[Jeroen]

I went to HBM yesterday. Exchanged the bend reamer and got a few more bits and pieces.



So this morning I tried to finish the driving rod, all it needed was reaming. But when I tried my new reamer I found this one was also not particularly straight!!





Easily a 0,45mm wobble!! That is way too much.

So I decided not to use the reamer in the chuck, but ream the hole manually. That ensures a much more true hole anyway.

Got to use my special tap follower as well. Worked a treat!



Pretty pleased with the end result!





Trial fitted the bearing. It will need a bit of lock-tite, but other than that it will do fine!



Next, back to the cylinder head. I decided to bore out the hole. I mistakenly had drilled this to 10mm. Whereas it needed to be appropriate for M10 thread. So I drilled it to 12mm.

First thing, get it properly aligned in the four jaw chuck. I am getting pretty good at this. Will take me just a few minutes!!



Drill to 12mm



I decided to cut a little edge for the bush I was about to make.





Produced a bushing 12mm outside with a little boss (edge) to match the cylinder.



Cylinderhead in my wife’s oven at 220oC and the bushing into the deep freeze at -20oC.



I left them for about an hour. Took them out and pressed the bushing into the cylinder head without any problem. Next I put the cylinder head into the lath again for some final finishing.

I had drilled the bushing at 6mm only. Now I drilled to 8,5mm, the diameter for a M10x1 fine thread.



Next, with my new M10 tap and my tap follower I made the thread:



Looking good!





Test fitting with the spark plug:



Beginning to look like a real engine!!!!!



Jeroen

[Jeroen]

Less than two hours work on Debbie tonight. But pretty productive.

I made the glide bearing on the piston side from bronze. Needs to be pressed into the driving rod, so dimensions are critical.



Pressed the bearing into the rod, again using my trusted hot/cold technique using my wife’s oven en freezer. Nice fit!



I then proceeded to make the pivot to connect the rod to the fork. Pretty precise. Press fitting in the fork, but the rod with the new bearing needs to rotate freely, but without play!



It’s beginning to look like a proper little engine already!



Jeroen

[Jeroen]

Last night I started the work on the two supports. These need to pretty solid, as they will be supporting the full weight of the fly wheel. Also they need to be precise in terms of dimension. Especially the bearing fitting and the height of the bearing.

I have two pieces of aluminium. Almost the correct thickness and the two bearings:



As always, I start by marking up the part. Which always requires some careful consideration. Where to leave additional material. In this case I added 2mm to the bottom of the part. I can always take that off later. But it will ensure I have sufficient material to ensure a perfect alignment of the two bearings at a later date.



I could have taken the mini mill to cut off all material. But it is slow at the best of times. So the old trusted hacksaw to the rescue.





It does not have to be precise. As long as you get within 1-2mm of the lines of the part, it’s ok. Not to bad!



In order to mill the radius on top of the support, I am going to use the same technique as with the driving rod. However, for this part the radius as well the thickness of the material is twice the size. The boss I made for the driving rod was only 6mm. I decided to upgrade to a more manly 10mm!

First thing to center drill the hole and then drill it to 10mm







Next, some quick work on the lathe producing the boss. Actually, this is the boss I made for the cylinder of the wobbler. I am just modifying it. Nothing going to waste.





The trickiest aspect of this part is how to drill the hole for the bearing. It needs to be 26mm, but not all the way through. If you have a proper mill, and the necessary bits, I guess it would be very straightforward. But there is no way I can handle such a cut on my little mini drill. So my strategy was to use the lath. Which meant having to put the support in the 4 jaw chuck. However, that was going to be incredibly tight. I would not know if it would work until I tried.

I had to make a few more cuts with the hack saw, but I am happy to report that this is very likely to work. Very tight, but that is all we need!





Next I will be milling the radius first on the mini mill with the help of my new tool boss. Then I will drill the bearing hole and then finish the rest back on the mini mill. And then do it all once more for the second support.

Jeroen

[Thad E Ginathom]

Awesome. You seem very happy with he good old hacksaw, but... bandsaw on the shopping list?

Why didn't you drill that bearing hole on the mill? Just curious.

[Jeroen]

Originally Posted by Thad E Ginathom

Why didn't you drill that bearing hole on the mill? Just curious.

The outside diameter is 26mm. Which is way to big a diameter for me little mini mill!

Jeroen

[Jeroen]

I was still not hundred percent pleased with the lights in my garage, in particular around my workbench, the lathe and the mini mill.



So I ordered myself a proper desk light. From Ikea on line. Ever since the Corona crisis Ikea was one of the very first shops to close completely and move all its business to online.

It happens to be exact same light as I have at my office desk as well. Looks smart and very practical.

Proper Ikea style it comes as DIY assembly





I ordered the wrong bulks. This one uses these small narrow fittings. Bummer, I will have to go and get some I had one other spare bulb lying around, but it is really a spotlight bulb. But even so, it does already a pretty good job!



Jeroen

[Thad E Ginathom]

That is a very nice lamp. Mechanism from the original Anglepoise lamp. I wish I still had the old one that was my fathers: I think they are saleable now! But I do have a more recent one. It was used in my Jewellery workshop. It is in need of restoration, but still sits, and works, by my side.

[Jeroen]

Some more work on Debbie over the weekend.

First order of business, using my newly fabricated boss, mill the top of the support to a nice smooth circle.





My new lamp came in handy too!



Pretty damn perfect; 34mm it says on the drawing, 34mm it is!



Now for the tricky part, finding a way to get this support set up properly in my 4 jaw chuck.



After about an hour of messing about, it became clear to me that it was not going to work. The problem is that whilst two of the jaws provide good support, the other two were just digging into the side of the support. That does provide sufficient strength to hold it in place. The problem is, you can’t adjust the support to align properly.

So I made two separate cuts, one on each side of the support. Which meant the respective jaw would grip, but would also be able to move the support. I am very glad I left some extra material all around the support!



Tried it again and it was a lot easier to get the support properly aligned. I could not get it better than about 0,1mm on the measuring dial. But that is fine. The final allignement of the shaft is done through the height of the support and the fixing on the base plate.





First thing I did was to enlarge the 10mm to 13mm so I could get my boring bar in. The other day I checked all my various drill bits and made a proper inventory of all the various bits, so I know what I have and where it is:



I used my measuring dial to keep check on the depth. The bearing is 8mm thick.



With the quick change post it is easy to take the boring bar out, which means I can take good measurement without upsetting the measuring dial.



Test fitting the bearing. It needs only a bit of pressure and fits in nicely. So pretty much perfect.



Now I still need to open up the back of the support. It only has a 13mm hole, I will need to flip the support, align it and use the boring bar to increase it to 24mm. Then the support can be finished.

And then I have to do it all over again for the second support.

Still, it’s going better than I had anticipated!

Jeroen

[Jeroen]

Some more work done on Debbie, but unfortunately it is one of these cases of one step forward, two steps back!

First thing was to put the support back into the 4 jaw chuck to increase the opening at the back of the support.

I used the center to align the existing hole, visually. Worked really well





Pleased with the end result so far





Next, back into the mini mill to mill the sides of the support to the correct dimensions





I was pretty pleased with all of this and myself. What remained was to mill away the inside of the support. But when I was checking the dimensions, trying to put the correct lines for this on the support I noticed the overall dimensions are way off!!!



The support is way too high!! I messed up some of the dimensions. Even though the part looks good, it can’t be used. I can’t remodel it either. Only thing for it is to start all over again!

I am getting worse and worse on these sort of relative simple and straight forward jobs. Transferring measurements from a drawing to a piece of aluminium should be straight forward enough, but I am struggling more and more with these sort of tasks these days.

It’s not the end of the world, but I will have to order some more aluminium as well. I don’t have enough to make two support.

Jeroen

[Jeroen]

At long last I managed to spend some hours on Debbie again! Some mixed results, but progress is being made as they say.

Also, the remaining materials for Debbie arrived. This is all I need to build the carburator later on . So i should have everything to see me through our second lock down for the next five weeks. I also have 2,5 weeks holiday, so I am looking forward to make some good progress with Debbie!

Before ordering material I go through the Debbie drawing and right down what I need, check it against what I have in Stock and what is left to order. It all goes into my Master Spreadsheet. I hope that will be useful to someone building Debbie after me.



Materials arrive well packed, long brass tube taped on a piece of wood, so it doesn’t get damaged!



First order of business; make the second support. Which means transferring the dimensions from the drawing on a piece of aluminium. This permanent marker works really well. I do need to use some emery paper and de-greaser first for best results





Some additional lines, so I know where to put my hack saw to work!



I tried a different set of protectors on my Vice. These are cladded in rubber, instead of all aluminium. Not much difference though.



Ten minutes with my hack saw:



Ready to go back into the mini mill, to cut the rounded top using my well proven method with a boss, on which the support rotates



Pretty good result! Identical to the earlier one!



Back onto the lath. I am using the center to line up the support. Works really well, I got it well within 0,1mm centric. I checked afterwards with my gauge dial, but this is good enough as it is!





I am doing everything the exact same way as on the first support. But it is all going twice as fast. Practice makes perfects, as they say!

Drilling with my largest 13mm drill bit, so I can then put my boring bar to work.



Boring bar and dial gauge set up to ensure I go only 8mm deep!



The end result, test fit with the bearing. Perfect!





Next I was going to try to figure out how to mill the bottom end of the support and how I could modify the first support along the way. Problem though. I made another error on the second support as well. The first support was way too high. The second support is not as high, but it is still the wrong measures!!

@#$%^&*



So I came up with a very different approach to rescue both parts. Not much choice, because due to the lockdown it is going to be difficult to get hold of new material.

So I made a bushing out of Delrin. Exact same diameter of the bearing, twice the width. So it holds the two supports together and alligne the centre of the shaft to be exactly.





Next, after some more carefully measuring and a lot of checking, double checking and triple checking I cut off the base of both supports!!!



Now I can produce two half supports with identical measures easily on my mini mill:







Only took me about 30 minutes, but the results look good!






Next I need to mill two basement parts for the support. I think that should be possible with the cut offs I have. I will then drill, tap, bolt these to the earlier made supports and Bob’s your proverbial uncle once again.



The final milling will be done with everything bolted together. I need the bearing centre (now the Delrin bushing) to be exact 60mm above the bottom of the base. That should be doable.

I still have a few days of work, not even full days of work. By Thursday I will be done completely work wise and I will take two full weeks holiday. So plenty of time to get going with Debbie!

Jeroen

[Jeroen]

Over the course of the last couple of days I managed to finalise the supports!!

So I made the second support identical to the first one I showed earlier. Put them together with the special bushing I made earlier



With the two supports properly aligned I spend a long time measuring and measuring, and checking and measuring and checking and some more measuring and checking before I made the final cut off the base of the support to get the correct overall height!



These supports have been clamped down endlessly in so many different machines and positions. No matter how careful you are, you will end up with some scratches and some dents. Even though I use soft protectors all the time when clamping them down.

But I had a cunning plan all along. The original aluminium plate I used for these support was 10,45 mm thick. The design thickness is 10,00mm. So I had always planned to hone them down a few tenths of a millimeter both sides at the very end.

My fancy fly cutter to the rescue:



Here you see the difference after one single pass with the fly cutter compared to the rough finish on the original plate



Lots of emery paper and elbow grease required for the final finish!!




I really like the finish, looks smashing!!





Test fitted the bearings one more time





The overall height is perfect!! The centre of the bearing in the support will align perfectly with the centre of the piston rod!!



Tomorrow is the 24th of December, Christmas eve. We are back into a major lockdown again. We can only entertain two people per day outside our own safety bubble. Which means our Christmas will be spread out over three days to see all three kids, their partners, our grand daughter and my eldest sister. Traditionally they will all arrive Christmas eve and spend one or two nights with us. Very traditional Christmas celeration, lots of pressies, my wife does an outstanding Christmas dinner, Christmas Crackers, the works. And on Boxing day we would take them all to the cinema. Not so this year.

So I cleaned up my workshop as I won’t be doing any work for the next couple of days. Always gives me satisfaction to have everything tidy, clean and put in their appropriate place







Jeroen

[Thad E Ginathom]

Great progress, Jeroen... Well done!

Enjoy your family Christmas break. Looking forward to more engineering in the new year

[Jeroen]

I have been busy with Debbie’s crankshaft.



First the shaft itself. 99mm long, 10mm main diameter. I checked the diameter endlessly at different points along the shaft. As you will recall I had quite some problems with the alignement of the Lathe.

I am happy to report that along the full length of the shaft I have less than 0,02mm deviation. So that is pretty good!!







I am at the stage now, where, whenever a part is ready, I can do a quick assembly with other parts and get a feel for it all. Very rewarding!



Next the crank itself. Back to the lathe





All pretty straightforward, and fitting the new part, once again!





Now for a very tricky and very crucial part. A hole needs drilling into the crank to accommodate a crank pin. The position of this hole is crucial, as it determines the stroke! So it really needs to be positioned very precisely!!





Looking good and very precise!



Next the crank pin. Small, so a bit of a fiddly part.



The inside thread is M2. So with the help of my special tab tool I made a perfect thread!





Used a parting plate on the back, very carefully, easy does it.





Once I had the exact correct dimension, identical to the hole in the crank, I parted it completely. Still needed a few tenths of a mm taken of, just a few seconds with some emery paper.



Perfect fit:

[Jeroen]

Another quick trial fit:



Next, the washer. Careful measurement on drilling the reces for the bolt.



Parting is going very well indeed!!



Another part ready!



Some more test fitting of everything!









Very happy so far! Next the fly wheel. I had bought the material from the little machine shop. It was only 5mm to large a diameter. So into the four jaw chuck and getting it set up properly



It was very difficult to get going on this piece.



I tried different speeds, different feeds, different cutters. But I could not manage more than a cut of 0,1-0,2mm at the time. Anything more and my little lathe would stall. After a few hours I stopped, this is not going anywhere and I think I am really straining my little lathe. I need to figure out something better.

Jeroen

[Jeroen]

Bits and piece for the ignition have started arriving from China. Dead cheap, but it takes a while to arrive. This is the electronic ignition circuit and a hal sensor. The original design is based on a mechanical micro switch with a 12V car coil. But all my Dutch model forum friends tell me this should do better. I am not a hundred percent convinced yet. This little engine is going to need quite a spark to ignite its mixture. We will see. This is the relative easy part of the build and can be changed quite easily afterwards.



I have run into another problem though; my mini mill is buggered! Not sure how it happened. But the last few holes I drilled were not up to my usual standard at all. So I investigated a bit this afternoon.

Looks like the spindle and or the chuck is slightly out of whack. I have measured it in various ways and on the chuck I am getting almost 0,2mm wobble measuring just underneath it on a brand-new drill bit. So that is not good at all.



I called the guys from the shop I bought it from. They told me to bring it in, most likely still covered under warranty. They claim it usually takes just a week for these sort of repair. Might be a bit longer because of new year. So that is quite allright.

Spoke to my little local machine shop too. They are closed this week, but open up on Monday morning, so I will drop it off there first thing in the morning.

Jeroen