Cast Iron V Steel

I turn some of the soft brown stuff from time to time so I invariably see adverts and pictures etc of associated machinery. Whilst the majority of wood turning lathes still have cast iron beds, and often legs, there are a couple of manufacturers that use welded steel. I’ve read before about how good cast iron is at vibration damping so I guess maybe the choice of welded steel is down to cost? The only problem with that theory is I’m not sure they’re any cheaper. What do folks think?

Cast Iron.

Welded Steel.

I have an old noname wood lathe made from folded sheet metal with internal braces. I use it very rarely but dont seem to get much vibration. Go for CI if you can though as it is supposedly better at damping than MS. As for cost it is entirely down to the size of your pockets.

regards

I think the well-known sound dampening properties of cast iron are really only applicable to high frequencies where acoustic waves travel through the material. Legs on a machine is more about low frequencies, youngs modulus and rigidity, and there will be little difference between steel and cast iron in this case.

The amount of metal is the most important thing here and the more the better, if you ignore the cost of course.

Gerry

Like any lathe if turning off centre the heavier the better. I know people that add an extra shelf below the bed which is hollow and they put sand into it to prevent this. The faster you can turn (To a point) the better the finish especially if turning something with plenty of air like this.

Remember that wood turners tend to hand hold the cutting chisels and when turning fast gives less chance of the tool getting pushed into gaps.

The more mass the better from a vibration and dampening point. I don’t think the material matters for a wood lathe. During working on a wood lathe there is no metal to metal movement as you are using hand held tools, except obviously for drills etc. It is easier to produce a heavy cast iron base than a welded steel fabrication. The problem these days is finding a foundry and the cost, fabricators are easier to find although getting ones proficient in welding thick sections will increase the labour content. So in order to keep costs down lighter steel fabrications are probably the order of the day, leaving the buyer to add mass as required, tuning the machine to their liking.