The Doll Forum

Greetings.
The RnC in the topic is mimicking the RFCs known in the Unix world, but stands for "Reference and Comments" instead.
What I mean is to provide some photos for future reference should others encounter a similar problem.
I'd also like useful comments as there is a good chance to find a better solution with more experienced brains thinking.

The issue at hand( pun, I know ) is a broken wrist on a Sanhui 165 first generation doll.
This doll got replaced for the original owner by Sanhui through George's relentless efforts and judging by the damage I would consider that a good reaction.

First off the symptom: With the silicone thankfully still completely intact, if you gently take the hand you can move it slightly up and down with reference to the forearms axis and you will encounter a roughness and scratching feeling if you do so with a little pressure of the hand towards the arm. Now, after making a cut, it initially looked like this( please ignore the fancy plastic item used as a spreader) : After a little bit of cleaning( Q-tip, Aceton) and trying to somewhat align it again to indicate what it should look like: Measuring with some accuracy but limited in precision due to accessibility gives a metal rod diameter of about 3.3mm wich is also no direct imperial size, but near 1/8in.
The length between the widening at the hand assembly and the ball surface inside the arm is about 8mm give or take a little.

I consider it lucky that the break is pretty much halfway, that should allow a slightly easier repair( due to material to use on both sides).

I do not consider this a design flaw by Sanhui, in fact I think the design itself is working pretty well, imho it was just bad luck possibly aided by poor choice of material or just slightly too low rod diameter( though 3.3mm is quite a bit).
I cannot yet tell how "hard" the balljoint is to move, so too tight adjustment there is another possibility, if we're lucky we'll get that info later.

That's it for now, now for the brainstorming.
I do have 2 ideas I may follow up on my own so far, but helpful Comments( see above) are appreciated.

Kind regards.

The point of break would seem to suggest there must have been a lateral force on the hand at the wrist, otherwise the wrist should have moved normally. Most of the joints of dolls are very hard to move by hand without leverage using the limb or hand. I couldn't even move the joints on my DS100 mini's plastic skeleton locally. However, it could be that the wrist joint was too tight which meant the next thing to give would be the rod.
I can't see a way of repairing this without taking it out of the doll to use welding. You could try a 'sleeve' but it's going to be bulky in her delicate wrist area as it will need tightening screws around it.
I hope there's a solution that doesn't require major surgery!

The RnC in the topic is mimicking the RFCs known in the Unix world, but stands for "Reference and Comments" instead.
What I mean is to provide some photos for future reference should others encounter a similar problem.
I'd also like useful comments as there is a good chance to find a better solution with more experienced brains thinking.

Very nice photos and detail . Good stuff for reference.
Thank you

I hope you can find a method to fix her. BTW what are the things you are using to keep the incision open? I need to rig something up like that to fix Akiko's loose knees. Thanks and best of luck!

Hollywu wrote:I hope you can find a method to fix her. BTW what are the things you are using to keep the incision open? I need to rig something up like that to fix Akiko's loose knees. Thanks and best of luck!

Thanks, I'll gladly take the luck, she may need a bit.
As for those thing, its a 3d printers printout for a test part that happened to lie around nearby, so I can't really help you here, sorry.
If I can aid you with Akiko's knee by making comments or some such, I will gladly do so - if it's not "just" a re-tightening and you actually need some part made feel free to PM and I'll see what I can do.
My best wishes to you and your lovelies.

Kind regards.

Hi,

have you had a look at this thread: 88cm broken wrist fix? In this repair from last June, a tube was used (similar to what hollows+fentiman suggested). You could print such a sleeve in nylon, drill holes into the fractured bone and then screw the nylon tube onto the bones.

Or, if you have a thread cutter roughly matching 1/8in, you could try to cut a thread on both sides and connect with a (thinner) tube with an inner thread (hopefully allowing to avoid making the wrists baggy).

However, what is the goal? Just to fix the wrist somehow, or are you considering enhancements as well?

Sandro

Looks like you do not have much on either side to work with, that being said, if it were me I would bore a collar to get a somewhat snug fit and as much depth as possible on both sides. Make it thick enough to use two small set scews and space them about 90 deg's apart and tighten them as tight as you dare use a bit of blue locktight and call it good.

Please let us know what you decide on and how it turns out!

Thank you for sharing this with us!

Good luck fixing her first of all. I like the original SH 165! She is a classic now.

I like the sleeve idea, it seems like you wouldn't even have to screw it on, because once sealed inside the silicone will hold the two ends in the sleeve. Not saying you shouldn't weld/screw the ends together, just saying the ends being forced together is an added benefit.

I think you should take your time and consider enhancements.
You'll find that the wrist starts to get loose and won't hold a pose. While not broken, it will fall towards gravity.
While you're in there, you might as well try to prevent this.

For science:
I'm reeeeeeally curious to see what the elbow joint looks like. I wonder if it can be modded to get a more acute bend. Don't do it unless you are feeling very adventurous.

I got loose joints in mine. I'm looking for a way to not only tighten them, but to keep them from coming loose again.

TheIQF++ wrote:I got loose joints in mine. I'm looking for a way to not only tighten them, but to keep them from coming loose again.

Have you considered Loctite 242 "medium strength mil-spec blue threadlocker" for the joints?

http://www.na.henkel-adhesives.com/prod ... 7716250625

Sandro

Dollstudio wrote:Hi,

have you had a look at this thread: 88cm broken wrist fix? In this repair from last June, a tube was used (similar to what hollows+fentiman suggested). You could print such a sleeve in nylon, drill holes into the fractured bone and then screw the nylon tube onto the bones.

Or, if you have a thread cutter roughly matching 1/8in, you could try to cut a thread on both sides and connect with a (thinner) tube with an inner thread (hopefully allowing to avoid making the wrists baggy).

However, what is the goal? Just to fix the wrist somehow, or are you considering enhancements as well?

Sandro

Using a sleeve is the first thing that occurred to me when I viewed the photos.

Dollstudio wrote:have you had a look at this thread: 88cm broken wrist fix?

Actually, I had not, thanks for pointing it out.

Dollstudio wrote:In this repair from last June, a tube was used (similar to what hollows+fentiman suggested). You could print such a sleeve in nylon, drill holes into the fractured bone and then screw the nylon tube onto the bones.
Or, if you have a thread cutter roughly matching 1/8in, you could try to cut a thread on both sides and connect with a (thinner) tube with an inner thread (hopefully allowing to avoid making the wrists baggy).

Actually, for both of these, either drilling miniature holes or cutting a thread on each side of the rod stumps I would have to cut the hand off in order to work on both ends.
I do not really consider the drilling doable as they would have to be below 1mm diameter and also would take away from a material that broke in the first place.
The threading on the rod ends is an interesting idea that I will keep in mind, the loss of material would still be there but the connection would be pretty good, however for now I do not wish to cut the hand off.

Dollstudio wrote:However, what is the goal? Just to fix the wrist somehow, or are you considering enhancements as well?

For now the goal is to make this joint working reasonably again.
Since I do consider the original design to be a good one I see no immediate need to try and modify it.
If I have to take rough action in the future - like taking her hand off anyway then I may reconsider.

Kind regards.

CrazyCajun wrote:Looks like you do not have much on either side to work with, that being said, if it were me I would bore a collar to get a somewhat snug fit and as much depth as possible on both sides.

That is pretty much my current analysis and consideration as well.

CrazyCajun wrote:Make it thick enough to use two small set scews and space them about 90 deg's apart and tighten them as tight as you dare use a bit of blue locktight and call it good.

Yeah, I thought about this as well, but here is a problem on the ball end side - if I make the sleeve diameter thick enough to hold a set/grub screw it will interfere pretty severely with the ball joints movement range, so I have to try and use a slim but sturdy sleeve end at least on that side.[/quote]

CrazyCajun wrote:Please let us know what you decide on and how it turns out!
Thank you for sharing this with us!

That was the major idea of making this thread.
You're very welcome and thanks for your great work.

TheIQF++ wrote:I like the sleeve idea, it seems like you wouldn't even have to screw it on, because once sealed inside the silicone will hold the two ends in the sleeve. Not saying you shouldn't weld/screw the ends together, just saying the ends being forced together is an added benefit.

Actually, the silicone is nicely durable and stretches good enough( mm~cm) to do a little bit of cleaning or work without having to worry to additionally damage it accidentally in addition to the incision.

TheIQF++ wrote:I think you should take your time and consider enhancements.
You'll find that the wrist starts to get loose and won't hold a pose. While not broken, it will fall towards gravity.
While you're in there, you might as well try to prevent this.

Hmm, to get this sort of info from someone who is renowned for his work with this doll is actually a little troublesome, but thinking about it makes it clear that this is likely to happen some time in the future.
I am however not really inclined to cut her hand off this time so I guess what I will do is just try to repair it as is for now.
However, with the information on whats likely to happen in the not too far future, I will try to take a few more measurements while I still do this repair and that should allow me to consider developing my own 3d printed hinged wrist in between now and the joint failing to hold position, assuming the doll stays with me.

TheIQF++ wrote:For science:
I'm reeeeeeally curious to see what the elbow joint looks like. I wonder if it can be modded to get a more acute bend. Don't do it unless you are feeling very adventurous.
I got loose joints in mine. I'm looking for a way to not only tighten them, but to keep them from coming loose again.

Foorrr Scciiieeeennnnncccccceeeeeee
OK, fun aside, I have no immediate plan for the elbows as they are currently still fine as is - albeit limited to 90 degree angles - this is something I find interesting enough to consider improving, but not for right now.
I do however have issues with joints too loose to hold positions, one in each shoulder, funny enough different ones, so there is a certain likelyhood that investigating there would be next on the menu.

Kind regards.

hollows+fentiman wrote:I can't see a way of repairing this without taking it out of the doll to use welding. You could try a 'sleeve' but it's going to be bulky in her delicate wrist area as it will need tightening screws around it.
I hope there's a solution that doesn't require major surgery!

Yeah, I hope so, too.
Welding would be the usual way to reconnect those two ends, but that's among the skills I do not possess and do not plan to acquire ... and yes, doing it in-place would likely be a challenge.
A sleeve is what I have in mind as well, its just the bulky part and the screws that's an issue.

Kind regards.

Obin wrote:Using a sleeve is the first thing that occurred to me when I viewed the photos.

Yup, same here when I viewed it live.
And it seems the prevalent idea most agree on and can be done without needing further damage, so I guess that's what I'll attempt to do first.

Kind regards.