Foreman Elite Z-20 Braking motor upgrade problem(I stripped a bolt)

Machines (Elite Series)
1

Hi, Folks!

It has NOT been a good day. The Foreman Elite came in the other day and I’ve been chipping away at assembling it. There’s no rush because my electrician won’t be here for almost a week. It’s all together, my 2.2KW 220V water-cooled spindle is installed, and an 18x50 drag chain is installed. I ran it last night and it’s homing and jogging fine. I am going to mount the power supply, VFD, and chiller and she should be ready when my 220 is installed. This morning, I was going to install the Z-20 breaking stepper. I disconnected the wiring and started taking out the four bolts on the original stepper. The first three came right out with no issue. I have no idea why, but the head of the fourth stripped! I took the first three out with my impact and a 3mm bit. I can’t figure out why the fourth one stripped out. I’ve done everything I can think of but decided to put it back together and use the stock motor. There goes $137!

After thinking about it for a while, I came up with a possible plan. As you know, the bolts are partially recessed into the corner of the motor so they are a little hard to get at fully. I’m thinking about using a Dremel, cut a slot in the bolt head, and use a straight screwdriver to get it out. Not sure yet if I want to attempt it, but I do want the upgrade.

Do you think it’s worth the risk of trying it?

Thanks for any input you may have.

2

My initial thoughts are that you will weaken the small bolt head, and given the challenge already, it may break it into two at the top.

I have two ideas…

  1. try to loosen the set screws for the motor coupling, and see if you are able to turn the motor base, even a little. It may loosen the bolt to the point where a small pair of locking plyers can turn it.

  2. perhaps try from the bottom, to remove the two SHCSs (M5 I think) that hold the two rectangular standoffs that go between the motor mount and top plate of the Z axis assembly. At least that way it is easier to work on, and if you decide to grind a slot you won’t get small steel grit on your machine. You may even decide to drill the bolt out, and replace it with a new longer bolt and lock washer and nut.

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