Aveling Road Roller.

[Fluffy]

G'Day All,
I am attempting to build a 1.5" scale model Aveling road roller from a set of plans found while looking for another type of road roller & then inspired by an article of this roller in issue 19 of Model Engine Builder magazine by Mr. A. Suttie. The plans were drawn by Mr. E. Westbury about 1938 to suit castings that were available at that time. My first job was to draw a set of working drawings to metric measure & to scale the original drawings to allow the various cast components to be drawn & then machined from solid stock. The first task was to machine the helical timing gears for the engine. I used the information from the MEB article & the two gears eventually turned out to run very smoothly after a good deal of lead up machining for the jigs required & a number of prototypes to obtain a tooth profile that appears to be OK.
The crown wheels & pinions for the differential were the next to be machined. These gears are the first attempt at machining bevel gears & as the crown wheels have 60 teeth each a lot of milling was required to reach the finished gears. Now that all of the gears appear to be useable I have started on the engine.
Will continue as the engine components progress.
Regards,
Don.

 

[Jasonb]

Fluffy if you don't already know the castings for this engien are still available which may save you a lot of work, Engineers Emporium in the UK do them.

J

 

[Fluffy]

Jason,
Thanks for that information. I could not find any info on this project before I started it. I have now spent too much time on the crankcase/water jacket to not finish it. I will have a look however at the site that you mentioned.
Regards,
Don.

 

[Jasonb]

The supplier does not show the castings on their site, if you want to PM me your e-mail then I have their printed catalogue scanned in.

They do other parts not just the engine so could save you fabricating all the front end etc.

J

 

[Fluffy]

G'Day All,
I have all but completed the rollers crankcase/water jacket. Only the threaded holes remain to be done.
The crankcase/water jacket started as two pieces of 25 x 145 103mm 6061 aluminium plate. Each piece marked out & the pockets manually milled into each half. This was done with a Ø10 ball nosed endmill to give the outer contour of the pockets & then the remaining material removed with a Ø10, standard endmill. The halves then held together with 14, M3 countersunk screws & the bores for the crankshaft bearing housings & the cylinder liner added.
The final contour of the crankcase & openings into the water jacket & crankcase cavities then milled with the corners rounded with R2 & R3 corner rounding endmills. So far, so good.
Regards,
Don.

 

[Fluffy]

G'Day All,
Progress continues on the roller's engine. I now have completed the cylinder liner, piston, conrod & piston rings.
The piston was turned from 6061 aluminium.
The cylinder liner & rings are 4E cast iron . The bore has been honed to size (25.4mm - 1") using the hones shown here.
The piston rings have been made using the information by Tom Schwartz from MEB issue 27. I initially turned to OD of the rings 0.2 mm oversize to allow the rings to be turned circular when turned to final size.Two mandrels were turned to, firstly to hold the rings ganged together to be slit with a 1.0 mm slitting saw & then all compressed onto the second mandrel that has an external diameter the same size as the diameter of the piston ring grooves. The rings were compressed onto the mandrel using a ring compressor turned to suit the application. When the rings are compressed onto the mandrel a clamping sleeve is tightened up to the rings using a threaded fastener. The ring OD's were then turned & polished to final size. When the rings are individually fitted to the cylinder bore there is no visible light showing between the ring & cylinder wall. You can be lucky sometimes.;D Hopefully the compression will be good!
The small inner holes on the cylinder liner flange are to allow engine coolant to pass through to the cylinder head.
I think the crankshaft will be next.
Apologies for not putting the text before each image but, I have not been able to work out how to do this???
Regards,
Don.

 

[weez]

Apologies for not putting the text before each image but, I have not been able to work out how to do this???
Regards,
Don.

Check out this post for an explanation.

 

[danstir]

Interesting build. And the work you have done looks excellent. I will definitely be watching. Thanks for sharing.

 

[Fluffy]

Thanks Weez,
I'll try it next post.

Thanks Danstir,
There is plenty more to do.
Don.

 

[Fluffy]

G'Day All,
The crankshaft has consumed quite a few hours to finish the crank pin.
The crankshaft blank (4140 steel), was marked out & the centre holes of both the crank axis & the crank pin were centre drilled in the mill, held with a rotary table. I have started to use etching primer as a marking medium as it is not affected by cutting oil as is the marking blue.


The blank was then setup to rough out the crank pin. This was close to the limits of the rigidity of the lathe but eventually the pin was roughed out. This piece of 4140 is the toughest piece that I have turned in this lathe & I thought for a while that I was not going to be able to use this material. I had intended to rough out as much material as possible with a parting tool but there was too much chatter to be useable.





As the crank pin is longer (16mm) than the width between the inner faces of the webs (11mm) this presented a problem as to how to finish the crank pin to size & to be parallel over the length.
The tools below are from the left; the initial roughing tool, the tool to reach the pin diameter & the ugly old forged HSS boring bar that has lived in the bottom of a tool box for many years. To turn the pin to diameter the grooving tool was used to reach the Ø11.07, then the boring bar was used to turn the pin diameter to the web face on the headstock side. The work was then reversed & the other side of the pin turned to the web.



The final sizing of the crank pin was achieved by more good luck than good management. A piece of 7 x 8 mm key steel was milled on one end to accommodate a piece of 600 grit x 7 mm square abrasive stone. The abrasive was glued to the key steel & a small top clamp attached. The width of the abrasive block is about 13mm to allow the block to be moved back & forwards across the pin surface. This was an experiment that I am pleased to say has worked well.
The spindle speed was set as high as was allowable due to the offset of the material & the abrasive moved across the pin using kerosene as a lubricant until the finished size was achieved, about 30 mins. Doubtless, there would be other ways of achieving this, but I am very pleased with the outcome.



Now the main journals & other diameters are under way.
Regards,
Don.

 

[AussieJimG]

That's a clever use of an abrasive block Don, I haven't seen that done before.

Jim

 

[RonGinger]

Nice work and very nice photos.

In your parts made with the 4 jaw chuck I noticed you have some kind of paper or tape between the jaws and the work. Can you tell me what that is and why you use it? A couple of those setups must have been hard to get together, with paralleles between the jaws and work. Do you remove the chuck and lay it on its back to make that kind of setup?

Thanks,

 

[Fluffy]

Jim,
I had not used an abrasive on a stick previously, but I could not think of any other way to obtain a good surface finish due to the variations in size. I took it slow & steady & it worked well.

Ron,
The paper (standard photocopy paper) used on the set up of the crankcase is to increase the frictional resistance between two smooth metal surfaces. A couple of thickness of paper under a cast surface being clamped to a machine table takes up the irregularities of the casting & protects the table surface from indentation. All of the setting up is done with the chuck on the lathe spindle.

Thanks for your interests.
Regards,
Don.

 

[Charles Lamont]

I am a bit surprised you have finished the crankpin without first roughing out
the rest of the shaft. I would be concerned about possible distortion.

 

[Fluffy]

Charles,
The crank pin had to be finished prior to roughing out the journals as the centre holes for the crank pin are removed during to achieve the journal diameters. To prevent distortion, a distance piece is fitted between the inner web faces. The distance piece is an interference fit & has 680 loctite applied. I am almost to the size where a fixed steady will be used for further support.
Regards,
Don.

 

[Fluffy]

G'Day All,
After a fair few hours more than expected the roller engine crankshaft is finished.
All turning of the crank has been done between centres, with all final surfaces finished to 0.03 mm oversize with HSS & then honed to the final size using an external hone.
A fitted aluminium distance piece was between the inner web faces to stop any distortion while completing the journals & the flywheel shafts. It is shown below with a cable tie around it as a backup for the interference fit of the spacer.



The milling of the web profiles was straight forward & was also done between centres. Clamping of the crank was cause for concern as I was very conscious of bending, but fortunately all when well.



The crankshaft finally finished with M10 x 1 threads on both ends.





The reasons I decided on turning the crank from solid material was mostly due to the lack of a suitable gas set to enable a fabricated crank to be silver soldered together and as the webs are under 7mm wide at the journal diameters I thought that using tapered pins to hold the crank together was a big ask.
This piece of 4140 steel was very tough to machine with HSS, however, coated carbide cutting edges were quite OK. The milling cutter is a Ø10 mm solid carbide end mill but, due to the lack of the correct spindle speed (about 1/4 of that required) being available the cutting edges have not survived too well.
Regards,
Don.

 

[Fluffy]

G'Day All,
It has been a while since the workshop has been used, too many jobs to do outside during the cooler weather. It has been wet for a couple of days so a little more progress has been achieved.
The cylinder head, head cover plate & the valve cartridges have been completed. All aluminium components are 6061-T6.
Cylinder head showing the outer side. The semi-circular groove & holes are coolant passages.



Cylinder head showing the cylinder side.



Cylinder head cover plate & retaining nut.



Valve bodies & valves.
These are the first valves that I have fabricated. The stems are Ø4mm, while the heads are Ø10mm both silver steel. Both the stems & the heads were threaded M4 & then silver soldered together. The valve bodies have been fabricated & silver steel valve seats were silver soldered in position. After the soldering was completed the valve bodies were then re-chucked & the guide diameter reamed & the valve seat turned to 60 degrees to ensure concentricity. The "E" clip grooves were ground with a 0.63mm wide Dremel cut off wheel.



The head assembly shown in position.





If it keeps raining I will get something else done.
Regards,
Don.

 

[AussieJimG]

It's looking good Don, if you need any more "cooler weather" I have an abundant supply.

Jim

 

[nemt]

Hello FluffY,
I follow the build with interest.
In the attachment is a drawing of the engine as I made in SW.
During stay in hospital I made this.

Never had plans to make the roller complete.
Good luck with the build and I will follow your progression.

Greetings from Holland,

Nemt

View attachment Avelingengine.PDF

 

[Fluffy]

Thanks Jim,
Progress is slow, but its getting there. Don't want any cool weather though.

Nemt,
Thanks for the drawing. Hopefully my engine will look the same in time. I found the original drawings on the Model Engine News site & converted these to metric sizing.

Regards,
Don.