Brought home a Boxford Mk2 yesterday!

Thanks for that post, Greg. Lots of good info there to ponder as I get this little machine back up and running. I had considered brazing, but the largest piece broken out of the clapper is scarce bigger than my little fingernail cubed. That would be a mighty fine brazing job and I don't know anyone with that level of skill at it. My friends and I would be better suited to brazing a manhole cover back together, or something of that sort.

That's a good analogy, comparing the 4 and 8 cylinder engines at highway speeds. Makes perfect sense. Most of my work will be light duty cuts in aluminum, brass, iron, and mild steel, so a loss of momentum is unlikely. I may yet upgrade to a 3/4hp for the very reason you mentioned. Letting the motor work comfortably suits me fine, especially since there appears to be little price difference between the two.
 
And I've officially arrived at the "woe is me" portion of this project. While tentatively breaking down the ram assembly yesterday, I broke the clapper box! The protective oil coating discussed earlier had managed to expertly conceal a small set screw retaining the 7/16" taper pin upon which the toolholder plate pivots. This setscrew was also not illustrated on the ram assembly blueprint posted on Boxford's spares website here: http://www.boxford-software.com/spares/SHRam.html Sadly, I even consulted their print before beginning disassembly, looking for just such a trap as this. Note to self: in the future, pre-clean assemblies before teardown commences...

I was using a wee ball-pien hammer (~10 oz.) and a 1/4" brass punch, just to give an idea of the limited force applied to the taper pin. On the second tap the taper pin began moving. Not much, but it clearly moved. Each successive tap moved it a bit more, so I continued. After the taper pin had moved perhaps 1/8", the hidden set screw reached the end of the flat machined on the taper pin and encountered the sharp shoulder of said flat. On my next tap, the pin popped free and I heard/saw several somethings bounce off the bench and onto the floor. My initial thought was that something lying on the bench had vibrated off or been knocked off by the ejecting taper pin, but it was not to be. A quick glance at the underside (from my perspective) of the clapper box showed significant damage and to say my heart sank would be the understatement of the day:

View attachment 229759

I've already gotten an email sent off to Boxford to request pricing on a replacement. It's shown as an active part number on their spares website, at a cost of £30.25 ($37.74 USD as of this morning's exchange rate) and what I consider to be an extraordinarily fair price. Of course, that cost may have been posted in 2003 and never updated but I'll worry about that when it comes up.

Today, I'll be trying to put this amateurish mistake behind me and continue cleaning the undamaged components of the ram assembly. It's now fully disassembled and I'm happy to report none of the remaining pieces have suffered additional damage at my hands. Yet...

As it seems easy enough to find a comparable single-phase motor for around $125, I will probably end up going that route. Should I consider going to a slightly larger motor, say 3/4hp, when switching from 3-phase to single, or is this a consideration I've made up entirely in my own mind?
Ouch not good
 
Well, if we never broke anything, we probably wouldn't be able to appreciate it nearly as much when something comes apart painlessly. At anywhere near that price, replacement seems like the easiest option. If I were going to braze it, I would just throw out the piece and braze it up solid and re-machine. Cheers, Mike
 
Well, if we never broke anything, we probably wouldn't be able to appreciate it nearly as much when something comes apart painlessly. At anywhere near that price, replacement seems like the easiest option. If I were going to braze it, I would just throw out the piece and braze it up solid and re-machine. Cheers, Mike
I would buy the new one if it is available
 
IMG_5453.JPG IMG_5456.JPG
 
Yesterday brought some good news on the Boxford project. Looking through eBay and craigslist ads for electric motors, I was finding mostly incompatible motors at near-new prices, so wasn't overly impressed with the chances for any near-term resolution on my power issue. There was this one ad that had just been posted overnight, though. I initially blew that one off because the entire ad consisted of "Electric motor, good shape." That description covers a lot of ground, ya know? It could be anything from a slot car motor the size of your thumbnail up through that 300hp motor I once saw being rewound where my wife works. Having no luck anywhere else, I sent the guy a text. It took most of the day to extract all the info from him but by mid afternoon was satisfied that his motor was almost exactly what I was looking for. Best of all, he only wanted $40 for it. I'm scheduled to pick it up this morning and it should be a bolt in, plug and play swap for the original. I stated earlier that the original motor was a 1/2hp, but was confusing the Boxford with a tool post grinder I'm also currently working on. The Boxford motor is 3/4hp and the one I'm picking up today is 1hp. That appears to be the only variation in spec between the two.

As to the damaged clapper box, I mentioned the possibility of inserting the damaged area to carry along until I can make an entirely new one. On the chance that some of you may have never dealt with inserting procedure, I thought it may be helpful to briefly discuss what this involves. I've worked in plastic injection molding off and on for many years and inserting damaged areas in tooling is so common a procedure that we come to take it for granted. The internal forces produced during a molding cycle are tremendous, so it only makes sense to me that the clapper box could be repaired, at least temporarily, using these same techniques.

I was taught that capturing an insert on at least three axes would usually produce an acceptable repair. Using this advice, I've envisioned what I think is a suitable insert to withstand the forces acting upon the clapper box during operation. Sorry about the cheesy MS Paint sketch, but it's what I've got to work with...
Clapper Insert.jpg

You should be able to see how the insert will be captured on the X, Y, and Z axes above. The X-axis will be controlled primarily by the flat head screws seen near the bottom of the insert. To reinforce this, I may turn out a temporary taper pin with a threaded section on the small end. A locking nut snugged against the undamaged side would transfer support from the good "ear" over to the inserted side, which would in turn give us three points of support for the insert. The Y-axis is pretty straightforward, as there will be original material blocking the insert in at two points along this axis. The Z-axis will be captured at three points, both a "foot" running along the underside of the clapper box, the undercut seen running along the Y-axis toward the rear, and the flat head screws will also be resisting shear forces along the Z-axis.

This insert will be fitted pretty tight and since it isn't backed up (on the right side, X-axis) by standing steel as it would be in an injection mold, I'll be coating all the mating surfaces with some type of epoxy, such as DevCon Liquid Steel, during assembly. I can't imagine this not holding together long enough to get the new clapper box blanked out. Actually, I can't imagine ever generating enough force with the little Boxford to blow this repair. I may be dead wrong, but I don't think so. I'll try to get video of the first cuts in case it does. :eek:
 
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Yesterday brought some good news on the Boxford project. Looking through eBay and craigslist ads for electric motors, I was finding mostly incompatible motors at near-new prices, so wasn't overly impressed with the chances for any near-term resolution on my power issue. There was this one ad that had just been posted overnight, though. I initially blew that one off because the entire ad consisted of "Electric motor, good shape." That description covers a lot of ground, ya know? It could be anything from a slot car motor the size of your thumbnail up through that 300hp motor I once saw being rewound where my wife works. Having no luck anywhere else, I sent the guy a text. It took most of the day to extract all the info from him but by mid afternoon was satisfied that his motor was almost exactly what I was looking for. Best of all, he only wanted $40 for it. I'm scheduled to pick it up this morning and it should be a bolt in, plug and play swap for the original. I stated earlier that the original motor was a 1/2hp, but was confusing the Boxford with a tool post grinder I'm also currently working on. The Boxford motor is 3/4hp and the one I'm picking up today is 1hp. That appears to be the only variation in spec between the two.

As to the damaged clapper box, I mentioned the possibility of inserting the damaged area to carry along until I can make an entirely new one. On the chance that some of you may have never dealt with inserting procedure, I thought it may be helpful to briefly discuss what this involves. I've worked in plastic injection molding off and on for many years and inserting damaged areas in tooling is so common a procedure that we come to take it for granted. The internal forces produced during a molding cycle are tremendous, so it only makes sense to me that the clapper box could be repaired, at least temporarily, using these same techniques.

I was taught that capturing an insert on at least three axes would usually produce an acceptable repair. Using this advice, I've envisioned what I think is a suitable insert to withstand the forces acting upon the clapper box during operation. Sorry about the cheesy MS Paint sketch, but it's what I've got to work with...
View attachment 230078
You should be able to see how the insert will be captured on the X, Y, and Z axes above. The X-axis will be controlled primarily by the flat head screws seen near the bottom of the insert. To reinforce this, I may turn out a temporary taper pin with a threaded section on the small end. A locking nut snugged against the undamaged side would transfer support from the good "ear" over to the inserted side, which would in turn give us three points of support for the insert. The Y-axis is pretty straightforward, as there will be original material blocking the insert in at two points along this axis. The Z-axis will be captured at three points, both a "foot" running along the underside of the clapper box, the undercut seen running along the Y-axis toward the rear, and the flat head screws will also be resisting shear forces along the Z-axis.

This insert will be fitted pretty tight and since it isn't backed up (on the right side, X-axis) by standing steel as it would be in an injection mold, I'll be coating all the mating surfaces with some type of epoxy, such as DevCon Liquid Steel, during assembly. I can't imagine this not holding together long enough to get the new clapper box blanked out. Actually, I can't imagine ever generating enough force with the little Boxford to blow this repair. I may be dead wrong, but I don't think so. I'll try to get video of the first cuts in case it does. :eek:
That should work good . Most of the force is against
The bottom of the Clapper Box where it mats up
With the head .
I don't think you will have any trouble out of it
 
You could braze that Brocken piece right back on there and bore the hole back out .
I bet it would last 50 more years
 
Was the tapered pin that you had to remove threaded on the end with a nut to hold it in place and temper it? I forget the name of these tapered pin but the nut holds it in place with the prober tension.
 
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