Monday, November 16, 2015

A Ming-Inspired Cabinet (9)

While I'm letting most of the bubinga for this project sit for the next few days, and with more bubinga about to get shipped out to me I am holding off on any more rough stock breakdown for the time being.

I thought it would be worth exploring what sort of job the Zimmermann FZ-5V would do with its helical shell mill. A few people have been letting me know over the past couple of weeks that they are interested to see how I make use of the mill, so here goes 'part 1' in that regard.

I had planed the leg stock to a solid 1/4" over dimension, and could have taken them down further by planing them in the SCM S630 planer or the Makita shoebox planer. However, I've been finding that the planers are tending towards a little bit of tear out with some of the figured bubinga, even with fresh knives fitted, so taking the pieces right down to dimension with a planer seems decidedly unwise. I'll probably have to get the panels thickness sanded to remove the remaining 3/16" of material standing in the way of final dimension.

I thought therefore, that it would be worth a look-see with the milling machine, as I had been considering whether or not the Zimmermann would be a good way to process the leg shapes into their ultimate cross-section, which is rhomboidal. Getting these legs shapes done precisely is the most important part of cut out for the entire support stand, so I will do my utmost to get the results I want

This was mostly a test, and if it went awry there is plenty of material left on the legs to correct afterwards, not to mention that there is a spare leg to mill. The set up is pretty basic, with the bubinga leg placed across the vise and sandwiched between a couple of precision parallels to spread the clamping force:


The shell mill is helical with a positive rake:


Here's how this process looked, with a 0.3mm deep pass:



I realize that might not be the most exciting youtube clip ever, but I enjoyed watching the machine do the work. The machine takes shavings, and it can take them in thousandth of an inch increments. I did receive the cutter used along with the machine, and it seems sharp, however I am unsure as to how worn the edges on the cutter actually are, or what sort of materials it might have been used upon previously. As it is right now, it seems to cut well.

What I obtained from the shell mill was not what you would call a polished surface, like you can get off a hand plane or super surfacer, but it is very clean, with no significant traces left of the cutter and absolutely no tear out:


The lack of telltales from the cutter means the head is trammed in correctly, and the surface quality is better than what I would obtain out of my planer with 4-knife Tersa. The overarching idea here is to get the surfaces close to the mark with the mill, and finish them off with a hand plane and/or super surfacer. I'm glad to know now that is a fully-realizable plan.

The leg came out very square and within 0.1mm of dimension without me having to have been particularly fussy about getting to those results:


Whee!:


I enjoyed making some shavings in a whole new way today. That face mill worked very well I thought and should be the cat's meow for processing these leg sections into rhomboidal shapes, which will be the next step with these pieces once I have completed S4S with all the pieces.

That's it for installment 9 of what promises to be a lengthy build thread. Hope to see you again next time. On to post 10.

5 comments:

  1. Ever since a friend let me play with a "baby" Bridgeport back in the '90's, I have wanted this machine to exist - - and you have hunted, acquired, and gotten one running. Way to go!

    ReplyDelete
    Replies
    1. Jim,

      thank you! It was quite a journey - an expensive journey - getting that Zimmermann from Germany to my shop, and I'm feeling modestly chuffed at having resolved enough issues with the machine that it is finally doing something beyond drilling holes. While I do need to replace the 'start' switch on the machine, and possibly another switch, otherwise it seems to be working well so far.

      There's a vast potential I'm looking to tap into with this miller - we'll see where the trail leads.

      ~C

      Delete
  2. Amazing work, keep it up, love reading your blog.

    ReplyDelete
  3. Cooooool!

    Do you have plans to retrofit some sort of dust collection to the machine?

    ReplyDelete
    Replies
    1. Brian,

      good to hear from you. Yes, I am contemplating some dust collection for the mill. I had previously hooked up a 4" hose nearby to extract from the table saw's overhead guard, but that guard is a PITA so I will likely leave it off the saw, which frees up that 4" collector, just 5' from the milling machine. I'd just need to swivel the 4" collector lateral around 180˚ and get some sort of plastic funnel with rare earth magnets to mount flexibly on the milling machine. For the time being I don't mind spraying chips and shavings as it helps soak up any oil the machine cares to drip onto the floor.

      ~C

      Delete

All comments are moderated:

Anonymous comments will be deleted

Spam will be deleted

Comments containing links unrelated to blog content will be deleted