Beekster's Mad Mack

[Beekster]

This is the kit I will purchase for this project:

I've got the remains of two just like it, dissected for my Mack DM895 conversion projects.  The trailers are intact, and I will use pieces of both.  I want to make a three-axle trailer, with a fifth wheel at the back so that I can couple another trailer as a B-train behind it.  This mock-up gives a general impression of what I'm after:

I will have to cut the frame of the second trailer's wheel mounts and graft it onto the trailer's own frame, then add structure to mount a fifth wheel.  For the DM895 projects I collected an assortment of built kits and a couple of contest vendor table scores for spare parts.  Some of these bits might find their way onto this project somewhere:

Then there are these wheels:

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I started them six or seven years ago for possible use with the DM 895 conversions, but the off-road tread pattern I created isn't really recognizable as anything typically used on those trucks, on or off road.  But for a fantasy build they will be perfect, if I can afford to get enough of them cast up.  I'm looking at four of the front singles and twenty (!!!) sets of the duals for what I have in mind.  I made these and another set with highway tread for the DM895s, since those heavy tractors used six-spoke rims more like these than the Alcoa rims found in all the snap-fit truck kits.  They aren't exact, particularly the fronts (cribbed from the Mack fire truck kit), but better than civvie aluminum rims.

[JCON]

Looks like a fun idea, now to get the kit,and execute that plan to completion...

[dogfish7 (R.I.P.)]

This is going to be very cool.

[BUCKY]

Nice project, beekster!! All the wheels wouldn't hafta match, possibly being scrounged from abandoned wrecks.

[Beekster]

Nov 19, 2017 12:32:39 GMT -6 BUCKY said:

Nice project, beekster!! All the wheels wouldn't hafta match, possibly being scrounged from abandoned wrecks.

True...but that probably means making more wheels. What I was going for was a 24 x 14.00 wheel & tire, common on military heavy tractors like the M123 and M911 and heavy civilian rigs like the Mack DM895. The wheels & tires that come with the snap-fit truck kits aren't tall enough for those, which are almost four feet tall. Since the suspension parts won't articulate on these simple kits, tires with shorter profiles will hang in the air unless I do something. What that likely means is a lot more scratch building work to add something like a non-directional military tread to other wheels and then turning them on my lathe to get the same outside diameter as these. I still want to get some of these cast, but getting just enough for the tractor drops the number to four front singles and six sets of duals.

[Beekster]

Just picked up my third Mack kit. I've also been taking inventory of the wheels I have on hand, and have decided to proceed with finishing some that I started several years ago for potential master patterns. Now I'll just use them on this project. This shot illustrates one of the challenges of working with a snap-fit kit: Hollow backs to the wheels:


These four will be sufficient for one trailer. You can see that for six of these eight pieces I have filled in the backs with styrene and epoxy putty, or started to. Two I have yet to work on, and most of this was done years ago and put aside. Fill'em up, sand 'em smooth, and on to the next step: Chucking them in the lathe to remove the tread. Look at these two:



The one on the left has been altered; the one on the right hasn't. Notice that it has a pronounced crown to the tread, and if left alone the whole model would look like a ballerina on point. So the tread has to come off and be built back up. I want to do a military-style non-directional tread like I did for the masters on the Mack DM895 in my tank transporter fetish thread. That's easy, if tedious: Build up the base with a band of styrene strip, then use .040" x. 040" strip to make a centerline. Then alternate with blocks of the same material to create the tread pattern. When it is dry, it's back to the lathe to turn everything down to the chosen diameter and clean up the tread blocks with a scalpel. Yes, this will take a long time...

[JCON]

Very cool, good luck!!!

[BUCKY]

Nice looking work, beekster!!

[MARCO]

MAd Mack? No, Mad Beekster (in the good way )

[Wes]

Ive book marked this build. Going to bee sweet.

[Wes]

By the way, what are those snap tite kits? Do they not need to be glued?

[Beekster]

Nov 20, 2017 5:31:23 GMT -6 Wes said:

By the way, what are those snap tite kits? Do they not need to be glued?

Wes, they are indeed snap kits. That being said, I've found that they often don't want to. On that tanker, I cut off all the locating pins because the fit was too tight. I feared that I would break the trailer halves before I pushed everything home.  So  I cut the off and glued the trailer halves together normally.  The top part clicked in and fit pretty well, but left gaps so I applied glue and taped it down.  Filler will be needed where the main click tabs are because the fit is necessarily loose at those points to get the parts together.  For a toy, this engineering is fine, but for a model it isn't good enough so all my usual modeling rules about seams will apply.  And of course, when I get into truck frame surgery and trailer extension, that all has to be glued as well.

[Beekster]

Behold the wonder of the Amazing Tread-B-Gone!



Also known as a Sherline lathe, undoubtedly the second-best thing I got from a former employer. The first was all that stock, both options and other shares bought cheap, but I digress. I've turned these all down to remove the crowned tread, and on most have started building it back up with strips of .020" stock. Now the tedious part begins, adding a center rib and chopping dozens and dozens of bits of .040" x .040" strip to make the military tread. Following that, more lathe work to trim the tread blocks. You can also see that the backs have been filled in with strip and epoxy putty, and milled so they fit over the outer wheels. Sharp eyes will notice at least one of them isn't entirely even, but that won't matter...the discontinuity is too far down to be visible when assembled.

[JCON]

Interesting work!!!

[BUCKY]

Game plan looks good!! Keep up the great work!

[intimidator]

Watching....

[Beekster]

And now I'm stuck in to the really tedious part of this:


Being rather uncertain about the chances of getting some castings made from my masters in the next three months or so, the only other way forward is to make the kind of wheels I want. Seen here is the start of a directionless off-road style of tread on one set of duals. This is a job that will take a very, very long time. As you can see, I put on a few pieces at a time, setting them with .040" spacers, and then leave them to dry so that the pattern doesn't start walking out of alignment. I'm done messing with these two for a few hours and will soon start this process on the next pair. Once all these tread lugs are done, I have to trim them up to the sidewalls, then use the lathe and a sanding stick to shape the tread blocks and get the overall diameter I want. Sally Beauty Supply will be seeing me very soon to purchase more of my preferred nail finishing sticks for this kind of work.

[dogfish7 (R.I.P.)]

OMG!!

[Beekster]

Nov 27, 2017 15:56:56 GMT -6 dogfish7 (R.I.P.) said:

OMG!!

You got that right...unless I can get some castings done, this sort of treatment will have to be done for sixteen sets of duals and four singles.

[BUCKY]

That'll take a couple minutes!! Looks good, so far!!