Harrison Horizontal/Vertical Mill Restoration

[Carl Wilson]

This beastie turned up today. I shall give it a go over the weekend.

Came with medium knurl wheels fitted. A coarse and fine set were also included.

 

[Carl Wilson]

Slow progress at the moment. Eating the elephant one bite at a time...

Pump has new plate that was made to replace the corroded one. New gasket made for it. Cleaned up the strainer and refitted it with new-old-stock 4BA bolts (cad plated no less..)

 

[Carl Wilson]

This evening I've been having a play with the clamp type knurler. Results were initially disappointing until realisation dawned. The material I thought was free machining steel was no such thing. I tried the knurler again on a piece of 230M07 and got far better results.

Still not the best, I'll grant you. That said the tool could have done with coming in a bit more on the cross slide. Unfortunately I'd managed to create a clash with the tailstock so I couldn't get in as far as was needed.

This is a better attempt, using the coarsest knurling wheels on a piece of 6082 bar. When I was desperate to prove that I could put a knurl on something...

I think I'm going to make two new change wheel retaining nuts now anyway. The inside of the changewheel cover has some rather nasty retaining nut shaped witness marks in it. These tell me that perhaps the old ones were not dimensionally as they should have been.

I've also been rooting through this bag of assorted lubrication nipples. I'm going to use some of them to come up with a repair scheme for the damaged push fit ones that had to be extracted, on the table assembly.

 

[Mark Davison]

Well the heat didn't work. I made a fundamental cognitive error, which I will explain shortly.

After trying the heat gun I decided to get serious and I cut the heads off the nipples. Judging by a nipple removed from elsewhere on the machine and the size of the offending items, I made an educated guess that a 6mm drill would basically take the core right out of them.

Thereby having removed any hold the threads might have, I could just go in with an easy out.

It worked, but not quite how I supposed.

View attachment 200984

Once I'd drilled down about 6mm I tried the easy out. Bingo, it turned. And turned, then turned some more. I pulled it and the nipple came out. Of course, the nipples were push in.

Now, there are literally thousands of push in lubrication nipples on machine tools the length and breadth of the UK. However, because these looked like grease nipples, and because there are threaded ones elsewhere on the machine, I made an assumption. A foolish one as it turns out!

View attachment 200985

They are all out now. Those of you who remember my Lathe VFD and DRO threads will be pleased to see that the CT90 photo bomb is back.

I want to replace all the nipples on the machine with fittings so I can have centralised lubrication, ie one shot. I'm assuming these below are pressed in too. I can get no purchase on them. I'm going to let sleeping dogs lie. It'll do my wrist good to pump some oil into them every so often.

View attachment 200986

Ive just bought the vertical version of this mill and took the table saddle and knee off. My Oilers are all threaded, but try this if yours are plain

https://www.lathespares.co.uk/myford-oil-nipple-concaved

 

[Carl Wilson]

Thank you for commenting Mark. It's always good to find someone else with one of these machines.

The vast majority of the lubrication nipples on my machine are threaded, but the ones in the saddle were pressed in. Mine was built in about 1969. I wonder if in later versions of the machine these were modified to be threaded too. That's what I intend to do anyway.

Thanks for the useful link!

 

[Carl Wilson]

Could be time for a sub-project. I need to cut a narrow slot in the change wheel retaining nuts. You'll recall from earlier on in this thread that the slot is part of the locking arrangement for the nut.

I have several slitting saws of varying thicknesses and diameters that I bought as a job lot, a few years ago. I don't have an arbour for them though. So I think I will make one.

What I have in mind is something like Stefan Gotteswinter's design, that will fit into an ER32 collet.

 

[Mark Davison]

Threaded ones here. I assume ours are 0BA as opposed to M6 but they'll almost certainly fit.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/232999335966

 

[Mark Davison]

Carl, what is your solution for the feed motor as you rightly point out it is already 440v delta configured? I plan on making up abthin adapter plate and fitted a NEMA32 stepper with 1/2" shaft (most seem to be 14mm mind)

 

[Carl Wilson]

Hello Mark,

My solution to the feed motor is the conversion to delta to run from a 240 volt 3 phase VFD.

If you go to page 5 of this thread, posts 94 to 96, you will see that I disconnected the star point and reconfigured the stator to delta from star as it was from the works, for the original 440 volt supply.

As far as I'm aware the machine was designed all unified, but that wouldn't rule out the lubrication nipples being BA. I will check later today. I've got a lot of assorted unified and metric ones (and probably the odd BA one too). Going back further in my thread you will see I discovered that the nipples on the main motor were gas thread, of all things.

I like your idea of using a large stepper motor. I want to do something similar to motorise the knee.

 

[Carl Wilson]

I have just consulted the machine manual and a typical lubrication nipple can be seen here, item 36 on the vertical head attachment.

The parts list gives this as 1/4 UNF, so 1/4-28.

The upshot of this for my repair of the saddle lubrication nipples is I either get new press in fittings, or I bore out the current 6mm holes to 6.8 and tap them to M8, then use M8 screw in nipples.

I can't use 1/4 UNF as the tapping drill for that is 5.5mm.

I like the idea of screw in types as they are easy to replace if damaged.

 

[Carl Wilson]

Another little step forward.

A' bonny 'an a' 'hing, as they say in these parts.

 

[Carl Wilson]

No more updates for a while - back at work.

 

[Mark Davison]

Bear in mind the nipples on the vertical head will be grease nipples for the bearings, not for way oil. I wouldnt fancy my chances of injecting oil into a grease nipple (unless grease guns will take oil?)

 

[Carl Wilson]

That's a good point Mark. However I think that they are basically the same. Looking at other parts of the machine, for example the knee mechanism, the same 1/4 UNF nipples are found.

In order to inject oil into the nipples, the ball is depressed against the internal spring by the cone shaped end on the oiler. Then the oil is injected through. Once done, taking the cone away allows the spring to reassert itself and the ball seals the nipple again.

The issue with pumping grease is usually that you are trying to pump it into voids with tight clearances between mating parts. I've been using the phrase "lubrication nipples" to try to avoid confusion. "Grease" nipples can be used for oil.

 

[Carl Wilson]

Back at home now. Work soon to resume on the project.

 

[Shox Dr]

I was lead to believe Grease nipples will take a fitting that lock on to the nipple. Oiling nipples dont have the rounded head for the 3jaws in the grease gun to grip over.

 

[Dieselman 63]

I was lead to believe Grease nipples will take a fitting that lock on to the nipple. Oiling nipples dont have the rounded head for the 3jaws in the grease gun to grip over.

A machinist once told me they’re all ‘machine jewellery’ just for looking pretty as people never use them

 

[Carl Wilson]

You are right in essence. However a grease nipple can be used for oil. There is absolutely no reason why not. And in the case of my mill, they have been.

When used for oil a cone shaped end on the oil can depresses the ball in the nipple against the internal spring. There is no requirement for it to grip onto the nipple as is the case with a grease gun.

That's why there is really no such thing as a grease nipple, it's a lubrication nipple.

 

[Shox Dr]

You are right in essence. However a grease nipple can be used for oil. There is absolutely no reason why not. And in the case of my mill, they have been.

When used for oil a cone shaped end on the oil can depresses the ball in the nipple against the internal spring. There is no requirement for it to grip onto the nipple as is the case with a grease gun.

That's why there is really no such thing as a grease nipple, it's a lubrication nipple.

For sure they can, but it would be careless to replace an oil nipple with a grease nipple. If someone decided to lubricate the machine and wasn't aware of the incorrect nipple use they could use grease potentially causing damage.

 

[Carl Wilson]

For sure they can, but it would be careless to replace an oil nipple with a grease nipple. If someone decided to lubricate the machine and wasn't aware of the incorrect nipple use they could use grease potentially causing damage.

I quite agree, which is basically what has happened on my mill. Someone, well meaning it has to be said, has been assiduously pumping grease into the oil nipples on a regular basis, and for years.

Fortunately it doesn't seem to have done any real harm.