Dear Sir,

Please let me know the technical difference between Copper Drawing machine Rod Break Down Machine and Bull Block used for copper drawing.

What is the advantage to RBD over Bull Block machine.

Thanks & regards,

S J Yadav

Hello Again,

First of all, we believe your reference RBD is actually to the RBD Drawing Machines that are manufactured by Listrong Mechanical & Electrical Co., Ltd. in China. Please confirm because RBD drawing machines are not well known in North America.

Secondly, the conventional rod breakdown machine is a bathtub type or a lubricant spray type drawing machine. The capstans of these machines are partially submerged in drawing lubricant or pressure sprayed with drawing lubricant when the machine is running. The dies in both designs are pressure sprayed with drawing lubricant.

Finally, this is a very good question because the lines separating these two types of drawing machines have blurred a bit in recent decades.

The major difference between bull block rod breakdown drawing machines and conventional rod breakdown drawing machines is that bull block machines are zero slip by design and the capstans after each die are dry. This means that each capstan must have its own individual drive system and that the drawing dies, often rotating, are lubricated inside a small box filled with some powder lubricant or drawing liquid. See www.mariofrigerio.com/trafile_en.htm

Conventional bathtub type and lubricant spray type rod breakdown machines on the other hand are slip machines meaning that there is some difference between speed of the wire on the capstan (slower) and the peripheral speed of the capstan surface in contact with the wire (faster). See www.niehoff-usa.com/graphics/pdf/EDR13-15.pdf

There is some confusion here now because there are a few zero slip conventional drawing machines with individual drives to the wet or for that matter, dry capstans. See www.frigeco.com/zero_slip_en.htm

Because the conventional drawing machines use one or possibly two drive systems to the capstans, there are a lot less motors and drive systems and thus the capital cost of this machinery is somewhat less. The cost of constructing a drawing lubricant holding tank and managing that drawing lubricant is not taken into account in this exercise but it certainly adds to the capital cost. None-the-less, conventional rod breakdown machines are generally the standard used for copper rod breakdown in the world today.

This should be all the information you require.

Regards
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com

I believe that they were only referring to RBD as abbreviation for Rod Breakdown Machine as opposed to a specific brand.

Erik Macs
VP North American Machinery Sales
Fine International Corporation
148 Oak Street
Natick, MA 01760 USA
508-315-8200 fax: 615-658-1988
This email address is being protected from spambots. You need JavaScript enabled to view it.

Thanks Eric, You may very well be right. I guess I have just spent too much time in Asia in the last couple of years, especially where this chap lives. The absence of "the" in front of "RBD" made me think of the drawing machine series above instead of an acronym.

Cheers and Best Regards
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com

When I was at General Cable we had a double deck Syncro bull block. The rod entered the machine through a die, then a rotary scoring tool and then went around the bottom block. It left the bottom block, rod passed through a shave die, over an idle pulley and then around the top block. From the top block it went to the spooler. We used this to reduce a variety or rod sizes to a size that we either annealed or sent to a rolling mill.

We also had a 7 and 13 die Syncro rod breakdown machine. Typically the 7 die drew to 8 AWG for further drawing to smaller sizes. We also used it to make some sizes for enameling such as 7 to 13 AWG hard wire. It did not have an annealer. We modified the machine and spooler so that we could draw square wire for enameling or serving. The 13 die machine was used to draw to 18 AWG for redraw or for enamel sizes from about 15 to 22. This machine also had an annealer. The machines we had made pretty good wire for both breakdown or enameling.

It is not that one has an advantage over the other because you may not be using them for the same thing. The bull block would probably only have 2 or so dies so you are limited in what you can do .

Richard

Hi Richard,

If you examine the flash photographs on the web page at www.mariofrigerio.com/trafile_en.htm you will see machines containing 10 blocks.

Cheers and Best Regards
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com