Feldbahnmodule with ship

[EZnKY]

While they may "only be rivets," to the crazies on this forum, the quality of details like this is what makes the model.  (They don't call us rivet counters for nothing.)
I'm as impressed with your fabrication and assembly methods as the model.  My grandfather was a machinist, and he always said the quality of your final work was dictated by the care you put into "making the parts to make the parts."
I've grown to understand this phrase more and more as I get older - it didn't make much sense to a ten year old. 

I enjoy watching you do the same thing.  Like making a soldering jig to keep parts correctly positioned, etc. This is where I still have so much to learn.
Thanks for sharing it with all of us!

[artizen]

I am definitely modelling with crayons... and ten thumbs!

[Hauk]

I have browsed all the pages of your postings on different forums, and it seems you use blackening a lot on your brass parts. If I understand things correctly, you use a grit blaster before blackening the parts.

So my questions are:

-What type of blackening do you use, and how do you apply it?
-And what type of grit blaster do you use, and with what blasting medium?
I also wonder what type of CNC-machine you are using.

Hope I am not poking into any trade secrets...

Best regards, Hauk

[fspg2]

Hi,

@Eric
Thanks for your comment. I am very satisfied, if you count rivets ...and finally you gets a very accurate miniaturization of the prototype. The effort to build a soldering gig will probably takes a little bit longer, but the result is usually faster and better built very often

@Ian
Ten thumbs are much better than only five

@Hauk
First I blasted the parts with a small sand blasting gun Badger, like this.
The blasting material I bought here, it has a very smal grain size.
For larger parts like the crane cabin this blasting gun is to small but it works - only it takes a while.

I´m using a burnishing stain from a friendly professional company. Previously I had used a stain from the Tiffany area.
At the following picture you can see the way from brass, sandblasted, two minutes bathed in the burnishing stain and four minutes at last.



My CNC-machine is this one:


found at: http://cnc-step.de/


For more information you can see here!


Meanwhile I have soldered the chassis. I am always pleased how accurately works such a ("cheese"-) milling machine. I had used a lot of time to make a to small sawn part again in former times, so now a lot of the time goes into designing at the computer. It makes much fun if I can put the milled parts together simply without any rework at the end! : D

Münzel-Kran_029 (fspg2)

[Hauk]

Thanks a lot for the reply! Your crane is coming along beautifully.

I know what you mean when it comes to CNC-milling.  I had access to a large CNC hi-speed milling machine for a couple of years, and it was flat out addictive. Do you do all of your milling on the Hi-Z S720? I am seriously considering purchasing one.

And what type of milling motor do you use? I guess it is quite important to get a good one.

Best regards, Hauk

PS: That browning potion seems to work darn good. Any more clues on brand, contents, etc?

[fspg2]

At buntbahn forum you can get some more information about blackening of metal (it is the google translation from the original German web page).

I don´t know the brand from the fluid I use currently, but at RS-Modell you can get the patination fluid I used in former times. It´s part No. 2004. It is the same fluid that I saw in a tiffany shop. It works at brass, nickel silver, white metal and tin (solder).
By using this fluid take care that the workpiece is free of fat, e.g. sandblasting. Then immerse the metal part into the burnishing stain (while constantly rub with an old toothbrush) for about 10-15 seconds. Finally rinse well in soapy water.

I do all of my milling on the Hi-Z S720! There are better machines surely, but for milling part made of brass, plastic and wood the results are always fair enough for my hobby. The High-Z is not strong enough for steel and high speed milling! Some people are calling it "cheese"-milling machine...   but for my request it is acceptable mostly. For more than 2400 hours I used only the Kress milling motor E6990 (it is an older one). It is replaced from No. 1050 FME. The sound level ist very high so you need ear protectors!!
In addition I have placed a slot table and I use slot nuts to fix my parts on it.



Here a little movie from milling with the Kress.

Best regards
Frithjof

[fspg2]

Today a little update.
The roof of the crane shall be removable, also it should be stable, because it will carry the boom.


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First I drawn the roof bow frame. It can be lifted from the housing together with the yellow U-profiles.


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The curved roof beams were milled from 2mm brass.


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Each two of them I soldered against each other. So I got this double-T profile in the correct roof rounding. It's easier to me than to bent a purchased profile without it is warping.
The lateral U-profiles were also made of 2mm brass with corresponding recesses to position the curved roof beams exactly.


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As previously I have used a pertinax gage to align everything exactly.

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[Mr Potato Head]

Do you just feed the 3D info into the mill? is that how you made the curved beems?
I think the Space program needs you!
MPH

[finescalerr]

I am impressed by every step. Wow. -- Russ

[Ken Hamilton]

Holy Smokes.  This is......is........(I can't think of any words to describe it).

[Ray Dunakin]

Holy frijoles! Simply masterful work!

[JohnP]

What a treat! I like to see the CAD images and then the real parts.

From what I have read on the web the home CNC concept can become a self-absorbing hobby of its own, so it is nice to good results from a small machine.

John

[fspg2]

@ MPH, Russ, Ken, Ray, John
Thanks for the appreciative statements

The modeling and the drawing, both are two areas of my hobby. In the CAD I can determine exactly all sizes.

I still remember a few years ago when I came into contact with the CAD, there was very often the "how can I do it?" in my head. Today, I can check with the CAD already the idea even before production! It does not have to start with a huge project. Step by step you can continue.

A friend helps me very well, so I'm now able to realize my next step.

The roof was the next challenge for me.

First, the curvature of the roof was drawn from the side and extruded into the depth.


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It was followed by a new layer from the top, which received the contours of the openings and the rear roof rounding. The next step was a negative extrusion into the depths of everything - like a punch.


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It was followed by a winding-up of the rounded roof, in order to generate a DXF file. For each milling the corresponding lines have been inked.


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The  visible black lines mark the lower contour of the once vaulted roof. They should not be milled.


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Sheetcam is a very helpful software to generate the neccessary  tap-file format .


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Each color is assigned to a cutter. There are depth of cut, number of runs with different depths, speed, feed, ... predetermined.

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I milled with a maximum of the half of the cutter diameter in the deep.

After cutting out the 2mm brass plate the next step was the bending  of the roof.


Experience I had already done with a 1mm sheet earlier. Shown here.

So now, the sheet was annealed with a gas burner and then bent in several passes, each time the radius of the bending machine was set narrower.

Some care is important so that the sheet is also parallel, it must be given absolutely perpendicular to the machine!
If you bent one too much ... no problem: Simply roll the plate with a large radius setting of the machine from the back flat again. Then go to work with the right attitude once more! The metal is soft enough from annealing.
The manufacturer of the bending machine stated as the greatest thickness at 1mm brass. I used on both sides "victim plates" and so I got to a total thickness of 3mm - the machine has survived without any effort!

But see for yourself - all parts are put together only loosely:

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[1-32]

hello munzel
from a person who does not have a clue as to how you do it-
just lovelly work
kind regards kim

[Ray Dunakin]

Thanks for the step-by-step, very interesting!

The latest addition to the model is, as usual, superb.