- Joined
- Oct 30, 2019
- Messages
- 225
The last few years I've been bartering with neighbors more. One of which is the guy we buy our dirt/gravel/etc from for multiple projects - as well as borrow the occasional equipment.
Something he asked me about roughly a year ago was making a new front guide pulley for his line puller that he uses for crab fishing. This was originally designed to pull plain ropes/lines or lift crab/lobster pots. However, his crabbing uses ~1000ft lines with 6" bungees every few feet that hold bait (chicken necks). Those bungees tend to get fouled up in the front guide pulley. His request to me was at some point to make something twice as big in all dimensions, with a flat-bottom groove
Not this exact model but this general design:
He had a pile of scrap on his property including a pile of aluminum, and gave me this 7x28" piece of aluminum round stock so I could take a slice off it to make this.
Here's the stock as well as the original pulley:
My horizontal bandsaw has been a bit neglected, its coolant evaporated and gunked everything up. I used this project as a reason to clean it out, replace a couple cracking hoses, and replace the seized/corroded pump.
Also I swapped in a 4-6 TP blade and then took off the 4.5" slice to start the part.
Turned the 4-jaw jaws around and chucked up in the Chipmaster to start clean-up. I needed to reduce the OD to ~ 6.5" to clear the carriage, so that set the target OD of the part
Started hogging out material from the middle. None of my TCMT insert tooling was a great geometry, in hindsight maybe I should have use a HSS tool for the initial shaping
I was pushing my feed rate and spindle rpm to maximize material removal, which was generating a decent amount of smoke from various oils - especially when I was applying WD-40 to test what speeds/feeds I would want for final surface finish. I strung my smoke eater over from the welding table which helped cut contain that quite a bit.
Lots of swarf on the floor, about 4 lbs by the time the project was done:
The horizontal saw cuts pretty true, s most of the challenge here was clamping the part cleanly and truly to remove the puck of extra material I left myself to work with originally.
To face the remaining side, I made some soft jaw wrappers out of some aluminum flashing I found in my scrap pile.
A bit of cleanup and the final outside profile was done. The chipmaster can pull 3000 rpm and it only took 1200 rpm and light feeds to get some unnecessarily great surface finishes
The last step was some weight reduction. I originally was going to try and bore around a hub on the lathe, but didn't find a decent tool setup to plunge without rubbing, and didn't grind a HSS tool. Instead I lad out a circular hole pattern, and can always do something different in the future.
Alternating 1/2 and 3/4 holes to leave enough web for structure and a grease passage. Started with a small pilot, then through drilled with something like 1/4" (whatever I had that was sharpest around 1/4" size). Then the 1/2 or 3/4 final bit.
Took a decent amount of time, but got faster as I went and succeeded in removing a bunch of material
The floor looked a lot like this too:
The last feature was adding a grease zerk. I could not find a reliable way to drill at an angle and mount the zerk in an accessible fashion, so I opted for two intersecting 1/8 passages with the zerk recessed in the side.
I didn't take a couple pictures of the first steps - drilled the 1/8" passage in from the side first at the drill press, aligned with one of the spokes to be able to cross-drill and meet the spindle bore.
I decided to bias the hole to one side, to leave options for how I would potentially remove more weight in the future or need to change the profile of the guide groove.
The end of this passage will be sealed with a set screw, and I'd rather have that end up in the taper/side than risk the horizontal path being exposed by future changes to the part, requiring a new greasing solution. The only downside is this means grease won't be applied to the center of the spindle bore, but that's not a big deal - and can be fixed with a pressed-in steel bushing that brings the flow of grease to the middle (something that may be added to this part in the future anyway)
The sketchiest part of this is the corner I backed myself into for workholding and aligning the longer passage. It had 3 constraints:
- Meet the horizontal passage
- Fit in one of the "spokes" between the weight-reducing holes -- DO NOT break into one of those holes
- Meet the center bore
To hold it, I set it on some aluminum flashing in a t-slot in the mill table (to keep the corners of the t-slot from leaving a dent in the OD of the part). Then put a 3/8" threaded rod through the middle and threaded my 1/2/3 blocks onto each end. Then used the strap clamp set to pull down on the 123 blocks. This worked surprisingly well.
Prior to mounting it I drew a center line with a pencil that should be where the 3 criteria above align.
Once loosely set up in the mill, I used a level to sight the part in parallel with the line in question, then moved in line with the mill spindle as well.
In my drill bits drawers I found a few brand new extended-length chip-clearing 1/8" bits, which were perfect for giving me the best chance at reducing wander in this operation.
Something he asked me about roughly a year ago was making a new front guide pulley for his line puller that he uses for crab fishing. This was originally designed to pull plain ropes/lines or lift crab/lobster pots. However, his crabbing uses ~1000ft lines with 6" bungees every few feet that hold bait (chicken necks). Those bungees tend to get fouled up in the front guide pulley. His request to me was at some point to make something twice as big in all dimensions, with a flat-bottom groove
Not this exact model but this general design:
He had a pile of scrap on his property including a pile of aluminum, and gave me this 7x28" piece of aluminum round stock so I could take a slice off it to make this.
Here's the stock as well as the original pulley:
My horizontal bandsaw has been a bit neglected, its coolant evaporated and gunked everything up. I used this project as a reason to clean it out, replace a couple cracking hoses, and replace the seized/corroded pump.
Also I swapped in a 4-6 TP blade and then took off the 4.5" slice to start the part.
Turned the 4-jaw jaws around and chucked up in the Chipmaster to start clean-up. I needed to reduce the OD to ~ 6.5" to clear the carriage, so that set the target OD of the part
Started hogging out material from the middle. None of my TCMT insert tooling was a great geometry, in hindsight maybe I should have use a HSS tool for the initial shaping
I was pushing my feed rate and spindle rpm to maximize material removal, which was generating a decent amount of smoke from various oils - especially when I was applying WD-40 to test what speeds/feeds I would want for final surface finish. I strung my smoke eater over from the welding table which helped cut contain that quite a bit.
Lots of swarf on the floor, about 4 lbs by the time the project was done:
The horizontal saw cuts pretty true, s most of the challenge here was clamping the part cleanly and truly to remove the puck of extra material I left myself to work with originally.
To face the remaining side, I made some soft jaw wrappers out of some aluminum flashing I found in my scrap pile.
A bit of cleanup and the final outside profile was done. The chipmaster can pull 3000 rpm and it only took 1200 rpm and light feeds to get some unnecessarily great surface finishes
The last step was some weight reduction. I originally was going to try and bore around a hub on the lathe, but didn't find a decent tool setup to plunge without rubbing, and didn't grind a HSS tool. Instead I lad out a circular hole pattern, and can always do something different in the future.
Alternating 1/2 and 3/4 holes to leave enough web for structure and a grease passage. Started with a small pilot, then through drilled with something like 1/4" (whatever I had that was sharpest around 1/4" size). Then the 1/2 or 3/4 final bit.
Took a decent amount of time, but got faster as I went and succeeded in removing a bunch of material
The floor looked a lot like this too:
The last feature was adding a grease zerk. I could not find a reliable way to drill at an angle and mount the zerk in an accessible fashion, so I opted for two intersecting 1/8 passages with the zerk recessed in the side.
I didn't take a couple pictures of the first steps - drilled the 1/8" passage in from the side first at the drill press, aligned with one of the spokes to be able to cross-drill and meet the spindle bore.
I decided to bias the hole to one side, to leave options for how I would potentially remove more weight in the future or need to change the profile of the guide groove.
The end of this passage will be sealed with a set screw, and I'd rather have that end up in the taper/side than risk the horizontal path being exposed by future changes to the part, requiring a new greasing solution. The only downside is this means grease won't be applied to the center of the spindle bore, but that's not a big deal - and can be fixed with a pressed-in steel bushing that brings the flow of grease to the middle (something that may be added to this part in the future anyway)
The sketchiest part of this is the corner I backed myself into for workholding and aligning the longer passage. It had 3 constraints:
- Meet the horizontal passage
- Fit in one of the "spokes" between the weight-reducing holes -- DO NOT break into one of those holes
- Meet the center bore
To hold it, I set it on some aluminum flashing in a t-slot in the mill table (to keep the corners of the t-slot from leaving a dent in the OD of the part). Then put a 3/8" threaded rod through the middle and threaded my 1/2/3 blocks onto each end. Then used the strap clamp set to pull down on the 123 blocks. This worked surprisingly well.
Prior to mounting it I drew a center line with a pencil that should be where the 3 criteria above align.
Once loosely set up in the mill, I used a level to sight the part in parallel with the line in question, then moved in line with the mill spindle as well.
In my drill bits drawers I found a few brand new extended-length chip-clearing 1/8" bits, which were perfect for giving me the best chance at reducing wander in this operation.
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