Mini servos are not very strong at all.

I don't know what make/model EZ-Robot use but I have uploaded a 3D printable STL of a Tower Pro MG90. Most are roughly the same size give or take a few mm.

I think it's public, you can get it on AutoDesk's site here

thank you rich i will have a look.

Hey nomad18.08... Why do you want to use mini servos with JD? What's wrong with the regular sized ones? As Rich said... mini servos are weak... some can barely lift themselves let alone any measurable load...I use them for light loads like for eyebrow movement, butterfly wings or maybe even as a ping servo....

my idea was to make jd whit turning waist.so i need to make a case where a servo fit in. consider that his chest is 10x8x6 and the horn is at the end.so not much space, to put in a servo.

Ok, I understand... You also need room to adapt the servo for lateral loads which unless it is a heavy duty servo, most will be weak in that area...

this pic is better.yes a case where a servo fits in,and mount the rgb or sonar on. and have room to slide the wire thru. the problem is to get the horn in the middle,

You'll at minimum want a metal geared mini servo. Moving the weight of JD's upper half will be hard on the servo. If I were you, I would use a heavy duty normal servo. They cost really the same. Power consumption is only thing that's different, but its not a big thing you need to worry about.

For twisting a waist the micro servos may be OK since the load isn't as much as if lifting. If lifting anything they may struggle. I wasn't happy with the MG90s in Melvin's arms when I was building those which is why I scrapped that idea and ended up making new arms from scratch which would accommodate stronger servos (work which is still in progress).