Member postings for Rick Kirkland 1

Edited By Rick Kirkland 1 on 21/05/2017 17:13:29

To clear up a couple of points. The main overcurrent protective device, (main fuse) for domestic installations supplied in particular on P M E has a value of 100 Amperes, as per the suppliers requirements. If a smaller capacity fuse is fitted it will be for a reason specific to the installation. The motor in question on this thread cannot be wired for Star or Delta. The plate clearly states the CONN, (connection) is Delta. The voltage rating backs this up by stating the voltage requirement to be 380 /420 v. The Amperage at 28.6 and 25.8 in relation to these voltages gives further weight as does the Service Factor and the Service Factor Current draw relating to the voltages, They are the between phase voltages for a Delta connected motor. Now, I would like to learn something here. I know that 3 phase machines can be run by various means from a single phase and if I'm reading the O P correctly it was stated that a 3 phase motor can be connected to run off one phase. I'd be interested to learn how this is done, How the motor actually starts and how smoothly and efficiently it runs. I love learning new stuff. I've recently discovered something called CNC. I'm going to be learning about that next.

I'd like to help but I don't understand Chinese writing although, a thought has occurred which I'll keep to myself at the moment.

Hopper, It appears there are two of these ML7's in the world. last night I was in The Shed and I was looking at one of the ML7's that are awaiting refurbishment and I noticed that the spindle on one of them is bored out in the end in an identical fashion to yours. The lathe has in fact been abused and I was told that it had been used mostly for cylindrical grinding. the fact that the threads on the leadscrew are nearly non existent seems to be testament to this. Still, , there's not much that can't be put right with a little time, effort and enthusiasm.

Rick.

First off, the shaft is NOT in the wrong way round. Secondly it is completely correct to have a left hand thread at the left side of the shaft and a right hand thread at the right side of the shaft. This prevents the Clamping nuts working loose during use of the grinder. therefore you will never , ever be able to tighten the nuts by using a spanner at each end of the shaft. This , even if it were possible , which thank goodness it isn't, is absolutely NOT the way to tighten grinding wheels. It matters not that it's a cheap bench grinder, what matters is that before you play with it you MUST adhere to the correct wheel securing practice. If you don't you're in for disaster, , and believe me, I've seen a wheel burst and the resulting damage. Please get sound advice from possibly publications regarding securing and mounting grinding wheels but absolutely not from someone who says " just do it like this, I've been doing it for years and not had a burst wheel". Be safe before you play with potential life threatening tools. This is simple to do. Merely learn about them and understand them before you try using them. I'm not in anyway a H & S nut, but in this case I implore correct knowledge is sought and followed.

Well that's a bit more information David so I'll assume it's 1/4" diameter with a two start. the next question is what is the lead of the screw required? This has a major bearing on how much core diameter remains once the threads with their associated root clearances have been machined in. Also it means that for a decent core diameter to remain the thread pitch needs to be relatively fine on small diameter screws. If you're using form tool inserts you may be able to purchase one small enough for your purpose but if you're grinding your own form tool from HSS toolsteel You'll need loads of patience, a decent grinding jig, a good magnifier a little bit of luck and remember also, if the nuts need screwcutting you will need an internal tool to the same form , which will be pretty small after all is said and done. An Acme tap may be a better solution the only problem being the availability of 1/4" Acme form taps with two starts. I'm willing to bet THAT is a non start! My next question is does it absolutely HAVE to be Acme form in that particular diameter and application.? I'm not saying it's not possible but it's a bit of an involved process.

First of all metric Acme threads don't exist. Metric pitch threads of that appearance are called Trapezoidal threads and they have a 30 degree included angle as opposed to an Acme thread which is Imperial and has a 29 degree included angle. Also are you talking about 6mm/ 1/4" pitch or 6mm / 1/4"diameter ?

Good to know that. I can put an album up now without panicking about resizing etc. Thank you Neil.

Forget paint, , chucks would look beautiful Blued. And rust resistant. T I C posting, , let's not have the pedantic posters go getting uptight.

In the same locality. 3 minutes and 42 seconds from M1 J28. Welcome to the site. We are Legion.