New Toy s/h RF45 Mill

Sorry, I was leaving the house when I wrote what I wrote and I should have specified an oil bath. Let me explain.

A friend had an old lathe, I think it was a Clausing but I'm not sure. It had shielded bearings in the gearbox and he wanted to change them to sealed bearings. I didn't see why he couldn't and encouraged him to switch them but he queried SKF about it first. These bearings apparently live in an oil bath that gets hot and the concern he had was that this would thin the grease in a sealed bearing and reduce bearing life. SKF agreed with him for this application - low speed, oil bath, heat. I learned something that day and was glad he didn't listen to me. SKF also mentioned that oil baths in lathes can get hot and when they cool, water can condense - never thought of that one before. Water = rust, so they recommended he change oil on a regular basis (annually).

Ran home and opened up the gear box on my Emco lathe and found open FAG bearings - no shields, no seals - but no rust because I'm anal about gear oil changes annually.

Apparently, there is a great deal of controversy about which bearings to use in a gear box. Some guys use sealed, some shielded and some use open bearings. I don't know who is right but I do know I was wrong on this occasion.
 
Another time I was wrong about bearings. When I changed the spindle bearings in my RF-31, I went from open tapered roller bearings that were greased to angular contact bearings that were sealed both sides. Everyone knows you have to run in new spindle bearings, right? I thought so anyway, but queried FAG just to be sure. Turns out that their precision sealed bearings don't require any break in at all. Wrong twice. Now I contact the maker anytime I contemplate a bearing change from the original spec because conventional practices that I thought I knew have exceptions.
 
Another time I was wrong about bearings. When I changed the spindle bearings in my RF-31, I went from open tapered roller bearings that were greased to angular contact bearings that were sealed both sides. Everyone knows you have to run in new spindle bearings, right? I thought so anyway, but queried FAG just to be sure. Turns out that their precision sealed bearings don't require any break in at all. Wrong twice. Now I contact the maker anytime I contemplate a bearing change from the original spec because conventional practices that I thought I knew have exceptions.

Mikey, please excuse my delayed response but had a busy couple of days - many thanks for your input and candour here. I make plenty of mistakes, but avoiding repetition is definitely the key to wisdom :)
 
All up and running - and looking pretty good. I do get a little intermittent noise from the motor, which has a plastic press on cooling fan with a split hub - It turns with the motor and keeps it cool, but needs to be replaced before it finally gives up.

I also broke the oil sight glass on reassembly - I purchased a new M18x1.75 sight glass (as per the grizzly manual/spec), but on arrival this was much smaller than the old one (27mm thread diameter). Temporarily bodged with a stainless steel washer/reducer and plenty of RTV silicone and new one on order.

Other than this all sounds and looks good. The gear changes are a little hit and miss and bear only a vague relationship to the marked positions on the front plate. It needs a little work to ensure the gears are properly engaged and avoid crunching, but once in gear it stays put and runs very well.

I've done a little test milling on a scrap piece of 3/4" ms bar and quite pleased with removal rates and finish (not a great picture), but squared off with a 3" HSS facemill and then the corners shamfered off with 5/8" endmill (the rough turned ends are from old lathe alignment)

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Now spent a small fortune on Vertex Clarkson type holders, endmills, clamping kit, edge finder and 3 axis dro kit (incoming).

First project will be brackets for mounting up the DRO, and then a small permanent magnet alternator as part of a school science project with my son.
 
The bearings in the top cover should be sealed as they aren't in an oil bath and don't get a splash feed. I have some very high spec synthetic grease I was given, low viscosity, so I popped the seals and re-greased with the good stuff,(not saying what was original is not good). A bit of fettling and these mills give great service. Leadscrew nuts are the weak point but as CNC conversions have been done to so many ballscrews are available if they war out.
 
Thanks - I will keep a close eye on these bearings and not to painful to access to check, relube or replace if needed.

Point taken on the lead screw nuts, but actually X and y move very well with little back lash. However, the Z access is horrendous and will need some attention in the near future!
 
Hi darkzero,

In UK I sourced online from simply bearings - good range and easy site to navigate. I can't recommend a US site, but possibly www.qualitybearingsonline.com - at least they seem to stock skf, timken etc.
 
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