Good Afternoon;

Late check in for me today but wanted to catch up. The cold weather made it down to FLorida last night. Of course is a relative term we made it down to 43 but up to 67 now.

My bride is back from her trip to Europe with the rowing club group she is part of, it is great to have her back. Tonight we will meet up with my daughter for dinner and gift exchange since for Christmas the Mrs. and I are heading out on a cruise. 

Not much else going on, I keep busy with stuff around the house and my current bench project, the prototype lift bridge I am making using CAD and printing the parts using the 3D resin printer. At this time I have completed the lift section of the bridge and am now working on designing the rolling lift section. He is a photo of the computer design and what came together after gluing the printed parts together. I only needed to make 13 separate sections for this part of the bridge. 






Have a great day.

Jim

Good Morning;

I agree, Star looks very happy tucked in. Rick thanks for breakfast, I am getting to second cup of coffee. 

It is OK here in Florida, gray but in 60's. With my better half off on a girl vacation I am finding it hard getting going or finishing anything. However need to get moving. Hope everyone has a great day. 

Jim

Agree, never forget. In many ways Americans are better since we do often gloss over history, but not this, not ever. 

Jim

While most of the country is cold here in Central Florida I have the windows open. It is a little gray but upper 60's going to 80 today.  My bride is on a tour with her rowing club in Europe so the house is mine and the pups. Each day I try to get something done around the house which makes a mess until cleaned up. With her not here I get to move at my slower pace. Today we will attack the floor trim which is chewed in the corners form when the dogs were just puppies. I have the supplies at hand so no excuse not to get done. Other projects so far done is a pocket door replaced (had help on that one), pool area cleaned up and float hooks installed. I also want to get my train room fixed up and cleaned up. So I will be keeping busy.

Hope everyone has a great day.

Jim

Good Morning;

Love the pictures. As Karl said the Lions won so my wife is happy. Yesterday I went to see my brother-in-law at the hospital to see how he was doing having had his right artificial hip replaced the day before. Instead the doctor said he was good to go and I was able to bring him back to his home, so a red letter day. He was in a lot of pain with the old one and is already feeling better.

The computer I ordered for my bride as her Christmas gift arrived yesterday as well so getting it running and ready for her is the project of the day. Hope everyone has a great day.

Jim

Good Morning;

Really cool vacuum stuff guys, I am impressed.

A little muggy and off again cloudy but nice day. I did some cleaning this morning as I am a bachlor for a week. The bride is off on a trip to Europe with a girl rowing club she is part of. They are taking a river boat. I hope to get some house repair work while she is gone so no supervisor, flying solo.

Hope everyone has a great day.

Jim

Quote from: PRR Modeler on November 29, 2025, 11:01:51 AMJim my Dad is has the same mobility issues. There are relative light weight models of power chairs. My Dad has one that folds up for storage or vehicle transport. If you want additional info let me know.

Curt your Dad? You young whippersnappers! Well I remember being at 35,000 feet when toxic gas filled the cabin and I had to hold my breath until I could land the plane 45 minutes later (In a snow storm with thunder and lighting, had to taxis to ramp uphill both ways as well). Oh well, that story might be a bit stretched.

Thanks, unfortunately I have two brother-in-laws that for other reasons already have some type of powered wheelchair so the research was pretty well done already. I did check out online Amazon and such but decided the local service and care was worth the cost and bought a slightly used model that is exactly like you say, 28 pounds with battery, 10 miles on charge, folds up and is comfortable. I was dumb enough to ask why it was turned back in after three months, be careful what you ask.

Anyway I am good to go and I will do my damndest not to give it back in three months.

Jim

Good Morning Folks;

Sounds like a lot of snow going around, but not here. We are in the 50's heading to 70's. Yesterday I went over to brother-in-laws place to fix his Sonos sound system. He had bought a new TV and the Geek squid could not figure out how to get it running with the TV. Not to long ago the kids danced circles around us old farts on electronics. This is second time I have followed behind Geek squid to fix something they could not. In this case it was two different apps arguing who was in charge. 

I decided I want to be a little more productive on our trips when we travel so today I am going to look at portable powered wheelchairs. My compromised breathing and neuropathy combine to limit my travels to perhaps a 1/2 a mile before I really just want to sit. There are new wheelchairs that weigh 33 pounds, go up to 25 miles, travel at 4 miles an hour and fold up into car. It does not replace my days of hiking but sure beats staring at walls. So off I go, have a great day.

Jim

Happy Thanksgiving Everyone!

I just had coffee this morning as the spread the wife's have prepared will feed a regiment. Weather here is cloudy but in the 60's going to 70. We are headed to wife's sisters where all are gathering for food and football. My bride already had her parade fix watching the MACY parade so next up the Lions football game. Have a great day folks.

Happy Thanksgiving to all in the US and all the best to Everyone, Everywhere!



My better half and I are heading to one of her sisters where others will join us as well. It is indeed a day to be thankful for all we have. I hope everyone has a great day.

Jim

Quote from: KentuckySouthern on November 27, 2025, 09:59:53 AMGreetings from a snow covered and freezing Michigan.  Dinner will be at one of the girls' so no big cleanup here.  It's around 30⁰ and the snow has paused, covering the ground but the driveway is clear so the Deere can rest.

Speaking of Deer, the media reported that Michigan hunters have culled 106,000 from the herd since the season started on the 15th.  There season ends at the end of November but there is another month for those using blackpowder arms and bow and arrows. 

Sports today will be interupted by travel to the dinner, LIONS at 1 and SPARTY HOOPS sometime around 4:30.

I started a small 3d project yesterday.  Using a FREE set of drawings from a website called CULTS that has thousands of free or very low cost predrawn items from every imaginable interest, Trains to Dungeons and Dragons, anywhere in between.  Discovery of that site has taken the urgency off learning a CAD program.

Enug from here.  Do enjoy the day, family and food! 

Karl

Karl check out Thingverse.com. it is the other great site for all sorts of free files.

Jim

Good Morning, the clubhouse is open and coffee on. Another great day here in Central Florida, sunny and currently in the 60's. I hope to get some time in on modeling stuff and I'm taking the bride out tonight for diner, just to get out. Tomorrow I drive my brother-in-law to Gainsville for a hip replacement consultation. He's worked hard to lose the necessary weight to be able to have it done. 

Well off to clean up, have a great day.

Jim

Quote from: deemery on November 19, 2025, 11:21:31 AMAre you worried about the strength of the 3D printed parts when the bridge operates?  Certainly the engineering of the bridge should help mitigate that risk.  One clever thing I remember seeing before 3D printing was on a Silver Crash tank car kit, the railing posts were a composite part.  There was resin castings for appearance with a slot for thin brass strip for strength.

dave

Dave that is a great idea for something I have been worried about. I will slide cut to shape brass plates though the bottom trusses to improve strength when I get to the construction part. Great idea and thanks for the tip.

Jim

With the design finalized I export the items one at a time creating separate .stl files. This is a file type commonly used when dealing with three dimensional objects. In order to print the file I need to imported the .stl file into an application called a 'Slicer'. These applications take the .stl file and allow you to make the item 'printable'. The application has the parameters of the 3D printer being used as well and the liquid resin type (you tell it what you have). Further it allows you to set up the necessary supports to hold the item in place while it is made. You can use the program to do this for you, do it yourself or a combination of both. I use a slicer application from a firm called Chitubox. The version I use is free but still has way more ability than I need.  After importing I orient the object in the manner I want to minimize the number of supports needed versus the time needed to print the item. It is a trade off, the more vertical space the object takes up in the print space the longer to make but the fewer supports usually required. For example if I printed these trusses as shown in the CAD photo they could be made in about 30 minutes but would require a whole row of supports across the bottom to keep the part in place. Maybe 50 supports each needing to be removed and each might leave a blemish on the item. If I print them on end vertically I can reduce the support count to just 4 but it will take almost 8 hours to make. Since I am more interested in great detail and not time on this project I went with the vertical option. A side note, the slicer programs are getting better but learning how to place supports manually is still a great help. I usually have the program place the initial supports and then I make adjustments. However for complex or really detailed items I add the supports one at a time by myself. This allows me to adjust support size, placement and type.

OK, a lot of explanation. Here is how the trusses look in the slicer program after all supports added and everything checked to make sure it will print:



I sent the file to the printer and here is how those parts came out:


Removing the parts from the printer using a plastic scraper I wash the parts in isopropyl alcohol to remove all excess resin, Supports are removed with a sharp sprue cutter, making sure I don't break any of the soft fragile parts since at this point the part is very pliable and easy to tear. Finally they are placed in a UV dryer to complete the hardening process and we have a finished part!



So that is today's update. As I write the printer is busy making the other parts I designed for the two bridge side lift sections. I am now designing the roadbed girder system. Till next time.

A quick note, I am not a mechanical engineer so my determination and use of dimensions are simply my best guess based on observation. I also adjust as needed in order for the model to be structurally sound. In other words the dimensions are a SWAG and good enough for government work!

So now I need to make a list of the various beams and other parts that make up the bridge so as I design the parts I will have a starting point and goal for the CAD model. I will do this one section at a time, the first being the lift section of the bridge beginning with the two side trusses that support the roadbed. 

Reviewing the photos and diagrams I settled on the following dimensions:

 Since HO is a metric scale with 3.5mm = 1 foot all measurements are in metric for printing purposes. I have converted each to scale inches to show what they would be if 1:1 in scale.

The U channel main beams are being sized at .5mm thick, 1.5mm wide and 3.5mm high. This makes the beams 1.7 inches thick, 5 inches wide and 12 inches high for HO scale. They are used for the side bottom and side top trusses.

The plates used to tie the main beams together are .75mm wide, .2mm thick and 6mm long (rounded ends). This would work out to .69 of inch thick x 2.5 inches wide and 6 inches long. Each plate is tied to the beams and each other by rivets. I designed the rivets to be .3mm diameter by 1mm long resulting in 1 x 3.5 inches. Still close to original just a little higher to stand out.

The diagonal beams are 1mm wide x 3mm high and .3mm thick. In 1:1 scale they are  3.4 inches x 10 inches x .3 inches. The diagonal plates and rivets are same as used on main beams.

Finally, the upright beams that hold the diagonal beams together are .4mm wide x 3mm high and .2 thick, or 1.4 inches x 10 inches x .7 inches thick. The diagonal plates are the same .2mm thick and sized as needed.

Not exactly the original sizes  but they are in the ballpark and allow the model to be sound and printable by the 3D printer.  .2mm thick parts are right at the limits of my 3D printer converting to .00787 inches, really thin.

These are no means the original specifications just where I ended up in the end. In the beginning I attempted to match exactly what I saw in the diagrams and photos. Then, through trial and error over the past week I test printed each part comparing it to the information I had. Some parts like the rivets ended up having to be larger than original in order for the detail to be seen. Some of the beams needed sections made thicker in order to offer proper support for the model.

I wanted to capture as much detail as possible. The real riveted plates in the V formation consist of flat iron plates overlapping each other and held together by a single large rivet at each end of the plate. So three rivet were needed for every two plates. These rivets also passed through both U channel beams to created a complete truss the upright trusses attach to. To simulated this I offset the V of the plates so they look like one is over the other (but still part of each other for model support) and the rivets are long enough that when dry brushed they will show up against the background. 

Here is how the parts look like in the Tinkercad CAD program when put together on these specs: