IME's causing internal motor problems

[VHS_Crusaders]

Whenever we use the IME’s; the motor’s internal axles seem to be able to fall out of place, allowing the gears to move about in the motor itself. Obviously, this is a serious problem for our robot as if it happens in a match, those motors will do nothing but damage the internal gears. This problem, if not fixed, makes the use of IME’s to risky. Is there a way to fix this?
Would you consider allowing a small amount of glue to be used to secure the axle?

Thanks in advance!

[Charlie_Wensel]

Hi,

Unless your motor has been modified, the shafts that the gears ride on should be retained when the IME is installed. Have you had any gears come loose during practice? If you are concerned about being able to hear the gears move inside the motor housing when you shake it, it is intentional and completely normal.

As far as gluing the shaft goes, you’ll have to ask that question in the Official Skyrise Q&A forum here - https://vexforum.com/forumdisplay.php?f=400

Let me know if you have any more questions,
Charles

[VHS_Crusaders]

@Charlie Wensel

Unless your motor has been modified, the shafts that the gears ride on should be retained when the IME is installed.
…If you are concerned about being able to hear the gears move inside the motor housing when you shake it, it is intentional and completely normal.

No. We have not modified the motors in any way. I notice that my first post is not very clear in explaining the problem.

With a normal motor back, the axle is firmly in place between the motor itself and the backing; leaving no room for movement. (see first attached picture)

With the IME backings being approximately ½ in longer, the axle has the ability to move into the IME further than with the normal motor backing. This allows the axle to fall out of the slot on the motor side. With the axle only being supported by one side, it can damage the internal gears and no longer function properly.

@Charlie Wensel

Have you had any gears come loose during practice?

We have had it happen not only during practice, but also during a competition. It got very frustrating as you can imagine. That’s why we want to fix this problem before we use IME’s again.

Thanks Charles. I look forward to your response.

[Charlie_Wensel]

Thank you for bringing this to our attention and for the nice “paint” graphics (you have no idea how much the VEX engineering team uses paint to communicate ideas in emails). I spoke with the rest of our tech support crew and this is the first time we have heard any complaints about this problem. I looked at some of the IMEs and motors that are in our shop and found that your illustrations are correct. However, since the axle is a press fit into the motor housing, it is unlikely (but clearly not impossible) that the shaft will “back out” and cause the problem that you are describing. I encourage you to call our tech support hotline at 1-903-453-0802 so we can “make this right” with you.

One thing that I would recommend for now - since the axles are press fit into the motor housing I would not just re-insert the shaft into the motor housing if they fall out. I would swap the IME to a motor that has not had the axle fall out of it. This ensures that the “problem” axle is as tightly installed as possible.

Charles

[VHS_Crusaders]

Ok, we have done what you have suggested. Hopefully the problem will not reoccur. I got a PM from frogs2345, so I guess we are not the only ones having this problem.

@frogs2345

To fix your issue, you have to scrap an older motor. Take the axle from the next gear in the system(after the replacement gear for the encoder) from the scrapped motor. Trim 2-3mm off of one end and force the longer section into the hole of the problem axle after taking out the one that is too short. We have had to do this on my past robot, and Vex really should fix this, but this is the only solution at the moment.

Thanks for all of your help Charles.