1:22,5 Gmeinder 10-12PS/German Feldbahn

[W.P. Rayner]

Stunning work as always Frithjof... most impressive. Are you bead blasting the brass pieces after machining to get the slight matt texture?

Paul

[fspg2]

@all

I am glad that you like my work!


@ Gerald

... does "re-designed" that mean, it would fit my Struppe Akkulok now too ... ?

Dont worry, the drive for your Struppe-Akkulok just has a different level in the transmission blocks...




I can reach different axial distances by the modular design . The average transmission block are also fitted front or rear.

... and a slightly different wheelbase. But everything else is equal.
And how are you going to mount the gearwheels to the axle(s)? Fix them with superglue ... or are they going to be adjustable (with a screw), so you could swap them in case of damage ...?

In this design I will use Threadlock Adhesive. A small drop of it is applied to the axle. A few minutes later, it has been pretty neat. After 24 hours, I can only remove the gear from the axis again with a lot of heat (flame). I also did it here in the same way:






Right now, I think about the replacement of the drive belt. A colleague said that the belt should be adjusted over time. A slotted hole for the attachment could help.


Plan B involves the use of three gears (brass, steel, brass or Hostaform C) instead of the belt.





I ordered a couple of gears... so we´ll see! I will keep you up to date!


@nalmeida

Who belongs to the professional group of students, teachers and faculty can purchase the program "Inventor" including a 3D space mouse very cheap. In Germany for example here.


@ Paul

You guessed right, I sandblasted the parts usually before I show them in the forum. So it looks much better for the spectator.

Frithjof

[finescalerr]

A man has to know his limitations. All I can do is admire what I see. -- Russ

[artizen]

I watch your stuff on Buntbahn and really wish I could write and speak German so I could contribute! So glad you are posting here so I can make comments.

This is exceptional work - waaaay waaaay better than I will ever achieve!!!!

BTW whatever happened to the thread on Buntbahn on the narrow gauge railway you were building (it reached about 46 pages if I recall)? Some cool work with CNC and laser in that. That was the thread that convinced me to buy the Preiser bricklayer in memory of my father.

[fspg2]

Hello,

After a long time there is a small step forward.

Via prototyping the master of the axle box has been created last year.


Gmeinder_Gussteile_1 (fspg2)


The steps at the upper slope were smoothed with sandpaper (1000 grit) and sandblasted final.



Last week a silicone mold was created from the master. In contrast to a rubber mold the constraction process is less. In silicon only about 0.2% shrinkage.
The rubber can be quite shrink at 3%. Depending on whether you want to use a form of rubber or silicone, the master model is created correspondingly larger.


Gmeinder_Gussteile_5 (fspg2)


For each casting of nickel silver a red wax sprue was injected by the pourer.


In the internet I found a few more details about the lost wax technique.


Gmeinder_Gussteile_6 (fspg2)



Because it was much to annoying to cut all the cast-on section with the coping saw, I removed the sprue with a 2mm cutter...

Gmeinder_Gussteile_7 (fspg2)



... and with a sand paper (taped to a square wood) I smoothed it.


Gmeinder_Gussteile_11 (fspg2)



Gmeinder_Gussteile_8 (fspg2)



Gmeinder_Gussteile_9 (fspg2)



Gmeinder_Gussteile_10 [/ b] (fspg2)

[finescalerr]

Most satisfactory. -- Russ

[lab-dad]

Great information and facinating progress.
Thank you for sharing and taking the time to show and tell.

Are you going to sell the axle box castings??
Marty

[fspg2]

Hi Marty,

I´m building a small-scale serie of 10 locos only.

The drawings for the transmission blocks were created some time ago.


Gmeinder_10_12PS_Antrieb_05 (fspg2)



Gmeinder_10_12PS_Antrieb_006 (fspg2)



The four shells were merged into a milling file. Several auxiliary layers has been added to mill out the individual contours accurately.


Gmeinder_10-12_Antrieb_014 (fspg2)



The DXF file shows different colors for each layer.

Gmeinder_10-12_Antrieb_015 (fspg2)



So I can distinguish the different drills and routers in the milling program exactly.


Gmeinder_10-12_Antrieb_019 (fspg2)



The milling machine has finished the parts after one hour. The tools were changed six times.


Gmeinder_10-12_Antrieb_016 (fspg2)



Gmeinder_10-12_Antrieb_017 (fspg2)



After sandblasting the parts you can´t see any milling tracks.


Gmeinder_10-12_Antrieb_018 (fspg2)


Frithjof

[artizen]

This is art!

[Ray Dunakin]

Wow! Incredible!

[finescalerr]

The man amazes me. I am truly honored to have his work on my forum! -- Russ

[mad gerald]

Frithjof,

I'm still wondering what kinda wheels you're going to use ... or do meanwhile have the opportunity to manufacture them yourself too ... ?

Cheers

[michael mott]

Frithjof, Thank you for the time you are taking to post the drawings and photographs of the processes and the finished parts, your workmanship and design methodology are inspiring.

Michael

[fspg2]

Thank you for your interest and approval.

Round about 15 months passed I have built something for the little Gmeinder 10-12ps - hard to believe ☺


Gmeinder_10-12_Schutzgitter_01 (fspg2)



For the protection grid I have milled the two holding bows made of 3mm brass.
A 0.7 mm pocket dilute the material to 2.3 mm. A 1.0 mm cutter for the outer contour was used thereafter. Right and left two small retaining webs keep the material, so that the strap could not be damaged by the milling cutter. The remaining material is 0.5 mm thick now.


Gmeinder_10-12_Schutzgitter_03 (fspg2)



For assembly the two holding bows to the vertical 0.4 mm x 1.8 mm vertical metal strips, I have milled a small mounting jig of Pertinax.


Gmeinder_10-12_Schutzgitter_02 (fspg2)



After soldering this assembly jig helps drilling the holes for the hex bolts from the backside. Corresponding holes in the jig already exists.


....a new thought came overnight.
To separate the supernatant strips the same assembly aid could still be used. So a new one you can see.


Gmeinder_10-12_Schutzgitter_04 (fspg2)



With Cad a separate layer was created for each milling pass and labeled with the depth of cut. The colors in the DXF file to make it clear once again.


Gmeinder_10-12_Schutzgitter_05 (fspg2)



Gmeinder_10-12_Schutzgitter_06 (fspg2)



For comparison both jigs side by side.

Gmeinder_10-12_Schutzgitter_07 (fspg2)




Helmut then asked me why not build the grid of one piece?

So I tried it and milled the grid out of a 35mm x 3mm Ms58 profile.

As before, I first did a matching bag milled into the MDF material. I put the brass profile into it and fixed it with small screws additionally.
Then the profile got drilled four 2.0 mm holes. They range 5mm deep into the MDF board.
Corresponding brass tubes were put into it. They are used for the exact positioning of the front and back.


Gmeinder_10-12_Schutzgitter_08 (fspg2)

(milled from backside)


45 minutes later I was able to disconnect the grid of the retention standoffs. The outer bending edges were rounded with a small metal file and the protective grid were sandblasted. Four hexagonal screws with 1mm width across flats serve the subsequent assembly of the front panel.


Gmeinder_10-12_Schutzgitter_09 (fspg2)



The protection grid has an ,,inaccuracy":
With a 1mm ball cutter I wanted rounding the inner corners too. Since the existing milling cutter has a conical shaft , I wouldn´t  get into the corners anyway, so I did it without rounding. I hope that the reader will forgive me

[finescalerr]

I forgive you. Disgustingly good work. --  Russ