Garden Railway Forum

Posted: **Wed Jul 10, 2019 1:14 am**

GTB wrote: ↑Wed Jul 03, 2019 1:01 pm
-steves- wrote: ↑Tue Jul 02, 2019 3:40 pm The chassis that I made above required no fettling of con rods, wheels, bearing, cranks etc, it all ran when just bolted together, I was as surprised as anyone, but also very pleased
One can't ask for better results than that......

I forgot to ask earlier. You mentioned you milled flats on the axles to set the quartering on the cranks. How did you machine those?

Regards,
Graeme

As Ian said, a very good question. I spent ages trying to work this one out, I thought about rotary tables and the like, then realised that a simple solution was best. I took a square bit of brass, drill through it from one end to the other at the thickness of the axle, then on the side drilled a hole and tapped it for a grub screw. Simple pop the axle in sticking out of both ends, mill one end, take it out, turn it around 90 degrees and mill the other end, simple and works perfectly every time. The only down side is you need one tool for each size of axle, but no real biggy.

Posted: **Wed Jul 10, 2019 1:15 am**

Oily Rag wrote: ↑Wed Jul 03, 2019 2:42 pm That's an interesting question Graeme. I have often wondered about milling grub screw flats for flycranks. I drew the conclusion that under the circumstance of them NOT having to be exactly 90 deg (R.H. by convention leading), one axle could be milled both ends using the rotary table, accurate enough I would think but only mill one flat on the other axle leaving the remaining flycrank to be set to give best running. The other conclusion I came to was that in future all flycranks and the like mrequiring securing to round shafting of any sort would have two grub screws set about 90deg apart unless there was suitability for a roll pin.

The other way is to leave the axles over long, centre the outer end and mill the flats indexing along, then machining the axle to length.

I hope the post above clarifies how I have been doing it, really simple but it works

Posted: **Wed Jul 10, 2019 1:20 am**

A bit more time on the shed, the pictures do not show the con rods, but I made those as well and tried it as just the 6 wheels and again, works perfectly, no fettling required. Spot drills and DRO's are a massive improvement on the accuracy I used to get. The flycranks will be filed as before so they are not round and resemble something with a fly weight.

I have not tried the motor drive side of things as I ran out of 4mm stainless steel so I am waiting for my local metal shop to get that in so I can build the 4th axle for the dummy motor drive. The actual motor drive will be the same as the 0-4-0 chassis previously made.

Posted: **Wed Jul 10, 2019 5:07 pm**

-steves- wrote: ↑Wed Jul 10, 2019 1:20 am A bit more time on the shed, the pictures do not show the con rods, but I made those as well and tried it as just the 6 wheels and again, works perfectly, no fettling required.

You're on a roll.........

I wondered if you'd used that sort of jig for milling the axles, as I made one recently while I was waiting for some parts to turn up in the mail. Not an original design in my case, as a friend who works in the ride-on scales made one a while ago for milling keyways.

Now the $64 question, how are you keeping the tapped holes for the grub screw and the crankpin in line from one crank to the next?

I was thinking of making a jig based on the one I use for drilling crankpin holes in wheel castings, to hold the cranks in a fixed position while drilling for the grub screw.

Regards,
Graeme

Posted: **Sat Jul 13, 2019 6:26 pm**

First a bit of an update. The dual gauge 0-6-0 chassis is now working, all be it with the con rods in their raw state that still need a good fettling down to take the proper shape, however the theory was all good and the thought became a working reality. Very happy with both the 0-4-0 and the 0-6-0 chassis, I already have an order for couple so that should cover some of the initial outlay costs.

32mm gauge

45mm gauge

Posted: **Sat Jul 13, 2019 6:36 pm**

GTB wrote: ↑Wed Jul 10, 2019 5:07 pm
-steves- wrote: ↑Wed Jul 10, 2019 1:20 am A bit more time on the shed, the pictures do not show the con rods, but I made those as well and tried it as just the 6 wheels and again, works perfectly, no fettling required.
You're on a roll.........

I wondered if you'd used that sort of jig for milling the axles, as I made one recently while I was waiting for some parts to turn up in the mail. Not an original design in my case, as a friend who works in the ride-on scales made one a while ago for milling keyways.

Now the $64 question, how are you keeping the tapped holes for the grub screw and the crankpin in line from one crank to the next?

I was thinking of making a jig based on the one I use for drilling crankpin holes in wheel castings, to hold the cranks in a fixed position while drilling for the grub screw.

Regards,
Graeme

OK, the cranks are not a definitive thing. I use the lathe to take the steel down to to size and centre drill at 4mm. Then I pop the crank into the vice and use a steel rule to centre it and drill a 2.5mm hole ready for the grub screw. I the turn the crank on it's side, use a 2.5mm drill bit in the grub screw hole to eye centre the drill bit equal distance between the vice jaws, it's pretty easy to see when it's straight. I then use a 4mm upside down spot drill to centre the mill bed so that it slides inside the 4mm centre hole, once this is set, I zero the DRO and move the bed 9mm and the drill a 2.5mm hole ready for the crank pin bolt. The I tap both holes to 3mm thread and that's it. I could do with a jig to make this job easier, there is a lot of changing tools and collets but the end result seems good so far. Then I just saw and file off the round cranks to give it a flyweight effect. All crank pin bolts are turned from 4mm steel hex and then tapped to 3mm for 2.5mm and left just round for however long is needed for the con rod(s).

Posted: **Sat Jul 13, 2019 6:51 pm**

How much are you selling these units for?

Posted: **Sat Jul 13, 2019 7:19 pm**

tom_tom_go wrote: ↑Sat Jul 13, 2019 6:51 pm How much are you selling these units for?

The 0-4-0 chassis runs at about £65 and the 0-6-0 chassis with the extra rear drive crank runs at about £100, an 0-6-0 chassis with no rear crank probably around £85 I would think. These are just rough as they do not really include any time as I am just doing them for fun

Obviously I don't really take orders as I am not a business and one chassis takes me over a week to make assuming I get a fair bit of shed time, so in reality around 2 weeks to build just one chassis, lol

Posted: **Sun Jul 14, 2019 8:59 am**

Well I think you are doing a nice job on them Steve. I am well impressed...

I will be putting an order in for both when funds are available. But one at a time.

Do they come with the R/C has well Steve....I am cheeky.....

Posted: **Sun Jul 14, 2019 10:35 am**

FWLR wrote: ↑Sun Jul 14, 2019 8:59 am Well I think you are doing a nice job on them Steve. I am well impressed...

I will be putting an order in for both when funds are available. But one at a time.

Do they come with the R/C has well Steve....I am cheeky.....

Hi Rod

That's ok, they take me ages to make so no rush on any orders

No R/C I am afraid as just the RX/ESC is around £45 these days. The motors are 12v to 24v unless otherwise requested, however the one in the video is a 12-24v motor being run on about 8.2v and it works ok, but would need more voltage to pull heavy loads.

Posted: **Sun Jul 14, 2019 7:33 pm**

Well that's the first two completed (apart from buying one motor as it's shared at the moment).

The 0-6-0 is just about as short as I can get it, but the 0-4-0 I can make pretty much as short as the wheels fit to as long as I need, pretty handy as I might build myself a couple of bogie motor units at some point in the future and make another 0-4-0 0-4-0 diesel unit.

For now I just have to decide what bodies I can start to build for the chassis, though the first one I intend to make into the Whisbech / Upwell tram type thing.

I think at some point I will try a steam outline electric but that will take some more planning and designing to get it to work.

Posted: **Mon Jul 15, 2019 4:03 am**

Thanks for that. Your description kicked my mind out of a rut. For some reason I had got it fixed in my head when machining cranks to drill the axle hole, then drill and tap for the crankpin and finally drill and tap for the grub screw. Sigh.........

By using the sequence of axle, then grub screw and finally the crankpin, only a simple drilling fixture is needed. I'm waiting on some bits again, so I knocked one up yesterday afternoon.

The photo shows the fixture that I made earlier for machining the quartering flats on the left and the fixture to hold the crank while drilling and tapping for the crankpin on the right. I use a standard size axle for locos, so I only need one set of fixtures for outside cranks.

: Outside Crank Jigs.jpg (54.12 KiB) Viewed 6251 times

The only reason they are machined all over is that the only suitable size piece of square bar under the bench was hot rolled steel and far from square, so the surfaces needed cleaning up. I used a fly cutter instead of a milling cutter, as the mill scale on hot rolled steel is as abrasive as the skin on an iron casting and fly cutters are a lot easier to sharpen than a milling cutter.

The axle retaining screw in the quartering fixture is positioned diagonally to use it as a marker, so if it is always facing forward in the vice the quartering flats will be at 90deg when the fixture is changed end for end.

It's a bit hard to see, but there is a flat milled on the 'axle' end sticking out of the crank drilling fixture, effectively it is just a stub axle sticking out of half a quartering jig, but is machined in one piece to maintain alignment.

With a DRO on the mill and a self-centering 4 jaw chuck in the lathe, making these fixtures was quick and easy. I'm not a great fan of jigs/fixtures, so the simpler the better.

Regards,
Graeme

Posted: **Mon Jul 15, 2019 7:53 am**

They do look the business Steve...Could a 0-4-0 be used has a power bogie....Are you getting what I am looking at for my Railcar......

Posted: **Tue Jul 16, 2019 7:52 pm**

GTB wrote: ↑Mon Jul 15, 2019 4:03 am Thanks for that. Your description kicked my mind out of a rut. For some reason I had got it fixed in my head when machining cranks to drill the axle hole, then drill and tap for the crankpin and finally drill and tap for the grub screw. Sigh.........

By using the sequence of axle, then grub screw and finally the crankpin, only a simple drilling fixture is needed. I'm waiting on some bits again, so I knocked one up yesterday afternoon.

The photo shows the fixture that I made earlier for machining the quartering flats on the left and the fixture to hold the crank while drilling and tapping for the crankpin on the right. I use a standard size axle for locos, so I only need one set of fixtures for outside cranks.

Outside Crank Jigs.jpg

The only reason they are machined all over is that the only suitable size piece of square bar under the bench was hot rolled steel and far from square, so the surfaces needed cleaning up. I used a fly cutter instead of a milling cutter, as the mill scale on hot rolled steel is as abrasive as the skin on an iron casting and fly cutters are a lot easier to sharpen than a milling cutter.

The axle retaining screw in the quartering fixture is positioned diagonally to use it as a marker, so if it is always facing forward in the vice the quartering flats will be at 90deg when the fixture is changed end for end.

It's a bit hard to see, but there is a flat milled on the 'axle' end sticking out of the crank drilling fixture, effectively it is just a stub axle sticking out of half a quartering jig, but is machined in one piece to maintain alignment.

With a DRO on the mill and a self-centering 4 jaw chuck in the lathe, making these fixtures was quick and easy. I'm not a great fan of jigs/fixtures, so the simpler the better.

Regards,
Graeme

Strangely enough and before seeing this post I was in the workshop today finishing off a batch of 12 wheels. While I was in there I decided that some sort of tool could prove useful of doing cranks. Unfortunately I did not have the same idea as you as that would have been far quicker and easier to make. But I took a bit of 1" square block, milled out two of the sides to give me something to grip in the vice that won't move and will always be flat compared to the mill head. Then turned it over, put it in the vice and used a fly cutter to ensure the top was parallel with the bottom. I then milled out one end by 4mm deep (which is the shoulder of the length of my cranks) then I am going to drill a 4mm hole in it to take a cut off of axle, which will have a side milled flat. This will be held in the tool with a grub screw (or two) from the side and the crank slid over it and held with a grub screw. The top will than have a slot milled in it so that when I drill the crank I won't be drilling the tool. It's not finished yet, but when it is I will post up a picture.

Love this finish on your tooling, very neat, unlike my very rough finishes.

Posted: **Tue Jul 16, 2019 7:56 pm**

FWLR wrote: ↑Mon Jul 15, 2019 7:53 am They do look the business Steve...Could a 0-4-0 be used has a power bogie....Are you getting what I am looking at for my Railcar......

I am not sure exactly what you mean as this will always have outside cranks where as the power bogies I have seen generally have no cranks or con rods and everything is held inside the unit. I think Essel do a power bogie that I am thinking of. I have not worked out how to do a 4 wheel drive power bogie with no cranks and the downside to power bogies I have seen is that the motor is usually mounted vertically.

Do you have a larger picture of what you are looking for and I can have a think and see if I can knock something up to suit

Posted: **Tue Jul 16, 2019 8:12 pm**

Those chassis are really nice. If you get fed up cutting out frames and connecting rods by hand let me know. They wouldn't cost a lot to laser cut.

Posted: **Tue Jul 16, 2019 8:41 pm**

Busted Bricks wrote: ↑Tue Jul 16, 2019 8:12 pm Those chassis are really nice. If you get fed up cutting out frames and connecting rods by hand let me know. They wouldn't cost a lot to laser cut.

Thanks, appreciate that, we will see how it goes

Posted: **Wed Jul 17, 2019 8:04 am**

Something for this Steve.

: DSCN4059.JPG (415.42 KiB) Viewed 6762 times

Cranks wouldn't be needed really, just the ability to move like front and rear bogies. Yes the ones I have seen are all with the motor pointing up. I want to replace the one in my Railcar with a power bogie. I would be using the motor as is, so it's a question of if it can be done....

Posted: **Wed Jul 17, 2019 3:02 pm**

FWLR wrote: ↑Wed Jul 17, 2019 8:04 am Something for this Steve.

DSCN4059.JPG

Cranks wouldn't be needed really, just the ability to move like front and rear bogies. Yes the ones I have seen are all with the motor pointing up. I want to replace the one in my Railcar with a power bogie. I would be using the motor as is, so it's a question of if it can be done....

I would think anything is possible, but for something that specific I would need the entire railcar at hand to measure and see what would fit. A shame you are not closer or you could have popped over and we could have seen if we could have made something to fit.

What is wrong with the one that's in it?

Posted: **Wed Jul 17, 2019 3:08 pm**

GTB wrote: ↑Mon Jul 15, 2019 4:03 am Thanks for that. Your description kicked my mind out of a rut. For some reason I had got it fixed in my head when machining cranks to drill the axle hole, then drill and tap for the crankpin and finally drill and tap for the grub screw. Sigh.........

By using the sequence of axle, then grub screw and finally the crankpin, only a simple drilling fixture is needed. I'm waiting on some bits again, so I knocked one up yesterday afternoon.

The photo shows the fixture that I made earlier for machining the quartering flats on the left and the fixture to hold the crank while drilling and tapping for the crankpin on the right. I use a standard size axle for locos, so I only need one set of fixtures for outside cranks.

Outside Crank Jigs.jpg

The only reason they are machined all over is that the only suitable size piece of square bar under the bench was hot rolled steel and far from square, so the surfaces needed cleaning up. I used a fly cutter instead of a milling cutter, as the mill scale on hot rolled steel is as abrasive as the skin on an iron casting and fly cutters are a lot easier to sharpen than a milling cutter.

The axle retaining screw in the quartering fixture is positioned diagonally to use it as a marker, so if it is always facing forward in the vice the quartering flats will be at 90deg when the fixture is changed end for end.

It's a bit hard to see, but there is a flat milled on the 'axle' end sticking out of the crank drilling fixture, effectively it is just a stub axle sticking out of half a quartering jig, but is machined in one piece to maintain alignment.

With a DRO on the mill and a self-centering 4 jaw chuck in the lathe, making these fixtures was quick and easy. I'm not a great fan of jigs/fixtures, so the simpler the better.

Regards,
Graeme

Well my attempt is now finished and seems to work well too. Once set up once for zero it's very quick and easy to pop a new crank on and drill it, it will save me sooooo much time going forwards

Thanks for the idea of making a tool for this, both yourself and Ian.

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