Recent Posts

Pages: 1 ... 5 6 [7] 8 9 10
61
Radio Control Models / Re: 1/16 scale Terramac RT7R
« Last post by vtsteam on July 22, 2025, 09:19:08 PM »
Interesting tailgate on that thing.

I can imagine a boulder hitting it when the dump body is halfway up. A virtue of a conventional tailgate is that it can be hinged at the top or bottom, or dropped completely. If hinged at the top and chained partially open at the bottom, a controlled dump can feed material over a longer distance as the truck moves forward. Blacktop, gravel, crushed stone. etc.
62
Radio Control Models / 1/16 scale Terramac RT7R
« Last post by ddmckee54 on July 22, 2025, 08:21:42 PM »
About 3-4 months ago, my Project Muse turned into a real slave driver.  The muse decided that I wasn't busy enough, what with yard work, looking for a new daily driver to replace the one that got totaled in late April, and all the other projects the Muse already had me working on, I NEEDED another project.

I really have no one but myself to blame.  While watching the Designs In Orbit video series documenting the rebuilding of 40+ miles of the CSX railroad's track that were destroyed during the Hurricane Helene flooding, the rotating tracked dumpers were bright and shiny enough to catch the Muse's eye.  Can't really blame the Muse, they're cute little things as far as construction equipment goes.  We watched enough of the videos that we determined the rotating tracked dumpers were Terramac's RT14R. 

A 3-view was found on their website and, with a little computer tom-foolery later, I had a JPG file that I could import into Alibre and start 3D modelling the beast.  I was making pretty good progress, right up to the point where Murphy threw his monkey-wrench into the works.  You see, to save myself a lot of headaches I'd been planning on using Bruder excavator replacement tracks for the dumper.  The monkey-wrench delivery was triggered by the fact that at scale, the RT14R's tracks are over 60mm wide - the Bruder tracks are 40mm wide.  The RT14R wasn't gonna happen, this was the cause of MUCH whining and complaining from the Muse.   After about a week of the Muse's complaining, and being told that there was an RT7R on Terramac's website, AND that the Muse was positive that 7R's were also used on the jobsite...  I gave up, got the 3-views and promptly checked the track width.  Humphh... 43mm, that's close enuf for Gub-mint work.  I guess we're gonna do this thing.  In case you're wondering, this is what a Terramac RT7Rlooks like.

Like I said, cute little thing.

Design work started with the important stuff, the tracks and lower frame.  The following images show the progress of the Alibre RT7R assembly drawing as the various bits and pieces were added.


Then design work started on the dump bed.  I had noticed that I didn't have anything to keep the tracks from rubbing on the top of the track frame, so I added a guide strip.  I also added a sample track plate so I could check for future clearance issues.


The dump bed was completed , and work on the upper frame and rotating assembly was started.


The bed lift mechanism was then designed.

It took many attempts, and visiting several DIY scissor lift websites, before I had a version that could fold itself into the 21-22mm space I had available.

The working lift was then added to the 7R's assembly drawing.


By this point the back half of the model was basically done so it was time to start on the front.

TO BE CONTINUED....
63
Our Shop / Re: Expanding the old "tiny shop"
« Last post by vtsteam on July 22, 2025, 08:04:07 PM »
Well I scraped and shoveled the area quite a bit smoother. But I'm having a third re-think! I have a much larger shed about 300 feet from the house, uninsulated and unheated, and a partial dirt floor in one section. I use it only for storage now.

But I'm thinking now that if I finish out the floor, add a ceiling, install insulation inner paneling and lighting, and some form of heat, it would be a proper and much larger workshop than adding piecemeal to the little shed up by the house.  It's on relatively level ground , so a lot easier to bring materials to and work on. It's exterior is also already built, and it doesn't need any addition, just finishing out. So  easier work than trying to make a silk purse out of the tiny shop/sow's ear. The only drawback is the distance from the house in winter and at night. It's also down a steep hill that the house is on. Heh, walking the drive at night I sometimes imagine bears are watching (it's through the woods).

But if it's a nice clean well lighted place, I think I won't mind the hike. Hell, If I get too lazy I can always drive there!
64
Our Shop / Re: Expanding the old "tiny shop"
« Last post by Brass_Machine on July 22, 2025, 01:51:24 PM »
Shop builds can be fun and exciting.

I understand the motivation bit. I am working on building an office in my shop.... feels like it is taking forever. I tell myself to keep moving forward, even if it is just a little at a time. Some progress is better than no progress.

Good luck!
65
Our Shop / Re: Expanding the old "tiny shop"
« Last post by vtsteam on July 20, 2025, 06:31:05 PM »
One of the problems I face in expanding the shop is that it's perched on a hill -- as is everything in the near proximity of my house. Another is that the shop was really an afterthought, patched together out of what once was really a wood furnace, not an actual building. It has been added onto twice for a generator space, and a molding/casting lean-to roof.

I've been moving earth in front of the shed this week, here's a pic of the state it's in presently.

  [ You are not allowed to view attachments ]  

Looking from the front, on the right side is a rather low space containing the emergency Lister-clone generator for the house. The central portion is the shop. It measures 6' by 8' internally but usable space is more like 6' by 6' because of the old chimney structure at the back. On the left is a hastily added casting molding area lean-to roof, which is now filled chock-full with items that really need storage space elsewhere. An iron casting furnace covered with a tarp is out front.

I've decided to build out from the front of the building, and to replace the multi-pieced roof, as well as raise the wall height on the generator side. To do that, I needed to build up the ground level in front of the shed. The only reasonably close material for that was located in a bank in front of the shed, which is just uphill from our parking area.

 So the last week has seen me chewing into that bank with my old Ford tractor mounted backhoe, and placing the dirt in front of the shed.

 [ You are not allowed to view attachments ]  


Because of the hill and the short reach, and short swing range of the backhoe, this has been a very slow process, requiring lots of shifting position. It's definitely NOT an excavator. I'd say it wasn't much faster than digging by hand and transporting by wheelbarrow. But of course definitely easier. The heat has been terrible for it - temps in the 90F range, so I've been taking frequent breaks. We are also going through a dry spell. As can be seen in the photo, the soil is very dry.

Anyway, here's where I am at this point, pretty messy, and in need of cleanup, probably with a scraper blade on my old '51 John Deere tractor. But some progress. An 8' wide level area has been added in front of the shed structures, and though it needs a little more material, and cleanup that represents an additional 112 square feet. If I rebuild and enclose the former casting area as part of the shop, I will have gone from 36 square feet of shop to about 215. That would definitely make a difference!

  [ You are not allowed to view attachments ]  
66
Member Videos / Re: Homemade Metal Casting Course - Class Zero
« Last post by celsoari on July 19, 2025, 01:21:12 PM »
i=BARxCWxQDRAnaqme


another class[/QUOTE]
67
Member Videos / Re: Model Engine running just off a naked flame
« Last post by Jim Dobson on July 19, 2025, 12:06:48 AM »
Quote from: BillTodd on July 18, 2025, 03:32:49 AM
That runs really well  :bow:

They are fascinating engines. They actually work using a phase change between the fourth state of matter , called plasma,  and  a gas .

The flame (or at least the blue part) is so hot the molecules are ripped apart in to charged ions in a very low density plasma. When they cool , they rapidly condense into a hot gas that is relatively much denser causing a partial vacuum. 

The plasma cools entirely through radiation, so polishing the inside of the bore will make a few more photon to bounce back into the plasma and keep it hot . That'll allow a bit more of the good stuff into the cylinder before the valve closes. 

Also it's important that the hot gas can escape the cylinder as the piston comes up . The vavle should spring open to allow this.

G'day Bill, thanks for the post I enjoyed reading that.
I have a fair to middling collection of these now and they never fail to amaze me how they work.
Hope you have a great weekend.
Cheers,
Jim
68
Member Videos / Re: Model Engine running just off a naked flame
« Last post by BillTodd on July 18, 2025, 03:32:49 AM »
That runs really well  :bow:

They are fascinating engines. They actually work using a phase change between the fourth state of matter , called plasma,  and  a gas .

The flame (or at least the blue part) is so hot the molecules are ripped apart in to charged ions in a very low density plasma. When they cool , they rapidly condense into a hot gas that is relatively much denser causing a partial vacuum. 

The plasma cools entirely through radiation, so polishing the inside of the bore will make a few more photon to bounce back into the plasma and keep it hot . That'll allow a bit more of the good stuff into the cylinder before the valve closes. 

Also it's important that the hot gas can escape the cylinder as the piston comes up . The vavle should spring open to allow this.
69
Member Videos / Model Engine running just off a naked flame
« Last post by Jim Dobson on July 17, 2025, 07:31:45 PM »
This is a Model Engine running just off a naked flame, thought some might be interested in seeing it run.
They are most commonly called Flame Licker Engines or Flame Gulper Engines or Vacuum Engines.
Very interesting to muck around with and I've done a lot of modifications and work on this one -

70
CNC / Re: My CNC Router
« Last post by vtsteam on July 17, 2025, 02:07:14 PM »
Well the Bosch Colt router bearings finally arrived after 14 days. I thought the order had gone astray from eReplacementParts dot com. Gee, whadya expect for $12 shipping for 2 small bearings that fit in a small envelope? Bearings were $12 so the shipping cost doubled the price.

Next time I'll order the bearings elsewhere, now that I know what they are. One is a 6002rs, the other a 627zz. Both common and like $10 per 10, and 2 day free shipping from the big river company. The ones received were made in Maylasia, so not exactly Timkens. Even Timkens are $5 ea. Oh well!  :dremel:

  [ You are not allowed to view attachments ]  

  [ You are not allowed to view attachments ]  
Pages: 1 ... 5 6 [7] 8 9 10