Member postings for Stuart Bridger

My Chipmaster came without a guard and it was one of the first jobs I did to fit one. It is a decent fitting one from Nelsa and it doesn't get in the way for 95% of operations. I also use coolant and it does catch the fling off the chuck. My mill is different. The factory supplied one on my Warco VMC was useless, in that it prevented any sensible work and was soon removed. I use a screen on a mag mount where I can.

Thanks, good information

I have a Chipmaster where the motor/variator assembly is mounted on the cast U shaped frame. Does anyone else have this arrangement who could point me to how the frame is mounted to the base of the lathe. The rubber anti vibation pads on mine have degraded into a gooey mess. While I could strip it down, I thought it would be easier to get some advice before starting

1) The manual shows three bolts but only two pads, but is not clear which location has the pads. Mine appears to have a sticky rubber mess around all three?

2) What form are the pads, do they just rest on the base or do they have a through hole

3) How is the motor assembly secured to the based? Mine seems to pivot from the single mounting at the front, which applies tension to the drive belts. But i'm not sure if this is correct or just down to the fact that the pads have disintegrated. I get an alarming banging at high speed, which implies that the assembly is bouncing around.

4) Lastly if anyone has replaced these mounts, what have they used?

Thanks

Stuart

Thought it was amusing that he reversed the spindle rotation before starting his parting adventure

For me the biggest issue with the US and older UK plans is not threads, but the use of fractional dimensions. They are OK for woodworkers but don't sit well with the lathe or DRO. A recent rediscovery of my 1980 Zeus book really helps here.

I am currently going though this exercise with Elmers Mine Engine, no issues so far
2-56 > M2
3-48 > M2.5
5-40 > M3 etc.

Mind you I am still working in imperial for the main dimensions ....

I remember asking this exact question to my metalwork teacher at school. He told me off for being a smart arse, most likely because he couldn't ask the question. There is a lot of info on this subject out on the internet, the TLDR answer is the hole does get bigger.

I was taught in metric at school in the '70s. Started an apprenticeship in 1980 with British Aerospace and all apprentice training projects were imperial. The only "metric aircraft" at the time was Concorde, athough the airbus work was coming online. I do still "think" in imperial, I can visualise 5 thou but can and do work in both systems. Luckily my lathe has dual dials and I have a DRO on the mill.

I was working in the USA earlier this year. Hotel shuttle bus had a dry powder extinguisher behind the drivers seat. The pin was missing. Person sat next to me manged to kick the trigger getting out of the bus. That was a surprise!

+1 for the Volkel set, but somewhat surprised that the price is nearly double what I paid, but it was a few years ago.

I bought a carbide spotting drill 5mm x 50mm from MSC a number of years ago. It gets used in the lathe and mill. It certainly wasn't cheap, but a worthwhile investment.

Bit of time in the shop today, initial conclusiion is that the issue was a dodgy die.
Brand new split die from Tracy Tools, stock turned to dead on size, no lead in taper, Trefolex.
Thread cut under power with no issues at all.

Howard,
I can confirm that the die holder is on a sliding mandrel. I now have all the pieces in place to get this sorted.
Just need some shop time....

This a a downright dangerous and potentially lethal situation,

Two pin plugs are designed for double insulated equipment, where there are two independent functional levels of insulation that prevent contact with anything that could come into contact with live components. One of these is typically a plastic case. The fact that a machine tool has exposed metal means that it can never meet this criteria.

It needs to be properly earthed, end of....

Edited By Stuart Bridger on 12/09/2019 14:57:34

Hi Chris, how did you work out how much to "beef up" the original design?
Also having read Mike's article, I did find his rapid/return feed logic a bit difficult to get my ahead around, but i guess it makes sense when you understand it.

Nice project, inspiring. Especially given the cost of original equipment units.

A few observations, no time for practical tests yet
ID of my dieholder is 20.72 mm (a bit bigger than 13/16 - 20.64mm)

Original die is 20.48mm OD
New split die is 20.49mm OD (Tracy Tools)
Both are a slightly loose fit in the holder, without tightening screws - I will most likely make a new holder a bit closer fit.

New solid die (from Arc Euro) is 19.90mm OD - New hold holder to be made

Screws in the die holder are cup point, not cone point, so they need to be replaced

Thanks for for all the advice, some really useful stuff there. I have today ordered up some trefolex
and a couple of new dies, one split and one solid. I will update further when it arrives and I have had time to experiment.

Thanks for the feedback. I must have a very short memory. Last weekend I successfully cut two threads M2.5 on a 3/32 bar. Apologies for the mixed units 2.5mm is 0.098in on 3/32, 0.09375, so about 4 thou under.

So three possibilities, 4-5 thou under is the trick, I got lucky with the die adjustment or the die is a better quality.

I will try again with 4-5 thou under the nominal major and see how I get on.

I am fairly sure that the answer here is practice, but would appreciate any advice.

Trying to cut an M3 x 0.5 thread with a split die on mild steel. Two attempts have failed so far with stripped threads. Adjusting the die, I'm either not getting the thread to start or the thread is so fine that it strips very easily.

I am using a lathe with a tailstock holder, by hand.

What major diameter would you recommend starting with? Dead on 3mm?
Possibly the die is not of best quality, would I better off going for a die that isn't split? If I do carry with a split die, what's the best way to set the size?

Thanks