Frames to carve

[trainforfun]

Hi ,
I was thinking of sending a KATO SD40-2 frame to Aztec to be milled , but he does not mill this particular one , they did many for me in the past with great service but I guess I will have to do this one this time .
The loco is already all dismantle and I would like to use my Dremel tool to carve the half frame , I have many DZ125 and intend to use it in there .
Anybody have a part number of the best carving bit available from them ? I tried before with some bits I bought at Home Depot and was only able to scratch the surface ...
Thanks !

[WBRRVP]

For an older SD40 if have a few options for decoder placement. First is the hardest to mill and that would be the fuel tank, this is were Aztec used to mill the frames for so if you have other SD40/45s with milled frames from them you can just copy them. This requires more milling and requires a large wire path along side the motor to get the wires from the fuel tank to the light boards. It also requires more of the frame (=weight) to be removed.

Another option and what I prefer to do these days is to mount the decoder in place of the light board. Installing a DZ here much easier as you only need to remove and 3/4 inch from each frame half and carve a smaller wire patch to the motor and the front light board. I typically remove the rear light all together but you can wire a resistor and LED directly to the decoder for the rear light if you want.

For milling the frame I use the High Speed Cutters http://www.dremel.com/en-us/Accessories/Pages/SubCategories.aspx?catid=2070&catname=High+Speed+Cutters. To make quick work of the back part of the frame I use a 115 cutter, for the wire runs I use the 199 or 198 as I can get them into places better than the 115 and the wire run don't need to be that big.

PS If you don't already have the DZs on hand you might want to look at the TCS CN-GP decoder as it's more of a drop in as it replaces the lightboards and only needs a little room for wires to and from the light boards and motor.

Jerry
www.washingtonbeltrr.com

[trainforfun]

Thanks for the info , yes I already have many DZ decoders , my older frames were also done by Aztec the way you describe , and not where the fuel thank is . I usually can fit the decoder under the rear headlight board .

[mmyers]

I use a dremel high speed cutter for most of mine. Looks like a 3/8 diameter saw blade. I usually can get 3 or 4 frames before the cutter needs to be replaced.

Under the long hood light board is my preferred location. It's much easier now with DZ decoders. Used to do it with DN93's. That took a lot of space.

Martin Myers

Martin Myers

[Ike the BN Freak]

The SD40-2 is DCC ready and uses a DN163K1B from Digitrax.

[mmyers]

SD40-2 also has room under the board to fit a small Z scale decoder. Then just make isolation cuts to the traces on the DC circuit board and solder the wires to the appropriate part of the board. I do this when a wired decoder or three are already on hand and want to save $28 on a dedicated board.

[Ian MacMillan]

The SD40-2 is DCC ready and uses a DN163K1B from Digitrax.

The "new" frame does. First run 40s, 40-2s and 45s have frames that require some milling.

[Ike the BN Freak]

The "new" frame does. First run 40s, 40-2s and 45s have frames that require some milling.

Just the 40s and 45s, the 40-2 has always been DCC ready.  The first run of them was in 2000, and DCC ready, as seen here,
http://www.visi.com/~spookshow/katosd4x.html

Also the "new" version uses the DN163K1C, as Kato redid the frames to the screwless frame.

So being every SD40-2 that Kato has ever done being DCC ready, guessing that is why Aztec doesn't mill those frames for hardwire decoders.

If you are set on hardwiring, I'd do as mmyers suggested.  I've never done it, never really thought about it, but don't see why it wouldn't work.  I just find the drop ins available on the market more to my liking.

[Ian MacMillan]

Just the 40s and 45s, the 40-2 has always been DCC ready.  The first run of them was in 2000.

Ah, I thought they had done a 1995ish run as well with the black handrails like the 40 and 45. Noted.

[trainforfun]

The loco was in the wrong box ... it's really an SD40   

On the other hand I know I have to dig in the frame and that is for sure !!!

I already cut some part of it , it goes well , there will still some fine tuning to do . Thanks all for your time to answer and guide me !

[daniel_leavitt2000]

Why not use those light board DCC chips that do not require milling?

[Philip H]

Why not use those light board DCC chips that do not require milling?

Well I can see a case where the existing board might not fit your loco. Plus those generally rely on some kind of internal power pickups, and if the loco doesn't have them you have to start soldering anyway.

[mmyers]

A TCS CN-GP would work. Still have to disassemble the mechanism, run the motor wires to the brushes. Solder to the brush caps, and isolate that connection from the frame. I would cut some metal at the brush caps and cut a channel for the motor and wires connecting the front and rear circuit boards. No metal would need to be cut to fit the actual decoder. It is a two piece unit that replaces the front and rear light boards.
Here's a link to an installation: http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/N_Scale/Kato/SD401/Kato%20SD401.html

This is similar to the way I did mine many years ago: http://mysite.mweb.co.za/residents/grela/katosd40.html

[jagged ben]

A TCS CN-GP would work. ... No metal would need to be cut to fit the actual decoder. ...

That's not right.  You have to remove some bits below the decoder to make it fit.  I've done 3 of these.

Here's a link to an installation: http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/N_Scale/Kato/SD401/Kato%20SD401.html

The link has a picture entitled 'Milled Frame.'

With that said, it's much less milling than would be required for a conventional wired decoder, and could even reasonably be done with a hand file.

[jagged ben]

To answer the original question...

Any of the cutters on this page would probably work.
http://www.dremel.com/en-au/Accessories/Pages/SubCategories.aspx?catid=2070

The different shapes all have their uses depending on what's around the area your, how careful you need to be, etc.   I'd probably recommend the cylindrical ones for taking off lots of material to fit a conventional wired decoder. 

I have some cheaper off-brand cutters that are perhaps slightly less durable but were much cheaper.  Got them on ebay, but you got to be careful because a lot of the substitutes are soft crap.

Now that I think about it, I think I have an extra set for sale.  PM me if you're interested.