Building a Gallows Turntable for the Horace and William Creek R.R.

DACS · July 09, 2014, 06:21:05 PM

This next step is one where you have to be very careful. It is on tedious side, but as you can see in the above photo of the TT, it is well worth the effort.

Now, a problem rears its ugly head when using a blade to cut these notches. Just ask me!
A blade is easier, but can cause undue stress and strain on the psyche.

A blade has enough of a wedge shape to it, that it can cause problems from two directions. Getting right on the actual mark.
And cutting at an angle, no matter how you hold it when making the cut.
I have tried different methods for cutting, but none but what I am going to show you, gives the clean, no angle cut required.

You may not think it much, but it does make a very obvious difference in the work you produce.
In some things, this is not an issue, but when the model is an in your face piece, such as a very detailed turntable, it is very noticable.
To get away from this issue, I used a razor saw to make all the cuts. It makes them very straight. Also, the way they are cut, allows for very nice friction fits of all the cross ties.

You will notice in this pic, that all the slots have been cut. Do not think I started at the outer end and worked inward. It is quite the opposite. I just forgot to take the pics of the first and following cuts.
So, I am showing you where to begin, with a belated pic.

I cannot find the pics of all this, so I will do my best to explain it with words. My apologies for this. I hope the pics I am posting show this with some clarity.

The first cut is made against the inboard stops or tabs. Keeping the saw tightly against the stops, make your first cut. Keep the saw flat against the tabs, cutting down to the glue line of the 1/8" inch piece of stripwood.
You can see this in the above pics.
Your second cut is with the first cross tie held tightly against the stop tabs. Begin the cut, holding the saw at approximately a 30 degree angle, then push the saw away from you. Cutting both sides at the same time. Do not get into a hurry here. Cut only to the depth shown.
Once the cut is made to the correct depth, you can remove the pieces. Or, the slot tabs you just cut. This will be four tabs for each cross tie. Don't forget, we are cutting all four side beams at the same time.

All cuts are made in this same manner. Cut the first...remove the cut pieces. Place the tie. Put the next spacer in, make the first cut against the spacer. Then place the tie against the spacer, hold it there tightly, then make the second cut on both sides at the same time.
Remember that each cut begins by holding the saw at a 30 degree to make the initial cut, then bring the saw blade to a 90 degree against the spacer, then once this cut is made, place the cross tie against the spacer and make the second cut the same way. Then again remove the little cut pieces from the table and put the tie into it's slots.

Do not glue the cross ties in yet!!

This is what you will get when when one side is finished.

Both sides

This shows what you have labored to produce

Now, all the ties are replaced with friction fit only.

Again...do not glue anything in yet!!

Next, I will show how to make the center cross ties.

If I have not made this more clear than mud, please do not hesitate to ask.

Dave HWCRR
Seattle

DACS · July 15, 2014, 09:19:49 AM

Before I go any further with this, I want to apologize for the picture quality. They are awful and I know it. But, I hope they do show what I am trying to convey. Also, I think I did something to cause the above pics to disappear. I believe it's because I removed them from the gallery. I will work on correcting that today also. Sometimes, ignorance is bliss. Sometimes, it causes extra work.
Now that said:

This pic and the one below, are to show what we are going to construct next. All the center cross ties. These are all longer than the outboard ties.
Measure these according to the drawings using the correct dimensional scall lumber.
There is two sizes of lumber used. 8" x 16" and 6" x 16". There are 10 6" x 16" pieces cut to a length of 3 41/64" and 2 8" x 16" pieces cut to the same length.
Odd length dimension, but, that's what my measuring device shows.

This pic shows the saddle plates . There are four of these made.

First, I would like to make a slight correction to my use of the word dimensional lumber. I don't actually use dimensional lumber, I use scale lumber. Forgive me for any incorrect word usage here, or if I caused any confusion. Dimensional and scale are two different things. I get all my scale lumber from Kappler. I have no affiliation with this company. So no promotion intended here. But, it is an excellent product and I use nothing else.

There, got that said.

Now it is time to cut, build and mount the center cross ties, for the T/T.

As I mentioned in my last post, there are two sizes of scale lumber to be cut for these.
8" x 16" and 6" x 16". Cut two 8" x 16" pieces at a length of 3 41/64".
Cut ten 6" x 16" pieces at the same length.

These will all have a 30 degree angle cut on the lower corners.

I use my trusty miter box to do this. Notice where the cut is done. Push the strip in until you get an top end width of 5/32". Then make the cut.

This pic is a top view of the two sizes or thicknesses used.

Once all is cut, I then stain and grain. For color, I first use an A/I mix, then I follow with a A/burnt umber mix. I don't know the ratio's, I just mix till I get what I am looking for. Sometimes, I sort of go by the "seat of the pants," method.

This pic shows the materials needed to build the four doubled up cross ties.

The 8 pieces of lumber.
4 pieces of 1/32" x 3 1/4" brass rod, used for the tension/compression rods. These can be cut to a shorter length if you so choose. Just cut them to a length where the cut ends cannot be seen when they are place in the cross-ties.
The 1/4" x 7/64" strip of styrene, used for making the saddles.
The 1/32" x 3/4" pieces of strip wood used as spacers.

Here is the orientation of the cross-ties, with the spacer strips in place. The small strips of wood are attached using ACC. Do not glue these strips even with the bottom edge. Leave a slight space between the bottom of the strips and the bottom edge of the cross-ties. This is strictly for esthetics and not mechanical means.

Next, putting ACC on the face of the strips, we then join the two pieces. This leaves an automatic 1/32" gap between the two. This is where the c/t rods will go

The next step is to find the center point of the ties. As the length of these is 3 41/64", it makes it somewhat difficult to figure out where the center-line will actually fall.
As I use a digital caliper, all one has to do is change it to MM, which in this case is: 92.55mm. Divide that by 2 and you get: 46.275mm.
I just make it 46.27mm, or in our venacular, 1 53/64". Finding center on anything becomes so easy with this. Almost makes one feel brain lazy! Almost!!
Such amazing devices, the digital caliper and calculator! I feel so intelligent!

Once we find the center-line, then we make scribe marks on either side of the center, 1/8". These lines, are where we make out cuts in the cross-ties for the saddle plates.

Cut to a depth of 7/64". Finish with a file until you have a width of 1/4" between the bottom of the slot and the bottom of the cross-tie.

Here, all the center ties have been cut and await the saddles.

This shows how they will be oriented on the T/T.

Next, I will show how to make and mount the saddles. (No pun intended there)

Dave HWCRR
Seattle

DACS · July 15, 2014, 01:05:55 PM

Take the piece of plastic strip and measure in 15/64". Make a shallow cut with your trusty blade. This is the width of the saddles.
Then using a flat file, begin rounding off this section, up to the shallow cut.
Once you have done this, you should have a piece that looks like this.
It should have 15/64" flats left on both sides and be rounded between.

Do not cut this piece from the plastic strip yet. Now we have to cut the slot for the rod.
To do this, I place the filed piece into the ties then using a razor saw, I make a slight cut in the piece, using the actual gap between the ties, as my reference for the cut.

Once all this is finished, cut off the piece at the 15/64" length...
And voila!
Do not glue this piece in yet!

This pic shows the brass rod placed. Now we make it.

To make the rod, take the angles from the drawings you have and transfer them over to a piece of paper. Then take the brass rod and bend to those angles.

Once you have all of rods made. Glue them into the slots in the saddles. Do not glue the saddles with the rods into your ties yet. You first want to trial fit them. Then remove them, paint them and weather them. Then glue them with ACC into the cross ties as they belong. Because they are made to fit a specific cross tie, do not get the wrong one into the wrong tie. If you do, you will see why. That will explain it better than I could with a 100 words.

Next, we will begin placing the center ties into the table. So far, the only thing that has been permanently bonded to anything. Are the saddles and rod and the center ties to their mating pieces. NOTHING ELSE HAS BEEN PERMANENTLY FASTENED YET!

Dave HWCRR
Seattle

DACS · July 16, 2014, 08:51:40 AM

To mount the center cross-ties. The same method of mounting them, is the same as when mounting the outboard cross-ties.
The only difference is in two of the spacers used to get the correct spacing.

Cut two spacers out of pieces of stripwood.
One will be cut to a width of 3/16". One will be cut to a width of 1/4".

Reason being that the spacing is different between the end cross-ties and, the next. Hope the pic makes this more clear.

The first double cross-tie, is made up of one of the 6" x 16". This is spaced from the first inboard crosstie, with one of the 1/4" x 1/2" spacers you used to space all the inboard ties.
Mark and cut the slots for the first center crosstie.

The next is a single 6" x 16" cross-tie. Space this with the 3/16" spacer you just cut from stripwood.
Then next single is done with the same spacer as the previous, including the last double made from the 6" x 16" and 8" x 16" pieces.
The 8" x 16" side faces to the center of the T/T.
Once you have these all cut and in place. Start from the last inside cross-tie on the opposite end and come to the center again.
If you have done everything correctly, you should be left with a 1/8" gap in the very center of the T/T.

Gap left at the center of T/T. It looks off center, but this was caused by the camera angle.

Now, place a piece of 1/8" x 3/4" stripwood in this center gap to fill. Attach with ACC.
This will enable you to mark the exact center of the table to drill out the necessary hole for the brass tubing that will go down through the table of your layout.
Don't drill yet though!

The center cross-ties as well as all the outboard cross ties are attached to the main beams with ACC at this time.

You can remove the Turntable from the jig at this time, remove the two spacers you placed between the main side beams. Then admire your work for a little bit, then put the turntable back into the jig.
Next we will be building and placing the end beams.

But first: have a nice, hot cup of joe and a bacon and apple fritter on me!

Dave HWCRR
Seattle

DACS · July 23, 2014, 08:57:20 AM

Sorry I have not posted on this project in awhile. Been busy with other projects and wanted to take a break.

Next up on the t/t...building the end beams.

To build these, I use two different sizes of scale lumber. Three pieces of 8" x 16" and one piece of 6" x 16".

I cut off the three pieces of the 8" x 16", to a length of 4 1/32" and the one 6" x 16" to the same.
Using these measurements, does make it a slight differnce in thickness than the drawings call for. But, I have a tendency to put some things in my building, on a slight diet. It gives a better perspective and look to the model. Such as, trestle bents. Instead of using 1/4" x 1/4" material to build these, I will use 'S' scale 3/16" x 3/16". To me, it just looks less bulky and more realistic. IMO of course! I am digressing.

Gluing the end pieces all together with wood glue in this configuration. Sorry about the crudness of it, but it is still worth a thousand words.

I cut a template out of 1/32" plywood using the drawings of the t/t. With this, I mark the outline of the endbeams.

I do not have any power saws or such, so everything is done with razor saws, razor blades and sandpaper.
I trim off all excess material, then sand with 100 grit sandpaper down to the outside edge of the line line, then go to a finer grit to smooth away to the inside edge of the line. It works pretty fast and gives a good finish.
Make two of these beams.

Then stain and grain.

Remember the two tabs we made and glued to the end of the jig in the beginning. Here is where they come in.

Place the beams between these tabs glueing them with ACC onto the lands you cut earlier in the side beams ends. It places them exactly where they have to go. No fuss, no muss.

Voila'!!

Next up. We will be building the gallows sections of the turntable.

Dave HWCRR
Seattle

DACS · July 23, 2014, 06:12:53 PM

First, build a simple jig for the gallows support structure.

I cut out the actual image for these, from the drawings.
Then I glue scrap pieces of basswood strips on the jig base around the image. Makes for extremely fine accuracy. This is a plus when building something like a turntable. Not to mention scale lumber ain't cheap!
The amount of time it took me to just cut one set in this manner, is 10 minutes. I timed it!

With this, all the correct angles are there and it is a simple matter of just cutting the lengths and the angles, using the jig.

First, I will place a piece of 10" x 10" post not cut to length yet, into the jig. The bottom must be cut to the correct angle first. Then, cut the top of the post to the correct angle and length using the jig.
Next, I cut the upper angle on the post, along the centerline. DO NOT START GLUEING ANYTHING YET!!

Now cut the other post in the same manner.

Doesn't look like a good edge to edge match here, but once glued and clamped, it is a very tight tolerance. Once glued together (NOT YET), it is very hard to even find where the two posts come together once stained and grained.
I have gained a great love of jigs for building many things.
Once done, I can knock out several of the same thing in half the time or less. It just depends on how much stay-to-it-ivness I have.

Now we have both posts cut and we are ready to fit the cross spacer beam.
For this to fit correctly, we will want to cut notches into the main frame posts. These notches will hold 10" x 10" pieces in place.
I have cut them somewhat deeper than shown on the drawings. I use a combination of razor blades and a needle file to get this where it belongs. Because the inside edges are following a true vertical up and down line, the top of the slot is at 5/64" depth and the bottom is 3/64" depth. Then, I just gouge and cut until I am close to depth, then use a needle file to finish.
I do not cut these deeper because they are wrong on the drawing, I just prefer the look of it. Personal preference rearing up again!

Because I cut the length 31/32" of this beam to fit the notches, it is a little longer than what is shown on the drawing.
Now, we slip the cross beam into it's waiting spot. This should be a good, snug fit while in the jig.

Next, we cut and make the center posts and caps. Now is a good time to stain and grain the gallows support posts. Just remove the three pieces from the jig, then when finished, replace them back into the jig and continue on with the next step. Do not glue yet!

Out of time today. Will take this up right here tomorrow.

Dave HWCRR
Seattle

DACS · July 24, 2014, 06:41:13 AM

For the center posts, first cut four pieces of scale 6" x 12" lumber to a length of 1".
Here are the first two being cut and assembled. These two will make one post.
Begin by cutting in from one edge 1/16". Cut down to a depth of 1/8" or 6 scale inches. Don't forget, I am working in 'O' scale. Be careful to keep the cuts parallel to all surrounding surfaces.

Then again, at the bottom of the 1/8" cut, cut across the wide part of the post, leaving the 1/16" side attached to the post.

Do this to all four of the pieces for the posts.
Once you have this step done, you will file and sand to the correct inside width for the 10" x 10" center beam to fit into.

Next, we have to cut a notch in the top of the cross beam, for the top cap to fit into, until it rests on the top of the center post lands.

This cut goes only to the depth of the top lands of the center post top and the exact width of the post. Then cut the cap piece and fit it up to this notch.

HINT: When making this kind of fittings, I always cut small, and file to correct dimensions. Makes for good snug fits.

Will be back shortly

Dave HWCRR
Seattle

bparrish · July 24, 2014, 11:47:37 AM

This whole build thread is just too cool.

Thanx
Bob

DACS · July 24, 2014, 01:08:18 PM

Thanks for the drop in Bob and your comment.

Now, it is time to grain and stain all your pieces and begin to assemble the gallows A-frames. Use ACC to fasten all the pieces together, using your jig.

Now that we have this all done, it is now time to drill the holes through all three pieces for the 1/32" brass rod going from one side of the gallows frame to the other, under the cross beam.

Notice that this step is being done with the pieces not stained or grained. The reason being is, that I did it the former way, but for some reason it did not show well in the pics. So, I used the plain, as it shows up better. It can be done either way, but it is better if you at least grain and stain the wood before assembly and glueing.

There are two ways to drill the holes necessary for the rods passing through all three gallows posts.
The first way is this:
The drill press is set at the angle necessary with an .026 bit, to drill straight down through the posts. As the next three pics show.

This is one way. Another is to build another jig. I love building jigs for projects such as this. They keep everything accurate and consistent.
The jig is built according to the distance between the outside edge of the vertical top of the gallows main frame post and true vertical. Also, when using the jig, the drill angle is straight up and down. No angle set. It's all in the jig!
Using pieces of scrapwood for this to build the actual jig.

The angle is very apparent in the pics. Doing it this way, is so much easier, once the jig is built, than the former way. But, I show both ways. You choose.

Once you have all the holes drilled, and the rods in place...Oh, and I get the color of the rods (brass), by dropping into ferric chloride for a few (up to 10) minutes, then rinsing off very well. Gives a nice gray/black coloring. Once the rods are in their proper locations, I then weather them with Bragdon weathering powders. It is hard to get a good pic of them in place!

Another way, is to just paint them black, then use bragdon powders to rust them up! Or, you can just do it your favorite way.

Do not glue the gallows support posts in place yet. These are just sitting in place. Still have to make the iron pedestals that go under each leg, and the rod saddles for the top of the gallows frame and the top of the center post.
Also, I have not yet put any of the NBW's onto the model yet. Just before I start putting all the sub assemblies together, this is when I do that.

Next to build, is the top gallows beams.

Dave HWCRR
Seattle

deemery · July 25, 2014, 08:14:23 PM

Nice angle drilling set-up! I'm really looking forward to seeing how you ensure the turntable/track is centered on the pivot/spider, that's the key to the whole project :-)

dave

bparrish · July 25, 2014, 09:58:33 PM

Dave..............

What is the box car that always seems to be in the background ? ? ? ? ?

see ya
Bob

DACS · July 29, 2014, 10:44:16 AM

Here is is, another week since my last post. But, we do have to support our habits, eh?
Dave, thanks for the drop in and your curiosity about the centering method. I will tell you now, it is involved...

Bob, thanks again for your drop in and comments. As for the boxcar, that is a scratchbuilt, board by board, frame up'er, 18'er. I use individual strips for the sides and the interior framing. I have also built flatcars based on the same frame. The boxcar is waiting patiently to be finished.
I also want to add this little tidbit of info...The amount of time it is taking to do this thread, I built four complete turntables. Each one an almost exact copy of each other. Two of them were for other model railroaders. This is due to the jigs I built before hand.

Today, I am going to start with building the gallows cross member that supports the rod saddles and rods.
Using a copy of the drawings from the On30 gallows turntable plans for my template, here we go. If you have not remembered, I posted a link to these drawings earlier in the thread.

Cut the cross pieces out of the specified scale lumber size, according to the dimensions on the drawings. Grain all the pieces as you cut them. This sub-assembly is glued together as you go. I use ACC for this. Staining it can be held off till later. Just be careful about where the ACC goes. It will not take stain once it is on the wood. I am using a piece of foam core board as a work surface, taping the drawing to this.

Next, cut the two diagonal support pieces.

The next three pics show each step very clearly.
A picture is worth a thousand words. Or so I have heard it said.

Now that it is assembled. Place the unit on top of the gallows side posts. Do not glue in place yet. This is just a test fit. If you glue now, it will be very hard to place all the NBW's where they belong.
For this to fit correctly, you will notice in the drawings that the tops of the side support A-frames are notched to fit inside the gallows cross beams.
Notch them far enough down the supports, that the top edge of the cross beams, sit level with the tops of the support beams.

You can go ahead and stain the cross beams at this time. Again, do not glue them to the tops of the support beams. Leave this as a separate sub-assembly. There are still many things that are going to be done with them before they are ready to be attached permanently. Also, if you have stayed to close tolerances, these pictured, are a friction fit!

Now, dissasemble it all and finish staining everything.
So far, we are making good progress. Five main sub-assemblies so far, if you also built or are building the spider assembly (not pictured), the table operated on.

Next installment, will be making the saddles for the support rods and the iron plates that go on the bottom of the gallows side posts. I will get to this part at least, today. So much time and so little to do....er.....So little time and so much to do. Yeah, that's it!

Then I will be adding all the NBW's to the assemblies, but still we do not glue the assemblies together.

Dave HWCRR
Seattle

DACS · July 29, 2014, 06:09:28 PM

I may have gotten just a bit of myself with the last posting, saying next would be the drilling of the center hole for the tube.

Not yet time.

Am making the saddles and pedestals though. For the rods and the posts.
Will also cover drilling all the holes for the NBW's and mounting the rails on the table.

First, lets mount the rails.
It is paramount that these be exactly centered. Anyone ever building a turntable knows just how critical this can be. Off by just a little and it becomes a mountain. Especially when it comes to the table rails aligning with the enter/exit rails.
We can measure for exact center, then divide that by 2 for the rail centers. But, then we have to also be true all the way down on both sides. Don't want to end up with a curve in it.

Well, I thought about this and came up with a better way without all the hassle involved.
You got it! Another jig. Very simple to make also.

I cut out a piece of 1/64 plywood, to the exact inside dimensions of the side beams. Using my trusty digital caliper, I get an exact, friction fit. I cut it to a depth that is sufficient to reach from the rail ends to inside of both beams by 1/4" .
The slots I cut are taken from a correctly gauged piece of flex track. These are cut to the width of the rail web. You know, the part below the head and above the base. The thin part.
Not that most of you do not know what I am talking about, but beginners do visit.

Now, before you make the jig, you cut both rails to the exact length of what is called for in the drawing. Then put pliobond on the bottom of both rails and set aside to dry.

While this dries, then make the jig. Hope the pics make it clear.

By the way, the measurement you see on the caliper face, is only if you are making your side beams of the 6" width lumber. If you make them with the 8", that measurement is meaningless.

I use pliobond to fasten rails to ties. Just run a small bead along the entire length of the rail bottom, set aside and allow to dry. Once dry you are ready for the following.
This jig, along with a rail gauge, and a good hot soldering iron to bond the rail to the cross ties, keeps it all true and aligned. Just heat well and move on, the pliobond adheres quite well. Just move slowly enough to melt the pliobond and move on, allowing it to cool and take hold. (Again, that was for beginners). Make a gauge for each end if you so desire. I just made one and it works just great!

Once more for the finished rail placement pic. It's so purty!!

I have said that next I will be doing the rod plates and bottom plates next. But, it might be best if next, is making the locking mechanisms. These mechanisms are strictuly up to you. All the tables I have built so far, move very freely with not friction to speak of. If the locks are not placed, you may end up with a loco running off into the pit! But, as I said, this next step is entirely up to you.
So far, none of the subassemblies are glued in place. Be patient, that does come along. Don't get in a hurry with the glue yet.

Dave HWCRR
Seattle

deemery · July 29, 2014, 06:43:27 PM

I wondered how you were going to tackle the two geometry problems (exactly centered rails and exactly centered pivot/post). So my first question is answered...

dave

DACS · July 29, 2014, 06:54:23 PM

I will tell you this Dave, it involves....surprise!! A jig.