RMweb Premium polybear Posted June 24, 2020 RMweb Premium Share Posted June 24, 2020 3 hours ago, 26power said: With regard to brittleness, I wonder if you saw the comments from Arun Sharma on the WW thread on Monday at 16.59 (last post on page 1877)? (Wish I could link it or quote it here, but not sure how!) They suggest that it would be better to use a 3D print as a master for a polyester resin casting as it would overcome the brittleness issue. It would also, presumably, reduce your time and effort input for producing individual 3D prints that I think you mentioned earlier in this thread. Perhaps there is some loss of detail or other disadvantage?vestigations! I know not a lot about the mystical world of 3D printing, and little more about resin casting However, I do know that resin casting may/will open up a range of other issues, such as mould life, castability (e.g. can the item be released from the mould without damage to item or mould), shrinkage(?), risk of bubbles etc etc. It also sounds a much more involved and labour intensive process for which Mike may not be happy to take on. I consider that we're really lucky that Mike is offering these to us - many thanks Mike 1 2 Link to comment Share on other sites More sharing options...
MikeTrice Posted June 24, 2020 Author Share Posted June 24, 2020 31 minutes ago, iak said: Might I be added to the list for this project please - Comet chassis please... Done 1 Link to comment Share on other sites More sharing options...
MikeTrice Posted June 25, 2020 Author Share Posted June 25, 2020 Another test proving shot. Even at this stage it needs a couple more tweaks but I will wait until I have assembled the Comet chassis. An observation for you. The rear footplate bracket does not continue up to the chassis on the print due to the additional width of cutout required for the motor. In spite of this I think it is worth including as is. 3 1 Link to comment Share on other sites More sharing options...
micklner Posted June 25, 2020 Share Posted June 25, 2020 That is the horrid old Bachmann chassis . I have the new version , I can take some photos and dimensions if needed? Link to comment Share on other sites More sharing options...
MikeTrice Posted June 25, 2020 Author Share Posted June 25, 2020 Thanks. That would be very helpful. Hope this does not mean a third variety of body. Link to comment Share on other sites More sharing options...
micklner Posted June 25, 2020 Share Posted June 25, 2020 Ok will take some pictures in due course. Link to comment Share on other sites More sharing options...
brack Posted June 25, 2020 Share Posted June 25, 2020 Regarding resin casting vs 3d printing. How many does Mike hope/wish to sell? My first 3D printed body kit (of a small narrow gauge bagnall 7 years ago) was originally intended to be masters for resin casting. However when I got the first test print I showed it to a very experienced resin caster (hoping for some advice) and his advice was that it wasnt an easy combination of shapes to cast, and certainly not something he would've attempted in his first few years of casting. As shapeways would print it for £40, and the primary motivation for producing the model was that I wanted one I decided against trying to cast it. This also had the benefit that I didnt have to go online and see pictures of 'my' models assembled with the chimney wonky, the boiler sloping or the smokebox out of square. 2 Link to comment Share on other sites More sharing options...
micklner Posted June 25, 2020 Share Posted June 25, 2020 (edited) Current Bachmann V2 chassis. Body fits inside body with a lug at the front and two tiny screws through the rear of the Cartazzi Truck into two round pegs on the bottom of the body (they are very fragile I have just had to glue both back onto my V2 body. ) The Bachmann A2 uses the same rear fixing method. Mike If you need anything else , let me know. Edited June 25, 2020 by micklner Link to comment Share on other sites More sharing options...
MikeTrice Posted June 25, 2020 Author Share Posted June 25, 2020 Thanks. Are you able to tell me the width over the chassis at various points? Although still the old shape it sounds as if the body was modified to cater for the new mounting arrangement. Link to comment Share on other sites More sharing options...
micklner Posted June 25, 2020 Share Posted June 25, 2020 Lwt us know which points you want measuremenst taken please. There are large areas of casting behind the rear drivers which support the Truck slide. I dont think they are on the split chassis ? I would think they will clash with the rear footplate support. Link to comment Share on other sites More sharing options...
MikeTrice Posted June 25, 2020 Author Share Posted June 25, 2020 I need to know what clearance is needed in the body for the chassis to slip in. It looks as if it is narrower than the earlier chassis. Link to comment Share on other sites More sharing options...
MikeTrice Posted June 25, 2020 Author Share Posted June 25, 2020 Does this help? Link to comment Share on other sites More sharing options...
micklner Posted June 25, 2020 Share Posted June 25, 2020 1 hour ago, MikeTrice said: Does this help? A= 26mm downward curve 28mm at base level with truck slot. B= 16.5mm C= 13mm D= 36mm E= 36 mm approx a very shallow curve in this area , hard to where tell where curve ends and straight section starts. F= 15mm approx as above comment E&F combined = 51mm G= 16mm Hole 3mm wide x 4mm long towards motor Angled shape to the casting at the left start point for D is 20mm wide 1 Link to comment Share on other sites More sharing options...
MikeTrice Posted June 25, 2020 Author Share Posted June 25, 2020 Thanks. 1 Link to comment Share on other sites More sharing options...
ScRSG Posted June 29, 2020 Share Posted June 29, 2020 Sorry, Mike, just discovered I would like three rather than two for Comet chassis please. Thanks. Link to comment Share on other sites More sharing options...
MikeTrice Posted June 30, 2020 Author Share Posted June 30, 2020 No problem. Link to comment Share on other sites More sharing options...
Stanley Melrose Posted June 30, 2020 Share Posted June 30, 2020 I can't help wondering from looking at the photos on Wright Writes if the cut-out in your V2 body is sufficient for OO width frames but not for EM of P4 width frames? Assuming Comet frames set the appropriate distance apart for the wider gauges, is it be possible for you to modify the body to suit the wider gauges? 1 Link to comment Share on other sites More sharing options...
Headstock Posted July 1, 2020 Share Posted July 1, 2020 On 30/06/2020 at 08:28, MikeTrice said: No problem. Good morning Mike, I would like to order a second body please, this time the Comet version, for an existing chassis. I hope that will be OK with you. Link to comment Share on other sites More sharing options...
MikeTrice Posted July 1, 2020 Author Share Posted July 1, 2020 Again, no problem. 1 Link to comment Share on other sites More sharing options...
Stanley Melrose Posted July 5, 2020 Share Posted July 5, 2020 On 30/06/2020 at 10:48, Stanley Melrose said: I can't help wondering from looking at the photos on Wright Writes if the cut-out in your V2 body is sufficient for OO width frames but not for EM of P4 width frames? Assuming Comet frames set the appropriate distance apart for the wider gauges, is it be possible for you to modify the body to suit the wider gauges? Bump! Link to comment Share on other sites More sharing options...
MikeTrice Posted July 5, 2020 Author Share Posted July 5, 2020 (edited) Sorry, I missed this. It would probably be possible but I would have to give it some thought and only after I have finished printing the OO versions. If I did a P4 version assuming the same one could be used for EM, how many people would be interested? Edited July 5, 2020 by MikeTrice 1 Link to comment Share on other sites More sharing options...
Paul Cram Posted July 5, 2020 Share Posted July 5, 2020 Hi Mike I would prefer P4 to OO. I had assumed that it would fit P4 without modiification Paul Link to comment Share on other sites More sharing options...
MikeTrice Posted July 6, 2020 Author Share Posted July 6, 2020 I will investigate. My plan is to contact people via PM to confirm before printing their models. Link to comment Share on other sites More sharing options...
MikeTrice Posted July 6, 2020 Author Share Posted July 6, 2020 P4 should be doable. The rear body almost fits as is, being wider to accommodate the Bachmann motor, but would need a little opening up at the front. The front body really needs widening. Both could be done by filing the current OO version of the body and narrowing the Comet chassis at the front to fit inside the frame extensions or arrange your own mountings. As stated previously I would not want to attempt to alter the current 3D model until the OO versions are finished. My brain could not cope with juggling all the variations. Link to comment Share on other sites More sharing options...
Paul Cram Posted July 6, 2020 Share Posted July 6, 2020 My plan would be to either reduce the height of the comet frames or alternatively I have a set of branchlines frames I could use. Link to comment Share on other sites More sharing options...
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