Bioloid PREMIUM Frames and certain types of GLUE

[PedroR]

Hi all

Robotis has issue a notice to Distributors advising that the new Bioloid PREMIUM frames are easily damaged by certain types of glue, in particular LOCTITE 242.
This is their announcement:

Recently, we've found that liquid type loctite/fixation glues would damage the Bioloid Premium Kit frames.
If you uploaded the Premium Kit on your website, please notify 'NOT TO USE liquid type or loctite 242.'
Instead, we have stick types such as Loctite 248 or 268, and they work well with no issues.
So, for your customers who want to purchase the Loctite for this application, please recommend the stick types.

The new Bioloid PREMIUM frame although looking similar, they are made from a different material that is supposed to be lighter and more resistant.
The issue with the glue damaging the plastic frames has also been observed with some Robobuilder frames (legs) as well.

[EDIT March 29th 2012] It seems Loctite 248 also damages the case of the new AX-12A and AX-18A. See here http://robosavvy.com/forum/viewtopic.php?p=34029#34029 [/EDIT]

Regards
Pedro

[UncleBob]

Pedro

Thanks for the tips. I also use some loctite as the big screws tend to come loose with excessive walking. I am careful with my loctite so not touching any plastic parts.

[tom_chang79]

I think it's any compound with methyl crylate ester in them. It has been known for years in the RC community not to use any thread-locking compound on polycarbonates. Perhaps the new premium frames have some mixture of polycarbonate in them?

[Taid05]

The head of my humanoid A fell off just now. The cause was that I had not realised that the loctite 268 I had used on screws melts the plastic of the Head (clear plastic)It can be repaired with a good old bodge! So fellow newbies beware

[robosavvy]

hi Taid05

The information we have is that Loctite 242 should NOT be used.

Instead Robotis says 248 and 268 are OK.

Are you saying that you used the 268 and it still damaged your plastic? That model should work according to Robotis.

Can you confirm this?

Thx
Robosavvy

[MOHIT JINDAL]

Hi Robosavvy,
I also purchased Loctite 268 but I am scared now.
Please tell me the Frames will melt or not
Thanks.

[PedroR]

Hi

The Official information we have from Robotis is that LOCTITE 248 and 268 should be OK to use.

The user who has reported issues with LOCTITE 268 has not really confirmed the information (see my post above) and so far this is an isolated report.

We here at RoboSavvy have tested and used LOCTITE 248 on Bioloid PREMIUM Brackets and it worked perfectly fine.

Also, please be advised that this warning is for Bioloid PREMIUM frames (which use a kind of plastic that is different from the Comprehensive and Beginner kits).

Regards
Pedro.

[garycmartin]

Hi,

I need to glue something onto the clear transparent shell included in the BIOLOID Premium kit, do these recommendations still stand (248 & 268) for that material? Just wanted to check as these parts don't seem to be something we can re-order replacements for.

Thanks,
--Gary

[PedroR]

Hi

We haven't tested this glue specifically the transparent plastic on the chest.

The information we got from Robotis was regarding the plastic used on the frames.

As for the chest, I would proceed with caution since it's apparently a different type of plastic.

I'd start by looking for a glue that is as compatible with plastic as possible. Such types of glue exist but I can't really name any at this point.

Your local hardware store or a model shop may be able to supply that.

I am sorry for not being able to offer more assistance but it's the first time we've had such a question.

I also will try and get more information about this.

Regards
Pedro.

[i-Bot]

I am always cautious of Cyanoacrylates with other plastics (great on metal, wood, and skin !). Not sure if it is the adhesive itself or the solvents involved. Always test carefully before use, often the effects are delayed and cause a brittle or cracked structure.

Had less problems with epoxy, but do test.

I avoid Loctite around plastics. full stop.. Sometimes I use a dab of acrylic white wood glue, but generally find a good JIS screwdriver a better investment with a firm grip. Using Loctite often causes damage to Robotis servos cases or brackets if you later dismantle due to force alone.

[garycmartin]

Thanks PedroR, i-Bot. I'll try to avoid if possible, and if not, will try and test somewhere non-structural/out-of-the-way first.

--Gary

[PedroR]

Hi

I think i-Bot's information is quite valuable with regards to this matter.

I also contacted Robotis about this and I am posting just bellow their reply to complete the information requested:

1) We haven't tested a specific glue on the transparent chest skin frames so far.
So we can not answer this with enough information now.
(I believe i-Bot's response above is quite adequate though)


I also took the opportunity to ask about painting the chest frames. This is something that has not yet come up but that you should also be aware of. This is ROBOTIS reply:

2) To paint the transparent chest frame, please use a paint designed for polycarbonate.
Otherwise, the chest frame can be broken or melted.
If you used any the paint for polycarbonate on the very surface of the skin, you may use a primary base or vanish for coating or more clear color expression additionally.

I hope this clarifies any further question and completes your inquiry.

We'll also be quite interested in learning about your findings and what was the approach you took to complete your project.

Regards
Pedro.