belt Specs & Drawing" - which is wrong, because real GT2 is curvilinear!!!

So, pulley profiles for 2GT and GT2 are different!

Look at this item
[aliexpress.com]

Again the name says GT2, but looking at the drawings the specified name in the drawing says 2GT-60T

It seems like hardly anyone from 3d printing community even used/seen real GT2 belts and pulley because 99% of people buy stuff from ebay/aliexpress and they actually buy 2GT stuff.

Description on Chinese sites are totally irrelevant, a mix of incorrect specs, overinflated qualities, all expressed in something that looks like english, sounds like english, walk like english but is NOT english !

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ArtemKuchin
Arghhh. God, help us all.

Pretty much. Its best to assume that unless the listing contains the words Gates PowerGrip® it is actually the circular profile. Misumi refers to all Gates parts as MR on their webpage to reduce ambiguity*, but that just makes it confusing in another way.

I have a roll of real Gates timing belt and it is loose in circular pulleys, although maybe if you applied enough tension it would squeeze out the backlash.
*Gates PowerGrip part numbers all end in MR or MG.

Edited 2 time(s). Last edit at 01/02/2019 03:52PM by 691175002.

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MKSA
Description on Chinese sites are totally irrelevant, a mix of incorrect specs, overinflated qualities, all expressed in something that looks like english, sounds like english, walk like english but is NOT english !

What talking about? Chinese sites all the time use the proper English, Can understand by everyone!

I would never take any brand name labelling from Ali Express as being accurate, nor would I want to bank on an exact specification match. I have some parts that only vaguely resemble their technical drawings (Which suggest that they would NOT work in my application, so good thing!)

You know that game where you use |Google translate to convert something to another language, then translate the result of that back to English to see how it gets mangled? I've found that Google will sometimes actually correct the "English" instructions on Chinese products to make it easier to understand, which makes me wonder... What ARE they using to make those horrid translations? I assume that it turns the instructions into a reasonably valid Chinese structure, which can then be turned back into better English than the original...

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MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.

Leadscrew self-built printer (in progress)
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Quote
SupraGuy

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MKSA
What ARE they using to make those horrid translations? I assume that it turns the instructions into a reasonably valid Chinese structure, which can then be turned back into better English than the original...

Probably Baidu