Shopsmith Forums

I have just tried to try tilting my 500 into the drill press mode.
The knurled screw used to lock the base to the vertical position
does not fit the hole that is drilled into the base arm. looking at the axis pin that the tilt comes from, I dont seehow itcould possibly be off by about .25 inch, but it is. If any has had this same problem, I would appreciate a fix. When the tool was new about 25 years ago. I never had this problem.

It is supposed to be that way. Not sure why, but it is covered in the book.

clementfeme wrote:I have just tried to try tilting my 500 into the drill press mode.
The knurled screw used to lock the base to the vertical position
does not fit the hole that is drilled into the base arm. looking at the axis pin that the tilt comes from, I dont seehow itcould possibly be off by about .25 inch, but it is. If any has had this same problem, I would appreciate a fix. When the tool was new about 25 years ago. I never had this problem.

They have been made this way for over 50 yrs! Do not know why!

I noticed this on my '82 model just a little while ago and thought it was a
bit odd.. Now I can sleep better knowing it's just 'because'..

JPG40504 wrote:They have been made this way for over 50 yrs! Do not know why!

If the screw (Arm Lock Knob) was to fit directly into recessed hole it would only push to the side of the base arm. It would not be forcing the base arm againest the base to eliminate movement. You may notice that the recessed hole is above the screw and will force the base arm down againest the base removing any looseness when the screw is tighten. The base arm and base are cast aluminum and are not machined for perfect fit so this allows for small differences in manufacturing to not effect the locking of the base arm to the base when in the drill press position. This type of fit is more vibration proof when hand tighten the screw then when the screw is fitting directly into the access hole.

billmayo wrote:If the screw (Arm Lock Knob) was to fit directly into recessed hole it would only push to the side of the base arm. It would not be forcing the base arm againest the base to eliminate movement. You may notice that the recessed hole is above the screw and will force the base arm down againest the base removing any looseness when the screw is tighten. The base arm and base are cast aluminum and are not machined for perfect fit so this allows for small differences in manufacturing to not effect the locking of the base arm to the base when in the drill press position. This type of fit is more vibration proof when hand tighten the screw then when the screw is fitting directly into the access hole.

And NOW we know the REST of the STORY.

billmayo wrote:If the screw (Arm Lock Knob) was to fit directly into recessed hole it would only push to the side of the base arm. It would not be forcing the base arm againest the base to eliminate movement. You may notice that the recessed hole is above the screw and will force the base arm down againest the base removing any looseness when the screw is tighten. The base arm and base are cast aluminum and are not machined for perfect fit so this allows for small differences in manufacturing to not effect the locking of the base arm to the base when in the drill press position. This type of fit is more vibration proof when hand tighten the screw then when the screw is fitting directly into the access hole.

So are we concluding that the "tilt lock" is designed to reduce vibration and that it is not really intended to "lock" the Mark V in the vertical position?

Well I guess that the old rule is stil right,
If all else fails read the instructions.
Thanks for all the info.

Clement

dusty wrote:So are we concluding that the "tilt lock" is designed to reduce vibration and that it is not really intended to "lock" the Mark V in the vertical position?

NO. Vibration could cause the screw (arm lock knob) to work loose if the access hole was directly under the head of the screw. Being offset allows the screw to more tighten the base arm to the base. The tilt lock is to lock the Mark V in the vertical position and remove any looseness at that connection. I have found some arm lock knobs with an allen socket in the knob. I use these allen socket knobs for dedicated drill presses as they can be tighten more then using your hand or channel-locks.

billmayo wrote:NO. Vibration could cause the screw (arm lock knob) to work loose if the access hole was directly under the head of the screw. Being offset allows the screw to more tighten the base arm to the base. The tilt lock is to lock the Mark V in the vertical position and remove any looseness at that connection. I have found some arm lock knobs with an allen socket in the knob. I use these allen socket knobs for dedicated drill presses as they can be tighten more then using your hand or channel-locks.

Thank you, Bill. That clears everything up.

The truth is, I move in and out of drill press mode so frequently that I hardly ever lock it down.

OKAY, I'm ready - give it to me.