M420

[mandealco]

I haven't done any more work on my M-420, other than getting the overall height sorted.  I have however discovered an interesting CN variation.  Apart from the modifications over the years, there are 2 different fuel tank sizes.  It appears the first order, about 30 units, has a larger fuel tank, the one that comes with the kit.  Later M-420s and HR-412s have a shorter tank, still longer than the BCR version.  This includes the 2574, and the 2 ME/M&E units.

Learn something every day.

Show us your M-420 progress guys. 

Cheers
Steve

[lock4244]

What is the advantage to using the U25B? Less milling of the frame? I've got four B23/30-7's modified for the M420 (all CN units) and didn't find it difficult... which is remarkable for me.

[mandealco]

I had the U-25B put aside for a long time, hoping for an M-420 kit to come out.  Its main advantage is the older style pick up system which means no wires are required.  It works well for the CN version(s), but not so well for the BCR.  If I was to build another, as long as it was a CN one, I'd use the Kato chassis.

I think Jeff's instructions are very good, which makes the job a lot easier.
Cheers
Steve

[lock4244]

Ah, I see. And I suppose since the AAR type B's are used on the M420R, all the better with the U25B. I actually found the wiring/milling to be relatively simple (with the right POWER tools, no tedious filing), though when it comes time to do internal repairs/maint in the future I can see that becoming something of a chore. With the other builds you've done (HR616, C636P come to mind), you should be able to whip a Briggs M420 up in your sleep!

Steve, have you ever considered casting an HR616 shell for sale?

[mandealco]

No I haven't, but I plan to rebuild the cab at some stage, so I could be tempted at that point to have it cast.  Any volunteers to do the casting?

[BCR 570]

I haven't done any more work on my M-420, other than getting the overall height sorted.  I have however discovered an interesting CN variation.  Apart from the modifications over the years, there are 2 different fuel tank sizes.  It appears the first order, about 30 units, has a larger fuel tank, the one that comes with the kit.  Later M-420s and HR-412s have a shorter tank, still longer than the BCR version.  This includes the 2574, and the 2 ME/M&E units.

Learn something every day.

Show us your M-420 progress guys. 

Cheers
Steve

Interesting - I ddin't know that.

I am working on my three M-630s at present so as much as I would like to rip into my M-420s, they will have to wait.  I will be sure to add to this thread when I do get to them,


Tim

[mandealco]

Hi Guys
Sorry for the slow progress.  Work pressures have kept me from modelling much lately.  The good news is I still have a job.  6 weeks ago, my position was to go, but my staff reacted to that and gave head office a few things to think about.  So, I still have a job, at least for now.

All I've done on the M-420 is apply the truck frames.  This was rather easy, and different from the method in the kit instructions.  If you are using the U-25B chassis, remove only the sideframe from the Kato truck, the new side frame is simply glued (CA) to the centre of the old part.  I used a wide blade and cut flush with the inside face of the Kato side frame.  This left a sizeable block of plastic to attach the floating Bolster side frame.

The photo shows the gap which will be filled with underframe parts from the Briggs Kit.

Not a great photo, but all I had time to shoot.  May get the underframe details done in the next, then I will leave it till I get some more projects off my desk.  Modelling will also take second place to BMX for the next 3 weeks while I  travel New Zealand with 2 of our boys in an attempt to qualify for the world champs in July.  Not a holiday, but away from work for 2 of those weeks.

Cheers
steve

[lock4244]

I have however discovered an interesting CN variation.  Apart from the modifications over the years, there are 2 different fuel tank sizes.  It appears the first order, about 30 units, has a larger fuel tank, the one that comes with the kit.  Later M-420s and HR-412s have a shorter tank, still longer than the BCR version.  This includes the 2574, and the 2 ME/M&E units.

Cheers
Steve

Looks like the one I've completed will be one of the first 30... except that the equipment access door behind the cab on the engineers side says 2560-2579 series. Going to have to swap that shell onto one of the other chassis I've preped. Think I might have to invest in a chopper before I attempt to mod any fuel tank parts.

The difference is considerable:
http://www.cnrphotos.com/gallery2/main.php?g2_itemId=8742&g2_imageViewsIndex=1
http://www.cnrphotos.com/gallery2/main.php?g2_itemId=8829&g2_imageViewsIndex=1