Here is a list of all the postings Martin Connelly has made in our forums. Click on a thread name to jump to the thread.
|Thread: What Did You Do Today 2019|
Helped my wife's uncle sell his lathe today.
Edited By Martin Connelly on 08/04/2019 20:42:58
|Thread: Slot Drills|
Broaching cutters can cope with half a hole as described as the centre slug effectively pilots the cutter. Too expensive for a one off job though.
|Thread: No 20 machine oil|
And this is the lathe.
The mill is in the vehicle pulling the trailer.
|Thread: Please help machining|
You can cut the grooves with a suitable radius ball nose cutter and the work piece supported along its length. Turning the part through 120 degrees can be done in numerous ways. You probably need a hardenable steel but that is also not a problem.
Looks straightforward. If someone said impossible it must have been followed by a modifying comment such as "for no cost" or "at a price you will pay" . Were these professional machine shops?
|Thread: Chester 626 and Warco VMC spindle size|
This has been stated numerous times but let's say it again, the tang does not drive a morse taoer drill, it is for ejection purposes only.
|Thread: Advice on chuck modification|
Are you talking about a step chuck?
|Thread: On/off at the top with red green lights. What edge finder I?|
I think Tony P got it with z axis setting. Try the micrometer as suggested by. Michael G and see what repeatability is like (when it is working again) .
|Thread: Aircraft General Discussion|
I saw one of the new f35 fighters doing a practice approach yesterday. Good roar as it put on the power to go around.
|Thread: Toolroom lathe?|
Smart and Brown model m has 4" centre line to bed height, 6.75" width across the bed and the carriage is 11" long along the bed. Looking at some of the more modern offerings with a larger centre line height I suspect they have proportions that are relatively smaller than this. It also has large bearing surfaces in contact with the ways and the tailstock runs on different bearing surfaces than the carriage.
Maybe if turning between centres having dedicated ways for the tailstock means that wear of the carriage ways will have very little effect on accuracy. Maybe this is a reason this lathe is referred to as a tool room lathe. It also weighs in at 750kg when on its cast iron/steel base.
|Thread: Cutting a concave radius on the end of a round bar|
Rotabroach mini cutters go down to 6mm. They mount on an arbor that can be held in a chuck or collet. Part numbers for mini cutters start RCM arbors are RA116 or RA118 (the latter for cutters over 20mm up to 25mm diameter) . I find them useful for counter boring for cap head screws amongst other uses.
|Thread: Removing large flange nuts|
Here is one I made for a similar nut. Don't know what size your nut is but this tool will not damage the nut and is less likely to slip than a hook wrench. This is what the earlier posts were refering to as modified sockets which is one way of making this tool.
|Thread: Lathe screwcutting|
If you set the top slide to 29 degrees do be sure to measure it from the right starting point. It's a common beginner's error to set it at 61 degrees. Remember that zero is when the cross slide lines up with the top slide and 90 degrees is when the cross slide lines up with the bed (the normal position for most work). Setting it to 61 degrees will cause roughness and what looks like multi start threads.
This is slightly off topic but is connected to the video and the issue with the tool post loosening. I had a problem with the cam action, i felt it was not locking the way it should so I made a new plunger. I made it long enough for the cam action to go just over the peak of the lobe and so make it lock in place.
|Thread: New drill-1PH to 3PH wiring|
Wiring for the VFD is dependent on the make and model and is usually given in the associated manual. They are generally available on line.
|Thread: Precision division plates|
Howard, one problem with a 127 dividing plate is you often need a larger than standard plate to drill all the holes on one diameter. 3mm holes with 4mm spacing requires a diameter of about 160mm. Not a problem if you can fit one that size to your rotary table but it may also require a longer crank and sector arms. It may be possible to do two rows of holes but then you may spend a lot of time reseting the setting pin to a different radius.
|Thread: Centre finder?|
Easier to use a dti and spare centre as shown on this page.
|Thread: Bowl shaped propellor|
Photographic recording with film exposed the complete frame al at the same time so the strobe effect didn't distort the spokes of wagon wheels or the blades of propellors and helicopter rotor blades. Using digital cameras the frame is scanned left to right and top to bottom (or some variation of this order) and this takes some time. During that time the propeller is still rotating so each scanned line will show the blade at a slightly different time. This results in a straight blade looking curved. There is a video somewhere on the web showing a car window's glass looking as if it is rippling due to this scanning of the frame.
|Thread: Hardened Silver Steel Shattered - How to Avoid?|
Were you clearing out the chips to avoid clogging the gullets?
|Thread: Lathe screwcutting|
I would suggest that if using carbide tipped tooling hand cranking may be problematic as a slight reversal of the spindle may break the tip off the carbide. Using hss this would not be a problem, we reverse hss dies to break chips when hand threading, we also do this using hand cranking at slow speeds. It is basically the same process that occurs when screw cutting in the lathe.
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