BS0 chinesium semi-universal dividing head problem

bbaley

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Hi,
I bought one of these (from Precision Matthews, but seems like it's a common device),
and only recently tried to rotate it to the "vertical" position
but cannot seem to get it to do so

The manual contains zero information on how to do so.

When I asked PM they said;
"There are locks on the side, loosen them up and it may be stuck and need tapped to move. . Usually they are pretty sticky from the rust proofing and dried up lubricant that gets on them. "

They did not respond to my question about "please describe the locks - hex bolts? the large slotted screw ? which?"

The only things on the "side" that might be "locks" are;
a) the two bolts going all the way through the "chassis"
b) the locking levers that serve as stops and a pin for the platen with holes behind the chuck (in 10 deg increments)
I know what b) does, not this

I tried the bolts, and whacked the unit with a dead blow, per PM's recommendation, to loosen from any "gunk" or "anti-rust stuff" to no avail.

I cannot get it to rotate.

I am sure I am being stupid or missing something, anyone suggest the next thing to try ?
 
You have to loosen the trunnions that squeeze the rotating center section tightly, I think there is a screw with large brass plugs (~1") that clamps it together. It has been way too long since I saw one. Someone else who has one will probably jump in with the "for sure" answer.
 
All the B&S type dividing heads have two hex nuts on the backside that lock the center section in place; loosen them, and the center section should be able to be rotated, a bit of persuasion should do the job. Did it not come with an instruction sheet?
 
A 50/50 mix of acetone and automatic trans fluid in the hinge area might be helpful also. May be just gunked up.
 
Yes, as mentioned in the post, the documentation contains no such information that I could see.

I did loosen the bolts mentioned, and it would not budge.
I will try some solvent as suggested and see if that loosens up the "gunk"
 
The Chinese BS0 has aluminum clamps that are engaged by the two bolts mentioned. If you can get one full turn out of each, and then tap on the heads with a light rap hammer, the divider head should swing free. It takes little more than thumbscrew pressure to keep them in place in the future. To make my life easier, I completely tore down mine, deburred and polished where needed, replaced the bearings with FAG units, and reassembled. Like every Chinese tool kit, the dividing head needs a little bit of love to work like it should.
 
Solved: Thanks all for the ideas!

A combination of the 50/50 mix acetone+ATF into the trunnion "ways" - then some light tapping with a dead blow to the sides around where it gets clamping pressure finally did the trick.

Looks like I'll need to tear it down and go through it to make sure de-gunked.
 
ok, well now I can't seem to get the chuck off of the back plate.

It "seems" like a standard backplate on a chuck. remove the three bolts from rear...
but it won't budge.

I don't see any other bolts/screws...
tried the 50/50 acetone+ATF soak overnight, some tapping with dead blow, twisting/rotating won't budge.

I "gently" tried tapping the bolts while they were threaded most of the way into the chuck from behind - no go, but maybe I didn't whack them hard enough in fear of trashing threads.
 
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