Chicago Dreis&Krump Box&Pan brake rebuild

[Firestopper]

Made more progress on the D&K brake. I was able to source the remaining six bushings from a local bearing house and saved a considerable amount and a very reasonable shipping charge. The remaining bushings are the largest sizes this machine uses from the smallest ID of 1.500 to the largest ID of 4" and lengths up to 3". I had priced them originally from D&K and they wanted $365 plus shipping of over $40. I was able to source them for $100.35 (including shipping and tax). Same ISO and SAE rating (Oilight).

I also was able to finish squaring the remainder of the extensions after replacing the inserts on the shell mill. They are all to exact dimensions and ready for the bevel cut on the nose bar end. I had mentioned in an earlier post that I would attempt to use the band saw for this operation by clamping the material vertically. More on that later.

The lager 4" ID bushing to the left will be made into two. They are used on the large clamp handle and cam over to open/close the heavy top clamp on the machine. The second set (middle) are offset within the handle creating the cam action (1.5" ID) and the last pair (2" ID) are for the pivot blocks that prevent binding of the action. They are 3.5" long and are pressed in the lower section of the main table.

The old bushings where warn and sloppy. The tolerance is .001" per inch of diameter. These felt like they had over .100" play.

This longer 4" bushing will be made into two and the ID fit was nice and snug. You can also see the cam over bushing that rides on a 1.5" pin.


The last pair also fit nicely over the pivot block. This also controls the clamping force for different material thickness being bent.

I took a measurement of the width needed for parting the larger bushing.

The large bushing was indicated in within .0005" using the 8" 4 jaw comb chuck. I then grooved the area to be parted to crate a bevel.

Set up the parting tool and power fed at 300 RPM using the chip brush handle to catch the cutoff. This material cuts well and is self lubricating.
The cutoff tool was slightly off center to preserve the bevel matching the factory end.
Rinse/repeat for second bushing. I really enjoy using this combo chuck. The repeatability is a time saver.
Re chucked the rings and bevel ID to match factory end and a tiny bit of facing to match the width needed.
Incidentally, D&K wanted $76 each for those ring bushings. I was able to buy the larger one for $45.

The original bushing width measurement came in at 1.5065
The new bushings:
#1,2

My seventeen year old chi com lathe still has it.

Next up was to cut the bevels on the finger extensions.

 

[Firestopper]

Here's the set up I used on the Ellis 1800 band saw.

The saw was set to 41º (matching factory bevel). A stop was clamped (right clamp) to ensure all 14 pieces ended up the exact length. A little gap was provided for though chip cleanup after each cut. The face milled edge provided a square edge to ensure the saw cut to be as square as possible in both planes. This piece was 4" wide with the widest pieces at 6". The clamp on the left holds everything in place while the screw vise does the real work.


I used a shot of WD-40 every 20-30 seconds as the material is .750" thick but at 41º it was cutting closer to 1.125". Each cut took about 3 minutes for the 4" wide stock and roughly 4.5-5 minutes for the 6". I adjusted the feed to produce a constant quality chip production but not so slow that the martial would work harden. I have made this mistake in the past when cutting CR, so I'm always keen on avoiding this. I once ruined a new blade ($60) cutting CR too slow.
For anyone using an Ellis saw with the lever lock style vise. Always use a secondary clamp (C-clamp) as the material will slip during an angle cut resulting in teeth stripping. This screw vise was money well spent saving countless blades in the long run. I still use the two original lever vice when cutting straight non round stock material.

Pretty good match on the angle. The green finger (5") was the only sole survivor and used as a standard for all measurements. The rest are junk bent scrap made of HR flat bar.

Ready for the next mill operations. I am very pleased with how well they turned out considering the method used to create the bevels.

2-4", 4-3",4-6" and 5-5" (including the green one) for a total of 15 finger extensions.

Got a few drops...Wondering what I can use them for.

Thats all for now. I should finish tearing down the brake and get it to the sand blaster. Once I get it back, I will pull old bushings and mask and paint. I still have a fair amount of repairs prior to this but we'll get there.
Thanks for looking.

Turn and Burn!
Paco

 

[mksj]

Paco, stellar work as usual. That Ellis is remarkable at it's accuracy, paid for itself many times over. Sounds like you got the shell mill to work well with the new inserts. Keep up the great work.
Mark

 

[f350ca]

Your making great progress Paco, can't believe how well that saw cuts.

Greg

 

[Firestopper]

Thank you Mark,
Your RPM recommendation for the face milling operation was spot on, Thank you.
The Ellis still impresses me after ten years. Its a simple proven design for sure.

I have another face mill question for you guys.
Should I keep the vise set up perpendicular to the table (X axis) and face mill in the -Y axis (away from the front of machine) or +Y towards the front.
Or should I set up the vise 90º and face mill in the +X axis (climb mill). I only ask because the machine is two axis CNC with ball screws. I will be using power feeds. I have read that ball screw are less desirable in manual machines and I use this machine mostly in manual mode. To me, I don't think it cares as its still tight but I will be taking respectable cuts to achieve the next operation of steps cuts. I do lock down the axis when not used.
Any input would be appreciated. Probably over thinking it, but face milling on steel is new to me.
Thanks,
Paco

 

[Firestopper]

Your making great progress Paco, can't believe how well that saw cuts.

Greg

Thanks Greg,

That saw has been good to me. I've pushed it to its limits on this project to say the least. I did spend over an hour detailing it after yesterdays workout.
Paco

 

[Firestopper]

Yesterdays project was to drill/tap the clamp bracket holes and drill and counter bore the nose bar clamp hole. I was able to get the first eight fingers done but was disappointed at the quality control of D&K hole location on the clamping bracket. Seems they don't really try to center the pair of holes. The new fingers where laid out from the center and set up on the mill using the DRO. Each set required center measurement changes due to the 4 different finger widths (3",4",5",6"). Other variations encountered where the hole spacing on the 5". Luckily, I verified each bracket and made adjustment to each finger, That said, each finger has its own bracket. Example: Two of four 5" brackets where drilled at 4.250" OC. while the other two where 4.284" OC. and three of four 5" brackets D&K failed to center the hole layout.
My mistake was not verifying this so as a result the brackets bolt on slightly off center about 1/32"-1/16". I can live with this as none overhang past the fingers, they just look like an eighth grader laid them out.

A "Z" drill was used on the nose bar hole followed by a Weldon cutter with a pilot diameter just under the Z. A large counter sink broke the edge.
The counter bore was .386"deep for the 3/8-16 Allen cap screw.

The pair of holes where drilled and taped to 3/8-16 and are centered to the finger.
The sharpie lines are just references for me to input the correct DRO reading.

A test fit, Heres when I realized the brakes holes where not centered on the clamp bracket.
This particular bracket was centered and shared the same 4.250" OC hole spacing with a second bracket.

The second bracket is close to flush on one side the finger and 1/16" short on the opposite side.
I could mill the difference but its really not an operational issue other than leaving me scratching my head and talking to myself.

I decided to keep all my holes centered on all the new fingers but will accommodate for the varying hole spacing.
The steps have not been milled yet but you get the idea. Gonna try and get the other six fingers (2-4" and 4-3") drilled/taped today.

Thats all for now, thanks for looking.
Peace,

Paco

 

[Firestopper]

Ready for step cutting operation.
Combined drilling came to 105", tapping 21" and counter boring 5.46" without drama except for the multiple razor cuts from handling these billets.
Those bevels really are sharp.

Paco

 

[f350ca]

Now thats funny, adding up the inches drilled and tapped is something only I thought I did.

Greg

 

[Firestopper]

Haha, Well Greg, I have to entertain myself when doing production runs. Now, if I was to add up my time figuring out how long it took to clean up the mess and divide the time by the number of holes drill/tapped I'd be . heheh
Not a single tool was harmed during the making of these parts