The last big workshop project undertaken was the refurbishment of a Bridgeport BRJ series 1 vertical milling machine. I hope these comments may be useful to anyone taking on a similar project.
I had always wanted a milling machine for model engineering projects and when one came up at a C Dugard Ltd, a machinery dealer in the UK, I took the plunge and bought it. The machine was a British built Bridgeport manufactured by Adcock and Shipley, a well respected machinery manufacturer and part of the Textron group to which Bridgeport belonged at that time. The mill turned out to be in reasonable condition considering the fact it had been worked fairly hard, however there was some damage to the table, the head bearings had considerable end float and there was a lot of wear in the saddle. It was decided therefore that a complete overhaul was needed.
Unfortunately the picture above is the only one of the machine in it's original condition, I wish now I had taken a few more 'before' pictures.
Before starting work I purchased a CD of useful information from www.Quarterbore-inc.com which included a large engineering drawing of the head. The head was fairly straightforward to recondition, with just a few bearings needing replaced and the main spindle bearings needing adjusted. They are a little noisy at 4700rpm, but there is no discernible play in them so they'll be fine for now. The only worn component to give any trouble was the main spindle where the splines gave rise to some rattles when flycutting. This has been reduced by some careful shimming of the splines with 0.25mm brass shim.
The rest of the machine was then taken apart and every hole in the castings seemed to be crammed full of steel swarf. The only part requiring an engine crane to lift it was the knee casting, everything else can be handled by one person and some ingenuity. It was evident that the saddle surfaces would have to be scraped flat as there was about 0.003in of wear in them. A book I can recommend for those contemplating scraping is Basic Scraping Modern Methods by Michael Morgan available from www.machinerepair.com. The best scraper I have found is the Sandvik one from Greenwood-Tools which has a replaceable carbide insert. It is worth also buying a diamond whetstone (red grade 600 grit is about the correct roughness) to resharpen the carbide inserts as they are very expensive. Be warned scraping properly take a lot of time and great care but the results are worth it.
The mill had a Bijur manual lubricator and the main pump body had been damaged by corrosion caused by water in the oil. This was cured by turning up a new pump body. The meter units also needed replacing and the ones used on my Bridgeport can be purchased from Lubeline. The manifold uses IM25 units and the supply to the manifold an IM29 unit.
The final part of the jigsaw was to tidy up the electrics with some minor re-wiring and then assemble everything.
And the first job on the new mill was to resurface the table on the machine to take out some of the heavier damage. The project took about eighteen months to complete but was well worth it.