Harrison Horizontal/Vertical Mill Restoration

[scottmk1]

It's a good interesting thread you have going here Carl, I should take more time to get as many photo's as you do. The red paint inside the castings also aids the return of the oil oil to the sump, as on a bare cast it would cling more, if you see what I mean. Modern 2 pack paints are probably what manufacturers would use now.There is probably something in that Glyptal stuff that makes it good at what it does, but isn't good for our health or something.

 

[Carl Wilson]

Thanks very much Scott. I tend to take photos more as I go along these days. Smart phones have made it so easy. I've always kept written notes and archived my projects, right from being a child. I'm finding the forum a great way to carry that on.

I find posting notes about my projects a really rewarding thing to do. It allows me to share my love of engineering with like minded people, not something I'd get to do much of otherwise. I also learn a huge amount from the massive pool of expertise that this site represents.

With any luck I'm adding a small droplet into that massive pool, and someone will find what I have written of use.

 

[Carl Wilson]

As I mentioned previously, I'm back at work now. So I've been trying to do a bit of research on the Gryphon motor for the power feed. As I can't yet physically work on the motor, my aim is to order the bearings and seals for it now, so I can strip it and replace them when I get home.

Unfortunately I've been unable to find any drawings or literature for these motors on the net. What I'm after ideally is a spares breakdown drawing. The one I have is a 1/8hp 415v 3ph version.

I wrote to Brook Crompton (the makers) and asked if they had any archived information on the Gryphon motors. They don't, but they referred me to a company called Massey Coldbeck in Liverpool. They hold some of the older drawings and other information, apparently.

Now I was wondering if anyone among the assembled on this forum would have any drawings of these motors? All help will be gratefully received, I assure you.

 

[Carl Wilson]

Just a quick update. Massey Coldbeck didn't have any drawings, so I'm wondering if anyone here has anything?

 

[Carl Wilson]

I'm back at home now so work can start again on the mill project. I have the bearings to rebuild the feed gearbox and I will be making a start on the Brook Gryphon motor. Stripping it down, replacing worn or damaged parts and converting the windings to delta.

I'm waiting on a seal at the moment that I couldn't get from bearing boys. Should be here in the next few days.

I'll also be doing some paint removal and hopefully priming and painting on the gearbox and motor. I'm going to be experimenting with my own paint removal formulation. It will consist of dichloromethane gelled with vaseline.

 

[Carl Wilson]

Did a bit more work on the gearbox this morning. Got the last shaft out with the large gear on it. This is the gear driven by the pinion on the Gryphon motor. Drive is transferred from this shaft to the worm via external change wheels.

As with the rest of the box, it was necessary to strip the shaft out in a certain sequence. First the bearing was drifted out from one end, then the whole shaft knocked out leaving the opposing bearing still fitted. This was knocked off in the vice.

It was necessary to remove a circlip from one end of the shaft to get the bearing off.

Here is the shaft held in the vice by the threaded end. The large spacer is splined to the shaft.

Here is how the shaft stacks up. Bearing then female splined gear followed by female splined spacer then second bearing. The spline in the gear is an insert. It's worth noting that on both shafts the bearing on the non threaded end is fitted to a lightly straight-knurled portion of the shaft, then secured with an external circlip.

Next job is to remove the bearing and remaining inner race from the Worm wheel/lead screw nut unit. I'm going to make a little slip in insert with a centre drilling in it for this. It will sit inside the leadscrew nut to give the puller something to react against. This will obviate any damage to the thread in the phosphor bronze nut.

Concurrent activity will be solvent cleaning of all the parts and the gearbox casting. Then paint stripping trials on the casting as I mentioned in my last post.

 

[Carl Wilson]

Got some of the gearbox parts cleaned in equipment cleaner this morning. A lot of the fasteners have silver hammerite residue on them, but I will remove that when it comes to paint stripping.

A bit more cleaning is required with some scotchbrite, but things are getting there. I shall clean the gearbox casting next.

 

[scottmk1]

Good work Carl, looking forward to more updates.

 

[Carl Wilson]

Well, I discovered today that I made a bit of an **** of selecting the new bearings for the feed gearbox. I went through the drawings and purchased them when I was on the ship, so I couldn't take any measurements.

Trialling them today I realised that two out of the three sets of bearings were wrong. The error came from my incorrect interpretation of the original RHP bearings part numbers.

Anyway, measurements done I have now ordered the right bearings and they are on their way. Lesson learned!

And thanks Scott! I'm hoping to get a bit more done tomorrow. I'll be posting a full list of the bearings got for the gearbox once the rebuild starts. I'm also looking forward to getting stuck into the Gryphon motor.

 

[Carl Wilson]

This morning I hit all the previously cleaned gearbox internals with a small wire wheel, driven by my 90 degree die grinder. They came up very nicely.

I've also been messing around with chemicals. I cleaned the casting in equipment cleaner, which is a mixture of IPA, Acetone and Toluene. That actually began to lift the external paint by itself.

Then I made up what I hope will be a decent paint stripping formula. Dichloromethane gelled with vaseline.

I messed with the concentrations until I got a wallpaper paste like consistency. Total dichloromethane content was about 100ml.

I put this on the casting and some on the really thick paint on the main body of the machine. Hopefully it will do the job.

The seal turned up today for the gearbox. The next thing I'll need to get is some paint and primer. I've decided to use Paragon Paint's Harrison Grey.

 

[Carl Wilson]

I also started stripping the Gryphon motor. It is held together by four 2BA threaded tie rods. There is a special nut on each end of these. Slotted at the driveshaft end and hex at the other end. Sistoflex insulating sleeves slide over the rods.

The rotor and bearing assemblies are, not surprisingly, smaller versions of the main motor ones, with a retainer/shield over the rear bearing.

The stator looks like it will be an easy job to convert to delta.

 

[Carl Wilson]

Got a couple of hours in this morning. While I was in the shop with the roller door open, the post lady popped in. So I've now got some more bearings and the 3/8-24 UNF tap. Ordered some paint this morning too.

I hit the gearbox casting with the wire wheel and also gave the bottom cover of it the same treatment. The cover is an aluminium casting. They are now both basically ready for priming/painting.

Cracked on with the Gryphon motor. Got one bearing off. The driveshaft end one is trickier, it's hard up to the cooling fan so I can't get the puller in. I'm going to try warming it up with a heat gun to see if that helps.

As can be seen below, no room for the puller.

 

[RichardM]

Take the outer off then cut diagonally through the bearing inner with a cutting disk, large screwdriver in the ground groove, give it a twist and the bearing inner usually cracks and is easy to remove.

 

[Maker]

It looks like there's a washer under the bearing, is it part of the fan or a free-floating washer? I took apart a motor recently with a washer under the bearing, I got the pullers on the washer and pulled it off that way, I do now have to replace the washer as well as the bearing as it put three big dents in it.

 

[Carl Wilson]

Hi Guys. Thanks for the advice. The part that looks like a washer is part of the fan. I suspect the fan is "pot metal" ie magnesium alloy die casting. In the main motor there is a large washer in that location.

Richard, I considered using a destructive approach as you describe. That's the road I'm treading if the softly, softly method fails.

 

[Carl Wilson]

Well, I attempted to press the shaft out of the rotor a little last night. The hope was I could take the bearing off this way.

As you know, I haven't got a press and I usually make up an arrangement that you've seen here before, when I pressed the new bearings onto the main motor shaft.

I got up to 2500psi (170 bar) without any movement, and I was reluctant to go any further with the makeshift set up. So it looks like I'm going to have to use destructive measures.

 

[Carl Wilson]

Post lady has just been and the new bearings have arrived for the Gryphon motor, from bearing boys.

I'll fire up the grinder later this afternoon...

 

[Carl Wilson]

I am just in from the workshop. I managed to get the front bearing off the rotor shaft, though not without incident.

Since the bearing was so close to the fan I decided to grind it circumferentially. I used a 4 1/2 inch grinder mounted in this little Einhell stand, caution being the name of the game.

I ground the outer race first and got it off easily.

The circumferential grind split easily and the outer race and ball cage was then off.

I then ground the inner race in the same way. I was able to split this too.

It was at this point that I realised the thing that looked like a big washer between the bearing and the fan was a big washer between the bearing and the fan. Just as Maker suggested.

The second half of the inner race wasn't for coming off. I ended up having to diagonally cut through the remaining section using a Dremel.

I said the removal was not without incident...I managed, cack handed moron that I am, to undercut the shaft a bit. OK, a lot. Fortunately not too deeply, but for about 3/4 of the periphery.

My plan to rectify this is to tig weld the damage and then turn the weld down to size, with the shaft between centres. I could probably get away with removing any burrs and pressing the bearing over this. The thing is, I'd know.

 

[Maker]

I'd leave the groove, you'll probably get some distortion welding it up, then it needs straightening, more trouble than it's worth IMO.

 

[Carl Wilson]

Thanks for that. I was thinking that actually. The whole thing could grow arms and legs...Maybe best to let sleeping dogs lie...