Turning Ropes

[thkoutsidthebox]

Hi all,
I imagine this will probably be a very short thread once someone knowledgeable looks at this.

So,
What type of lathe is required to turn ropes, would a 5 speed manual lathe be sufficient with practise, or is a cnc lathe required?

Thanks.

Example shown in the pic below.

[braidmeister]

You need to be able to synchronize or 'index' the turning with the tool movement. You can do this on a CNC lathe, a 3 axis CNC router with 4th axis indexer or a Legacy Mill.

If you want to do this REALLY cheaply, build the 'router lathe' that is featured in Bill Hylton's book 'Router Magic'...a must for every router user.

-Brady

[thkoutsidthebox]

Thanks Brady,

I'll buy that book in a few weeks. Found it on amazon....hope its worth it!

[erase42]

I make ropes in foam, anyone interested? probably not

[greybeard]

Erase - if that was edible, I reckon you'ld have a marketable product

John

[braidmeister]

Looks good in foam I'm pretty sure that they call that style of rope molding a 'barley twist'...they make a router bit specifically for doing them. I think you can get them off of the Legacy Mill site (and others).

BTW, Router Magic is an awesome book with plans on how to build all kinds of things from common materials. Things like your own Legacy style mill, and vertical router table etc. It's worth it! I'd take a quick screen shot of the indexer, but my dad swiped my copy last time he came to visit...

-B

[cueshark]

how long arethepcs. tou need to do? any certain turns per ft? craftsman makes a ruter crafter that will do a pc. something like 30-36 inches. but it will only do the 1 pitch it is set up to do. greg

[thkoutsidthebox]

Thanks folks. I dont have any specifics for the pitch or number of turns, but I want to allow for a 48" inch bed. Just figuring out what I require before I settle on a type of lathe to buy.

[Mcgyver]

Originally Posted by erase42 I make ropes in foam, anyone interested? probably not

yeah i'm interested - how'd you do it? I can see in the photo the profile of the waste stock - did you do this via hot wire? how do you set up a rigid hot wire (i know how the tension ones work)?

you can achieve what you want only be by either mechanically linking the x motion to the spindle or controlling their relative positions electronically. I'll assume its a wood lathe, so you have no motion along either axis. if its metal, its easy, is already indexed although you will have to play/change the gear ratios to get enough helix.

you'd have to build ways along which router would travel. cnc would be good, you'd have to have an encoder on the spindle though. with a second axis (depth) you could do all kinds if fluting. But just for rope, a mechanical method struck me. either way you have to devise a simple way for the router to move along (a pipes and skate bearing & plywood rig for example).

the mechanical idea is to connect the spindle to the router via a light steel cable. The cable wraps around a wheel on the outboard side of the spindle, changes direction 90 degrees via a pulley and then connects to the router carriage. The dia of the wheel would determine the feed rate. you could 'block and tackle' it to create lower feed rates and/or change the dia of the wheel. if you do so, cut the power at the breaker so you don't flip on the power by rote and send the rotor through the wall or worse

[Zumba]

This type of work screams rotary 4th axis.

I've used a legacy before for turning rope. It works just fine, but the machine is expensive, and literally takes 15-30 times as much labor as a CNC (1 minute for the CNC, 15-30 minutes manually). Programming with a CNC is ridiculously easy as well. In fact, the G-code program for turning rope is so short that you can use the trial version of Mach 3 to run it. Ha!!

[erase42]

i cut my first foam rope with the stepper jog window of Guilles MIllers foam wing cutter software and a mini lathe I made with and old printer guts.
an x value equal to one complete revolution and y value equal to the width of my rope thread. multiply both by the number of turns i wanted and away she goes. It was actually the first foam piece I ever cut. I thought that rope columns would be about the hardest thing there was to make so I wanted to prove to myself I could do it with simple NON 40k machines before i started my business using all homebuilt cnc machines.

[erase42]

oh and mcgyver, yes it was a shaped hot wire. its the same alloy as the nichrome wire the machines use, but its thick enough to be shaped to a profile. if you want a 2 start rope you make a wire with two "bumps" if you want 3 starts you need 3 "bumps" etc. Ive seen some columns made by people that dont understand that, they would make a 20 inch diameter column with one start that ends up looking like a stack of old tires painted white.