Here is a list of all the postings The Novice Engineer has made in our forums. Click on a thread name to jump to the thread.
Just watched the film Contagion .....Hmmmmm .....
You Tube Trailer https://youtu.be/xqLLPG8jMS4
Edited By The Novice Engineer on 30/03/2020 00:09:45
|Thread: Suitable stepper motor for CNC|
You have posed an open ended question with few details [ as the link in your post failed !} , there are lots of choices to make before considering stepper size.
The choice of what size motor depends on the design of the frame, the load they have to move and the speed you want get the Drilling head/Work Table to travel at. Higher speeds also need more torque, either a longer stepper motor body, higher running voltage or moving up to a larger frame size.
For example using a Dremel style Drill Body in a Prusa style 3D printer chassis, this light weight design might be what you are considering
3D Printer frame as CNC PCB Drill using NEMA 17 steppers
To give you an idea of what motors I have in the various machines
Emco PC50 milling machine uses NEMA 23 frame size stepper motors 76mm long. XY Table Assy weight ~15kg Running at 24Volt
A large 3D printer uses NEMA 17 35mm long. Print Head Assy ~ 0.75 kg Running at 24 v
Laser Engraver uses NEMA17 24mm long Laser Head Assy ~0.25kg Running at 12v
|Thread: Positioning of workshop lights|
I too like the flat panels , the back of the Garage is only 6ft high and these put plenty of light over the machine and bench.
|Thread: What to use for New Worktop?|
Mine are 20 mm Block Board with 14g Aluminium sheet covering, folded over 1" down at the front and a 2" Upstand at the back. Been good for last 30 years and should be OK for the next 20 !
|Thread: What are you reading?|
Model Engineer 1935-6
Tit bits include :-
The plight of clubs to find younger members !
The new apprenticeship opportunities in the expanding RAF
The Joy of Flash Steam hydroplanes
Edited By The Novice Engineer on 19/03/2020 19:34:37
|Thread: What Did You Do Today 2019|
Finally found an easy way of making gaskets for small steam engines, though took all day to get a useful sample. The original engine was not made with CNC but by hand with holes not quite lining up with my precision made bits !
A laser cutter -engraver with a 2 watt [how do you check the power ?] laser,
I used Fusion 360 to create the drawing and the G-Code, that was then copied to LaserGRBL , 4 passes and the gasket dropped out of the sheet. Now I can mass produce them ! Though I only wanted 2
Edited By The Novice Engineer on 17/11/2019 21:24:54
|Thread: DIY Bed Gap|
HI Myford did a special conversion of the ML7 that used raising blocks , catch up with the details here
did consider doing this once, .... wokred out quicker and cheaper to buy new discs!
Edited By The Novice Engineer on 24/04/2019 19:46:02
|Thread: Printing small parts for car restoration|
A few thoughts ....
Are you aiming to print the items yourself or get them made for you, and what sort of size are you looking at .
If you are looking for a bureau , I have a few friends who have used Shapeways , they provide a good service and online advice.
Home printing using filament FDM 3D printers is practical for objects that will fit within 200mm -275mm cubic build volume. 3D Printers with larger build platforms start getting expensive [unless you make it your self !}
The best material would probably be ABS as this can survive heat better and can be finished to a smooth surface.
You will always have a patterned surface finish with an FDM printer that will need work [post processing] if you want a smooth surface finish.
The Stereolithography 3D printing process will produce much finer results but is more expensive and is really for professional use ... or if you are really dedicated !
For ABS you need a printer with a heated bed and for best results an enclosed build space to keep the surrounding air temperature constant ~70C. This helps with curling and similar defects.
A number of cheap 3D printers only work with PLA filament,
If you decide to make them yourself then be prepared for a learning curve and occasional frustration till it comes right !
|Thread: Further Adventures with the Sieg KX3 & KX1|
XP can replace a Vista OS , reformat the partition and do a clean install.
Its one of the options from an XP installation CD when you boot from it
Edited By The Novice Engineer on 07/04/2019 22:07:39
|Thread: Chinese dovetail cutter|
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 !
|Thread: Machine tool suppliers|
Warco have a range of used items
Their open weekends have an interesting array of equipment and items !
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
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.
Edited By The Novice Engineer on 09/03/2019 23:39:40
|Thread: emco pc turn 55 conversion to mach3|
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.
Edited By The Novice Engineer on 01/03/2019 21:00:18
|Thread: Emco PC Mill 50 conversion to mach3|
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.
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.
|Thread: emco pc turn 55 conversion to mach3|
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 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.
Edited By The Novice Engineer on 28/02/2019 22:13:56
Edited By The Novice Engineer on 28/02/2019 22:18:50
|Thread: Emco 50 CNC Mill ...Increasing X and Y table travel ?|
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.
Here are some more details of what I modified on the Mill to gain the extra X Y workspace .
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
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.
Edited By The Novice Engineer on 28/02/2019 20:44:49
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.
|Thread: Rev counter (Tachometer)|
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.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.