Tuesday, May 17, 2016

Arbor for Burke #4 Horizontal Mill

Project:
Making a new arbor used on a #4 Burke horizontal mill

Difficulty Level (Easy, Medium, Hard, Insane):
Medium

Process:
I got a call from the same gentleman whom I made the Replacement Gear for 1974 Okuma Lathe for saying he had bought a #4 Burke horizontal mill but that the arbor was badly damaged and whether I could make him a new one.

The process was pretty simple:

1. Cut up a piece of 1.500" 4140 on my Metal Band Saw and chucked it up in my lathe
2. Center drilled both ends and mounted between centers
3. Turn shaft down to 1.250"
4. Turn 7.750" from the tail stock end down to 1.002" diameter and sand/polish down to 0.999"
5. Turn 2.375" from the tail stock end down to 5/8" and thread at 18TPI
6. Turn 1.750" from the tail stock down to 0.502" and sand/polish to 0.500"
7. Flip shaft around and put a B&S #9 taper (4.250" long, 0.800" on small end, 1.072" on large end" using the Digital Calipers Mounted on the Tail Stock
8. Sand/polish taper
9. Drill, bore and thread a 1/2" x 13 TPI internal thread for the draw bar
10. Mount arbor in milling vise and cut a 3/16" key way

I was glad to have the Cool Mist System for the heavier turning because 4140 work hardens pretty quickly so I was able to keep the temperature fairly cool. However, I did learn something the hard way. When using a slitting saw to cut a keyway on a shaft, cooling alone is not sufficient. I had the cool mist system spray (plain) water on the slitting saw and it worked great for about 60% of the length of the keyway but then something happened and it completely chewed up the teeth on my slitting saw. After spending a good hour sharpening the HSS slitting saw I decided to skip the cool mist but go back to the regular cutting oil and lo and behold, it worked like a charm. So, I will definitely go buy some water soluble cutting fluid designed for cutting to hopefully avoid that the next time.

Videos:

 
Pictures:
The old arbor
Close-up of the damaged arbor and thread
The B&S #9 taper with a 1/2" x 13TPI draw bar internal thread
Cutting off 13.250" of 4140 bar on my metal band saw
Doing some rough turning to get rid of the rust
Mounting between centers and turning the shaft to 1.250"
Using my mist coolant to keep the work piece cool
Another view of the mist coolant system (temporary setup)
The polished shaft
The shoulder which the cutter and/or spacers rest against
Getting ready to thread a 5/8" x 18 TPI
The threading setup
Chamfering the sharp edges
Cutting the taper end
The extension for my diy lathe dog
Another view of the lathe dog
The digital calipers mounted on the tail stock for easy resetting to zero
A different angle of when I was cutting the taper
The finished and sanded taper
Using the cool mist system for drilling the hole for the draw bar
Tapping the 1/2" x 13 TPI internal draw bar thread in the taper end
Another view
Close-up of the threaded hole
Dialing in the slitting saw
Dialing in the shaft
Another view
Cutting the 3/16" keyway
Another view
The old and new arbors side by side
Another view
Another view
Another view
The finished arbor
Another view
Close-up of the taper end
Close-up of the cutter end
Another view
Close-up of the keyway
Diagram with measurements
Tools:
Metal lathe & accessories
Metal Band Saw
Mist Coolant System
Digital Caliper Setup on tail stock
Emery cloth
Tap & die set

Materials:
13.250" of 1.500" diameter 4140

Time:
8 hrs

Conclusion:
Looks beautiful; I love my lathe!

2 comments:

Peter Metaxas said...

Chris, your doing great. Thank you so much for the photos of your work.
Now I believe you owe your wife that garden shed.

Enlightened Patriot said...

Just about to renovate an old '41 unmarked milling machine I've had little use for, stuck on my shed here in the UK for over 30 years to only just find out it is a Burke No. 4. A great little machine, it runs well. The cast-on m/c details must have been ground off for WW2 security. Cleaned most of the surface rust off, just about to repaint it in hammered-effect green and a bunch of bargain-basement s/h 7/8" bore side & face cutters soon arriving off Ebay. All to make it more saleable - sadly has to go. I really wish I had the vertical milling attachment for it but rare as hen's teeth. I could design/build my own but too much time and cost involved to recover. I was going to scrap it but now hope to get around £250/$300.

Nice job you did there. I assume your lathe has a taper-turning attachment for the B&S No.9 taper shank part. I could do with a similar stub arbour with collet to take a shell/face-type cutter to add more machining capability. My old lathe chuck runs out of true but between centres (like yours)would work. No taper attachment so I might put out to a machine shop. My school, collage and engineering training was in the imperial system before metrication in the 70's so I am OK with both:-) Regards from the UK.

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