Miniart Cat D7 & scratch built Hyster logging arch

Hi all - something out of my comfort zone.
I largely model aircraft so not certain if this belongs in Armor or Automotive so mods feel free to move
it .
I started the Miniart D7 with cable blade a few years ago and then shelved it after building most of the base machine . Picking it up again I want to make a logging machine with a tracked arch for skidding
( dragging) logs . To that end I purchased a second kit with the needed towing winch .



This is the current state of things - I’ve begun to assemble the tracks. Thank goodness for the new ZM nippers .

I plan on leaving the blade off - a “ wheel cat “ in logger’s terms apparently a machine dedicated to skidding logs . I want to scratch an arched roof like this one -

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Interesting, will be following along.

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That’s a cool looking rig! … Following along!

—mike

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:+1:t3: Cool, another subject I’ve never seen built as a scale model. I like the parts sourcing from kits

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Here’s a couple of photos you might enjoy:

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I will be watching closely as I wish to undertake the same build with a scratchbuilt logging arch all in in 1/48th scale.

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Thanks - are you aware of this kit ? While not 1/48 it is 1/50 , the common scale for die cast construction vehicles. They also offer a D 8.

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I’ve built up one set of tracks - each link is made up of 4 pieces . Track shoe , two guides and a pin . 36 links per side so one set is 144 pieces. Don’t know how you armor guys do this on a regular basis. It is supposed to be fun , right ?
Miniart gives you 8 of these sprues .


Twice the amount of pins you will need but no spares for the other components. I think someone goofed when laying out the sprues.
Here is where I outsmarted myself - thinking the pins should be perpendicular to the guides I made a jig out of scrap of aluminum by boring holes of the correct depth so the guides lay flat on the block when placed on the pin . 36 assemblies made and only when I started to glue the guide to the track shoe did I see that the pin was not parallel to the edge of the shoe . A little careful bending of each guide fixed it .

I taped two steel rules to a glass plate spaced with a track shoe at either end and assembled the tracks on this .

One side done …

I am going to have to install the tracks around the undercarriage cementing here and there in order for them to look right and worry about painting later.
I’ve also built up the winch …


This is the look I will be shooting for as far as paint/ weathering is concerned…

This new ground for me - hopefully this book will help .

Thanks for looking - RT

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Undercarriage done and tracks installed - lots of tweaking and I’m not 100% happy but it’s the best I could manage.


I’ve begun the structure for the arched roof . I turned a mandrel out of plastic to form the brass arches -

  • and a dry fit of all so far -

    I’ve ordered a resistance soldering outfit for assembling the roof system.
    Using the dimensions listed in the Hyster arch parts booklet I calculated what they would be in 1/35 scale then measured the size of the drawings in the booklet and calculated the needed percentage to enlarge the drawings . I will be building most of the structure in sheet styrene. I plan on making a master for one wheel ( there are eight on the logging arch ) and one track link and cast all in resin .

Thanks for looking!
Cheers- RT

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Great start. I will be following your progress.

Cheers,
Ralph

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A little further work on the roof. Fixture made up of MDF to locate and drill for horizontal members …


…and also hold components in place for soldering… a little trick to use when boring by hand with pin vise is to hold two machinist blocks to form a corner, thus insuring the bore is square .


The resistance soldering unit arrived today - looks pretty straightforward but will experiment with it a bit on some scraps
of brass - more to follow.
Cheers- RT

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Nicely done fixture & good tip for perpendicular holes !

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Very nicely done.

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The variables you “play” with when resistance soldering
is time and current. The current through the resistance
is regulated by the voltage.
Burning holes in some scrap metal is a good way to figure
out the needed voltage for a specific combination.

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Begun to explore the resistance soldering - it couldn’t be easier. Instantaneous localized heat at the joint and it doesn’t effect previous joints so far as I have found. I made up a test sample using the same materials as in the roof system , first one joint - let it cool for a few minutes then the other .
I bought two types of solder along with the unit . This test was with Tix. I think it will benefit to use a decent small artist brush to apply the flux as it will more easily control the area that the solder adheres to . This is the lowest price unit from Micro Mark . No incremental variation in current - only high or low , selected by which post you choose for the clip . This test was low power and as stated heating was instantaneous.

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Richard, I have the suspicion that you might just be a machinist or pattern maker by trade, yes?

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Michael - Just a dumb carpenter by trade . I do some machining- self taught. Machining is one of those subjects that the more you learn the more you realize how much you don’t know . To paraphrase my late father in law , “ what I know about machining wouldn’t amount to a pimple on a real machinist’s a _ _ ! I come by whatever skills I may possess by my father and grandfather - both of them master loftsmen and wooden boat builders .
Thanks for the compliment and interest . I admire your soft skin projects as well .
Cheers- Richard

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Richard, I had a somewhat similar upbringing ~ except today I only own a tiny little Austrian built Unimat. (Sort of the Shopsmith of jeweler’s lathes.)

See some of my story at:


But hope still springs eternal:

Wheel Lathe:

Ordinance, Split Base, Artillery Barrel Lathe:

Cass Scenic Railway; Cass W. Va.

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That is some serious machinery. I like railroad stuff too - had a few different layouts in my younger days . I like all things mechanical and nothing ticks all the boxes for mechanical fascination more than a steam locomotive. Here is one my early machining projects built from raw castings and metal stock . Stuart 10 V steam engine . While I have a vertical boiler kit ( yet to be built) I only run the engine on compressed air. Steam is pretty messy .


One of the axioms of this type of work seems to be thus - If a component being machined requires 10 operations you will screw it up on the 9th if you are lucky , 10th if you are not …
Cheers- RT

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I only dreamed of doing this kind of work in my hobby life and doubt that I even could.

Wanted to join the Navy and become a Machinist’s Mate but then a super high draft lottery number dropped into my lap and changed all that.

I bet you really like all the engine room shots in the movie “The Sand Pebbles”?
Not near enough shots in “Titanic.”