PDA

View Full Version : Aveling I.C. Model Roller



Don@2480
10th Oct 2017, 09:27 AM
G'Day All,
I started the build of this 1-1/2" scale Aveling model roller (designed by Edgar Westbury, circa 1938) early 2013. I found a set of copied original drawings from the Model Engineer magazine of the time, while looking for similar drawings for the Aussie built McDonald roller. The original drawings were drawn to be used with a set of castings that were available in the UK & apparently still are available.
I scaled up every sheet that had a drawn component on it & worked out a scale for each drawing from a dimensioned size. Then I drew a set of working drawings to enable all components to be either machined from solid stock or to be fabricated. This took three months to complete & finished up with 65, A4 pages of detail drawings.
As the camshaft is driven via two small spiral gears & this was the first problem to be sorted out. If I could not produce these gears the project would not proceed. Fortunately, I was able to make contact with a brilliant Canadian Modeller, Mr. Allan Suttie who steered me in the right direction as to how to make the two jigs required to enable the gears to be turned by plunging a formed HSS tool bit to depth, producing one tooth groove at a time.
This worked better than expected after a bit of trial & error.
To obtain a suitable tool profile a "hob" like cutter of 0.6 module was made to cut a spur gear to be used to grind the tool bit to a suitable profile.
370468

The two jigs (one for 60˚ & one for 30˚) shown below are held in a chuck & presents the gear blank in a position that enables a groove to be cut around the gear blank surface at the correct angle. It's a rather strange motion that the blank rotates through but, it worked.
370469370470370476

The final gears & a little jig to test run them.
370473370472

Once happy with the timing gears the crankcase/water jacket was started.
The material used for the crankcase was two pieces of 145 x 105 x 25, 6061 Aluminium. The internal cavities milled using both standard & bull nose end mills. A note here, all machining is manually done.
370477 370478
Regards & will continue,
Don.

chambezio
10th Oct 2017, 10:12 AM
Don welcome to the Forum. I will be looking at this thread with interest as you proceed. Great text and photos!! Isn't it great how "strangers" are willing to help you through difficulties we run into.

Don@2480
11th Oct 2017, 01:03 PM
G'Day All,
Thanks to all those that send a like for this thread.
To continue with the crankcase, both sides of the c/case were held together using 14, M3 c/sunk head screws positioned around both the internal & external contact surfaces. The bores for the cylinder sleeve & the bearing housings were then finished. The cylinder bore was done first.The centre positions of all bores were set concentric using a wriggler & dial indicator. The c/case was then milled to final form.

370490370491370492

The two crankshaft bearing housing were completed next. One was a straight forward turning & milling job.
370493

The housing with the cam gear housing was a different matter. Rather that try to make it in one piece, it was made as two parts that when fitted together & hopefully would appear as a casting. With the addition of a little liquid metal & a good sanding hopefully this will be the case. The housing being attached with two, M3 socket head screws.

370494370495370497

The crankshaft is made from a piece of 4140 steel & was turned as a whole part between centres.

370498 Marking out of the main lengths of the webs & journals.
370499 First cut to rough out the crank pin.
370500 Crankpin roughed out.
370501 Crankpin to finished size.
370502 Tools used to turn the crankpin. The tool on the right is a piece of key steel, milled to house a piece of abrasive grinding stick. The abrasive was held in place with a finger type clamp & a liberal amount of 24hr araldite. As this tool only had to improve the surface finish, it held together long enough to achieve the desired results. The old HSS boring bar was used to relieve the webs around the crankpin.
370503 To turn the journals & reduce the possibility of the crank flexing, a fitted piece of aluminium was placed between the webs & held in position with a cable tie.
370504 The crank was then milled to produce the two counter masses.
370505370506 The finished crank. The threads are M10 x 1, both screw cut. The journals are both Ø12.5, the crankpin Ø11.

This may be a little point of interest. For some time now I have been using pressure pack etching primer paint as a making medium, for two reasons. Firstly, if it is put on lightly, a good line can be scribed into it & the great advantage is that it is not removed by cutting fluids/oils. Secondly, it is readily available. I found in my area that small quantities of marking medium are on longer available, a five litre bottle was totally over the top! I use both black & grey primer. The colour depends upon the colour of the metal to be machined.
Regards,
Don.

Don@2480
13th Oct 2017, 10:25 AM
G'Day All,
The cylinder head was the next part to be made & started as a block of 6061 Al.

http://metalworkforums.com/attachment.php?attachmentid=370552&stc=1&thumb=1&d=1507846327http://metalworkforums.com/attachment.php?attachmentid=370551&stc=1&thumb=1&d=1507846385http://metalworkforums.com/attachment.php?attachmentid=370544&stc=1&thumb=1&d=1507847825http://metalworkforums.com/attachment.php?attachmentid=370550&stc=1&thumb=1&d=1507846431http://metalworkforums.com/attachment.php?attachmentid=370548&stc=1&thumb=1&d=1507846513

The head is water cooled & has an internal combustion chamber that also provides entry positions for the valves. The third image shows this feature. The cover plate & nut are simply to seal the water gallery on the outer side of the head.


http://metalworkforums.com/attachment.php?attachmentid=370580&stc=1&thumb=1&d=1507851789http://metalworkforums.com/attachment.php?attachmentid=370581&stc=1&thumb=1&d=1507848129http://metalworkforums.com/attachment.php?attachmentid=370582&stc=1&thumb=1&d=1507848723
Other engines that I have built, have had the valve seats as an integral part of the head or as inserts & I have had trouble trying to get the valve & seat to make a total seal without a lot of valve lapping. I decided to try a different approach & made the valve, valve stem/body & seat as "cartridge" type insert, so that the valve & seat could be lapped together & the valve cartridge could be assembled & then inserted into the head as an assembly. Happily this worked very well. The cartridge is sealed with a gasket under the top flange.


http://metalworkforums.com/attachment.php?attachmentid=370583&stc=1&thumb=1&d=1507848978http://metalworkforums.com/attachment.php?attachmentid=370584&stc=1&thumb=1&d=1507848950http://metalworkforums.com/attachment.php?attachmentid=370585&stc=1&thumb=1&d=1507849367
The cylinder sleeve is made from 4E cast iron & was a straight forward turning & drill job. To hone the cylinder to final size I had to make an adjustable hone by turning an arbor with a No2. Morse taper to expand the hone sleeve. Two hone sleeves were made one of soft brass & the other aluminium for finish lapping. The final lap was done using 1200 grit lapping paste & kero. The arbor has a piece of 1.5mm sheet let into it to act as a key to stop the sleeve spinning. Next time I make a hone like this, I will add a threaded section behind the large diameter of the taper to aid removal of the sleeve.

http://metalworkforums.com/attachment.php?attachmentid=370586&stc=1&thumb=1&d=1507850444

The original drawings had a spark plug size that was far out of scale for the size of the engine. I have used miniature plug with a 1/4" x 32 tip thread. Big difference when compared to a standard plug.



Regards for now,
Don.

chambezio
13th Oct 2017, 11:04 AM
Don the pics didn't load. You may have to do them again

Don@2480
14th Oct 2017, 03:24 PM
G'Day All,
I tried to post yesterday, but some thing went pear shaped & it did not come up. Try again.

The cylinder head started as a block of 6061 Al. Turned the threaded spigot first, then completed the milling & drilling.

370594370596370597370598370599

The head is water cooled & has a combustion chamber (forth image) with a valve on either side of the chamber. The hole in the top of the face of the head (third image) is the inlet port. The exhaust port is in the bottom surface of the head. When assembled the piston comes to within 0.5mm of the head. The nut & flange are to seal the water gallery on the head's external surface.

The valve cartridges have been modified slightly from the original design & I think a good improvement to positioning a very small valve seat in the head. I have had problems with trying to get small seats into heads & stay square to the axis of the valves on previous engines.
The cartridges contain the valve, seat, body & spring & are sealed with an oil jointing gasket under the flange. The the valve seats are cast iron. The valve stems & heads are silver steel. Heads being silver soldered to the stems.

370603370604370605


The cylinder liner was simply a turning & drilling job.
370600370601370602

The honing tool consists of parallel arbor & a No2. Morse taper to expand the hone. The taper has a 1.5mm piece of mild steel sheet in it the stop the hone rotating. What should have being made into the arbor is a threaded section at the large end to remove the hone. The brass hone was used for the initial hone & the aluminium hone for finishing. The finishing abrasive was 1200 grit paste & kero.

The original drawing called for a standard sized spark plug, which is way out of scale. The plug used is a miniature plug with a 1/4" x 32 TPI thread & suits the application far better. Not much of it when compared to a standard plug.
370606

Regards,
Don.

Don@2480
17th Oct 2017, 11:17 AM
G'Day All,
The carburettor body was next to be fabricated. Again I wanted the body to look as though it was cast, so the various components were machined, assembled & silver soldered together. The silver solder used was 45% silver, expensive, but so good to use. The carby body has a spring loaded choke type valve that sits over the main section of the body & is activated by the engine vacuum (2nd image) to open a series of ports in both the sleeve & body. The finished carby shown in the third image.

370641370642370643

The exhaust & inlet cams were milled with the aid of a boring head & dividing head. The boring head being set so the tool & cam blank only made contact on one side of the blank. The dividing head was rotated in 5 degree increments, with the tool being fed down the blank width to cut the side of the blank. This process continued until a radiused surface was left unmachined that a radius could be filed to suit the dwell of the cam at fully open position. The sides of the cams did finish up with a larger than required radial lift face, requiring filing to form a flat lift so that the valve opened & closed as required. The cams are both made from 4140 steel & will be heat treated. The cam shaft is a length of Ø6 silver steel, with the cams attached to the shaft with two M3 grub screws that align with small dimples drilled into the shaft. This sounds a bit dodgy for a cam shaft but, has worked OK.

370644370645370646370647

The big end bearing is made form phosphor bronze. The bore was turned a little under size & then was scraped to fit the crankpin. The two small tubes are the oil pickup tubes for the bearing lubrication.

370648370649

The piston rings are made from 4E cast iron. The Method that I used to make the rings was found in a Model Engine Builder magazine, where the rings are turned oversize for both the OD & ID. The rings are fitted to an arbor & then slit with a 0.6 mm slitting saw. The rings are put onto another arbour that is turned to the diameter of the piston ring groove & compressed so that the gap from the slitting saw is completely closed & the rings are then turned to the diameter required. The working ring gap is filled to size after the final turning.

370650370651370652

All the parts of the engine prior to assembly.

370655

Regards,
Don

Don@2480
20th Oct 2017, 09:28 AM
G'Day All,
Final images for the Aveling engine.
Had a few problems with the incorrect choice of material for the fixed ignition point. I initially made the fixed point from an M3, 316 stainless steel bolt. The spark eroded the contact face in no time & caused a scale to form on the contact face that greatly inhibited the spark conduction, causing the engine to run very erratically. A new fixed point was made by silver soldering a tungsten point removed from an old set of ignition points to a brass thread. Problem solved.
Fuel was also a bit of a problem. Firstly, I tried a commercial fuel produced for four stroke, glow plug aero engines. This stuff fired OK but filled the garage with smoke & set off the smoke alarm in a couple of minutes. 91 octane petrol made the engine run rough, 96 octane made it run too hot. A shandy of 50-50, 91 & 96 works well.

Images below are the engine being valve & ignition timed & general images.

370708370709370710370711

The image is a bit dodgy but its an old video camera that I borrowed.


https://youtu.be/zbHb9574rss

Thanks to everybody that have responded to this thread. Much appreciated.
Regards,
Don.

Picko
20th Oct 2017, 12:10 PM
Got to be happy with that Don. Good one.

Abratool
20th Oct 2017, 01:44 PM
Don
I, for one, have admired the marvellous skill & precise workmanship that you have put into this project.
Its an admirable piece of work, & the resulting working model is very satisfying to watch.
regards
Bruce

BaronJ
22nd Oct 2017, 12:52 AM
Hi Don,

Very nice work, runs and sounds quite good.

kwijibo99
22nd Oct 2017, 09:51 AM
G'day Don,
You've done an outstanding job on your engine and the video of it starting and running so smoothly is a testament to your skill.
I've been working on an engine myself since 2013 but my progress is dwarfed by yours.
I find the method you used to make the skew gears particularly interesting and one I might try replicating When the time comes.
Thank you for this thread.
Cheers,
Greg.

jack620
23rd Oct 2017, 08:39 PM
Nicely done. Any idea what it's maximum RPM is?

Don@2480
26th Oct 2017, 12:22 PM
G'Day All,
Thanks again to those who have liked & given nice comments.

Chris, I do not know what the maximum RPM of the engine is, as the electronic tacho has had a burn out. The highest engine speed in the video is at half throttle. I was not brave enough to take it any higher as the RPM was fairly high at this throttle setting.

Greg, if I can assist with any information for the spiral gears that you require, just give me a yell.

After the engine was running to requirements, I started on the differential & its gears. I thought that cutting bevel gears at home was going to be a rather large challenge. However, after reading the bevel gearing section of Ivan Law's book "Gears & Gear Cutting", the process was fairly straight forward. A HSS tool bit was ground to the form of the appropriate gear cutter & then mounted in a purpose made fly cutter.
Aluminium gear blanks were used to make bevel gear & pinion test gears prior to making the cast iron & bronze gears.
The first image is the test blank, being used to firstly check the indexing calcs. Second image is a cast iron gear being cut, then the test & finished pinions.

370801370802370803370804370805

The diff spider has a 95 tooth 1.0 module spur gear attached as the diff driving gear. To cut this gear a "hob like" cutter was turned to form on the arbor that it was to mounted in the mill on. The steel used for the cutter is 0.75% carbon tool steel. The teeth being relieved & the finished cutter after heat treatment. The spur gear blank was mounted on the diff spider & the teeth cut using 0.5 mm depth of cut during roughing & 0.25 depth for finishing.

370806370807370808370809

The finished differential.
370810

Another gear & pinion have been machined to be used in the transmission.
Regards,
Don.

Picko
26th Oct 2017, 02:25 PM
:clap: Nice work Don.

simonl
5th Nov 2017, 08:58 AM
Hi Don,

I'm a bit late reading this thread but I have thoroughly enjoyed reading your posts. Your techniques employed and attention to detail are to be admired. Boy do I have a lot yet to learn!

Nice work Don.

Simon

TheNutter
10th Nov 2017, 05:42 PM
Hi Don

This is really impressive, makes the 040 steam loco I am making seem... well steam powered.

Regards

Ian

Don@2480
19th Nov 2017, 01:30 PM
G'Day All,
Thanks again to all that have sent likes etc.

I have fabricated the pivot head for the front of the roller & after grit blasting it should look like a casting. It has been fabricated from six pieces of shaped materials & then silver soldered together. My MAPP gas torch was at it limits to keep enough heat into the assembly to allow a reasonable flow of the silver solder. The bearing housing was turned with a 12˚ taper over the height with the other pieces being cut & shaped by hand. The last image painted with aching primer to see if it would look like a casting.

371177371178371179371180

The drawing called for the chassis rails to be made from 25 x 16 x 385 channel. Fat chance of buying that! So, the two rails have been mill from 25 x 25 black bar. Also, 19 x 10 channel is required as well as 10 x10 angle. Both of these will be milled.

371181371182

The rear axle block was also to be fabricated, but after the heating problems for the pivot head it was machined from a 75 X 75 X 75 piece of mild that has been lurking under the bench for years. The block will be fitted with two bronze plain bearings & will be riveted to the chassis rails.

371183371184371185

Currently turning the rear rollers from Ø150 x 64 solid stock. The rollers were to be fabricated also but, are well beyond my heating capacity.

This is a photo of the real deal that started it all.
371186

Regards,
Don.

Don@2480
14th Mar 2018, 02:44 PM
G'Day All,
Finally back in the shed after the summer heat has subsided, just too hot to do any work since last November.
I have recently finished the two rear rollers, apart from the reamed holes that will house the drive pins.
The time required, as it turned out (no pun intended) to complete, took much longer that I had anticipated. The lack of suitable tooling for this job being the main cause. I would have liked to have had a number of face grooving tools but, at a couple of hundred each the cost was too high. The bulk of the material was removed by plunging a ground HSS tool to a depth of around 5mm & increasing the diameter with successive cuts until a carbide boring bar could be then used to remove the excess material. The inner face being tapered at 11˚only compounded the problem. After 3 wheelie bins of swarf, the turning was complete. The rollers are Ø149 x 65 wide. The roller that has the stepped centre spigot is the roller that will eventually house the differential centre.

372463372464372465372466

The front rollers are being turned at present & are presenting the same problems with regard to relieving the centres.
Regards,
Don.

Don@2480
25th Mar 2019, 09:34 PM
G'Day All,
Finally, back in the shed after the summer heat & other interruptions. I have finished both the front rollers, again turned from solid stock (Ø150 x 56) black MS. As the rollers are only ever to be rotating at a very low RPM, I have made the inboard & outboard bushes from 6061 T4 aluminium.

378585

The steering fork has taken about 20hrs to finish & required a lot of milling using a Ø5 mm end mill for most of the milling with the inner radiused corners of the relieved section completed with a Ø5 bullnosed end mill. I was trying to make the steering fork look like it has been cast & by using a mounted point in a dramel to rough up the surfaces of the relief, I think that it will have a cast look after the outer surfaces have been grit blasted.
The folk started as a Ø170 x 30 piece of black MS that was turned to Ø168 x 25.5. The blank was marked out & set up in the mill on a rotary table & the inner diameter of Ø150 was milled to form with a Ø5 end mill using 2mm deep cuts.

378586378587378588

Once this was completed, the folk blank was set up on an angle plate to mill the Ø12 grooves for the pivot trunnions that are to be silver soldered in position.

378589

The fork blank was then clamped to a piece of 12mm plate that was bolted to the rotary table. This was to allow the relieving of centre section of the folk.

378592
Shown here is the smaller diameter of the relief. When this groove was to depth the blank was repositioned to mill the large diameter of the relief.

Below is the fork after the relieving had been completed on both sides of the fork.

378595

The trunnions were held in position during the brazing with a piece of Ø6 rod, threaded at both ends so that a couple of nuts could be tightened to hold all the parts together. This rod also doubled as a clamping bar for the milling of the taper that runs down to the pivot trunnions.
Below is the fork with trunnions brazed in position & the body of the fork being milled to a taper of 4˚, both sides.

378596

And, the finished fork.

378597378598

As can be seen there has been a lot of effort to complete the steering fork, but I think that it was worth the effort. As I am not a welder, fabrication was not a consideration.
The forecarrige that connects the steering fork to the roller axle is now being made.
Regards,
Don.

caskwarrior
25th Mar 2019, 10:13 PM
Have to admire those results, that fork is lovely.

Don@2480
2nd Aug 2019, 04:16 PM
G'Day All,
Back again after the usual interruptions of retirement.
I have completed the friction drive transmission for the roller. I'm not sure that this is going to work effectively but, I am building the model as per the original drawings. I've made two friction wheels both with a linen impregnated bakelite centre. One has the bakelite in contact with the friction disk (mild steel), the other has an O-ring seated in a radial groove into the bakelite disk. The steel friction disk will be grit blasted to hopefully improve the frictional resistance. The original plans state that the friction wheel should be made from "hard rubber", whatever that is. I had the bakelite on hand so it has been given a trial. I will not know how successful the type of drive will be until the roller is a stage were it is drivable.
In an attempt to make the outer casing look as if it has been cast, the sides & ends have be machined from 50 x 10 black flat bar. Then roughed up with a mounted point in a die grinder to try & make it look like a casting.
The image below shows most parts of the transmission.

381101

The friction wheel body required a 10mm square hole to fit the square main drive shaft. This was achieved by drilling a Ø10.5 hole & counterboring it 3mm deep to the diagonal size of the 10mm square. A piece of HSS was ground as shown & pressed through the wheel in an arbor press. The resulting hole is a neat sliding fit on the shaft.

381102

HSS "broach" for the square hole.

381103

The transmission fully assembled.

381104381106
381105

The transmission in position on the roller chassis.

381107

Cutting the transmission to differential drive pinion.

381108

Progress is painfully slow, but is getting there.
Regards,
Don.

shedhappens
2nd Aug 2019, 07:35 PM
Progress is painfully slow, but is getting there.
Regards,
Don.

You are doing a good job of this and I can see a lot of hours in your work, and many more hours just thinking about
it I am sure.

cheers, shed

Don@2480
29th Oct 2019, 03:25 PM
G'Day All,
Back again with a little more progress on the roller.
Since the last post, I have fabricated the front roller forecarriage from 1.6mm MS plate & a milled centre section. A 6mm plate jig was made to hold all the components together & then, all components were silver soldered together. The front axle boxes are made from LG bronze.

383085383086

Once the forecarriage was completed, I could then set the front roller assembly & the pivot head in the correct position relative to the chassis. The original intention was to rivet the entire roller together using 3/32" solid steel rivets. This created too many problems trying to get into spaces around the chassis that simply was not practical due to space limitations. All fasteners are now 8BA bolts of both large & small head varieties. Below are some images of the assembly to date. Last Saturday, I spent all afternoon tapping 8BA threaded holes. I was just about a nervous wreck by the time the last hole was finished trying to avoid breaking the taps. Fortunately, I had two taper taps as one did not survive the afternoon.

383087383088383089383090

Currently working on the steering components, a worm, quadrant gear & a steering box.
Regards,
Don.

Don@2480
4th Dec 2019, 08:17 PM
G'Day All,
A little more has been completed on the roller construction.
I wanted the steering components to be completed before I went any further.
The worm was first. The original drawings called for an eight TPI worm which, I thought was a little too coarse. I cut a twelve TPI worm, with a Ø13 OD & a Ø4 bore. It has a M2 grub screw at each end of the thread to secure it to the steering shaft.

383517

The worm wheel was made from some cast iron from the scrap bin, The blank was bolted to a piece of aluminium & held in the dividing head. I made a "hob style" cutter to match the worm thread profile. The dividing head was set up on an adjustable angle plate to give the required lead angle of the worm.

383518

The steering quadrant was turned from Ø60, 6061 aluminium & then milled to the required profile. Shown with the segment of the worm wheel attached. The bolts used are 8BA small heads.

383519383520

The worm housing was fabricated from 1.6 & 3 mm sheet & a piece of Ø19 OD MS & turned ends. The piece of bronze tube was fitted into the ends & all silver soldered together. The bronze tube was cut out to provide the bearing surface at each end.

383521383523383524383525

The steering universal joint was an interesting little exercise.

383526

The completed steering assembly.
383529383527383528383530

I did not receive the worm wheel to accomodate the worm as the wheel is only 5mm thick. Happily, it works well & turns the front rollers with very little effort. I intend to fill in the last tooth gaps on each end of the worm wheel to stop the wheel being wound completely out of contact with the worm.

There is still a lot of work to do but, getting there.

Regards,
Don.

KBs PensNmore
5th Dec 2019, 11:22 PM
That is some awesome and intricate machining, plus fabrication work that you've done.:2tsup:
Kryn

Don@2480
12th Jan 2020, 11:24 AM
G'Day All,
Thanks to everybody that have "liked" the previous posts. Much appreciated.

Some further progress has been made on the roller. The first two images are the toothed engine to transmission drive pulleys, being cut using a formed HSS fly cutter.

384220384221

Each pulley then had a 1.5mm thick flange bolted to each side to act as the guide for the belt. I have used a toothed belt for the engine to transmission drive rather than chain, as I could not find a Oz supplier of short lengths of steel 1/4" pitch roller chain. Hopefully it will be OK.

The assembly of all parts made to date, are shown here in their etching primer livery next to a 300mm rule.

384222384223384224384225

Now that all the major parts have been made, the small fiddly bits are next such as the control levers, steering wheel etc.
Regards,
Don.

Don@2480
13th Apr 2020, 05:55 PM
G'Day All,
I am still building the roller & at present trying to fit an exhaust system that will clear all the other parts. My question here is, does anyone know where I can buy heat resistant twine/string, so that the exposed parts of the exhaust system can be insulated. I cannot use heat resistant tubing from the exhaust port to the muffler as there will be a couple of flanges to deal with. Any suggestions will be greatly appreciated.
Regards & thanks,
Don.

OxxAndBert
14th Apr 2020, 02:05 PM
G'Day All,
I am still building the roller & at present trying to fit an exhaust system that will clear all the other parts. My question here is, does anyone know where I can buy heat resistant twine/string, so that the exposed parts of the exhaust system can be insulated. I cannot use heat resistant tubing from the exhaust port to the muffler as there will be a couple of flanges to deal with. Any suggestions will be greatly appreciated.
Regards & thanks,
Don.

Don, a quick search online for "2mm fibreglass rope" turned up this:
https://www.ebay.com.au/itm/KT-Fibreglass-Rope-String-10-25-50-or-100-lin-m-Choose-1mm-1-5mm-or-2mm-/281424986626
I'm sure there are plenty of suppliers, but hopefully that gives you somewhere to start.

Steve

Don@2480
15th Apr 2020, 09:41 AM
Thanks Steve,
I'll start from this site & see what I can find.
Regards,
Don.

Don@2480
1st May 2020, 10:29 AM
G'Day All,
Some more progress on the roller. The exhaust system has been the most frustrating part of the build so far. I used K & S metals, 5/16" x 0.041" wall thickness hard drawn brass tube for the pipe work. I used the formula four times the pipe diameter for the minimum bend radius to make a tube bender to suit. The tube was annealed & packed with fine sand & plugged each end. I had no end of problems trying to get a smooth inner bend surface as the tube continually kinked. This was somewhat overcome by bending to about 15˚, re-annealing & bend another 15˚& so on. The result is not what I wanted but will have to do at present. The tube bent easier at a larger radius, but this was too big for the application as space is at a premium. The finished exhaust system to the tail pipe is shown here. The tail pipe will be left until the canopy is in place.

386203

The hand brake & transmission control levers & associated components were fiddly & time consuming. The lever positioning quadrants/ratchets were both initially turned into an annular ring fro 3mm ms sheet, mounted on a mandrel & milled to suit the the pawl profiles.

386204386205

The hand brake band is made from a piece of stainless "band-it" strap. It's very flexible & the exact width required. The brake material is a section of thin conveyor belt.

386206386207

Does anyone know where I may be able to buy miniature checker plate, locally? The pattern of standard checker plate is far too large for this application.
Stay well everyone.
Regards,
Don.

Don@2480
8th May 2020, 05:34 PM
G'Day All,
Thanks to everyone that sent a like to the last post on the rollers progress. It is much appreciated.

I have hit a bit of a brick wall at present. Having trouble finding a suitable ignition coil. The engine runs fine on a conventional 12V auto coil/condenser & points system.
My trouble is that I cannot find a supplier in Oz that can supply a coil small enough to fit into the space available. The coil needs to be no bigger than Ø35 mm & no longer than 40 mm. 6 or 12 volts does not matter. I was thinking of using a coil that the old style sparky model aero engines used to use, but cannot find any supplier of those coils either.
Can anyone offer some advice please.
Thanks in advance.
Don.

BaronJ
8th May 2020, 05:48 PM
Hi Don,

Very nice work there ! :2tsup:

I wonder if one of those camper 12 volt gas hob igniter’s would be any help ? The one on my camper hob sparks very rapidly when you hold the knob down. I've not taken the hob apart, but from memory when fitting it there looked to be two black cubes with wires to the control knobs and a single thick one to the spark probe. All that probe is, is a thing that looks like a pencil lead about 3 or 4 mm from the burner edge.

HTH.

GuzziJohn
8th May 2020, 06:35 PM
G'Day All,
Thanks to everyone that sent a like to the last post on the rollers progress. It is much appreciated.

I have hit a bit of a brick wall at present. Having trouble finding a suitable ignition coil. The engine runs fine on a conventional 12V auto coil/condenser & points system.
My trouble is that I cannot find a supplier in Oz that can supply a coil small enough to fit into the space available. The coil needs to be no bigger than Ø35 mm & no longer than 40 mm. 6 or 12 volts does not matter. I was thinking of using a coil that the old style sparky model aero engines used to use, but cannot find any supplier of those coils either.
Can anyone offer some advice please.
Thanks in advance.
Don.

https://www.dlenginesaustralia.com/dlshop/rcexl.html
Not sure if these are small enough. If not they may be able to suggest something

HavinaGo
15th May 2020, 12:23 AM
.....

Having trouble finding a suitable ignition coil. ...

My trouble is that I cannot find a supplier in Oz that can supply a coil small enough to fit into the space available. The coil needs to be no bigger than Ø35 mm & no longer than 40 mm. 6 or 12 volts does not matter. I was thinking of using a coil that the old style sparky model aero engines used to use, but cannot find any supplier of those coils either.
Can anyone offer some advice please.
Thanks in advance.
Don.

Hi Don,

Not sure if it is small enough or would do the job but in my efforts to get a motor bike going I came across this
386589
Case just 30mm dia if cut off mounting lug and 33mm long ignoring lead/plugs
From a Honda TRX300 1990 vintage motor bike.
One gotcha might be that it is a CDI system and expects a good wack on the primary of the coil to do its thing.

Another random thought - On the gas oven in our home there is a gas flame monitor and electronic igniter on a single electronic board -- the coil used to generate the spark for the igniter is smaller again than the one above and is mounted on the board with a socket for the high voltage wire. https://www.ebay.com/p/1975814970?iid=271226094292&rt=nc is an example of the board but the white thing to the top left is bigger than the one in ours. Some effort to drive it would be required.

familyguy
15th May 2020, 10:52 AM
You've done an excellent job on the roller, back in the mid 50's we were 15km from the CBD and "out in the sticks" and all roads were unpaved dirt, I recall seeing them in my street and surrounding streets when they were being paved. Would a coil from a car coil pack the type that sits on top of the spark plug be any good.

Don@2480
15th May 2020, 01:44 PM
Thanks for the input blokes,
I have looked into an electronic box as suggested by GuzziJohn & I think that is what will finally finish up as the ignition. My concern with these units is that the ignition is going to fire every rev. (please correct me if I am wrong) which is not what I really wanted.

I have tried a motor bike coil & after only a couple of seconds all the magic smoke came out of one end of the coil & it was all over. I wired the coil as per instructed by the supplier for a test sparking & turned the switch in the circuit on/off as rapidly as I could & got a good spark each time. Then, poof. Lots of sparks & smoke. All over.

As space is extremely tight & cannot use an over the plug coil as the smallest I have been able to find is far too big.

Baron J's suggestion of a gas igniter reminded me that I have some information on these units that have been converted to act a a coil. May yet be worth consideration.

So, thanks again to all for your combined input.

Regards,
Don.

BaronJ
15th May 2020, 06:16 PM
Hi Don,

Maybe not suitable but worth looking at ! I recently disposed of an old laser printer, actually stripping it for useful parts. It occurred to me that the printer generates very high voltages for the corona wires and drum, around 30 Kv between them. The transformers are very small about 25 mm by 30 mm and maybe 8 mm thick. There are several of them feeding recitfier circuits, providing positive and negative voltages. So putting out maybe 12 - 15 Kv.

They seem to be driven by a power oscillator using a big FET from a 24 volt DC power rail. Now it would probably work to feed the transformer in the manner of a Kettering ignition.

Some pictures.

386602 386601

386600 386599
These are quite small and compact. The high voltage winding is on the top two pairs of pins and the bottom ones have a tap on the winding, so probably feedback of some sort. I did try flashing a 9 volt PP3 battery across but failed to be able to measure a voltage across the output. But you can feel a sting when you do. On the circuit board the two middle pins are joined together. The rectifier diodes on the output are wired as a voltage doubler, so I don't think that the transformer produces the full 15 Kv, probably only about half that.

HTH.

familyguy
16th May 2020, 11:34 AM
In the video I can see what looks like valves opening and closing so I'm assuming the roller is a 4 stroke if the points are driven by the camshaft which is what it looks like to me then you should only get a spark every second rev.
In any case it shouldn't matter - some motor cycles do fire every rev but that is due to the design of the points and coil, on a twin cylinder, I seem to remember on certain Hondas the points were driven by the crank shaft so there was a spark every rev, the one coil fires both cylinders, one of the cylinders had the spark on the exhaust stroke - it did not affect the running of the engine.

Don@2480
17th May 2020, 12:32 PM
G'day Familyguy,
Yes, it is a four stroke engine. It has 15cc capacity & runs best on 95 octane petrol. Using 91 petrol it "chugs" a bit & 98 it gets very hot.
Regards,
Don.

Don@2480
18th May 2022, 05:37 PM
G'Day All,
After a bit of a break due to illness, I have started on the roller again & have only a few components left to make. As you can see, the canopy roof is to be completed. The tail pipe & the roller scrapers are the only parts left to make.
Then hopefully, I will be able to try a test run. If the proves to be OK, a competed strip to the individual components for painting.


398582398583398584398585

The roller dimensions are; 575mm long, 225mm wide, 335mm high & weighs 22.3kg.

As a side issue. Make sure that you have regular PSA tests. Prostate cancer crept up on me & showed no symptoms. If not for regular checks it would have been too late before detection.

Regards,
Don.

Don@2480
26th Sep 2022, 02:53 PM
G'Day All,
Finally, have all the components of the model Aveling DX road roller complete.
There has been 477 individual components made, a lot then fabricated into one assembly.

400021
Parts missing from the image are; the piston, conrod & sump oil pan. These are in the crankcase.

The video is the first self powered run.

https://youtu.be/_u3EcjojaS0

Regards,
Don.

BaronJ
26th Sep 2022, 04:50 PM
Hi Don,

Very nice ! Its a good feeling when you have spent hours making something and then seeing it working :2tsup:.

familyguy
26th Sep 2022, 09:13 PM
Excellent work, you should be proud of the job done - scratch building something like the Aveling or any other working miniature model is a labour of love - I started a miniature V8 engine some years back and got as far as making the block and a cross plane crank, and then other jobs came along and no progress on the engine - maybe seeing your great effort will give me the kick up the butt that I need to restart work on the engine.

Ray-s
26th Sep 2022, 10:33 PM
Wow! What a brilliant effort - well done.

Don@2480
5th Oct 2022, 04:20 PM
G'Day All,
Thanks to those who have liked the previous post. Final painting been done now. Hopefully totally finished in a couple of weeks.
Regards,
Don,

Don@2480
1st Jun 2023, 10:18 AM
G'Day All,
Well, after starting 10 years & 5 months ago, the Aveling roller project is now complete. During that time I have logged 1405 hours of workshop time on it.
The final component parts totalled 477 individual parts, some of which have been assembled into fabricated assemblies such as the carburettor, the front roller forecarrige etc. The parts list does not count the threaded fasteners used on the frame & chassis. This has been a bar stock build.
Trying to paint the timber canopy with automotive paint proved to be an impossible task (for me anyway) as the paint did not like the timber even though & was sealed & undercoated. I hade no end of trouble trying to obtain a decent finish. Finished up using spray pack enamel. I used rifle barrel cold blackening solution on all of the threaded fasteners & was very happy with the results. Simple to use & cheap.
Regards,
Don.

402722402723402724402725