Project355
Member
- Joined
- Aug 2, 2020
- Messages
- 672
I don't own a Summit, but I have been a machinist/mechanic all my life
There is a phenomenon "tolerance stacking"
I think a stand of sorts beside the press with a dial indicator attached accordingly could measure the difference between the slide movement of loaded (no case) vs. unloaded. Not impossible but a bunch of precision inspection tools would be needed...
My reference to the Interrapid (or is it just Inter-Rapid, who cares) may indicate my own experience around machines.
Any tolerance stacking should have been eliminated when I further lowered the die, thus requiring quite a bit of effort to "cam over" the mechanism. At that point, its pretty clear the press was under a decent amount of stress at full stroke. By adding more stress, with sizing, the parts no longer touched. The links sit on studs that have a fairly close fit. I'm not going to take out the small hole gauges and micrometer to see how much. Its a very close fit, and the amount of play to get say... the .060"ish gap shown is just not there. Total stacked tolerance, by my estimation is well under .005".
Measuring the slide movement compared with the bench, or the base, is sort of moot. We know the slide moves less when it has a load attached.
Submitted for your approval.... and I'm not 100 percent on this myself... but here goes. First attach the gauge's base to the base of the press. Bring the gauge up to the top of the column. Operate the column, as the die is already adjusted, and see how much back tilt there is at the top of the column. That one is straight forward. The next test is more tricky.... Attach the base of the gauge to the front of the die platform and with the platform say... an inch from full stroke, get adjust the gauge to touch the back of the column (where its accessible). See if the gauge movement, if any, is the same loaded and unloaded. That way, it can be determined if the platform is flexing against the column.
Personally I think its a bit of both. I think the bearing surface on the column, which essentially is a sleeve, has enough bias, or play, to become elongated under pressure. And I think the joint where the column fits the base has some give as well.
What say ye, MDI?
Last edited: