Asperger's & Autism Forum

That makes sense

The problem is that normally I would just use the right sized but for the target size. I've been watching dozens of people building kit guitars and drilling pilot holes, so I went with their recommendation. I wish I hadn't, as you say the bit wandered so I had to line one side up. So they are skewed to the left. It doesn't leap out at you. But I know it's there! Maybe about 3ish mm out :-(

maycontainthunder

One of the drills I use as a pilot for screws is about 150mm long with a very short helix. These follow whatever they want inside the wood and I have had them suddenly appear out the side of the bit of wood I'm trying to pilot!

MildredHubble

That must be darned irrigating! I would have probably been better off with a drill press. But I dont think I could justify the expense. I dont do a lot of woodwork really. That's why I have really tried to be very careful with this project. I guess I shouldn'tbe such a perfectionist sometimes.

maycontainthunder

If you do decide to get a drill press don't buy a Chinese one! There are multiple old British ones kicking around which will probably still be working well in 2050! Many have a lot of non-standard drill holes in the tables caused by previous users not making use of the depth stop. This is known as the 'Ring of Shame'.

MildredHubble

I do like to use good old fashioned sturdy tools. I dont know why some people, actually, quite a lot of people perceive modern as better. I find with a lot of things that decades old is more robust or reliable, probably because there were no short cuts at the time in the manufacturing process. A bit like certain "budget" guitars from the 80s.

maycontainthunder

With lathes when you look at value for money you can buy an monstrous old British lathe that's built like a nuclear outhouse for the same money as a far eastern machine. The problem comes when you want to awaken the monster... they're all 415v 3-phase (industrial supply). Holbrook were one of the nuclear outhouse lathe makers. Massive cast iron base with a tiny lathe sat on top.

MildredHubble

Ah yeas three phase! I believe you can get some device that will produce 3 phase power from an outlet, but I can't remember what it was called. I suspect it's not as simple as it seems. There must be a compromise somewhere. I have also seen plans to make lathes, or rather the chassis for one out of concrete. It's some sort of open source group that want to democratise machines for the masses.

maycontainthunder

Regarding 3-phase you have four options starting with the worst.
Static converter (uses capacitors to generate 3 phase). Not good for the machine and many don't run properly on them.
Inverter; electronically generates 3 phase. Causes the motor to get hot and not all will work with the original controls.
Rotary converter. Best option and the closest to the real thing.
Actual 3-phase... expensive!

MildredHubble

That was it! Rotary Converter! I was wracking my mind trying to remember that!

maycontainthunder

Down Dad's store we have a 7.5Kw rotary converter for demonstrating machines working. Home is better because 3 phase was put on before the electric companies started trying to charge £14k.

maycontainthunder

BTW. I wonder how rigid a concrete lathe bed would be? I can't see that being very accurate.

MildredHubble

I can't remember where I read about it, but I think that the compromise was that the chassis, or bed had to be quite chunky compared to the metal versions. I think I may have read about it in a magazine. If I can remember I will post it where I found it

MildredHubble

Ok think I've found it...

http://opensourcemachinetools.org/wordpress/

maycontainthunder

Fascinating thing. One thing about conventional lathes is that there is adjustment on the headstock and tailstock to get the alignment correct... those concrete lathes do not seem to have this feature. This means that unless you have a 100% accurate casting it will turn tapered or keep breaking tools.

MildredHubble

I see

I had half an idea in my mind when I first read about it, to make one. A lot of the parts on my car could be replaced with DIY parts if I had a lathe that could be used for metal. It was a "maybe one day" aspiration. Also brake rotors can be fixed by turning them or skimming them on a lathe. Apparently this was quite common up to about 20 years ago.