Lazer Cut Parts

[ron]

Hi All
I've just ordered some lazer cut parts for Simplex and as my engineering was learned in the days when Pontius was a pupil pilot I don't really know what lazer cutting and water cutting entails other than they save elbow grease, can someone enlighten me please?
Ron

[SteveW]

Ron,

They are both use a CNC based systems that move a cutting head around the target material.

Laser cutting uses a high power IR laser as the heat source and a stream of gas typically oxygen or nitrogen in a manner similar to old fashioned oxy/acetyaline cutting. You end up with some very hard cut edges that if you need to tidy up you'll need to invest in a set of diamond files. Also the cut edge isn't quite square to the main surface.

The mechanics of water jet is similar except it is a cold abrasion process. A narrow jet of water at many thousands of atmospheres pressure picks up and blows and abrasive power (garnet) and basically wears its way through the material. Better edges, a bit more expensive but as there is no heat involved there is no change to the base material.

[steamjohn248]

Water jet is the dogs b=======. We had all the metal for a 2 - 6 -2 Tank cut, frames, (eight feet long), motion, brake gear, cab, tanks. running plates , you name it. Dead square edges and accurate to 0.2 mm. Its going to save years of work, wear and tear and tooling. If you want to find out more, look in yellow pages and talk to firms in your area that do it.

Steamjohn

[Steve M. W]

Malcolm HIgh of www.modelengineerslaser.co.uk
gives a very good talk on laser and water jet cutting.

Steve

[Chris Kelland]

Hi All,

Ron, Is your build Simplex or Super Simplex?

I have spoken to www.modelengineerslaser.co.uk Malcolm High and he is to see if he can produce additional parts for my Super Simplex.

It is as people say very accurate it will save me a lot of work and more importantly will be right first time - I hope!

Chris.

[Shawki Shlemon]

Hi
Out of frames for 25 engines two were lazer cut . Like everyone I tried the new technology .One was cut wrong and had to be redone and the other was done in wrong gauge material . In both cases the drawings were supplied . The other point is are the drawings correct? Do you want to make any changes?
Marking is the longest job,once is done and the two frames bolted or riveted together , drilling cutting and filing for a week or so will do the job and will save money and have it done wright.
After all it is a hobby and one will get great satisfaction from a job well done.This is my opinion ,and I respect other opinions .

[ron]

Hi All
Thanks for the explanation, I thought it was something like that but wasn't sure.
Chris, I've ordered some of the parts from Malcolm High and some from Blackgates, they seem a very reasonable price for the amount of tedious labour saved.
Shawki, I spent a good part of a five year apprenticeship hacking and filing, it's had the same effect as aversion therapy, it's about the only bit of model engineering I try to avoid.
Ron

[Laurie_B]

Like most of us,I suspect,I've spent many an hour hacking out a pair of main frames.And very tedious it is too.Having made the main frames for my loco,I then didn't really fancy cutting out the tender frames,so I had them,and a few other parts cut out by a firm specialising in water jet cutting,and I was very pleased with the results,and they weren't expensive either.
They have a website www.sciss.co.uk/ which hopefully will be of interest.
As SteveW points out-with water jet cutting there is no heat affected edge,although you do get a draft on the edges,But Sciss make allowances for that.

[greasemonkey]

Hi Ron
I have had parts both water cut and laser cut and it depends upon what parts you are gettign done as to which methods Iwould use. I wouldnt get the motion laser cut as someone else said above cleaning the cut edge is a pain. I had the rods for Dougal water jet cut and cleaned them up with emery cloth. Frames I would get laser cut. Depending upon how new/setup the laser cutter is will decide upon wether or not they will cut the holes for you. A lot of palces will not cut holes less than material thickness plus 10%, a good machine can cut less, Ive had it done. Similarly the same goes for slots. Braas work I have cut on a CNC router and get all rivet holes put in at the same time, that way they are nice and straight!! It is worth having a chat with however is doing it and seeing some of there previous work. I have seen and recieved good and bad, a lot of places turn the power and cutting speed up for us models engineers giving a poor finish, but a cheap price, pay a bit more and you get an edge that doesnt need finishing.

Andy

[ron]

Hi All
I got the expansion links for Simplex delivered from Malcolm High today, they are water cut, seems you can't lazer cut gauge plate, they look very good, a bit of draw filing to fit the die blocks and that's it. They were £32 the pair, when you consider the amount of tedious work to make these by hand, it looks like a bargain.
Ron

[John Lee]

ron said:

Hi All
Thanks for the explanation, I thought it was something like that but wasn't sure.
Chris, I've ordered some of the parts from Malcolm High and some from Blackgates, they seem a very reasonable price for the amount of tedious labour saved.
Shawki, I spent a good part of a five year apprenticeship hacking and filing, it's had the same effect as aversion therapy, it's about the only bit of model engineering I try to avoid.
Ron

I did the same apprentiship thing Ron, and I agree, there is nothing more boring, tedious or soul destroying than hacking and filing. Machine work or final fitting is fine, but I too avoid this whenever I can. Each to their own I suppose....

John

[Jo]

Oh dear, I actually enjoy the hacking and filing....... It is especially good after a stressful day at work.

Jo

[ron]

Jo
We did it 8 hours a day 5 days a week for 6 months, at the end of it we could do amazing things with chisel, hacksaw and file but boy was I glad to move into the machine shop where we turned and milled 8 hours a day etc etc ;D
One piece we had to make consisted of a piece of MS approx 6"X2"X1" we had to remove 1/8" off the 6X2 face with a cold chisel then file it completely flat before continuing to cut it up to make a small machine vice, at least the cutting and shaping was done with a mill after that.
Ron

[John Lee]

jo said:

Oh dear, I actually enjoy the hacking and filing....... It is especially good after a stressful day at work.

Jo

Ok Jo.....picture this....this is where Ron and I come together with our apprenticeships I think..

Take a rough bit of mild steel, and with careworn hacksaws and files make a block exactly (I mean exactly) 1X1X1 inch.... what have you created is interesting...hmmmm

Now take a piece of mild steel and make a 2X2X1 block, with a hole in the centre that your previous creation will exactly pass through with a perfect sliding fit. Your tools I would say again are a hacksaw, files and a bench vice.

If you can see light between these two pieces..start again

How I wanted to move to the world of machine tools, surface grinders and mills that would do a months hand work in minutes. I did of course, but that was Navy Artificer training..in the 70's

It's aversion therapy for sure for me, laser or precision water cut frames etc etc...gimme...fitting is a 4 letter word to me..... but if you enjoy it no problem...

John

[ron]

Hi John
We did that test piece as well, only difference was ours was 3/4" square, the highlight was when one apprentice manged to get the bit with the 3/4" hole stuck on his index finger and it had to be cut off. [the metal bit, not the finger, as was suggested by the rest of us ;D]
There must have been a secret school somewhere for sadistic instructors, ours looked as if he's served his time with Brunnel [the father that is ;D]
Ron

[Lurkio]

Hello all,

Some make frames from scratch, some buy ready cut.
Some build their boilers, some buy ready made.
Some even make their own screws, or cast their own wheels/cylinders, while others buy in.
You get my point.
Nowt wrong with either approach IMHO.
I've been through the chiseling/hacking/filing apprenticeship too, and personally don't mind doing it still - though I wouldn't do it for the sake of it. If I was working on a large job such as steamjohn248's then I'd definitely be looking at laser or water cutting.
Time, finances, equipment all come into the equation too. Some board members will already have built a number of projects using mainly hand skills - they've 'got the T-shirt' and have moved on. Some are just starting out and relish the challenge of doing as much of the work as they can.
As John L says: "Each to their own..."

Now where's that hammer, chisel and tin of plasters?

Lurkio.

[Jo]

Hi Ron/John,

As an electronics apprentice we only got to do 12 months hand filing and the hardest challenge they found us was the E blocks. They only gave us 2 weeks on the power tools. (And this was not cut short due to one of the other female apprentices successfully friction welding a machine reamer to the chuck and milling spindle on the only vertical mill they had!)

Of course if you are going to use lazers to cut the parts you need a computer file for the component you need. And if like me you seek to avoid the things once outside work, the last thing you want to do is sit around drawing on a computer when you could be bashing metal.

Jo

[John Lee]

jo said:

Hi Ron/John,

As an electronics apprentice we only got to do 12 months hand filing and the hardest challenge they found us was the E blocks. They only gave us 2 weeks on the power tools. (And this was not cut short due to one of the other female apprentices successfully friction welding a machine reamer to the chuck and milling spindle on the only vertical mill they had!)

Of course if you are going to use lazers to cut the parts you need a computer file for the component you need. And if like me you seek to avoid the things once outside work, the last thing you want to do is sit around drawing on a computer when you could be bashing metal.

Jo

Metal dodging and scared of dirty hands... yes I have a friend, still is now, who went to a Leccie school after the first year of apprenticeship. Sparks and Volts..thats not engineering..just kidding Jo.its interesting too.

Mygod..they had one vertical Mill?? Where was this then? I did my apprenticeship with the Navy all expense not spared at HMS Fisguard...despite its name on dry land. Closed down years ago and they all do it now with the Army REME. Rough engineering methinks.. ;D

[dscott]

We have a 4" x 1" x 3 feet lump of mild steel, at work, now what shall I make from it in the morning. I to have bashed several frames by hand and finished up with the delight of the mill.
See the 517 and Prairie bits photos. So lovely to hear your 44XX frames being described as lazer cut by some in the model club.
Must get the River Class lazer cut with its sandwich frames, ( do they do zimmer frames with vices ) ?
David Scott.

[Deleted]

What River is that then ? Highland or Southern ?

Regards

Jim