Body mounting on MTL metal frames

[Lemosteam]

The general rule of thumb for using taps is 1/4 of cut in reverse to break chips until full thread is reached.  aAnd yes Peter, it is still a good idea to drill and tap plastic so the threads are clean and not made of displaced material (instead of cut).  The displaced plastic will not form into the root of the thread of the screw and will leave less thread engagement and will not withstand as much tourqe, miniscule though it is for a 00-90 screw.

[chicken45]

Since we are talking about taps...
Why does a tap set come with two additional drill bits?
I get that the smaller bit is to drill out the hole before you tap, but the larger one? Why would you need to use that?

[wcfn100]

Since we are talking about taps...
Why does a tap set come with two additional drill bits?
I get that the smaller bit is to drill out the hole before you tap, but the larger one? Why would you need to use that?

Clearance drill.

As an example, if you wanted to cut off the couplers from a MT truck and mount them to the under frame, use the clearance drill so the screw goes through the coupler pocket and then only tap the under frame.

Jason

[chicken45]

Clearance drill.

As an example, if you wanted to cut off the couplers from a MT truck and mount them to the under frame, use the clearance drill so the screw goes through the coupler pocket and then only tap the under frame.

Jason

Ah, so it has nothing to do with the actual tapping process, right?
I think that's where I was getting hung up. Thanks!

[Kisatchie]

Clearance drill.

As an example, if you wanted to cut off the couplers from a MT truck and mount them to the under frame, use the clearance drill...

I think cutting the couplers off the trucks in order to body mount them is a bad idea. The coupler box is very wide, so it limits how far the truck wheels can travel from side to side. If you have sharp radius curves, the wheels will hit the sides of the coupler box and might cause a derailment. Ask me how I know this.


Hmm... I'm afraid to
ask...

[bbussey]

Cutting the coupler box off and mounting it works as long as you're not running the cars on 9¾" radius.  And they don't look bad, once they are screwed in place and the front locking tabs are cut off.

[nkalanaga]

Bryan:  I still have some of those KD conversion floors in their original packaging.  Never got around to using them because drilling and tapping plastic floors was just too simple.

I've also used the cut-off couplers as body mounts, but as Kisatchie says, one needs to be careful doing it.  On the plus side, once the thing is screwed on, the box can be trimmed a lot.  In particular, the latches on the bottom can go, which may help in some cases of axle interference.  The sides can also be trimmed, as long as the coupler guide holes aren't damaged.

[lock4244]

I've BM'd one MTL boxcar, and did it with 1015's in the outer hole... I see what you mean Bryan, it looks goofy. I've a few 1027's laying around and will have to install them. One thing I'm not interested in doing at present is drilling new holes... it's a bit of a rigermorole to do them at work where we have an over sized (for N scale) drill press.

And I snapped the tip off my tap 

[bbussey]

Mike, 1027s are too bulky and (unfortunately) compensate for the high ride height.  You're better off with 1016s in the inner holes, which beats drilling a new hole between the two existing holes to accommodate 1015s.  Using 1015/1016 gives some leeway in lowering the model to a better ride height also.

A lot of people use the 1016 to simulate extended draft gear.  I don't like the look of it since the sides are open.  But hidden under the floor, they work well.  Rather — they work better than the 1015s.  the coupler neck is too long in my opinion, but it looks better than a portion of the 1015 coupler box sticking out.

[lock4244]

Dang, I've no 1016's kicking around.

[Kisatchie]

Dang, I've no 1016's kicking around.

In a way, you're lucky. The coupler pockets on #1015s and #1016s don't extend all the way to the end of the coupler box. As a result, the couplers can swing WAAAAY to the sides. If you back up some cars equipped with #1015s/1016s, the couplers can swing to the sides so that the two joined couplers are at 90 degrees to each other. It looks horrible.


Hmm... so does Kiz...

[nkalanaga]

Now Dee, that wasn't nice!

One of the reasons I still prefer the 1025, in spite of it not being available in bulk, is that it backs well.  As Kiz said, the 1015s tend to buckle under pressure.  That, and I've been using the 1025s for so long I can practically assemble them with my eyes closed...

Having bought 500 pair of 1025 coupler boxes a couple years ago all I do is take the truck mounted couplers apart and move the coupler into the new box.  Yes, they stick out, just like the 1015s, but the end of the 1025 box doesn't look quite as out of place, and it's a lot cheaper than buying new couplers.  In 2012 the cost was $15.00 per hundred boxes, or 50 pair, plus shipping.