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: Casting brass or bronze|
UK HSE state that drinking milk does nothing to prevent metal fume fever. Milk is sometimes suggested for ingested metal based poisons but I have not been able to find definitive research on the subject of milk for the prevention of metal fume fever.
|Thread: Fly Cutting|
Use a lathe bit in the chuck. I use a 6mm button tool in a flycutter for some work and the basic flycutter bit is ground like a lathe tool. There may be a need for some paper or card to be fitted between the chuck and the tool to increase friction.
|Thread: Boxford VM30 Milling Machine Motor|
Get a vfd that is big enough to suit this motor and a larger motor as well. A 2kw vfd will drive anything smaller as well and you may want a larger motor in the future or to drive a different machine with the vfd.
|Thread: Casting brass or bronze|
DMB, I tried to find evidence for the use of milk as something for welders to use as an antidote to welding fumes some years ago (for where I work) . I failed to find any research, do you know of any that exists, I came to the conclusion at the time that it may be an old wives tale but I would love to be sure one way or the other.
|Thread: something simple!|
If what you have is like mine then there is a clamp screw on top that needs to be released and a pin in the disk at the collet end that needs pulling out. There is a retaining ring at the other end that may need adjustment to stop it binding on the body of the indexer. There are videos on improving the squareness of the Base that may help if you find them.
BasementShopGuy did the videos I am thinking of.
Edited By Martin Connelly on 31/12/2015 14:31:12
|Thread: First day on milling machine|
Andrew, I said maximum metal removal rates are for production environment, not that people should not know what they are or work close to them. I just think that that is something to work on after the basics of feed and speed are understood. These are suggestions for a beginner to consider after all.
Gloves seem to direct splinters into my skin so I just have bare skin when using the lathe and mill. I was taught it is better to lose a bit of skin than a finger or hand. I keep rolls of paper towel handy to remove gross contamination and wash frequently.
|Thread: Loctite - Can I warm it up, move the joint and let it cool again?|
Loctite sets chemically not by cooling. This implies it is not a thermo setting plastic so once the bond is broken it cannot be remade.
|Thread: Feedshaft worm lubrication|
Power feed shafts do not spin at high rpm so will not sling the oil out of the trough so not a lot of topping up required, no grease sounds sensible.
|Thread: First day on milling machine|
There are theoretical values of maximum material removal for given power but they are best kept in production environments. What you should be concentrating on at this stage is getting correct speeds and feeds for you setups. You need to keep the chip thickness in the correct range. This involves considerations such as number of cutting edges on a milling tool, the spindle rpm and material. You do not want the tool to rub as it just reduces it's life. Spindle speed is the same as drilling speed for tool diameter. Work out feed rate for a chip thickness of 0.05mm for example and time yourself feeding to see how you compare, no need to be cutting metal when doing this. This is assuming you are working manually. If you have power feed find out the relationship between speed setting and feed rate.
Make sure you understand the difference between conventional and climb milling and the importance of minimal backlash for climb milling.
You may not be planning to use CNC but if you load Mach3 and set it up for milling it includes a wizard for calculating feeds and speeds for given materials and cutters. There are probably others available.
|Thread: Boxford goes crunch! Now refuses to turn.|
Oil on gears is less likely to form a grinding paste than grease on gears. Is there a Boxford recommended lubricant for these gears?
|Thread: How can I tell if a carbide tip is worn?|
I have a broach cutter (trepanning cutter) with 55mm diameter. I mount these cutters in an ER32 collet mounted in the tailstock. The standard length is good for 25mm thick material but working from both sides increases this. I would use this to remove the core then finish with a substantial boring bar. For spindle speed I use a drilling feed and speed chart. When using hss tooling the drill speed for a 60mm drill is about the same as the spindle speed for 60mm turning, double for carbide. This is a starting point and can be tweaked if required. I have a 3 phase vfd so setting a suitable spindle speed is a case of nearest gearing then speed up or down to get best results. The feed per rev is also relevant to turning, the larger the diameter the larger the feed per rev should be. This keeps chip thickness more constant and pressure on the cutting tool similar at different diameters.
|Thread: Fusible Plugs|
Lead has a higher melting point than eutectic solder (60 40 mix) so may be a consideration.
|Thread: Question: mounting slitting saw|
I have seen arguments both for and against keys in slitting saws. The view of some people is that if no key is used then in the event of the saw being grabbed it will slip on the arbor so will not be destroyed. It does assume manual feed rather than power feed so operator response is rapid. I have no view to push either way regarding key or not but thought I would let you know the use of a key with slitting saws is debatable.
|Thread: What did you do today (2015)|
Bri, if you have a single phase motor with a start coil and start capacitor then the start coil only starts the motor running in the chosen direction by supplying a suitable torque for a very short time. The run coils then maintain the motion. To reverse the motor the start coil gives an initial torque in the other direction. These start coil torques are quite small and of short duration so will not be sufficient to stop a running motor and force it to rotate in the opposite direction. You must allow the motor to stop before choosing the reverse direction. It is a characteristic of some single phase motors.
|Thread: New precision chuck for milling machine|
I second Vic's comment. Most problems I have seen with big drill runouts is due to bent arbors. New arbors are quite cheap and swapping out an old one for new on your drill chuck may cure the runout. Most of the ones I have sorted out have been bent by people at work swinging a radial arm saw so that the chuck or drill bit in the chuck clouts a solid feature such as a vice. They then put everything away without telling anyone so the next person to use the chuck has to get the problem sorted out.
|Thread: Coverting mitre saw to cut metal|
Once had to get an abrasive blade in angle grinder mounted in a stand to cut inconel pipe. It was too tough for standard circular saws or bandsaw.
|Thread: Chimney machining|
Why not thread the hole and screw it on to a carrier bar of suitable size. Once the flange is machined you can loctite the casting to a bar with the correct diameter to machine the rest of it. Add jubilee clips for extra holding if needed.
|Thread: Stirling Engine : Laura|
You could use stepped roughing to get the basic curve done on the piston then finish with a file. See ballcut.zip here:
|Thread: Acute (a cute?) tool sharpening system|
I have one from Peter Child woodworking tools on my double ended 6" grinder. It is an electroplated metal wheel so you can use the flat side as well as the curved rim.
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