Here’s my #9 frog (llagas #4 on the bottom). The gap is small enough that a wheel just clicks through. Another option for frog casting is just plain resin. That’s what my plan is to do. Sure it might wear out faster than a metal casting, but the process is a lot simpler, and a few people have already shown the resin frogs work and last.
Pete thank you for explaining that . I can see where Greg is coming from and why it is sound advice. I can also see why one might want a flange bearing frog if running various different wheel sets will be run. The idea being that the problem the big gap caused by a wide flangeway that would allow wheels to drop in at the flangeway intersection is eliminated or at leased reduced by having the flange supported as opposed to the tread f the wheel. I could see this being a plus on say a club layout.
Now for me I have plans at least to use one type of wheel all the way around. As I will be scratch building most everything and really at least to begin wont have a ton of rolling stock I think the use of finer scale wheels and tighter tolerance frog design will in the end make me a more happy camper. All of what you and Greg have said is clear as crystal now.
Craig,
After all of the above explanations on frogs and the pluses and minuses I like the looks of your frog and over all switch design. Looks lie yours has all the elements that Greg and Pete just explained. I think I am getting the hang of this and along with the drawings you sent me I think I can make a switch now. Need to buy some rail and give it a whirl. Your talking casting in resin as it is a much simpler process; why not cast in JB weld because you could do it in the very same manor I would think and JB weld I think would be stronger? A two part silicon mold could be made of the frog then inject the JB weld into the mold with a cheap plastic syringe.
Why resin and not JB Weld? Because I have some experience with resin and know how it works. JB Weld rumored to be conductive for those who use track power. I can also make a 1 piece mold in resin verses as 2 part for the JB Weld.
Craig Townsend said:
Why resin and not JB Weld? Because I have some experience with resin and know how it works. JB Weld rumored to be conductive for those who use track power. I can also make a 1 piece mold in resin verses as 2 part for the JB Weld.
I can’t comment on the track power issue, but I am not sure the rest of your concerns would be an issue. I am pretty sure if you can cast it in resin you can cast it in JB weld in the very same mold. I made the assumption that you would use a two piece mold for your resin casting. While JB weld is not as viscous as resin it is liquid enough that I am sure it would be easily manipulated into all the recesses with a tooth pick or some such device. JB weld just seems like a tougher product. Resin is tough though and unless your really operating a lot I would think it would last a long time.
Notice Theoretical vs Actual…
Gets more pronounced in our size.
I am a visual person, so I went out and drew a 10’ (5’ radius) diameter arc on my shop floor. I then drew a straight line on the apex of the arc perpendicular to the radius. Now I then marked out the rails 45mm apart equidistant from the center line of both the arc and the straight line. This gave me a rough idea of what # switch I would need in order to put a switch on that curve. Honestly I was expecting something like at least a #6 or even a #8. What I came up with is closer to a #3.75 or a #4. Am I off my rocker? I found where the rails leaving the frog were 1" apart and then measured from frog point to that point. It ended up a little over 3 3/4" but not quite 4". I realize that this is not accurate as the diverging rail I am using is curved and the numbered switch will come off straight but I figure it will get me close.
So am I right that a#4 switch would be a good switch to put in a 10 diameter curve to create a straight diverging track? If that is correct then how much would a six effect me in that place? would I have trouble realigning my 10 Radius curve?
BTW I randomly picked 10’ It is about half way between the 8.5 and 11 I am playing with now.
Well what your doing is drawing a frog that curves throughout the frog instead of being a straight frog the whole length. A #4 turnout isn’t that big in terms of frog length, but the question I would ask is what is the distance between the frog and the points? I started out with some #4 turnouts and will likely keep the, for staging/storage areas.
If you use a radius for the diverging route it will be smaller than a true numbered switch because you have removed the tangents which gave length.
Go to Train Li and look at their curved numbered switches, that might help you see the difference between gradual and toy like.
John
Devon
Let me provide a slightly different opinion.
I have spent hours observing how trains go through turnouts in lots of locations around the world. There are a whole lot of difference in how turnouts are designed.
Then I observed how our model trains go through our turnouts.
Vast difference.
Building turnouts is not one of the things I enjoy but alas there are several places on my layout that custom made turnouts are required.
Some things I learned.
Traction turnouts are close to our tight radius turnouts and the prototype ones that work best are flange bearing and curved throughout.
The filet on a wheel is key but our rails and the weight on our cars do not scale
Alas there are a lot of models out there that do not have wheels that meet the standards and that requires some some adjustments.
I keep the guardrail on the stockrail tight in the area of the point of the frog but widen the distance for guardrail next to to the frog.
The points and how they fit into the stock rail are much more important in our models. Wheels picking points is the cause of a lot of derailments.
Hope that helps
Stan
Devon Sinsley said:
I am a visual person, so I went out and drew a 10’ (5’ radius) diameter arc on my shop floor. I then drew a straight line on the apex of the arc perpendicular to the radius. Now I then marked out the rails 45mm apart equidistant from the center line of both the arc and the straight line. This gave me a rough idea of what # switch I would need in order to put a switch on that curve. Honestly I was expecting something like at least a #6 or even a #8. What I came up with is closer to a #3.75 or a #4. Am I off my rocker? I found where the rails leaving the frog were 1" apart and then measured from frog point to that point. It ended up a little over 3 3/4" but not quite 4". I realize that this is not accurate as the diverging rail I am using is curved and the numbered switch will come off straight but I figure it will get me close.
So am I right that a#4 switch would be a good switch to put in a 10 diameter curve to create a straight diverging track? If that is correct then how much would a six effect me in that place? would I have trouble realigning my 10 Radius curve?
BTW I randomly picked 10’ It is about half way between the 8.5 and 11 I am playing with now.
Devon, you are exactly right. Somewhere in this discussion I mentioned that the frogs on my Aristo 10 ft diameter turnouts measured 3.75, so you’re not crazy… much.
Now, forget about radius and numbered turnouts. We’ve been down this road before.
Guys,
I have forgotten all about curved turnouts. Lets start all over. On the reversing loops I wanted some turnouts. Now because you all have convinced me I did not want a toy switch I wanted to see what numbered switch would need to be placed in the curve to so that once I could start curving again. So roughly I measured it so give me an indicator of where to start. With the rail curving I came up with about 3.75" So I drew a straight through #4 frog and it was not diverging fast enough. This is just a practical experiment for me to visualize what is going on. I was surprised to see that on a 10 foot curve such a tight switch would be needed. I either have to do a lot of messaging the curves upon exiting #6 switches to get the track going back to where I would want it to go or I have to use smaller # frogs.
So If I make #4 frogs am I going to regret it. So this becomes a practical question in track design. Is it better to have larger switches and be forced to make some tighter corners to get the track back on plan or is it better to keep the curves roughly on track and use lower # switches. I am limited to the radius of my curves. It is a matter of compromise so where do you make that compromise?
So, if I understand you correctly, your mainline is a curve, and you are wanting to place a turnout on the curve. Do I have that right?
If so, Grasshopper, you are not yet ready to be initiated into the next level of railroad mysteries. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)You still have much work to do. When you can catch the fly in my hand, you will be ready.
Pssst. Hey kid, read up on curved turnouts. I will deny telling you this.
I think the answer to your question goes back to your givens and druthers…
For me I’d sacrifice the reverse loop to have #7 or #9 turnouts, but someone else might not.
For some fun reading check out Mike Cougill’s blog about his P:48 layout and the decisions that he’s been making about tearing out track. Sometimes less is more.
Oh you guys are killing me. I am going to scrap the whole darn thing and and model the St. Paul Metro rail. Point to point no switches no loops just straight there and straight back. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)
Ok so where I was going with this whole nightmare is this portion of the track plan:
How would one do this? The curved section of track would be the mainline and the straight to the left is just a siding and the straight to the right would travel off to the other reversing loop to form an loop.
Double slip? (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-tongue-out.gif)
Devon Sinsley said:
Oh you guys are killing me. I am going to scrap the whole darn thing and and model the St. Paul Metro rail. Point to point no switches no loops just straight there and straight back. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)
Ok so where I was going with this whole nightmare is this portion of the track plan:
How would one do this? The curved section of track would be the mainline and the straight to the left is just a siding and the straight to the right would travel off to the other reversing loop to form an loop.
You could do it with a #4, #6, #7, #12, or a #20. I wouldn’t try a #15 in that situation, though, they have always been trouble.
Devon, you can use whatever number turnout that catches your fancy. It doesn’t matter. Then come off the diverging leg with any curve you choose. The higher the number the less chance of derailment.
Thanks Steve that kinda what what I thought but needed confirmation.
gah my head hurts. What I dont understand is why would you want to cast a frog vs just usinmg the rails? Devon why dont you just take an aristo switch or something in the size you need and just copy that. My plan is to take the Arsito wide rad switch and copy that but use the rails for my frog rather then a mold. Or better yet get a template and lay everything out on that. All these numbers makes no sence to me lol…
Devon Sinsley said:
I am a visual person, so I went out and drew a 10’ (5’ radius) diameter arc on my shop floor. I then drew a straight line on the apex of the arc perpendicular to the radius. Now I then marked out the rails 45mm apart equidistant from the center line of both the arc and the straight line. This gave me a rough idea of what # switch I would need in order to put a switch on that curve. Honestly I was expecting something like at least a #6 or even a #8. What I came up with is closer to a #3.75 or a #4. Am I off my rocker? I found where the rails leaving the frog were 1" apart and then measured from frog point to that point. It ended up a little over 3 3/4" but not quite 4". I realize that this is not accurate as the diverging rail I am using is curved and the numbered switch will come off straight but I figure it will get me close.
So am I right that a#4 switch would be a good switch to put in a 10 diameter curve to create a straight diverging track? If that is correct then how much would a six effect me in that place? would I have trouble realigning my 10 Radius curve?
BTW I randomly picked 10’ It is about half way between the 8.5 and 11 I am playing with now.
The problem is that 5’ radius, 10’ diameter curves are too tight for fine scale railroads. I built mine with a minimum 10’ radius (20’ diameter) and used #6 and larger switches.
The concept of using a #6 in your 10’ diamtere curve and tightening the curve to match the switch makes very little sense. Your trains will know and it won’t look good (imho).
