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| equipment:metalshop:metallathe:howto:cutthreadsl2r [2024/08/16 11:11] – ralawrence | equipment:metalshop:metallathe:howto:cutthreadsl2r [2025/04/20 12:42] (current) – drew | ||
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| ===== How to cut Threads using the Left to Right Method. ===== | ===== How to cut Threads using the Left to Right Method. ===== | ||
| - | Please note this guide is specific to Bristol Hackspace’s Harrison M250 Metal Lathe. | + | **__//THIS IS WORK IN PROGRESS// |
| - | This guide describes how to cut Standard Metric Threads on the metal lathe such that the carriage moves from left to right during the cutting stage thus avoiding the risk of the carriage crashing | + | |
| + | Please note that this guide is specific to Bristol Hackspace’s Harrison M250 Metal Lathe. | ||
| + | This guide describes how to cut Standard Metric Threads on the metal lathe such that the carriage moves from left to right during the cutting stage thus avoiding the risk of the carriage crashing | ||
| ==== Stage 1. Preparing. ==== | ==== Stage 1. Preparing. ==== | ||
| Line 9: | Line 11: | ||
| Decide on what thread you want to cut:- | Decide on what thread you want to cut:- | ||
| - | Size i.e. M20 | + | Size i.e. M20 by 2.5mm. |
| - | + | ||
| - | Thread i.e. 2.5mm usually set by size | + | |
| - | Thread direction i.e. Right handed (the norm) I assume this in the guide below. | + | Thread direction, i.e. right-handed (the norm), I assume this in the guide below. |
| - | With the lathe in its normal operating configuration prepare | + | With the lathe in its normal operating configuration, prepare |
| - | If you are doing an external thread your stock will properly need to be as shown in the diagram below. It needs to be the correct diameter to take the required thread; this can be obtains | + | If you are doing an external thread, your stock will properly need to be as shown in the diagram below. It needs to be the correct diameter to take the required thread; this can be obtained |
| - | If you are doing an internal thread your stock will properly need to be as shown in the diagram below. The diameter of the hole should be the correct size for the required thread; this can be obtains | + | If you are doing an internal thread, your stock will properly need to be as shown in the diagram below. The diameter of the hole should be the correct size for the required thread; this can be obtained |
| ==== Stage 2. Getting the Lathe ready.==== | ==== Stage 2. Getting the Lathe ready.==== | ||
| Line 25: | Line 25: | ||
| 1. Remove the cover plate with an M3 hex key. | 1. Remove the cover plate with an M3 hex key. | ||
| - | 2. Use an M24 spanner on the end of the Lead Screw to rotate it until the edges of the cover become visible. Only pull the spanner towards you do not try to go in the other direction you will unscrew the nut of the end of the Lead Screw. | + | 2. Rotate |
| - | 3. Push the edge of the cover upwards to reveal the Shear Pin. You may need to use the spanner | + | 3. Push the edge of the cover upwards to reveal the Shear Pin. You may need to rotate the lead screw further. |
| - | 4. Now | + | 4. Now |
| - | 5. When the slot is lined up slide the unit across pushing the Shear Pin in to the slot. | + | 5. When the slot is lined up, slide the unit across, pushing the Shear Pin into the slot. |
| 6. Slide the cover back over. | 6. Slide the cover back over. | ||
| Line 41: | Line 41: | ||
| __**Step 2. Select the correct thread spacing.**__ | __**Step 2. Select the correct thread spacing.**__ | ||
| - | 1. Do I need to change the gears? The lathe should be in the “G” configuration which is suitable for most metric threads. If you do change the gears please return the Lathe to the “G” configuration once you have finished. If for any reason you leave the Lathe in any other configuration please leave a note on the Lathe. | + | 1. Do I need to change the gears? The lathe should be in the “G” configuration, which is suitable for most metric threads, so you're good. If you're doing a weird thread in banana units. Then you may need to change some of the gears on the headstock. This calculator on the amazing site CGTK can help you here. [https:// |
| 2. Set the Gearbox Knobs to the correct setting for your desired thread. | 2. Set the Gearbox Knobs to the correct setting for your desired thread. | ||
| Line 49: | Line 49: | ||
| 1. If you have set the Gearbox Knobs to an “M” setting you will need to use the Blue Threading Indicator otherwise use the Green Threading Indicator. | 1. If you have set the Gearbox Knobs to an “M” setting you will need to use the Blue Threading Indicator otherwise use the Green Threading Indicator. | ||
| - | 2. To fit the Indicator, ensure the metal bolt is screwed back in to the body. Then place the locating lug in the locating hole on the right hand side of the Carriage and rotate the Indicator | + | 2. To fit the Indicator, ensure the metal bolt is screwed back in to the body. Then place the locating lug in the locating hole on the right hand side of the Carriage and rotate the Indicator to bring the teeth of the cog to mesh with the Lead Screw. Now screw the bolt in to the threaded hole and tighten firmly with 6mm Allen key. Please remove the Indicator when you have finished using it. For more details on fitting the Indicator see…… |
| - | 3. With the Lathe in a safe configuration turn on the Lathe and check the Indicator is going round. | + | 3. With the Lathe in a safe configuration, turn on the Lathe and check that the Indicator is going round. |
| __**Step 4. Select the correct direction of cutting.**__ | __**Step 4. Select the correct direction of cutting.**__ | ||
| Line 63: | Line 63: | ||
| __**Step 6. Select a suitable cutting speed.**__ | __**Step 6. Select a suitable cutting speed.**__ | ||
| - | Start on the slowest speed until you are comfortable then you can up the speed. | + | Start on the slowest speed until you are comfortable, then you can up the speed. |
| __**Step 7. Mount the cutting tool.**__ | __**Step 7. Mount the cutting tool.**__ | ||
| - | Because we are running the Lathe in reverse the tool needs to be mounted upside down to normal. In order to get the cutting point to be on the centre line of the Lathe you will need to pack the tool up with some High Speed Steel. Then use the adjuster to set tool up. | + | Because we are running the Lathe in reverse, the tool needs to be mounted upside down to normal. In order to get the cutting point to be on the centre line of the Lathe, you will need to pack the tool up with some high-speed steel. Then use the adjuster to set the tool up. |
| __**Step 8. Test well away from everything.**__ | __**Step 8. Test well away from everything.**__ | ||
| - | Move the Carriage etc. so that the tool is well away from everything. Set the Lathe going and as the Gauge come around to one of the numbers gently lift the Threading Handle up and you should feel it engage. The Carriage should move from left to right. | + | Move the Carriage etc., so that the tool is well away from everything. Set the Lathe going and as the Gauge comes around to one of the numbers, gently lift the Threading Handle up and you should feel it engage. The Carriage should move from left to right. |
| __**Step 9. Set up the DRO.**__ | __**Step 9. Set up the DRO.**__ | ||