Hullo from Switzerland + some "probably daft" Q's

[AES]

Gentlemen, (& Ladies?)

Hullo. I’ve been skulking around reading all sorts of posts and topics on this site for some time now, and very informative and interesting I’ve found it too. But now that I have some undoubtedly daft questions I decided to register so I can ask for the benefits of your collective wisdom.

Introductions first – as you will have guessed from my complete lack of accent (!), I am originally a Brit but haven’t lived in UK for over 30 years now. For the last 20 years I’ve lived in Switzerland, near Basel (up in the N part, close to the French and German boders).

I’m an aircraft engineer by trade (maintenance management of large airliner type aeroplanes is my speciality) and although I’m over official retiring age I still run my own company and work “part time”. I like it that much!

I’m also in progress of setting up what I hope will eventually become a “proper” workshop in my basement. Although I have some wood “hankerings” and have messed about at it for years on a DIY basis, I’ll probably disappoint many of you by saying that apart from some toy making, plus perhaps a clock case or 2, I’m slowly finding more and more interest in “metal bashing” (“Model Engineering” if you want to be formal).

I do appreciate that this is a specialist woodworking forum but would appreciate some advice and guidance from those of you who like me do “maul metal” from time to time please.

Here we go (at last):

During a shopping trip with SWMBO yesterday I lighted on a special offer from one of the "pile it high, sell it cheap-er" chain Supermarket emporia we have over here.

It’s a radial arm saw (no known maker name, no doubt "lashed up in Outer Mongolia" or somewhere) which has the following spec:

Single Phase 230 Volts "hard metal" tipped blade, approx 8.25 inch dia, "tpi" approx 1 per inch (if I've done the arithmetic correctly), SINGLE speed, max no load rpm 4,800. It will "swing" between 45/45 degrees in both the Y and Z axes, and when set at 90 degrees will handle "material" (it doesn't say what material!) of just over 12 inches wide by 2.8 inches deep (oh, and no machine vice/workpiece clamp is included, though a floor stand is).

All of this for less than about £150, which for a machine which looks reasonably well made and robust enough for "hobby use" is a bargain in my view. So I bought it.

I haven't even had time to unpack it yet, and shan't have for a few days yet, so apart from a quick look inside the box at the shop, I "know" only what I've been able to transcribe from the Instructions Booklet (all in German and metric of course), as set out above (e.g. I presume the above "hard metal" blade means a carbide tipped blade – that’s what it usually means over here).

As above I do "fiddle" with wood at times (mainly softwoods and ply and MDF, etc), and I think this machine will do what I want it to as far as "carpentry" is concerned.

But for reasons of both budget and shop floor space, my question to all you learned Ladies and Gents is "Can I adapt this (hopefully) “magnificent device” to assist in cutting up Mild Steel, brass, ali, etc stock to support my model engineering efforts?"

I guess I will need a blade with a MUCH finer tpi count for metal, and I'll investigate that after I've got the thing unpacked and set up in about 10 days time. But it seems to me (speaking from a position of almost complete ignorance) that the above 4,800 rpm is going to be “mucho problemo” for cutting lumps of metal.

Do you all agree with that, and if so, has anyone any suggestions as to how to slow it down for metal sawing, and by how much please? (I should perhaps add here that from just a brief glimpse at the thing I see nil chance of rigging up any sort of countershaft and belt/s in traditional Model Engineering fashion, so I guess that I’m looking at something electronic if lower rpm is needed - something of which I have limited knowledge and experience please note.

For a possible "machine vice"/workpiece holder, I have 2 machine vices that I use on my pillar drill press, 1 "cheap and nasty", 1 quite nice. I was simply thinking of adapting the cheap and nasty to be a permanent fixture on the saw.

Any comments anyone please? And "Have I missed any points in the above Q’s?"; and "Am I barking completely up the wrong tree?"

Thanks in advance for your comments & suggestions

Krgds
AES

 

[Digit]

Welcome to the forum. First thing about this forum is that we have one rule. there is no such thing as a daft question, you might get some daft answers from us though!
Without a maker's name it's difficult to say, you will probably find out for your self as you progress.
Usually the supplied blades are rubbish, but if its arm slides smoothly, or can be made to and isn't sloppy it should do what it's paid to do.
Aircraft engineers are usually more than competant and in my experience most machines can be improved and be made to work properly.
Let us know how you get on.

Roy.

 

[yetloh]

Welcome to the forum. Roy may be right about getting it to work with a better blade but if it really was that cheap I fear you may have difficuty in mainatining any real level of accuracy in its operation. I must admit I am a wood person by preference - metal is such dirty scratchy stuff but at least it is more predictable than wood. Can't answer your main question I'm afraid but no doubt someone who can will be along soon.

Jim

 

[CHJ]

Welcome to the forum AES, if you can upload a picture of the saw when you get it unpacked then it's possible that if it's one of the 'generic' patterns others may well have some knowledge of its capability.

If it was marketed as a wood working saw I very much doubt that it would be safe to use for metal cutting, for starters what is the guarding made from, plastic or metal?

 

[Chris Knight]

I owned and used a good quality radial arm saw (RAS) for several years and was a generally enthusiastic owner. Based on my experience, I would say your plan is completely untenable.

First, a RAS tends to lose adjustment very easily meaning that you will constantly be needing to adjust it for inaccuracies in the cutting - the more so with a cheap Chinese knock-off.

Second, they need considerable care in their operation to ensure safety and again, a cheap machine is likely to have taken short cuts on the quality of stuff that contributes to safe operation (riving knife, the anti kick back fingers and guarding etc.)

Whilst it is possible to work brass and aluminium with carbide tipped woodworking tooling, it is not ideal and indeed, speed is one consideration as is tooth configuration. A RAS needs a blade with a negative tooth rake and this should be borne in mind when changing blades. The declining popularity of he machines means that suitable blades are harder to find.

Steel is a big NO-NO in my mind. It will definitely break the blade, machine or you.

For metal cutting a cheap powered metal cutting bandsaw such as those sold by Machine Mart works fine - it is not great on accuracy but is at least safe and creates less mess than an abrasive chop saw. You could of course consider an abrasive blade on your machine - after checking rpm requirements etc.

Lastly, I have to say I wouldn't consider the machine you have bought even for woodwork. I'm afraid it will likely prove a big disappointment.

 

[MickCheese]

This may be the stupid answer alluded to earlier, it is just to clarify.

Are we sure we are talking about a RAS? Could we be talking Sliding Mitre Saw? Not many of the DIY outlets over here sell RAS's and certainly not at that price but lots do sell Sliding Mitre Saws at that price.

Mick

 

[doorframe]

Are we sure we are talking about a RAS? Could we be talking Sliding Mitre Saw?

Mick

That's just what I was thinking as I read down the thread. The only assistance I can be is in relation to slowing the speed. I assume it's a brushed motor, so a suitably rated rheostat would give almost infinate adjustment, or a suitably rated DIODE, in this case a very 'BIG!!' one in the live wire so you are only running on half wave. This will definately slow the motor but will also mean less power. In the past I've paralleled 4 smaller diodes if I didn't have one rated high enough.

BUT... as has been statad before, I can only see an accident as the result of trying to cut metal with this machine. Seriously...get a dedicated chopsaw or bandsaw, and stay safe.

Roy

 

[AES]

Thank you all for your replies so far - I'll take the negatives on board too.

First off, I'm just about to leave home to photograph a damaged aeroengine when it arrives in the Zurich workshop for repair this afternoon. So though I don't have time to open the box, I have attached a couple of pix of the gaudy picture on the box. (You'll also maybe note that this device has a 3 year guarantee as per the box text - no doubt not worth the cardboard it's printed on!)

To answer some of queries:

@ Digit - I will not take your statement about daft questions as a challenge. But seriously, thanks for the encouragement.

@yetloh - your statement about lack of accuracy worries me a bit. I think I'm enough of an engineer to (eventually) be able to carry out any required "sensible" mods and adjustments. And as to metal, accuracy is not really required - the idea is "only" to cut off suitable-length bits of metal before turning or milling ops. But you'll also notice it has a laser device fitted - I have as yet nil idea what it does though. I guess everyone will appreciate that as yet I have precisely nil experience of using a tool like this, but isn't it reasonable to expect at least plus/minus, say 1 32nd (inch) when cutting timber & board?

@CHJ - as above, I hope my box pix give some idea.

@ Chris Knight - noted, thanks. Do you mean "untenable" for metal, or for every task?

@ Mick Cheese - during previous lurks I came across "RAS" several times and had no idea what it meant (being somewhat over-complicated I guess, I was thinking along the lines of "Rebatted Aris Special" or something!
And re "Radial Arm Saw" I used that term because in my ignorance I thought that's what it's really called. As you'll see from the box pix, in German it says "Zug-Kapp & Gehrungssaege". My German is not too bad but I admit I had to look the specific usage of words up after I read your Q and now come up with: "Zugsaege" = trim saw; "Kappsaege" = chop saw; and "Gehrungssaege" = mitre saw. So I guess my terminology in the original post was off. Sorry all.

@ Doorframe - I certainly don't want to do something dangerous (I'm a devout coward by profession)! Is it "only" the high rpm that worries you re metal cutting? I can confirm the motor IS brushed type (there's a spare set of brushes packed with the Instructions Booklet). So perhaps some sort of high-power "electronic light dimmer" could be used to slow it down?

Re sawdust, etc, I shall probably store the saw "upstairs" in the garage and simply move the car out of the carport and saw outside when using it - you gents should NOT think of my "Workshop" as ever becoming anything like the professional/production working units that I've seen on some of your posts.

Re how the unit was marketed, as said, it's says it's a "saw" - no indications of what you can cut with it.

BTW, it didn't come from a DIY emporium but a "food plus" cheapo Supermarket called Aldi who have various special offers of all sorts from time. They're a German company but now have stores in Switzerland, France, and Italy too - I THINK they may now be opening up in UK too?

And a last BTW - they also had a digital vernier caliper on offer (6 inch range, calibrated both metric & Imperial). At less than 10 quid each I bought 2. I've checked out one of them against various metal items and it's within one thou (inches) of measuremenents made by my Moore & Wright 1 inch micrometer.

So IF the above saw is anything like the caliper then I reckon I've done OK (even if I spend time adjusting and modifyoing, and some more cash on buying a decent blade or 2.

Or am I still "widdling in the wind"?

Again thanks for all the advice.

Krgds
AES

Wanna quick laugh? "Vernier caliper" in German is "Schiebelehrer". If you translate that into English literally you get "sliding teacher". How about that?

 

[woodshavings]

Welcome to the forum!!
You may find a suitable blade in the Rage Evolution series:
http://www.screwfix.com/cats/A350419/Bl ... Saw-Blades
The saw that you have purchased is a sliding mitre saw, and although a blade suitable for cutting steel may be fitted, the bearings on the saw (both sliding and arbour) may not be robust enough for the load imposed by metal cutting.
HTH
John

 

[sometimewoodworker]

Thank you all for your replies so far - I'll take the negatives on board too.

Re sawdust, etc, I shall probably store the saw "upstairs" in the garage and simply move the car out of the carport and saw outside when using it - you gents should NOT think of my "Workshop" as ever becoming anything like the professional/production working units that I've seen on some of your posts.

Re how the unit was marketed, as said, it's says it's a "saw" - no indications of what you can cut with it.

BTW, it didn't come from a DIY emporium but a "food plus" cheapo Supermarket called Aldi who have various special offers of all sorts from time. They're a German company but now have stores in Switzerland, France, and Italy too - I THINK they may now be opening up in UK too?

And a last BTW - they also had a digital vernier caliper on offer (6 inch range, calibrated both metric & Imperial). At less than 10 quid each I bought 2. I've checked out one of them against various metal items and it's within one thou (inches) of measuremenents made by my Moore & Wright 1 inch micrometer.

So IF the above saw is anything like the caliper then I reckon I've done OK (even if I spend time adjusting and modifyoing, and some more cash on buying a decent blade or 2.

Or am I still "widdling in the wind"?

Again thanks for all the advice.

Krgds
AES

First of as woodshavings has said what you have bought is a SMCS (sliding compound mitre saw) not a radial arm saw. That is good news.

SMCS's are usually quite capable of cutting softer metals using the correct blade (Most woodworkers don't but they can.) You must always clamp the workpiece, you should on both sides if it is metal, many don't but you should. The reason is that SMCS's are designed for the cut off piece to be either side of the saw so it does not fall away from the blade it can quite easily get caught and thrown. For a small piece of wood this is not a big problem but metal is not so good. Conversely metal cut off saws clamp the work piece on the left of the blade and the cut off falls away on the right

The kind of blade will be a bit like this one

It is for laminates but the factors which are the same as you need are the tooth spacing and the negative rake on the teeth. The tip grind will be different for a metal cutting blade.

You do not want one like this

because of the positive rake on the teeth

The laser is to show you where the saw will cut. On your machine it is probably not very accurate but you may be able to improve that
For cutting steel they are not good at all

CNCzone forum[/url]":ubx3ni1m]you should not cut alumn.,brass, bronze with an abrasive cut off wheel. Likewise you should not cut steels of any kind with a carbide toothed blade.

He does not talk about the cold cut saws that run at slow (100RPM ish) speeds

The speed of the saw is way too high to ever cut steel without an abrasive wheel and it is not usually a good idea to fit an abrasive wheel to a SMCS even if you could.

for steel cutting something like a cheap $34 cut off saw from amazon will be much better http://www.metalcutoffsaw.org/abrasive-cut-off-saw/
information on Cut-off Wheels