CT - sheared the bit locking bolt in the spindle

[jbrunot01]

So I went to remove a 60 deg V bit so I could install my carving bit... placed the T handle in the socket screw - went to back the bolt out and it sheared off. Broke about 1/2 down the length. The head and about 1/2 the threaded shaft came out - Cant get the other half unscrewd fron the spindle.

Question: can I replace the spindle only, or do I have to purchase and replace the entire Z truck ***'y?

Any body know?

Thanks,

jeff Brunot
Marietta, Ga

[DocWheeler]

Not an easy repair, but can't you use a small drill to drill from the good-end of the machine-screw and have it un-screw itself?

[henry1]

[QUOTE=jbrunot01;243123]So I went to remove a 60 deg V bit so I could install my carving bit... placed the T handle in the socket screw - went to back the bolt out and it sheared off. Broke about 1/2 down the length. The head and about 1/2 the threaded shaft came out - Cant get the other half unscrewd fron the spindle.

Question: can I replace the spindle only, or do I have to purchase and replace the entire Z truck ***'y?

Any body know?
go here and check this link

go here and check the link
http://store.carvewright.com/product.php?productid=20563&cat=285&page=1

[bergerud]

You cannot just buy the spindle. I think you have to go with Doc's suggestion and fix it yourself. You may have to take the z truck out of the machine to do it. It would be best to hold the chuck in a vise and drill the bolt out from behind. You should get lucky, as Doc said, and the bolt may just screw out once you start to drill.

[jbrunot01]

I tried that. I think the machine screw is pretty hard material. I was able to make a small divit in the good end, but unable to drill through or get the threads to turn themselves out.

[bergerud]

You may have to go and buy a better drill bit. A small cobalt drill bit would be good. Even better would be to drill a small hole first (5/64" say) and then a larger hole (say 1/8"). The second bit will "bite" and maybe screw out the bolt.

[aokweld101]

Do'nt know if you have the equipment, I hav'nt had this happen to me I think terry t had a porblem like this I learn from his experiance and changed the bolt every now and again, It would not be a good feeling to deal with.

[aokweld101]

Do you have a drill press, if I had a problem like this I would take the chuck off and use a machinist vise center the hole up and drill with a drill pres that way you could add the pressure without hopfully breakin the bit.

[Mugsowner]

I would agree with drilling in from the back side as suggested. I would think about trying to mount chuck into a vise mounted to a drill press to get and keep proper angles. You do not want to break a carbide bit off, they drill through almost anything, but because they are so hard they are brittle and will not take side loads. Yes the screw is hardened, all socket head cap screws are hardened a bit, most being a grade 8, some as high as grade 12. The drill bits you need are pricey, but in smaller sizes my need for this repair make them a great repair option over replacement. If you can not find any carbide bits at the local hardware, you can try machine shops, they may be willing to help you out, or you could jump inline and look in places like MSC, or McMaster-Carr. If by change you can not find what you need let me know, I have a small selection of small carbide bits. Good luck

[Mugsowner]

I have to agree again. These screws are cheap and sold in boxes of 100. We all tend to crank on them a bit just to make sure they do not loosen, but over time weaken from all the stresses they are put under. You will be happier in life, even if you do not see the result first hand.

[jbrunot01]

shopping now for a small dia. carbide bit.

[bergerud]

Carbide bits are so brittle, they scare me. If it breaks, the chuck could be history. I would just use a high quality high speed steel bit or, like I sand before, a cobalt bit.