Member postings for The Novice Engineer

A tip given to me by an old machinist to true up the jaws is as follows

Select a grinding stone that has a diameter so it can pass through the rear of the chuck.

Turn up a ring that will fit over the jaws so that when they are opened against the ring ,the grinding stone will pass through.

Now gently stone the jaws till true.

Not done it myself, but he did sort out an old chuck for me.

An alternative might be to source some replacement jaws Pratt Burnerd use to do spares .

Hi

My latest project is building a CNC Router for cutting out plywood/MDF/Aluminium and looking at ideas for controlling it.

Has anyone here any experience / views of these standalone compact CNC controllers

I have a Mach3 licence and use that on the Emco Mill and Lathe, these are in the "Clean" garage.. The Router will be shoehorned into the "Dusty" workshop and I'm looking at compact ideas that don't involve a PC , Laptop , Monitor, Mouse etc

The late, great John Stevenson was promoting the DDCSV1.1 in 2016 and hosts documentation for the RMHV2.1 on his website.

I have looked at the possibilities of using the Arduino and /or Raspberry PI [I have a supply of these boards from various "projects" ] but I feel there could be a lot of work and additional time to get a functional working system , compared to the One Box DDCSV approach.

The early versions have a 4.3" screen the latest are 5". The controllers come in 3 and 4 axis versions. 

For info typical costs for a 3 Axis controller start around £170 from China and ~ £220 from an EU based supplier.

Thanks for any input.

Steve

Edited By The Novice Engineer on 10/07/2020 10:50:38

Edited By JasonB on 10/07/2020 11:53:10

Hi

I believe the solvent used in 3D LAC is Denatured alcohol ,

I use IPA [ The industrial version not the Malty Amber type !! ] to clean the heat bed surface.

Methylated spirits could also be used

To get a decent area of a model to adhere to the bed I have often use the "Brim" feature about 5 -20mm depending on the size of the object and how large a flat area it already has on the base.

The brim is easy to remove from the object and doesn't use much filament compared to a Raft, serves much the same task as " Mouse Ears" but you don't have to design it in.

The Brim feature is in Cura and Slic3r, I use Repetier Host on the PLA printer [Leapfrog Creatr]  but the proprietary UpStudio doesn't have it for the ABS  UpBox !

Steve

Edited By The Novice Engineer on 06/07/2020 12:08:30

Edited By The Novice Engineer on 06/07/2020 12:25:33

I've come to a similar conclusion ,though for small objects and figures the 0.2mm nozzle with a 0.1mm layer height is outstanding. Tip if the items are very small print 2 of them, gives one a chance to cool down between layers and cuts heat distortion.

I also came across an article [can't find the source now !] that recommended for printing flexible TPU type filaments to use a 0.5mm or larger nozzle to avoid high pressures in the extruder and failure of the extruder gear to feed the soft filament.

Edited By The Novice Engineer on 05/07/2020 00:05:27

H Steve

In response to your questions

The UpBox uses 1.75 filament.

As regards smell not a lot ..The printer has a recirculating air flow fan with a filter , and the Tiertime filament is low odour.

I've not tried ABS-X but having looked at the data sheet , I'll get a reel or two to test it out.

The UpBox extruder is designed for high temp ABS use, being steel with no PTFE liner. To print with other types of filament PLA , TPU etc there are exchangeable extruder assemblies optimised for the lower temp/ softer materials, I've not tried these yet.

A couple of items that I'll mention with regards getting success with printing

As an aid to getting the ABS to stick to smooth beds I've used 3D LAC spray successfully [smells just like hairspray ! but having tried various sprays ... there is something in the composition of 3D LAC that works]

Bed Levelling and nozzle to bed distance is VERY important , this influences filament bed adhesion and surface finish. I don't find that the Auto bed sensing gets as good results as a Manual set up.

I'm experimenting with Chamber Heating using a 200W heater with a duct that directs a flow of heater air [~70c] across the bed along similar lines to a Stratasys professional printer that I dismantled. This keeps a uniform build environment and speeds up getting the printer up to temperature, I feel it is worthwhile time investment for bigger prints.

Hi here are some of my experiences

My material of choice is ABS , mainly for its strength and high temp capability. I use it for engineering bits, adaptors fixtures. and recently a set of Gauge 1 goods wagons. ABS is easier to bond than PLA and I can get a good finish with a small bit of effort. [ Sanding and /or Acetone vapour ]

I've found PLA is generally easier to print but not so easy to bond or finish [ no solvents smooth it like ABS] its outside durability is not as good as ABS [ The PLA bird feeders didn't last through a summer]

I have been playing with 3D printers for a few years and have been through a long learning curve.My first 3D printer was a Leapfrog Creatr that I have modified and rebuilt in a number of different configurations to get around issues of

- Getting the prints to stick to the bed [Heat it , Blue Painter's Tape or a PEI surface recommended for PLA]

- Stopping distortion, and getting dimensionally correct prints [Stiffen the machine and fiddle with the software]

- Getting a decent surface finish [fiddle with the software , slow down, lower layer height and patience]

PLA was reliable ABS was a problem lifting from the bed and distorting. The high temp causes issues with small features

My current printer is a Tiertime UpBox+ that has produced some decent ABS prints that are spot on dimensionally. It has an enclosed chamber with a heated bed with swappable perforated flexible build plates or a smooth plate with a PEI surface.Items pop off -ish when cool.

The software for the UpBox is Up Studio, this has fixed setting that produce consistent results. The filament setting are built in [ they can be edited but its not User friendly !!} The UpBox runs ABS at Nozzle 270 C and Bed 100 C. So far I've been using TierTime filament that is good, but not cheap! ~£50/kg Cheaper filament's have a lower working temp and appeared to soften at the feed mech and stop extruding , then char in the nozzle!

I am currently doing some tests of other High temp ABS filaments Multicomp and YOYI that run to 260-270 C these are looking favourable.

My penny's worth

For a similar job I used Waterproof Plastic self adhesive labels [Polylaser] that were printed with a Laser Printer.

Find them on E bay or Amazon or even local office suppliers

A while back I recovered  around 9ft of spring steel [0.012" x 3/8" ] from the

Mains Cable Retract mechanism of a Lidl Hair dryer that died !

Edited By The Novice Engineer on 30/05/2020 19:35:54

From my experience go for the biggest you can fit /afford.

My first mill was Warco WM14 size/style. It was great for doing small steam engines but I started doing bigger and bigger projects and ran into issues with the table not having suffient travel or being able to fit the parts under the head . The final straw .. burning out the motor after being too impatient taking too big a cut.

I replaced it with a Major Gear Head Mill / Drill. R8 quill . Good work envelope and more power for getting the jobs done. If I was going to change I would look at a similar size machine but with a Dovetail column and inverter speed control.

AND .... what ever you pay for the Mill , you will spend the same again [or more !] on tooling , vices, rotary table clamping kit .......

Just my two penny worth

Steve

Edited By The Novice Engineer on 26/05/2020 22:45:09

The Tool change motor is 24v DC,

The small control board for it will apply 12v to reverse the motor to locate the toolholder in position against a pawl/ratchet,

The 12v is maintained continuously to hold the tool in position. The motor housing has a large heat sink it does get warm but not hot.

Trust this helps

Steve

Hi

Found this link on another Forum and felt it should be shared to anyone interested,

3D Face Mask Instructions

The link takes you to a description page and print instructions with a further link to the STL file.

The build area required is 185mm x 215mm

The Transparent sheet can be any suitable A4 or Letter size clear film.

I shall be printing some off for ourselves and friends. My mother wants one when answering the door to the delivery drivers.

Stay Safe

Steve

Edited By The Novice Engineer on 03/04/2020 07:37:53

Just watched the film   Contagion .....Hmmmmm .....

You Tube Trailer https://youtu.be/xqLLPG8jMS4

Sobering similarities

Edited By The Novice Engineer on 30/03/2020 00:09:45

Raul

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

Steve

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.

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 !

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

and

LBSC

Edited By The Novice Engineer on 19/03/2020 19:34:37

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

HI Myford did a special conversion of the ML7 that used raising blocks , catch up with the details here

http://www.lathes.co.uk/myfordcapstan/ Here

did consider doing this once, .... wokred out quicker and cheaper to buy new discs!

Steve

Edited By The Novice Engineer on 24/04/2019 19:46:02

Andy

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 !

Steve

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

Steve

Edited By The Novice Engineer on 07/04/2019 22:07:39