Harrison Horizontal/Vertical Mill Restoration

[Carl Wilson]

I'm going to give my workshop a good tidy out this evening in preparation for getting stuck back in. I left off starting down the road of making new change wheel retaining nuts for the feed gearbox.

I think I will be making a slitting saw arbor first though, so I can cut the slots in the nuts. I've had a bunch of slitting saws for years with no arbor for them, so now is the time.

 

[Carl Wilson]

Here is a good example of the sort of confusion that can be wrought. Is this a grease nipple or an oil nipple?

Neither really. It's a lubrication nipple which in this particular instance is used for injecting oil. Vactra heavy to be exact. That said, it's possible to see why someone might just push their grease gun on it and pump away once every so often. Despite the fact that there is a plate on the side of the machine telling the user what oil is required!

As a comparison, here's a lubrication nipple from the vertical head bearings, which IS supposed to have grease injected into it (Shell Alvania 3 no less). It's easy to see why someone got confused.

 

[scottmk1]

My Eagle surface grinder is covered in those. So is the Semco mill.

 

[Carl Wilson]

My Eagle surface grinder is covered in those. So is the Semco mill.

I think it is pretty common to find this type of nipple used for oil, what I was taught in the RAF to call Tecazerk nipples. More usually we find the flush type of fitting used for oil injection on machine tools. My lathe has lots of them.

I knew this mill was going to be full of grease the moment I saw it. A lot of people just have a Pavlovian reaction to that design of nipple - they just want to plug their grease gun onto it and steady away.

To be honest I'm in two minds at the moment. My initial plan was to install a one shot lubrication system as part of the restoration. I'm not sure though if injecting a bit of oil into a few nipples every so often warrants such complexity.

 

[Milkybars]

Elliott Omnmill is just like this, almost all are oil ..but the odd one or two are grease !!
Like you say, no indication which is which to the user. I think if your running the mill in a production enviroment then the one shot is the way to go.
If your a hobby/light user a few mins with the relevant guns is not worth the outlay in my view...

 

[Carl Wilson]

Elliott Omnmill is just like this, almost all are oil ..but the odd one or two are grease !!
Like you say, no indication which is which to the user. I think if your running the mill in a production enviroment then the one shot is the way to go.
If your a hobby/light user a few mins with the relevant guns is not worth the outlay in my view...

Yes, everything is oil - a plate on the side of the machine explains - but the bearings in the feed motor and main motor and the vertical head are greased. Actually the feed motor won't be anymore as I fitted sealed bearings to it. Ditto the main motor.

The vertical head is of course an accessory as this is a horizontal mill really.

I'm not in a production environment by any stretch so I'm not going to bother with the one shot.

 

[Mark Davison]

Great to see you are back, I've been waiting for another installment!

I got a 1" INT30 slitting saw abor for about £35 from rotagrip the other month. Seems fine but havent used it yet.

I got mine reassembled (of sorts) only to find lots of backlash in the worm driven leadnut for the table. It looks like the nut itself, as opposed to the bearings. It made climb milling impossible. I opted for a 2005 ball screw from Zapp and some 16mm steel to make new end plates and a plate to bolt to the saddle to carry the nut (fixed). I'm going to remove the feed gear box completely and mount a NEMA34 stepper motor onto one of the new end plates and drive it with some toothed pulleys and a belt. If I can mount the motor onboard then I'll also recover some much needed space.

The bit I'm struggling with is adjusting the knee. Any idea what the proper method is? Theres nothing in the manual. I think mine is too loose as it sticks and then drops when I wind it down.

 

[Carl Wilson]

Hi Mark and thanks for your kind words.

Seems like you had a few issues with your machine. The leadscrew and nut on mine had very little backlash so I'm hoping it will be alright when it goes back together. Sounds like a good set up you have with the ball screw and the stepper motor.

I don't know how to set up the knee. It sounds like there is a lot of play at the top end if yours is doing as you say. On mine, the mechanism is very stiff and the housing for the nut at the bottom is cracked. I will make a new one. The bevel gears are covered in 50 years worth of crap, so I'm hoping that's the main issue.

 

[Carl Wilson]

Started making the slitting saw arbor this evening. First I turned down the driving feature. I also machined a narrow portion of the major diameter at the same setting. This meant when I took the part out of the three jaw to machine the major diameter end, I could put it in the four jaw and indicate off a section that is concentric to the driving feature.

Next I set the part up in the four jaw and machined the major diameter. I then turned a 4 mm long section to exactly 25.4 mm. This is the register for the slitting saw blades. There is also an undercut to ensure that the saw blades sit flat against the faced end of the major diameter. I am very happy with the fit of the blades to the register.

Here is the saw blade fitted. Next I will drill and tap M8 through the centre of the register. Then a cup shaped washer will be turned which will clamp the blade to the arbor. The register is long enough to accomodate all the thicknesses of 1 inch bore slitting saws that I have.

 

[Mark Davison]

In general the machine seems to be in very good condition. The knee is just a pig to setup as unlike adjustable gib strips there is no way to feel what is going on when you adjust the thing. When the rails that hold the knee are bolted on you can't adjust it, you have to loosen off the rail, then adjust the 3 hollow adjusters (as the rail is loose there is nothing to feel at this point) then bolt the rail tight again.

I tried clamping the rails tight against the knee without using the bolts (combination of wedges and clamps) in an attempt to feel the bit point. It has got it roughly in the right place, but not quite!

Hi Mark and thanks for your kind words.

Seems like you had a few issues with your machine. The leadscrew and nut on mine had very little backlash so I'm hoping it will be alright when it goes back together. Sounds like a good set up you have with the ball screw and the stepper motor.

I don't know how to set up the knee. It sounds like there is a lot of play at the top end if yours is doing as you say. On mine, the mechanism is very stiff and the housing for the nut at the bottom is cracked. I will make a new one. The bevel gears are covered in 50 years worth of crap, so I'm hoping that's the main issue.

 

[Mark Davison]

I assume you are mounting your arbor in a 1/2" collet? I'd had visions of you turning up the INT30 taper from 2" barstock !

 

[MBB]

Looks like you need your chuck demagnetised.

 

[Carl Wilson]

Yes I will be putting the arbor in a 15 mm collet. I have a Rong Fu drill/mill clone (Chester version) that will be doing the job, and it's MT3. It would be ambitious of me to machine an int 30 taper! I might have a go one day.

The knee does indeed sound tricky to set up. I have all that to look forward to. Thanks for describing how you did it; I'm learning all the time.

I have got a lot of old yokes from TV picture tubes so I suppose I could make a degaussing coil! There is a limit to the number and type of sub projects I'm prepared to tackle as a part of the mill restoration!

 

[Carl Wilson]

Bit more work on the arbor this evening. Hopefully this view gives a better image of the undercut.

Next I drilled 6.8 mm ready to tap M8.

More tomorrow.

 

[Carl Wilson]

Tapped the hole in the arbor today. The vfd I fitted to my lathe makes power tapping an absolute breeze.

 

[Carl Wilson]

More later today. The sketch shows how I do things. Just get the key dimensions in and then faff about with the others until there is enough metal in the right places. In a rule of thumb sort of way.

No autocad or finite element analysis here...

 

[Carl Wilson]

Started making the end cap for the arbor.

Got a new, larger 3 jaw coming today from RDG. I'll show a picture when it arrives.

 

[Carl Wilson]

As promised here is my new 3 jaw. It's a 160 mm one from RDG with a D1-3 mount, so it'll go straight on.

It's made by HBM. My self centring 4 jaw is the same make and I have no complaints.

In the box were the chuck, somewhat obviously, outside jaws, the three camlock studs and their retaining cap head screws, the chuck key and manual.

The figures they claim for runout seem alright, at least to my eyes. The largest value they quote is just a shade under 3 thou, if you like to think in imperial.

I might test it to see how true these claims are, and post it up. Then again, I probably won't. I'll more likely put it on and just use it to make stuff that will be more than accurate enough for the hacking about that I do.

 

[Carl Wilson]

Haven't had much time in the workshop recently as I have had in laws visiting and a trip to Glasgow.

I've managed to more or less finish the slitting saw arbor. I just need to mill two spanner flats on it now.

 

[Carl Wilson]

Finished the arbor. I milled a pair of spanner flats. I took 2mm off each side giving a dimension of 30mm AF.

I indexed the second flat from the first using an engineers square against the flat and the edge of the milling vice jaws.

Now I can get on and make the special retaining nuts for the feed gearbox changewheels. I have a piece of EN1 to make them from, for ease of knurling.

I think the arbor is made in EN8. I can't remember the exact spec of the bar end I used, save to say that it was free.

I'm taking the family up to Ullapool for a long weekend break so I may not get much done over the next few days.