Braze the front back on and fab a larger back tab, add as much brass as possible to the sides of the front tab.The front tab will locate the hole center. If you still feel the need to replace the front tab, mill it off after chasing the hole through the new back tab.
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Quill feed trip handle bracket - replace w/ Bridgport part?
- Thread starter jimmcw
- Start date
I often avoid making things if I feel like they need some special treatment (for example, hardening) or material (cast iron).
But if I can get away with just a piece of cold rolled steel and a few hours of my time, I'd say, making it is better than spending countless hours thinking about it.
But if I can get away with just a piece of cold rolled steel and a few hours of my time, I'd say, making it is better than spending countless hours thinking about it.
Back from 2.5 week motorcycle trip - 2600 miles, circumvented California. And while I was on my trip the eBay part arrived. First thing I did (after kissing the wife of course) when I got back was to open it and check it out. And ... nah. Not an exact fit, by any means.
But, after making some measurements, I decided I could make it work. And I did - here's some details.
The key thing that made me press forward modifying the part was that the distance between these two axis (dimension A in the drawing below) were the same as the original part (to within my ability to measure - not easy). And pretty much that was the only thing that was the same, but I figured everything else I could accommodate one way or the other. But the offset between those bores, one which the shaft from the gear box comes through, and the other for the shaft that drives the down-feed lock - those would be hard to adjust.
I drew up a quick (not to dimension at all - just for a visual) model to explain.
Dimension A - offset between two orthogonal bores, was same as Lagun part. I would have stopped here if not.
Dimension B - 16mm (maybe it was intended to be 5/8"?). Lagun is 16mm - it fit fine.
Dimension C - was 0.5 inch (!?), Lagun is 12mm. Bushing will fix it.
Dimension D - was a bit oversized, forget how much. Turned it down on the lathe to fit.
Dimension E - this was way off. This dimension serves two purposes - it puts the axis of "B" where it needs to be, on one side, and on the other, the back of the part holds in a bevel gear that is part of the reverse-feed assembly. I solved this two-part problem in two parts: I made a spacer to push the location of bore B where it needed to be, and I used the bushing that also served to solve diameter C to extend in and hold the gear.
But, after making some measurements, I decided I could make it work. And I did - here's some details.
The key thing that made me press forward modifying the part was that the distance between these two axis (dimension A in the drawing below) were the same as the original part (to within my ability to measure - not easy). And pretty much that was the only thing that was the same, but I figured everything else I could accommodate one way or the other. But the offset between those bores, one which the shaft from the gear box comes through, and the other for the shaft that drives the down-feed lock - those would be hard to adjust.
I drew up a quick (not to dimension at all - just for a visual) model to explain.
Dimension A - offset between two orthogonal bores, was same as Lagun part. I would have stopped here if not.
Dimension B - 16mm (maybe it was intended to be 5/8"?). Lagun is 16mm - it fit fine.
Dimension C - was 0.5 inch (!?), Lagun is 12mm. Bushing will fix it.
Dimension D - was a bit oversized, forget how much. Turned it down on the lathe to fit.
Dimension E - this was way off. This dimension serves two purposes - it puts the axis of "B" where it needs to be, on one side, and on the other, the back of the part holds in a bevel gear that is part of the reverse-feed assembly. I solved this two-part problem in two parts: I made a spacer to push the location of bore B where it needed to be, and I used the bushing that also served to solve diameter C to extend in and hold the gear.
Oh yeah - forgo to mention the bolt hole pattern was different! First picture is milling in the new bolt holes. It was hard to measure precisely, so I made a simple model and 3D printed a thin spacer with bolt hole patterns - took several iterations even after attempts to measure original part carefully.
Below showes the new part with the new bolt holes milled in, AND the bore for the bushing that will be 12mm diameter and extend out and into the Lagun to meet up with the bevel gear inside. The original Lagun part only loosely kept the gear in position - it wasn't like it was acting as a thrust bearing, it had ~5 thousands clearance. I dimensioned my part similarly.
Below showes the new part with the new bolt holes milled in, AND the bore for the bushing that will be 12mm diameter and extend out and into the Lagun to meet up with the bevel gear inside. The original Lagun part only loosely kept the gear in position - it wasn't like it was acting as a thrust bearing, it had ~5 thousands clearance. I dimensioned my part similarly.
For the spacer (needed to put the axis of the trip/engage shaft in correct location - axis defined by dimension B in drawing) I started out thinking I would 3D print a prototype until I got it right, then machine something. But ... after 3D printing prototypes until I got everything right, I decided to just use the 3D printed part. No stress on this part at all, does not need to be metal. Final thickness (and not this part I think) was 5.25mm
And here it is all assembled. You can see the black 3D printed spacer behind the part. The bushing is pressed in from behind and not visible here. And yes - the screw for selecting forward/neutral/reverse is lame. I'm going to fix that one of these days with a proper knob of some sort. Was that way from previous owner.
