hello,
this might be a stupid question but I need some help on removing bolts from the back panel of a nema17. I'm trying to attach a 3d printed part to the back panel like in this video. But when I try to use a screwdriver, the bolts are so secure that it doesn't turn at all. So I need some ideas. Like would a allen key work better or some machine?
Thanks
It's common for motor screws to have thread lock on the threads. You may need to use a screwdriver bit in an impact driver to get them loose.
If the threadlock is blue, you can try to break the bond by trying to drive the screw forward before trying to remove the screw.
You can try to prime the screw with a drop of acetone (nail polish remover) on the screw head and waiting.
You do not want to "swing for the fence" on removing the screw in one motion. You want "1000 little motions" to break the thread lock bond (fwd, rev, fwd, rev... not too much force).
An improvised "hammer drill" motion of tapping (1000 times) on the driver as you are turning (not heavy pressure) might help break the bond with microscopic "vertical" movement.
If the thread lock is red... that will take 800f heat, and probably a stripped head if the thread lock wins.
[edit] yeah... it appears dude in the video only got two of the screws out before all his allen keys were destroyed.
Maybe he did that on purpose. Getting all the screws out could stuff up the factory's rotor alignment. I too would not remove more than two opposite screws.
Can you get a thin soldering iron tip on the bolt heads to heat up them and the threadlocking compound ?
High‑temperature adhesive or double‑sided tape could be one option.
Not hot glue, steppers can get pretty hot...
I just had a look at the stepper motors I have and they all have bolds for Allen keys.
The motor in the video seems to have Phillips head screws.
Make sure you use the right screwdriver (there are at least four different head sizes).
Pre-heating the screwdriver with a blow torch is another way to heat up the screw and softening the thread lock.
had the same fight with a nema17 i pulled out of an old printer. the little L-shaped keys that come in those cheap sets are honestly the problem, they just round the heads out.
what finally worked for me was a proper hex bit on a small ratchet, the kind from a socket set, and pushing down hard while turning slow. way more control than the L key. if a head is already half rounded, pressing a wide rubber band between the bit and the screw sometimes gives just enough grip.
and yeah, don't touch the front cap ones if you can avoid it, learned that the hard way too.
So like heat the bolt with the solder iron then unscrew? Would the bolt heated up be dangerous if it landed on my wooden table?
it's a phillips head and I used a phillips screw driver, but yea it wasn't budging
Does the screwdriver fit perfectly inside the screw head, without wobbling sideways.
As I told you before, there are many phillips screwdriver sizes.
You can't put the required force on the screw with the wrong type, and you could even damage your screw head.
I don't think this approach is ideal at all.
From motor's point of view, it misses two structural bolts. There's no way you could tighten the bolts enough/reliably when you have plastic box in between. Also, be aware that steppers can get hotter than PLA can handle without deformation.
Yes, heat it then unscrew it. Once the bond between the screw and the motor has been broken it should move easier even if you let it cool down
Even if you remove the bolt the whole way whilst still hot it is unlikely to damage a wooden table but it might not be a good idea to pick it up with bare hands immediately
Yes
It's crucial to be able to identify screw heads.
The two you showed (Philips and Pozidrive) are good examples. All too easy to use a Philips screwdriver or bit in a Pozidrive head.
Also important to identify screwdrivers and bits.
Japan and China have their variations, Philips head often with an indented dot.
Removing stubborn screws is all to do with technique and choice of tools.
Give yourself the best chance of success by matching the removal tool, screwdriver, Allen key, to the screw. Size and pattern must match. Often mismatched are No. 1 and No. 2 Philips and Pozidrive.
Use good quality tools. Wiha, Wera, Bacho, Chapman (USA).
Clean out the screwhead before you start, a gentle tap with the screwdriver in place can shift paint and muck.
If there's room, use a "T" bar, gives you more torque and crucially, a better feel. I must own up to tool abuse by putting a Mole type wrench on the screwdriver shaft.
As mentioned, counter intuitively, try tightening a little first.
If it positively won't budge, there's heating and cooling (pipe freezer) and release fluid.
Diamond grit screwdriver bits can help, and there are compounds (Hexagrip from memory) that look like valve grinding compounds. Make your own from grease and silicon carbide grit.
Know when to stop.
If all that fails or it shears off, drill it out or try a decent quality screw remover and re-tap if necessary.
Sometimes, I'll replace screws from new if I think the original will rust etc.
As an additional comment, there are also impact screwdrivers. Maybe not that suitable for the smaller stuff, I used it when I had to get a stubborn JIS screw loose on a motorbike.
JIS might be one of the formats that tigger was referring to in reply #15 and differs from Phillips; see e.g. Phillips, JIS, and Pozidriv screwdrivers explained | Bike Gremlin US
Agreed.
I would just stick the circuit board to the motor with double-sided 3M foam tape.
Some heat resistant one like 3M VHB 5952 would be my choice.
