Shoulder bolts

[ronan]

I am in the middle of grafting a Bridgeport milling machine head onto the overarm of my Tom Senior. I have made what i can only describe as a long angle plate that i am going to bolt to the top of the overarm to support the back of the head. Not wanting the plate to move i was going to ream the mounting holes and then use shoulder bolts as in the piccy below. The plain shank of the bolt will be entirely in the plate and just the threads in the overarm.

Are these bolts strong enough ? What concerns me is the sharp reduction in diameter under the shoulder where it meets the threaded area. I am planning to use 8 or 9 bolts (m12) along the top.

 

[Fazerruss]

I am in the middle of grafting a Bridgeport milling machine head onto the overarm of my Tom Senior. I have made what i can only describe as a long angle plate that i am going to bolt to the top of the overarm to support the back of the head. Not wanting the plate to move i was going to ream the mounting holes and then use shoulder bolts as in the piccy below. The plain shank of the bolt will be entirely in the plate and just the threads in the overarm.

Are these bolts strong enough ? What concerns me is the sharp reduction in diameter under the shoulder where it meets the threaded area. I am planning to use 8 or 9 bolts (m12) along the top.

Got any picture of your conversion roanan? I'm doing a very similar project with my m1

 

[ronan]

Got any picture of your conversion roanan? I'm doing a very similar project with my m1

Not as such, i am just making up the top plate and the adaptor plate at the mo, the big step is cutting the overarm and then bolting the head to it and getting everything square and aligned. I hope to get it all done soon because i am sick to death of the lack of space under the vertical head, if i didn't do this conversion, the machine would have to go.

P.S i don't know if you have seen this link before, but its basically what i am doing, but instead of the block he uses i am using an angle plate fabbed from 1" bright mild plate.

http://www.anf.nildram.co.uk/workshop/major/major.html

 

[bricol]

Drill and ream into the mating part - then the (longer) shoulder bolt locates the two parts properly together. Use this method on guides that have to come off our machines.
Or use dowels through both - light press fit and they should be fine. Then you can use decent sized screws to actually hold the two parts together.
Also used keyways in both parts, bolted keys to one part - keyways at right angles to each other so one locates sideways, other fore/aft.