'Bobbling' points

[beavercreek]

This is only concerning how wheels go through a point not anything to do with how they operate, conductivity connections etc.

I use Bachmann, San-Val, LGB, Accucraft, AML and Aristocraft metal wheels on rolling stock.
Motive power is USA Trains, Bachmann (1.22.5 and 1:20.3), Aristocraft , Accucraft, Berlyn, and LGB locos

I use the following types of points. LGB R1 (on the small quarry line) R3 and R5, Aristo R3 (equivalent) and No6 (20ft radius). Trainline R1 as replacement for the LGB R1 in quarry line.

I have come up with a summary of what occurs and I was wondering if anyone has found alternatives:

LGB points especially R5 make nearly all makes of locos and rolling stock 'bobble' due to the depth of the frog being too shallow but the bottom of the frog is 'lined' with a strip of steel to allow conductivity through the long length, so it can not be 'ground out'.
LGB R5s also cause problems with USA Trains skates as they 'semi-drop' into the space before frog and catch on the point of the frog

LGB R3s also 'bobble most makes of loco and rolling stock but not as bad as R5s

Aristo R3s are not as bad as LGB but have deep frogs and this can cause problems with small diameter wheels.

Aristo No6 point frogs are very deep and as the frog is very long, can cause a problem with thinner profile wheels as on Accucraft 1:20.3 scale rolling stock. Aristo have produced a steel insert which seems to work well but there is still a small 'bobble'.

Is there any mass produced point that does not 'booble' any metal wheels?

I know that 'shimming' the guide rails with brass strip can help has anyone done this with a wide selection of points and got similar benefits?
Is there the 'magic bullet' point out there?

 

[chris m01]

This highlights a big issue with G scale. There is a distinct lack of standards. This applies to wheels and knuckle couplers and causes us grief.

Recent Aristo R3 points have deeper flanges than older ones which will affect this how stock goes through. I can live with bobbling but my LGB R3s sometimes derail Bachmann stock.

 

[Hutch]

I have had only LGB, REA (AristoCraft), and the early Lionel (solid rail, made in USA) points. These appear to be designed for the flange to ride on the bottom of the frog. I purchased a used pair of LGB's once that had the frogs cut deeper, they were unusable for my 0-4-0 engines and the wheels of some rolling stock would drop into the groove in the frog. I will be interested in seeing other responses and opinions.

---Hutch

 

[beavercreek]

I have had only LGB, REA (AristoCraft), and the early Lionel (solid rail, made in USA) points. These appear to be designed for the flange to ride on the bottom of the frog. I purchased a used pair of LGB's once that had the frogs cut deeper, they were unusable for my 0-4-0 engines and the wheels of some rolling stock would drop into the groove in the frog. I will be interested in seeing other responses and opinions.

---Hutch

Hutch, The LGB R5s have a steel strip at the bottom of the frog so unfortunately they can't be ground out deeper like the R3s.

The 'bobbling' is annoying but survivable but...I have an R5 which is at the bottom of a heavy incline and the track comes at it on the facing curved entry of the turnout. This puts strain on the frog as it has to take all the force of the weight of the train 'hitting' it as it is 'turned' through the switch (point). As there is also a 'bobble' due to the shallow depth of the R5 frog this can cause the odd derail.
Because of this, I have decided to replace the switch (point) with a R5 curve and have a closed 'spur' instead of a passing loop.

It is interesting that the Aristo No6 switch metal frog is really effective and with only small 'bobble' with the supplied metal 'insert' ..as long as the integral micro-switch, which supplies the correct polarity to the long metal frog, has not corroded away!

It would be interesting to hear what anyone who has used the brass strip 'shim' solution may have found.

This site has some good ideas about LGB R3s
http://www.girr.org/girr/tips/tips1/lgb_1600.html

 

[ntpntpntp]

Must admit the 2x LGB R5 that I have don't seem to cause any noticeable bobble, everything I have runs through them nice and smooth except Accucraft wagons but they don't really like any LGB pointwork due to the finer wheel flanges. I have replaced the plastic frog inserts with a handmade metal frog V to make them live frog, but I retained the metal strips in the bottom of the frog so the depth is unchanged.

I do plan to shim and lengthen the checkrails on my LGB R3 points to try and stop the noticeable "thump" as wheels follow the curved route.

 

[Hutch]

It would be interesting to hear what anyone who has used the brass strip 'shim' solution may have found.
This site has some good ideas about LGB R3s
http://www.girr.org/girr/tips/tips1/lgb_1600.html

I have used the brass shim mounted mechanically by forming the ends of the strip around the guardrail with great success. Unhappily, it is trial and error for the thickness of the strip that works with a given switch. This does, however give me extra shims for future use. The rolling stock that is most sensitive seems to be the LGB 4 wheel starter set coaches, even with added weight.
---Hutch

 

[Rhinochugger]

I don't have a problem with either Aristo #6 or USAT #6 except with my VW Speeder which attacks them at high speed

For normal stock at normal speeds with bogies, there is no problem, and I have a very wide variety of wheel manufacturers and standards.

Can't say much for 4-wheeled stock as I only have one caboose running on Aristo wheelsets.

 

[Tim Brien]

Switches/points are a railway item that cause most angst with railroaders since the majoroity of 'modellers' tend to be RTR. They simply will not modify their points for better running. I run over forty (40) Aristo wide radius (10 foot diameter) and several Aristo #6 switches. Each have their peculularities and must be treated separately.

The main issues with the wideradius switch are the height of the frog (standing proud of adjacent track railhead) and insufficient frog flangeway depth. Also, the point rails ideally should be 'checked' into adjacent rail, particularly the divergent rail.

Several years ago, at company request, I forwarded an example of my modfied switch to the company for evaluation. The resultant retooled frog came about with some help from my switch modfications. Other mods suggested were not taken up and would have made the switch far more customer friendly, such as a better positioned guard rail, better shepharding the wheel flanges onto the frog flangeway. The switches are 'built to a price'.

The #6 switch has several issues which need to be addressed. Firstly, the flangeway depth is too deep. A simple addition of styrene strip to the frog flangeway will assist wheels traversing the frog. Secondly, ditch the stock frog polarity switch and use a better method of activating frog polarity such as a LGB switch machine and microswitch pack.

I run stainless steel track and accomplished the many mods necessary to correct issues with Aristo switches/points, so working with brass would be child's play. A stock ready to run point is not going to tick all the squares as it is a compromise, catering for varying manufacturer's wheelsets.

 

[beavercreek]

Yes Ian, I agree, as I have said, the Aristo (or USA) No6 are the best behaved as far as 'bobble' are concerned. As long as you make sure that those pesky frog micro-switches are well protected from corrosion!

Nick, it is interesting that you have no probs with your LGB R5s, Gerry (lone ranger ) came around today and he also noticed that all of the R5s were making Bachmann Annie locos and rolling stock (all metal wheels) bobble (including my motorised combine which has LGB and AML ball bearing pick-up wheels and a USAT motor block ).
The R5s also 'bobbled' the Aristo C16s that we ran (the older ones with fixed wheel, non-sprung chassis).

The #6 switch has several issues which need to be addressed. Firstly, the flangeway depth is too deep. A simple addition of styrene strip to the frog flangeway will assist wheels traversing the frog. Secondly, ditch the stock frog polarity switch and use a better method of activating frog polarity such as a LGB switch machine and microswitch pack.

Tim, Aristo now provide a metal 'Y' shaped piece of metal to insert into the frog and it works great
Also the LGB R5s are too shallow and because of the metal conductivity strip, they can't be deepened

Although it is the shallowness of the R5s that is the problem LGB have put the steel strip along the bottom for conductivity through the long frog and that is why they want wheels to connect with it. Perhaps if wheels have less room to sink their tapered profile, they might not run too much along the bottom strip and therefore not 'bobble up so much.
I am going to try shimming the R5 guide rails as hutch has done with his R3s...I will report back.........

 

[Hutch]

The thick shim (.030 inch) shows wear at the leading edge (right side) only.

The thin shim (.020 inch) shows wear its' entire length. Interestingly the upper switch in this picture works perfectly with no shims.
I finally found the pictures, someday I will get organized...
---Hutch

 

[beavercreek]

Cheers for the pictures Hutch, it is interesting that the thicker shim only shows wear at the front (it might be to do with the fact that the wheel flange is directed away from the length of the shim when in contacts the front).
Also the fact that you have two identical switches and one shows wear on the shims whilst the other doesn't, just goes to show that manufacturing tolerances, where the switch is positioned etc really affects their performance.

My really real problematic LGB R5, that can derail at the odd time, is at the bottom of an incline and all trains come down to it. So it will probably be 'amplifying' any inconsistencies it has as well as the having shallow nature of the frog throat.....oh well as folk say, ready made mass produced switches (points) will always be a compromise and they have to be fettled in different ways to make them as perfect as is possible but then there is the use of different manufacturers wheels to consider.
The guys who make their own track can make their switches just right for their needs and they probably only use one type of wheel as well!

I will try the shimming but guess, even with that, I will just have to put up with a bit if bobble ...a bit of bobble dies you good...wayhayyyyy.... :impatient:.....

 

[whizzo]

Hi all , i have seen in 10 mm track where the check rail is removed from the point then clamped up to the inside of the outside rail , and drilled through both very lowdown on the web of the track and,then a thread taped to both holes at both ends -now with the small threaded screws you can adjust to your stock wheels regards Dave

 

[Cliff George]

Well as you probably know I'm all LGB R5 in the garden and I can't say I've noticed any problems. Maybe that's because I've got mostly LGB locos. The three Bachmann locos I have (Thomas, Percy, James) have smaller flanges than LGB so I guess thats why I havn't noticed any issues. I'll have to watch more closely when visiting locos come next time.

However I do take precautions with points, firstly when they are put down I always get out the spirit level to ensure they are level. It is surprising what appears to be level but isn't. Secondly given that lack of standards in this area I always try to fit LGB wheels to non LGB stock, where this is possible.

Maybe you could remove the metal conductivity strips in an LGB R5 on a temporary basis and see if that made any difference. The frogs would be slightly deeper and for longer wheelbase locos (which seem to predominate on your line) wouldn't make much difference to electrical conductivity. Any really short locos with few pickups could be fitted with a power buffer, or had power fed in from trailing trucks. If this worked you could possibly make the LGB frogs even deeper. I believe that replacement LGB frogs in metal are available from various places in Europe (but where currently where ecsapes me).

I got a new LGB R3 at a good price recently to play with in the garage and was quite disapointed with the quality. The rail height at the frog was higher than the frog at one end and lower at the other. The transition of a loco over the point was not smooth. I've fixed that issue now.

 

[Rhinochugger]

Yes Ian, I agree, as I have said, the Aristo (or USA) No6 are the best behaved as far as 'bobble' are concerned. As long as you make sure that those pesky frog micro-switches are well protected from corrosion!

Ah, should have said that I'm only manual - I think it's a Lagas Creek conversion (that actually uses a Tenmille lever ) and then, having originally wired it for live frog running, I converted it back to dead frog with additional feeds to the point blades and rails (as per Spike's method) last year.

 

[JRinTawa]

I made some modifications to my Aristo-Craft wide radius turnouts/switches when building our railway nearly 7 years ago, reseating and trimming parts of the frog moulding to get a constant rail head level (important) and also deepening the flangeway(?) through the frog to suit the Bachmann and LGB wheel sets I had then. I think the current frog moulding has corrected some of these problems as noted by Tim above? So my improvements may no longer be relevant?

I doubt if now I would deepen the flangeway due to the increasing number of finer flanged wheels finding their way onto the H&MGR (Accucraft, Tenmille, Haywood & Slaters etc). But that highlights as noted in a previous post, the range of "standards" the various manufacturers produce to. This must make it hard for turnout/switch makers to get a "one size fits all" turnout to work, and hard for us to tweak them to prevent bobbling. Good to perfect alignment of track leading into turnouts will also have a big effect as to just how well stock pass through, and checking a turnout (sorry switches ) is level side to side too.

I'm pondering using a Piko R3 turnout for a minor extension on the H&MGR, I wonder how they work, bobble wise. (I know I'll need to do some QA on their wiring).

 

[beavercreek]

Cliff
Yes you are spot on for what you say about your line as you are practically all LGB wheeled. The fact that LGB would have designed the R5 point with their wheels in mind would have caused them to set the depth they way that they did BUT they were also obviously aware of the problem that their short wheel base locos would have with the long frog so they used the metal strips at the bottom for the loco wheels to contact as they passed through and therefore get power...
So... the fact that this strip would have to contact the wheels would mean that, it would of necessity, have to be higher to make good contact and therefore make the wheels ride up a little. Now this is obviously made worse when the use of other manufacturers wheels run through the point as their flange depth, wheel profile might just be different enough to cause the excess bobble.

As I do use some shorter wheel base locos or ones that may have pick-up from only one block or some shorter steamers etc, the taking out of the conductive strips would not be good. I am going to try the shimming process ...BUT the cure for my most troublesome R5 will probably be removal and replacement with just a curve as it is not really used as a point and the passing loop that it feeds can just become a spur (siding) which is entered by the R5 point (which also bobbles!!!) at the other end of the passing loop.

Ah, should have said that I'm only manual - I think it's a Lagas Creek conversion (that actually uses a Tenmille lever ) and then, having originally wired it for live frog running, I converted it back to dead frog with additional feeds to the point blades and rails (as per Spike's method) last year.

Ian
The 'microswitch' on the huge Aristo No6 switches (points) are under the track and make the long metal frog live with polarity correct for the direction chosen. This would work well but they used terrible quality microswitches and they just rot if not encapsulated in silicon before laying (ask me how I know!). I have used wiring to 'liven' the frog but I have bought some new microswitches to swap over this winter when I take the points up.

 

[Cliff George]

I've often wondered how affective the metal strips in the LGB R5 points really are.

Firstly the strips obviously have no benefit for skates, they never get cleaned (well mine don't anyway), the wheel edges don't get cleaned, or even normally touch anything that would clean them, the contact points are very small and there always have been complaints about short wheel base locos running through R5 points. I image LGB point lurgy, where the power feed to the point blades fails after a time, may also affect the R5 frog strips. I think that skates actually tend to push the wheels away from the strips.

A point in case is the LGB track cleaner which would usually stop when running at track cleaning speed through an R5 points. I now always use my track cleaner with a trailing car that picks up power and feeds it to the cleaner, and now it never stops.

I might experiment myself some time to find out.

 

[ntpntpntp]

This is the live-frog conversion I've done with my R5 points. I could remove the metal strips and grind out the bottom of the frog but as I've not noticed any bobbling problems I've left as-is.

 

[Woderwick]

As you know, the reality is that the wheels should run along the wing rails of the frog. The various work-arounds (e.g. getting the flange to run along on a moulding at the bottom) are just fudges. Unless one commits to single type of wheels, back to backs etc then the reality is you will just have to live with it. (as alluded to by the standards comment above)

Its wheel drop (no fudgy bottom bit) vs Wheel jump, or bobble) with a fudgy bit . Getting a constant back to back, so the frog wing rails would work properly would go a long way to improving the sloppy performances of the more readily available stuff. I made bespoke point work for years in EM, O, P4 and O. I always had to get the customer to be quite clear on their requirements so as to avoid exactly the issues we duscuss here today.

Here is a section of Bristol Temple meads in EM, no issues, just a bit of care. Sorry about the poor quality, it's a scan from an old copy of the MRJ. I think you can just about make out the consistency in the frogs and guardrails. My point (ha!) is that if it's achievable in midget scale, then there is not really any excuse (except commercial and a will) for not managing it in larger scales.

As always IMO.

 

[Rhinochugger]

I think somewhere earlier in the thread we hit the real issue, and that is the lack of a standard wheel profile.

LGB go for a very deep flange, presumably because of their commitment to R1, they really need the flange to the keep the stuff on the rails.

Elsewhere, once you get to about R3 (8ft diameter) finer wheel standards as used by Accucraft US work fine.

Another factor is wheel diameter, and again, once you get up to 31mm of most US stock, then they tend to trundle over the gap in the frog a bit better.

Perhaps it's time for two different standards in G scale - coarse (LGB) and fine.

nphone:nphone:nphone: