Becker No 3 vertical mill - "restoration"

[metalmagpie]

The compound, or filler could be something like "Smooth-on", a compound used for repairs and sealing of cast iron. It was mainly used for things like sealing freeze cracks in engine water jackets or cracks in cast iron low pressure applications. Or, the filler could have been a shop-mixed thing, and any number of old texts have instructions on how to mix these sorts of fillers. Stuff like 'litharge', and even Portland Cement mixed with paint were used.

As to removing the filler in a timely and easy manner, I'd suggest using an air needle scaler. You could remove the filler with a welder's hand chipping hammer, using the pointed end and just pecking away at the filler deposits. The air needle scaler is quicker and does a better and more thorough job. An air needle scaler needs a shop air compressor to supply compressed air to run it. It will leave the cast iron in a clean 'frosted' condition. Blow or vacuum off the remaining dust and debris and the castings are ready for primer. Things like an angle grinder with a cup wire brush will load up with the filler or throw a lot of particulates into the air. The filler may be 'friable' (able to be crumbled), so the needle scaler will make short work of it.

Another thought is to leave the filler deposits in place. Use automotive body sanders to smooth out these filler deposits if necessary. Build up on them with modern auto body fillers, and finish by sanding. Removing the old filler may disclose really rough castings with porosities or 'blowholes' from the foundry, needing to be refilled to slick them off for the new paint. Back when the Becker mill was made, there were no handy air tools or electric tools like angle grinders, needle scalers and air sanders. The castings were 'snagged' at the foundry on large coarse grinding wheels, and sprues and gates and mold flash were chipped off with hammers and chisels and given a lick and promise with the coarsest and largest files imaginable. After that, it was a case of filling the holes and rough areas on the castings with whatever the flavor of the week was for filler. As I wrote, this filler may have been shop-mixed by the painters, and could have any likely substances that were at hand mixed in.
I've seen some fillers on old machinery castings that broke up readily when hit with an air needle scaler, nothing oily about them. Great bonding to the 'substrate' (fancy term for what a sealant, paint, or filler is applied to). However, these old fillers were brittle when hit with the needle scaler or chipping hammer and popped off in chunks.

I second Joe's suggestion to try a needle scaler, or needlegun as I've always called it. But with a caveat. I almost never use the needlegun alone. I use it along with an angle grinder with wire wheel. The two together work much faster and better than either tool alone.

I also agree with Joe's other idea of leaving it in place. It won't hurt anything under your paint.

metalmagpie

 

[geshka]

Thanks for your suggestions, folks. I am using all spectrum of tools I have and also I already borrowed needle scaler. I cleaned most of the old compound, not 100%, though. On frame I already used two parts epoxy primer - it has cured quite fast and stuck to the surface quite nicely (for now ) , Next step is paint with alkyd enamel, which I will be doing in next few days.

As per spindle - I posted photo here. It is, surely, not original one. No any markings on casting or anywhere else. May be someone can recognize it on the photo - it will be greatly appreciated.

https://www.practicalmachinist.com/...vertical-mill-restoration.413640/post-4078386

 

[M.B. Naegle]

Looking at the picture, it looks like they welded something around the bottom of the spindle? I think the spindle housing is possibly original and the spindle itself was adapted to it, possibly as a fix for a damaged or odd-ball taper/tool system. The spindle doesn't look like anything I've seen, but with it's size it might have once been part of a horizontal boring mill? The R8 taper is almost exclusively used on vertical knee mills and similar machines, nothing older than the 1950's IFAIK.

I assume the grease zerks are for your spindle bearings, and given the age of the mill it's more likely to have had oiled bearings originally. Some manufacturers use zerks like that with pressurize oil guns, but most mechanics unknowingly pump them full of axle grease when they see them. IMO it would be better to clean it out and oil it instead, but depending how the pathways interact with the bearings, gravity fed oil might not get where it needs to go, so using the zerks with a pressurized oil gun would be necessary, or you can use spindle grease which is lighter than your typical axle grease. In addition to whatever additives the manufacturer puts in, most greases are identified with an NLGI number. NLGI #2 is thicker like axle grease, and most spindles use NLGI#0 which is thinner like hand lotion so it doesn't retain debris and works with higher speed elements. True spindle grease like Kluber Isoflex can be expensive but is necessary on things like CNC mills with greased ways and spindles, but for a low speed antique machine in a non-production environment, Lubriplate #105 or John Deere Corn Head Grease are ok alternatives that are thin enough to work in a higher speed ball bearing.

If it works, run with it. The chances of finding an original spindle for this machine are slim to none. If anything, while you're cleaning it up, document how they put it together and you might find some parts of it that could be better executed or improved, but you can still be using the mill while you make new parts for it.

 

[4GSR]

If it's of any help, I had a old Becker No. 3 vertical mill back in my teenage years. 1974ish. I though it had a No. 10 B & S taper but it turned out to be a No. 4 MT. The spindle ran on bronze bushing which were adjustable for wear. It was a rough mill, the table feed was rack and pinion drive, no screw or nut version. It did until something else better came alone, a Gorton 9-J mill!

 

[geshka]

Looking at the picture, it looks like they welded something around the bottom of the spindle? I think the spindle housing is possibly original and the spindle itself was adapted to it, possibly as a fix for a damaged or odd-ball taper/tool system. The spindle doesn't look like anything I've seen, but with it's size it might have once been part of a horizontal boring mill? The R8 taper is almost exclusively used on vertical knee mills and similar machines, nothing older than the 1950's IFAIK.

I assume the grease zerks are for your spindle bearings, and given the age of the mill it's more likely to have had oiled bearings originally. Some manufacturers use zerks like that with pressurize oil guns, but most mechanics unknowingly pump them full of axle grease when they see them. IMO it would be better to clean it out and oil it instead, but depending how the pathways interact with the bearings, gravity fed oil might not get where it needs to go, so using the zerks with a pressurized oil gun would be necessary, or you can use spindle grease which is lighter than your typical axle grease. In addition to whatever additives the manufacturer puts in, most greases are identified with an NLGI number. NLGI #2 is thicker like axle grease, and most spindles use NLGI#0 which is thinner like hand lotion so it doesn't retain debris and works with higher speed elements. True spindle grease like Kluber Isoflex can be expensive but is necessary on things like CNC mills with greased ways and spindles, but for a low speed antique machine in a non-production environment, Lubriplate #105 or John Deere Corn Head Grease are ok alternatives that are thin enough to work in a higher speed ball bearing.

If it works, run with it. The chances of finding an original spindle for this machine are slim to none. If anything, while you're cleaning it up, document how they put it together and you might find some parts of it that could be better executed or improved, but you can still be using the mill while you make new parts for it.

Excellent write-up. Thanks. I did not cleaned (yet) spindle from inside , I just unscrewed zerks and looked inside - indeed it filled up with heavy grease. Need to search for suitable pressurized oil gun or may be I can retrofit one of my grease guns.

 

[geshka]

If it's of any help, I had a old Becker No. 3 vertical mill back in my teenage years. 1974ish. I though it had a No. 10 B & S taper but it turned out to be a No. 4 MT. The spindle ran on bronze bushing which were adjustable for wear. It was a rough mill, the table feed was rack and pinion drive, no screw or nut version. It did until something else better came alone, a Gorton 9-J mill!

It is definitely a help - thanks. My mill seems to be newer - there are
screws on each axes.

 

[M.B. Naegle]

I bought This one for our Rockwell lathe which has oiled zerks. Simple and decent quality (made in Germany I think, but still not too expensive).

 

[4GSR]

It is definitely a help - thanks. My mill seems to be newer - there are
screws on each axes.

Your mill was identical to mine except for the table feed. Mine was a production mill where yours was a conventional mill. They both are about the same age of each other. The spindle on yours is not original to your mill. That spindle reminds me of one built by Master or Setco and added to the mill later in life.

 

[4GSR]

Check this out. http://vintagemachinery.org/pubs/2524/19618.pdf
Becker did have a No.3 collet that looks very similar to a R-8 collet. This must be something that Reed Prentice made improvements to in the 1920's after take over of Becker around 1920. Your spindle may be original to your mill. What I said in my previous post may not be correct.

Edit: According to this catalog page, http://vintagemachinery.org/pubs/2524/17584.pdf
The spindle uses a 3V collet type.

 

[geshka]

Frame, knee and knee rising mechanism are installed. Wooden braces that yo see in the background - to strengthen seiling as I am rising and lowering heavy parts of the mill.

 

[geshka]

I started to think about drive and transmission - original assembly looks and works terribly . It is heavy, slow and noisy. To be honest -original parts are also somebody's improvisation, so I am not feeling like ruining something. Moreover, I am keeping all original parts and pieces of drive assembly, so will be able to get back to that, if needed.

Here i need to work on upper part of pulley assembly that is driving spindle. I need to flatten top part - it has casting cutouts. I put it on the shaper and removing some extra metal.


Now when it is flattened, I am mocking up countershaft assembly using CAD (cardboard aided design, well, in my case plywood aided)



I discovered another problem here - sum of diameters of two corresponding pulley steps is different between those steps. What the !@#$

 

[M.B. Naegle]

Looking good!

The diameters don't need to be the same, provided they have the same ratio of difference. For example, if one pulley had a 2" and 4" diameter step, the other side could have a 4" and 6", because each pulley has the same 2" difference between each step.

If you're looking to make some changes to the drive, you probably could go back to something like the original with the belt running in an 'L' pattern down to the base, where you have room to set-up whatever speed change you like. You could ditch the step pulleys and just run it with a VFD, or set it up with a transmission case like they did on a lot of converted lathes. If you want to keep it all up top, you probably can use the old idle pully mounting boss in the back as a support for the motor/pulley platform.

Lots of different ways to do it, all depending on what time/resources you have available, and how "original" vs. how modern or practical you want it to be.

 

[jim rozen]

The ODs should not be the same, if the pitch diameter of the steps, for the kind of belts it uses, is the same.

 

[geshka]

The ODs should not be the same, if the pitch diameter of the steps, for the kind of belts it uses, is the same.

Well, it creates an issue with belt length - I have to have long belt adjustment leeway to compensate it, right ?

 

[M.B. Naegle]

On edit: Sorry the example I gave before doesn't add up.

Add each pair of diameters together. If the numbers all match, then the same belt will shift between them without adjustment, regardless if the cones have matching diameters. Such As:

4" pulley and a 6" pulley = 10
5" pulley and 5" pulley = 10
7" pulley and 3" pulley = 10

Same belt will shift between each step.

 

[geshka]

Here is what I thinking about drive. (sorry for the clattered background )


DC motor on top with poly-V belt and two pulleys will be driving countershaft and step pulleys, I will be able to regulate speed - to some extend - with DC motor supplied voltage and if I need other range of speeds - I will move belt on step pulleys. DC motor is 2.25 HP continuous power with 3500. RPM.

Any critics is appreciated.

 

[4GSR]

The old Becker mill I had we mounted a 3/4 HP DC motor on top similar to yours but no belt reduction as you show. Kept the step pulley on the spindle and ditched the other step pulley. We ran a pulley about 3" in diameter on the motor. Gave me a maximum spindle speed of around 800-900 RPM. This was way plenty for the mill back then. The DC motor we had was not a PM type, had actual field windings which gave you a bit more torque in the long run.

 

[geshka]

Gave me a maximum spindle speed of around 800-900 RPM. This was way plenty for the mill back then

Right. I wanted slightly more - 1000-1200 RPM. I will follow your suggestion and will mount motor directly to drive spindle pulley (no intermediate driveshaft). DC motors usually have falling load/RPM characteristics - how was your motor keeping up with speed under the load?

 

[4GSR]

Snip...........- how was your motor keeping up with speed under the load?

With field windings to help you out instead of PM, it gives you a better torque advantage and less likely to stall out. Never had an issue with stalling out. But you have to remember, milling with endmills up to 1/2" diameter, use very little HP as well as drilling holes up to say 1/2" in diameter. You're not going to be doing production or competing with CNC for hogging power on this mill. My Index mill which is a bit bigger than your mill I very seldom run any endmills bigger than 1/2" in the past twenty years.
Now, facemills on the other hand, You run them wide open. 2" dia. is as big as you want to run on that mill. 2.25 HP PM motor should handle it.

 

[geshka]

Second variant for the drive - straight from the motor to the pulley with single belt transmission. Indeed, looks cleaner and simpler. Motor can move up and down to align with spindle step pulleys and the entire assembly - back and forth for tension adjustment. Need to estimate motor mount pulley from plywood to ensure belt clears spindle bracket.