Railsnail

Has anyone got deep enough pockets to model this event I wonder? (With apologies if this has been posted before)

Mine just turned up too. Royal Mail, Special Delivery, deliver by 1pm. Hope yours arrive soon. I ordered mine on the 28th June if that is of any relevance.

I was unaware of ePLA. Thanks for the information. It will be interesting to see how robust ordinary PLA works out in the longer term. The parts, once printed, appeared to be up to the job. Time will tell I guess, but I would certainly try ePLA if I have a future requirement.

Mine have just arrived from LTM! Haven't opened the boxes yet... Just savouring the anticipation

Indeed, very fiddly. There was much muttering as the final part of the re-assembly took place!

Thanks. As I mentioned, I am very new to CAD/3D so this was more an exercise in replicating a smallish component, getting to grips with Sketchup and tinkering with 3D printer settings with the ultimate aim of repairing the broken suspension parts on my Class 128. I doubt I'll be making other replacement parts unless I have a specific requirement. My other 3D printed object is a much larger enclosure for my DCC++ Ex Bluetooth Controller project. I may get around to documenting it some time as it has been tremendous fun, involving some electronics assembly/enclosure design and 3D printing. Here is the latest version of the 3D printed DCC++ enclosure.

So the issue here is to repair a Heljan OO Class 128 with two broken 'suspension bridge' components following the receipt of a used loco from an eBay seller which was dropped/mishandled in transit. For those unfamiliar with those parts, they are two plastic parts, (one for each bogie), that attach the two bogies to the chassis casting. They allow the bogies to swing horizontally and vertically. My options were to buy replacement parts from Gaugemaster or attempt to 3D print my own. So, I decided to do both meaning that if I failed in my component printing experiment, then I could use 'real' replacements. As I had the broken parts and they could be sized with my trusty digital calipers, I proceeded to attempt to create a drawing of them in Sketchup. I must add that I am very new to the whole 3D printing side of things, so I wasn't sure how this would all play out. After some time, forum searching and much trial and error I arrived at my model in Sketchup. Not as rounded and aesthetic as the original, but hopefully all the critical parts were correct and it would do the job. It looked right, but could I print it and would it work? I downloaded the STL file (from Sketchup) imported it into Cura, and all looked good. I decided to print with 100% infill using the 'Normal' profile on my recently acquired Neptune 2 printer. For those interested, I printed it with white eSun brand PLA. Extruder temperature 210 deg C, plate temp 50 deg C. I reduced the print speed to 25mm per sec and printed with 'tree' supports. Other parameters were defaults. Cura calculated a print time of 10 minutes, so I wouldn't have to wait very long to see the finished article. Sure enough, around 10 minutes later I had this... Pictured just as printed, still attached to the printing plate. After detaching it and trimming the supports with a craft knife, it appeared to resemble the Heljan part, and checking with my calipers, all appeared to be okay with dimensions. But as they say, the proof is in the pudding. I checked that the little pivot parts fitted nicely into the top bogie clip (see the pivot point inserted into the Heljan top bogie clip in the following picture). They fitted without recourse to a lump hammer 🤨, but were a little tight. I was happy with this as I didn't want play in this pivot point, but then I didn't want excess resistance either. So after a little whittling of excess support material with the craft knife, I was happy with clearances. Similarly I checked the chassis pivot clearances and with a few more seconds whittling I was able to turn the component freely in the chassis without there being too much slop and play . This picture shows the component inserted into the two holes in the chassis sides in its horizontal position. If anyone has ever disassembled these, they will know that this is the orientation required to remove/replace it from the chassis. The component is then rotated 90 degrees so that the top/bottom pivot points are in the correct position, the bogie halves are split slightly to allow the bottom pivot point to be inserted. The drive shaft is inserted into the drive coupler (which goes through the central hole) being careful with alignment so as not to damage the drive splines. Finally, the top clip was added... (located on the top pivot point), clips engaged and press down carefully but firmly. The final result Next check that the bogie is free to rotate and tilt freely without too much play. Repeat for the other end, and job was done ready to test on the track. Track testing was a success, so I can declare my 3D printer repair project a success - and the Heljan spares will be spare when they eventually arrive.

At least the seller was upfront about the sound issue and as you say, you have a working DCC Decoder.

Excellent! Good luck with the sound, although you may be out of luck with that if something like the chips sound output stage is kaput.

I have three different TTS modules that all presented no ack when trying to read CVs on the programming track. Certainly with the latest revision of DCC++Ex you can alter the ACK parameters (MIN, MAX and LIMIT) via the USB port. I really widened these three and now I can read/write CVs without the no ack problem. The commands and values I used are:- <D ACK MIN 2000> <D ACK MAX 8750> <D ACK LIMIT 20> You can also switch ACK diagnostics on with the <D ACK ON> command. (It's all documented in the command reference). These values, (or whatever you arrive at if you experiment a bit further than me), can be made permanent, so that they survive a power-down. Load your sketch up in Arduino IDE. Create a new tab named mySetup.h then paste the following into that tab (maybe change values if you arrive at something different). Then compile and upload to your Mega. Now these values will be reloaded on startup. (This is also in the documentation). SETUP("<D ACK MIN 2000>"); SETUP("<D ACK MAX 8750>"); SETUP("<D ACK LIMIT 20>"); Of course the decoder may be faulty above and beyond no sound as others have said, but this may be worth a try. Also, as I mentioned, I had to widen these parameters anyway for my TTS decoders plus a Laisdcc that didn't want to play ball! Good luck.

@esmedune, you say you use DCC++ and DecoderPro... In my experience using the latest revision of DCC++ Ex (the project that has arisen out of the original DCC++ system) with DecoderPro and TTS decoders, you have to open up the DCC ACK thresholds. Else you get the dreaded error code 308 (no ack from loco). So are you using DCC++ or DCC++ Ex? I may be able to provide a bit more info.

@96701... Your question was not asked of me, so apologies for jumping in here - but, to my very untrained eye the roofline of the KR Models Fell looks a little too high. ie. the distance between the very top of the centre windscreen and the very top (apex) of the curved roof? What do you think? If this is the case, I will still be happy with the KRM 10100 as I do not have the time nor skill to make a half decent model, however I can see how that could put some people off spending their cash.

Interesting! So the 245 is essentially a 4 engined (Caterpillar units?) diesel electric with some on-demand control system to start/stop the units? I also read that one of the power units could be replaced by battery storage? (A very large number of 18650's ?). I think the gearbox/hydraulic transmission design used in the Fell is what makes it truly unique. On the down-side the transmission also made the loco very complicated.

Indeed! Also, one of them should be frantically searching for a bolt that somehow fell out of his overalls pocket while he was doing some servicing work on the gearbox. I wonder where that went? (He mutters)

Yes, I feel the same about the early prototype locos, but my favourite must be the Fell...The moment I clapped eyes on pictures of this wonderful machine, I wondered who on earth could design a locomotive that even looks that different! For me, its beauty was its odd quirkiness, curved roof/window line of the main body juxtaposed with the box like ends of this machine. Its appearance fascinated me, and then to learn about its 6 diesel engines (4 main) plus differential gearing/hydraulic drive arrangement led me to want to know more about its inventor, Lt. Col Fell, his engineering background, involvement with Paxman etc. For me, researching the history and the people behind these prototypes brings another aspect to this great hobby of ours. Yes, I am really looking forward to running my model when she arrives. (My earlier comment about her languishing in the shed was made in jest). I think its great to have the opportunity to own a little representation of what was an amazing prototype. So thanks KR Models for taking this development on. Finally, I wonder what Lt. Col. Fell and the other designers/contributors might have thought to see this machine in miniature?

Before installing, I set up the TTS with provided speaker on a DCC decoder tester and recorded the sound then swapped the Hornby speaker for an iPhone 6 speaker with the 'bit on the side' removed and the resultant hole plugged. Once again I recorded the result to try to compare the two and thought there was slightly less volume with the iPhone speaker, but the difference was hardly noticeable. My 'other half' who is more musically inclined and has better hearing than me thought the iPhone speaker sounded better. So who am I to argue Anyhow, the iPhone speaker (with the metal bits insulated with sellotape) fits snugly under the loco PCB and the insulated decoder sits on top of the PCB. The loco body just fits with the decoder mounted in that location. A quick check for working lights, motion and sound of course, screws replaced and the job was done and I didn't have to make any space by removing the fan assembly. So happy days! Good luck with yours and I hope you enjoy the result! If you need any pictures then feel free to contact me. I'm certainly no expert, but I'm happy to share my experience. PS Quick tip. If you install the decoder above the PCB as I did, make sure the connecting wires do not show through the little engine viewing windows on the side of the loco.

Having just installed a type 31 TTS into a Hornby detailed Network Rail loco I would say the sound is great for a cheap decoder. I swapped the provided rectangular speaker for an iPhone 6 speaker mainly due to space issues, (I didn't want to remove the fan), and was very pleased with the result. The iPhone speaker fits snugly under the Hornby main PCB, and the TTS decoder once insulated sits on the main PCB thus no chopping chassis, removal of bits etc. Although my memories of the sound of these locomotives date back to my mid-teens in the early seventies, I would say that Hornby has captured the EE engine sounds admirably given the tiny speaker in my model. Well let's say it brought a smile to my face. So thanks Hornby. I would like to add one of these to the old 1960's Tri-ang version of the Class 31 at some point, but I have concerns regarding the current capability of the TTS decoders which may prove to be an issue with the old motor/mechanisms of these circa 60 year old models. Has anyone had any experiences of this?

@96701, I too look forward to receiving my KR Models Fell. Just to add to the realism of this engine, I intend to leave it mostly in its shed above the inspection pit and surrounded by 1:76 scale detailed fitters/engineers all scratching their heads.

Thanks for taking the time to reply Ian... As I tried to explain it is not a patience issue, I just wanted to ask someone at Locomotion when dispatch would take place as I wanted to ensure I would be at home to receive my model, having previously had items stolen from my doorstep when left by delivery drivers while I was out! As a new forum member I presume Locomotion No.3 is also a forum member who frequents this forum? As it happens, I didn't receive a call back from my answerphone message, however I did receive an email from UPS with a delivery day, and I was at home to receive it. So all is well that ended well and thanks to the obviously pressured staff at Locomotion and those who replied to my initial question on this forum. I now look forward to some sort of post-Covid 'normality' when I can travel up to Shildon and experience the real thing for myself.

Thanks for the replies. I have never visited the museum so I am unaware of staffing levels etc. I'm sorry if I sounded impatient, I'm just asking so that I can plan to receive an expensive order that may get left on my doorstep due to delivery drivers leaving things outside, ringing the doorbell, then driving off without checking that items have been taken in. (Amazon take note!). If I know when something may be dispatched, then I can plan accordingly thus the attempt to speak to someone.

I have tried phoning Locomotion Models a few times today to ask about when an order for a loco made at the weekend will be dispatched, however, I get a recorded announcement requesting I leave a number so that someone can call me back. I am wondering if the museum is closed or only opened part time due to Covid as I haven't yet had a follow-up. Does anyone know how quickly the folk at LM usually follow up? Thanks in advance Chris