Restoration and modifications to a Tom Senior light vertical mill

[Miles HellonParticipant @mileshellon]

Regarding a source for leadscrew nuts **LINK**

[ianjParticipant @ians]

Yes mine is a metric machine as well X , Y and knee (quill is imperial) I have a DRO fitted so I very rarely look at the dials. I've seen that seller on ebay his nuts are brass if I did replace mine I would prefer them to be bronze.

When you remove yours Simon I would be interested to see a photo of it, If its just a threaded cylinder held in the casting with grub screws (like mine) or like the E type with a spigot.

Any way good luck with your repair.

Edited By ian j on 04/01/2019 10:28:25

[Simon Williams 3Participant @simonwilliams3]

Tonight's update:

Pulled the half nut out of the casting. It was a moderate press fit, came out with a bit of help from a piece of M12 studding. Could have used 1/2 whit, but it is a metric machine….

And here it is fitted in it's proper position.

There, that was an easy fix (if only).

Set up and machining tomorrow, after I've got the wood burner going well.

Rgds to all

[ianjParticipant @ians]

While it's in your hand Simon can you confirm it's dimensions as 1 1/4" os diam by 2" long.

I know we can only surmise but I wonder if the damage happened when a new nut was been inserted?

Edited By ian j on 04/01/2019 19:27:50

[Simon Williams 3Participant @simonwilliams3]

Posted by ian j on 04/01/2019 19:26:27:

While it's in your hand Simon can you confirm it's dimensions as 1 1/4" os diam by 2" long.

I know we can only surmise but I wonder if the damage happened when a new nut was been inserted?

Edited By ian j on 04/01/2019 19:27:50

Ian –

Bush measures 1.243 OD (mostly) by 1.960 long overall. Material is visually bronze, not brass it's not yellow its pink. (phosphor bronze?)

I like the suggestion of having broken the casting by over-enthusiastic bush fitting, that's a simpler and more plausible suggestion than somehow it fell over leaving no other visible marks. The only thing is, that bush is a slack sloppy fit in the remnant of the proper location. The socket left is about 200 degrees of a circle so it's pretty easy to gauge the diameter, and although it's significantly scored it's pretty much round albeit oversize. I wonder if someone failed to realise there was a grubscrew locating the bush axially and radially, wound happily on some kind of extractor and only stopped when it was too late. Ping!

Best rgds Simon

[Simon Williams 3Participant @simonwilliams3]

Good afternoon all.

Spent my weekend worshipping the god of swarf, so here is the preparation for my repair to the broken leadscrew mounting casting:

And here it is assembled

xxx

And just to prove that it clears the channel in the bottom of the table casting (if only just):

The orientation of this photo is a bit odd, only so I could get the camera near enough. "Up" is about 10 o'clock.

So bung it all back together and it all fits and lines up and slides and wotnot. X travel now measures 18-3/16, which is a result I'm very pleased with.

Thank you gents for your help in determining that it needed surgery, hope your restoration s equally satisfactory.

Best rgds and a Happy New Year.

Simon

[ianjParticipant @ians]

Simon that's  an excellent solution and work, better than original in my opinion. I'm sure you are very happy with the end result not to mention the extra table travel !

Now we need to see how Miles is progressing?

best Regards

 

ian

Edited By ian j on 06/01/2019 16:22:24

[Miles HellonParticipant @mileshellon]

Good work Simon. That looks pretty bombproof!

No progress at all here, I'm afraid. I've been working hard at getting my new workshop ready. That is the priority, at the moment. I've given myself a deadline of the end of Jan.

Any luck with the feednut Ian? Maybe you could ask the guy in Cardiff if he would do one in bronze? There are short lengths of bronze bar available on Ebay. I would order one too, if it makes it more worthwhile. I presume that the cross slide nut is the same dimension? That is the one with excessive back lash on mine…

ATB

Miles

[ianjParticipant @ians]

Miles.

You must have read my mind as I did contact the ebay chap.I think he would have been prepared to make one but he must screw cut the thread and then finish with a tap. But he only has a LH 3/4" by 5mm pitch tap.OK for the Y axis but the X is RH.

The Y AXIS nut is not just a cylinder, see photo.

If you join the yahoo Tom Senior group , in the files section there is a file showing how to modify the nut to compensate the back lash..

[Miles HellonParticipant @mileshellon]

Ian.

Oh, that's a pity…

I'll check out that file. Thanks for the info.

Miles

[old martParticipant @oldmart]

I realise that this is an old thread, but I couldn't resist a few comments.

Regarding the X axis nut being in the wrong position, I would have first tried turning the leadscrew the other way round, so the handle was on the left. I removed one of these nuts the other day and came close to breaking the casting as yours was. I removed the grubscrew and started drifting the nut out, to no avail. Looking closer and cleaning the grease off of the outer end, a round mark appeared. It turned out to be an axial threaded hole centred on the bronze/cast iron joint line with a 2BA x 1/2" long grubscrew in it.

I have to make a 3/4" X 5 acme nut, and have ordered a tap from Tracey Tools, they also sell trapezoidal taps.

[VicParticipant @vic]

Nice job on the repair.

[Peter Simpson 1Participant @petersimpson1]

I have a Tom Senior Light vertical. I have had is for about 12 years, I cannot remember what the backlash was when I purchased it but I measured both the X and Y axis last week. I measured approx 0.6mm. This week I stripped the leadscrews and nuts from the machine an took them to Kingston Engineering Hull. They are going to clean up the leadscrew and make new nuts.

Ballpark figures for the new nuts. X nut £60. Y nut £150 as there is more machining required. Appox 3 weeks delivery.

[SteviegtrParticipant @steviegtr]

Bump.

Anyone else done modifications to this model of which I have recently purchased. A lovely old machine. The No is K3400 with a 4 above the long number 4 ??? I have fitted a Mondeo wiper motor for the X Axis travel . It has a 3ph motor & inverter. A M DRO 3 axis kit. Anyone else done any other mods to one of these. I am just working on a chip evacuation system which I will post pictures of once done.

Steve.

[Miles HellonParticipant @mileshellon]

Hi Steve,

Timely bump. Just about to start working on mine again.

Just received the No. 6 chuck removal wedge set which I ordered from the U.S. on Monday!

Any one have advice on using these to extract a very tight MT2 arbor?

Miles

[SteviegtrParticipant @steviegtr]

Not used one of those. When I bought my mill, the chuck was very tight in. Managed to get out with the draw bar unscrewed 2 threads & a hefty blow. Since then not had a problem. I do not tighten the bar hard, Never slipped so far.

Steve.

[JasonBModerator @jasonb]

Hold chuck and arbor horizintally with wedges lightly in place – tapered edges together, rest one wedge on something solid and tap the top wedge with a copper hammer and it should pop the chuck off the arbor, a third hand to catch the chuck helps.

[Miles HellonParticipant @mileshellon]

I've already soaked mine in penetrating oil and hit the drawbar as hard as I feel comfortable doing. I was worried about damaging the bearings. Will try with the wedge set and a clamp.

Miles

[Miles HellonParticipant @mileshellon]

Thanks Jason,

This is to remove a collet chuck from the machine. I could turn the head horizontally and support the wedge on a machine vice on the bed?

Miles

[SteviegtrParticipant @steviegtr]

Yes there is room under the spindle base to get a wedge in there. It is not a big area . There is a posting about this on here. He used wedges successfully.

Steve.

Edited By Steviegtr on 07/05/2020 13:44:45

[Miles HellonParticipant @mileshellon]

I found this thread: **LINK**

[SteviegtrParticipant @steviegtr]

https://www.model-engineer.co.uk/forums/postings.asp?th=158617

Here it is.

Steve.

[Miles HellonParticipant @mileshellon]

Thanks Steve

[Miles HellonParticipant @mileshellon]

Tried heating up the chuck's collar with my soldering iron, in an attempt to free it. No luck with that.

Anyway, managed to extract the chuck with the wedges, using this setup:

Thanks again for the help.

[SteviegtrParticipant @steviegtr]

Since I have had my machine I have always struggled with the 1/2hp motor easily stalling. Today I went at the inverter with an attempt to see what was wrong. It is a Toshiba .75kw one. These things have a 160 page manual. The way it kept hunting I was sure that a winding was down on the motor. The other thing was no matter how I set the upper Hz limit , it would never go above 52.5. Very deep into the manual there is a section on RS232 interface programming, which until now I have steered clear of.

So I slowly went through every parameter. It seems that this inverter which was 2nd hand when the previous owner fitted it, had been controlled by a interface.

The base motor frequency was set at 60hz instead of 50. Also there was a setting waiting for an input at 52.5hz. Settings for this are on or of by the selection of a simple 0 or 1. — 1 being rs232 on. I changed this to 0. Came out of the program & saved the settings. Now the motor is great. Also i have set max to 85hz for now. Runs fantastic & the power is much higher than before.

Nothing wrong with buying 2nd hand electronics but you never know what they were previously used for so a good scan through works wonders.

Strangely a lot of forum members had been telling me that there was nothing wrong with the 1/2hp motor on these machines. To any of them who may read this, my sincere apologies you were correct.

Steve.

.

Edited By Steviegtr on 08/05/2020 00:22:45

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