Member postings for The Novice Engineer

Hi,

I have used a number of Chinese sourced cutters over the past few years Carbide and HSS and generally they have been value for money.

I have not specifically used Dovetails cutters but I have used T Slot cutters to successfully make an Aluminium Slotted Table for a small mill.

Give them a try, its not a lot of money !

Hi,

Warco have a range of used items

https://www.warco.co.uk/content/6-buy-used-lathe-milling-machines.

Their open weekends have an interesting array of equipment and items !

Steve

I have had an inverter fitted to my Myford ML7R for 5 years with no problem.

Currently it is set up so the motor runs at full rated speed [to keep the air flow cooling] and I use the belts to change the spindle speed. The inverter is set up with a soft start [5 sec to speed] and a dynamic stop [1sec] .

When doing threading there is a lot of stopping / starting / change of direction with no ill effects.

The inverter is an IMO Jaguar CUB

Steve

I have done some Aluminium casting of small items , upto 600g . I used a 3 Kg electric furnace [3kg is weight of gold it will take !] that I picked up from e-bay a few years ago.

It takes about 45 -60 min to getup to temperature ~ 750C and melt the aluminium, the process can be speeded up by preheating the scrap with a gas torch.

My source of Aluminium is old cast items , eg chair bases, car engine pistons , hard drive chassis etc ... , tin cans , extruded sections and foil are not good they produce a lot of slag and pour like treacle and is a soft alloy that is horrible to machine.!

I use oil bonded sand in home made wooden cope and drag moulding boxes, this is a find sand that gives a good finish.

Pattens are made of MDF , 3D printed, or if its simple Polystyrene that is burnt out at the pour ...outside ! for good reason ...it smokes and stinks.

Have a look with google for more information ...there's loads out there , Back yard foundry etc ...

As Brian said ...its a satisfying process.

Steve

Edited By The Novice Engineer on 09/03/2019 23:39:40

Update:

A bit of a senior moment dyslexia with the spelling of the drives I used!

The 5 phase drivers are by VEXTA , to use these the Emco Berger-Lahr stepper motors have to be re-wired internally about a 5 minute job changing links around. The Vexta pentagon drivers have five output terminals; each one connects to two motor cable conductors

I've added the information about how I did my modification to this thread as the title may draw folk in who are looking to do a modification.

Steve

Edited By The Novice Engineer on 01/03/2019 21:00:18

I have been curious about CNC machine tools since I saw my first one in action in 1984 when I worked at Ricardo's in Sussex.

I had been looking at obtaining my own CNC mill for years and contemplated converting a small Hobbymat 65 mill that I had. Then I came across a pair of ex college Emco PC 50 Mill and Lathe that had been used to provide spares and been left to rust in a storage unit.

I did a lot of internet searches and gathered a folder full of snippets and information.

The project is evolving as I try out new ideas.

The machines were stripped de-rusted and cleaned, mechanically they were good . The electrics were good , but the electronics were suspect. I didn't have the Emco software or the PC interface card

I looked at what control software was available and decided to go with mach3 as the Artsoft Forum had a lot of useful infrmation and at the time when I started this project it was still being actively supported. The fully working demo version was a good start, I could do testing without too much of a learning curve.

As a cost effective solution for a hobby machine for myself I looked at Chinese control cards. These are available from ebay from £5 upwards ..... I had a couple of old XP pc's and decided to use parallel port control. This is an obsolete technology dead end , but it works and I was confident to support it myself.

The current card is a TB6600 3 axis all in one control , drivers and relays.

https://www.ebay.co.uk/itm/New-3-Axis-TB6600-CNC-Controller-Max-Current-4-5A-36V-Stepper-Motor-Driver-Board/271634683200?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

This runs off the 24v power supply of the original Emco

On the panel is a TB6600 driver card for the 4th axis, it picks up its control signals from the all in one card. There is also a voltage control card for the LED lights.

The spindle Main drive is an Omron VFD rated at .4kW. This is run from a manual control box with Stop ,Start Direction switches and a Cotrol for speed.

I have recently trial fitted an additional High Speed 24,000 rpm 1.5kW spindle and there is an additional 2.2kW vfd contoller [the red one] along side the Omron.

I'll post more later.

Steve

Here are some photos of my Emco PC Turn 50 cabinet with the rewired power side , the Rack mounted PC and 5 axis controller, the Drive motor VFD and the Vertex 5 Phase stepper drivers.

I had been using this as test bed for trying out ideas before modifying a Emco PC 50 Mill, The lathe retains the original  Emco 5 phase stepper drive motors and the 3 phase main drive. 

The transformer was retained to provide 24v for the tool changer. The Vertex drives are 110v and are run form tapping on the primary side of the transformer.

The Power supply at the front is for powering the PC [a Mini ITX dual core running XP off an SSD ..very quick] it also powers the Mach 3 control card, and recently the Tachometer RPM meter

The terminal block is a power take off for testing the RPM Tachometer of the Main drive.

Steve

Edited By The Novice Engineer on 28/02/2019 22:13:56

Edited By The Novice Engineer on 28/02/2019 22:18:50

Here is a shot of the parts from the Emco manual, part 19 is the rear cover that operates the Y axis limit/home switch.

Update 3

Here are some more details of what I modified on the Mill to gain the extra X Y workspace .

Y Axis

This is where the greatest improvement was made. By removing the front Guard and rebending the front of it I gained around 24 mm of movement on the table [when moving to wards the rear column], I also changed the lower cap head screw that secures the cover over the Z ballscrew on the rear column for a low profile dome head, another couple of mm for little effort.

The rear cover [accessed from behind the mill] includes the limit switch actuator for the forward movement [Home position] of the table, this was gently re-bent to allow more movement

X Axis

There was slight gain on this axis when moving to the left, by shortening the microswitch actuator rod ,~ 8mm removed. [this operates the limit switch under the right hand cover over the stepper motor]. This allowed the stepper motor assembly to come up to the ball nut housing, I set the switch for about 1mm gap here.

The other item to be modified was the cable gland fixing for the stepper motor cables. The gland plate was moved back ~ 18mm with a spacer plate. before I did this when the table moved to the maximum right and back the stepper motor cover would jam against the gland.

I hope this information will be useful to others.

I will post some information on the electronics I used as another thread.

Steve

Edited By The Novice Engineer on 28/02/2019 20:44:49

Update 2

After altering the covers on the Cross Slide I now have 124mm Y travel , and shortening the switch actuating rod on the RH side I have 205 X travel.

So a useful work area of 204x123 [allowing 0.5 mm at each limit switch before hitting the end stops!].

I have fitted a tapped plate to the table that allows greater flexibility for fixing items down.

I have fitted one of the eB*y Tacho's to my Emco, although I used a smaller sensor than the one supplied [originally it was fitted to the emco Steppers]. The sensor is fitted into a housing that is stuck around the spindle with industrial double sided foam tape.

I have placed the magnet side on to the sensor, its position is not ideal but it works.

Steve

Having bought the Aldi Bandsaw I agree that for the price it is very effective, though as you say the vice leaves something to be desired holding small and irregular items.

I have modified the vice using the body and fitting larger jaws and a threaded rod. With a bit of fettling to clear the saw it meets my needs. Cutting steel sock and sections & aluminium castings are no problem.

Hi,
I took early retirement 4 years ago and spent a lot of time crunching numbers with spread sheets, before taking the plunge.

What I noticed was that the pension companies gave me a default option of an Index Linked Pension with 50 % to my spouse upon my demise. This had the lowest starting sum [around 2.5% per year of the money pot with index linked increase every year ~2.5% of the 2.5% !! ]. Reading the smaller print there was up to 5 alternative options.

I chatted to a number of relatives and older friends, their consensus was take the highest payout so that you have the most money to use whilst you still can. As they aged they could do less and spent less. No one in our family has ever made it to living in care ... they just kept going at home then pegged it.

I took the option that gave me the highest starting sum [around 5% per year of the money pot with no increases]].

Running the numbers though the spreadsheet showed that all the options paid out the roughly the same total amount after 22-25 years. The index linked pension with the lowest starting sum would beat the payout of the highest starting pension after this, by which time I would be 83 .... if I was still around!

To maximise my return from my pension pot I took the Tax Free cash [25% of the pot] and put the money into Shares within an ISA [invested with high Dividend shares] which gives tax free returns.

I have another pension yet to take , I shall probably do drawdown with this.

My 2p worth

Good luck

Update
Thanks for the input.

I have had a bit of time to take a look under the covers. I reduced the stepper current so I can run to dead stops without causing damage. Then disabled the limit switches.

At first glance the Y axis can be extended by modifying the Front and Rear covers to give around ~120mm.

Gaining more movement on the X axis is a bit more limited , moving to the left running up to the ball nut is possible to gain ~8mm. Moving to the right the limitation is the stepper motor hitting the case side. There is a Cap Head screw under the Table that is the physical stop, [it appears to hit the Ball Nut housing] removing this an option.

A little more time later this weekend.

Steve

Hi

I have had the Mill now for a year or so and love what it can do.

During my conversion of the mill from Emco control to Mach3 I did alter the limit switches to gain about 6-8mm on each axis, however I now find I am hitting the limit of what I can machine in a ~198x 95 work area.

I was recently looking at making some spoked wheels ~ 4" dia and before that cutting out a 4"x8" control panel. Both times disappointed . Trying to machine the part in 2 setups wasn't really good enough. [An optical finder is on my build list !]

I was thinking that I could maybe replace the ball screws and push the work area upto 275 x 125.

Has anyone got any experience of doing a modification like this?

Thanks Steve

Try here for 6BA Studding

https://maccmodels.co.uk/ba-fastners-washers/ba-studding/6-ba-steel-studding.html

or click on the link below

**LINK**

UPDATE

I found the information here from Madhackers very useful

https://www.matterhackers.com/news/how-to-succeed-when-printing-with-flexible-filament

or use this **LINK**

I bought some Priline TPU filament from Amazon and spent a few hours finding the best setting printing a variety of 20mm cubes.

The the standard Leapfrog Creatr feed mechanism seems to be able to feed the flexible filament OK so far.

I created a profile for the Filament that had a higher temp than PLA [240 C] and increased the Extrusion multiplier to 1.15.

The setting for the Print profile was created using a much lower speed setting , Max speed 30mm/sec down to 10 mm/sec.

There is probably scope for tweeking as I print different projects.

Steve

Hi,

I've converted an Emco Turn 50 to run of Mach3 a while back, ripped out all the Emco controls but kept the original Main Drive motor and stepper motor's.

I used a Generic Chinese [E-bay] parallel port interface controller card, Vertex 5 phase stepper drives, and a Omron VFD .

It was mostly re-wiring rather than building new electronics.

I run off a Windows XP pc the Operating System has been stripped down to the essentials and NEVER connect it to a network or the Internet. [Mach 3 control via the Parallel Port only works under XP or 2000. Windows 7 and above should use a USB interface card]

The Main drive is under manual control as is the Tool changer, Mach 3 looks after the X and Z axis.

So far this has done every thing I have asked of it, including taper turning, threading .... the awkward stuff ...etc.!!!

I use Fusion 360 for the CAD - CAM, and the Mach3 Wizards for simple stuff.

Steve

I'm looking at making some Lens covers [ for Camera and Telescope Lenses ] has anyone got any advice and experience of using Flexible filament.

Here is an example of the type of cap

**LINK**

Any recommendations on manufacturers of good [ and duff] filaments would also be welcome

My 3D printer is a Leapfrog Creatr.

Thanks

Steve

Try this

**LINK**

for more choice

**LINK**