Tom Senior Type E Main Column Issue

Hi,

I have just got a Tom senior Type E and cant get the column to lower. I have:

Loosened the two hex head cap heads on the clamp at the base.

The keyway guide is engaged.

I can freely lift the column up, but when winding to lower it, it only drops so the main column is about 6mm past the bore of the bottom bracket and stops.

From below I can see the keyway coming through, and it seems clear of any clashes at the keyway of the bench mounting?

Any ideas?

Regards

Jeff

Rancid grease gumming up the socket in the base casting?

Try flooding it with penetrating oil and see if it changes.

Rgds Simon

Hi Simon,

Yep tried that. I clearly have oil coming through the lower end.

Regards

Jeff

Jeff,

I also have an elderly Tom Senior E type on which the column s sometimes is reluctant to lower. This is because the it sometimes "pitches" due to the mass of the head being at the front with very little weight at the back to balance it. When this happens I lower the column adjuster a shot way and then rock the head a bit which then fall down nicely onto the adjusting jack. Do this in shot stages as it comes down with a clonk!

Eric

Hi Eric,

Yes I tried that. I found that it freely falls when the wheel is rapidly wound up, then pushing to and fro, as you suggested, gives me another 3 mm or so. And there it stays!

I just noticed the guideway adjustment screws at the base. I will give these a bit of slackening, but as mentioned I cant see the keyway guide coming through the base, so I'm struggling to see how its held.

Thanks

Jeff

Hi Jeff, have you by any chance got a bruise or a dink in the surface of the column where it enters the base casting just enough to make it a tight fit?

Good luck

Simon

Jeff,

I have sent you a PM.

That's an idea, I will have a gander. But it would need to be a big dint to stop it so quickly and it does not get jammed.

But that worth a go as it has just been transported by me.

Found the issue.

I finally got around to looking at the jamming column.

After taking the motor, the head, column and column base apart I found the issue - the vertical lead screw was bend!!

Simple fix, put the lead screw in the base bearing casting and bent it back!!! All is well and mill is great.