设为首页收藏本站

科技网

发动机建造 Kiwi Mk2(绝对精华)

[复制链接]
 楼主| 发表于 2014-4-23 04:36:10 | 显示全部楼层
Started work on the breather assembly body. Took a piece of 10mm brass and faced it off (lathe motor still working - keeping my fingers crossed). Took some measurements for the breather holes. Put in dividing head and drill six 1.5mm holes.

发动机建造

发动机建造

 楼主| 发表于 2014-4-23 04:36:40 | 显示全部楼层
Yesterday and this morning I continued work on the breather.
I cut down the breather body to size and reduced the side that goes into the crankcase to 6mm and then threaded it with a 6mm fine die. I then drilled and reamed the through hole 4mm. Reversed it in the chuck and with a 5mm slot drill increased the bored to the desired depth. Then tapped the first part of the 5mm hole 6mm fine. Yes, I should have drilled it 5.2 mm but brass is a bit forgiving. After tapping I passed again the 4mm reamer and then the 5mm slot drill to clean up the body of any burrs that might have been produced with the tap. Tested the cap and it fits nicely.
I then parted the cap off as it was still attached to the bar stock and cleaned it up.
Also yesterday I received an email from Kirk @ Hemingways that the gears should be available 1st week of January. Looking forward to receive them so I can check the bore and see if I can increase it slightly to a metric bore and then get started with the main castings.

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

 楼主| 发表于 2014-4-23 04:37:23 | 显示全部楼层
And here it is nearly finished.
I now need to put a 5mm tufnol disc inside. I ordered a small sheet of 1mm tufnol from ebay (postage cost more than the tufnol but what can I do if I can't find it locally). Now I need to machine a 5mm punch and die and see how that works.

发动机建造

发动机建造



 楼主| 发表于 2014-4-23 04:37:53 | 显示全部楼层
Today I received the 1mm teflon sheet and immediately went to the garage to try out the punch and die I made. I put the die in the headstock chuck and the punch in the tailstock. It works although the punched out teflon was slightly wider than 5mm. Fixed that by sanding it. The breather assembly is complete and it works.
In the photo is the teflon sheet, the breather parts and the punch and die. Not visible in the photo is a 3mm through hole in the die so that I can push out the punched out teflon.

发动机建造

发动机建造



This morning I went shopping for some metric ball bearings. The ones I got in the kit were 3/8 x 7/8 x 7/32. The ones I got were 10 x 19 x 5 (61800). I wanted open bearings (without shields) but could not find them, so I got them with rubber shields and removed the rubber. I hope I did not compromise them by doing that.
In the photo the ones on the left are the original bearings and the ones on the right are the ones I bought.

发动机建造

发动机建造

 楼主| 发表于 2014-4-23 04:38:41 | 显示全部楼层
This evening I plucked some courage to start work on the front crankcase casting. I put it in the 4 jaw chuck and centered it as best I could. It's so difficult with nothing really running true. I trimmed the chucking piece of the casting and then replaced the 4 jaw chuck with a collet holder. Clamped the casting (the part that had been cleaned up) in a collet. Turned the front face and bearing housing face to dimension. Hopefully tomorrow I will turn the front face spigot.
I am not really enjoying working on this casting because I can't exactly take any real measurements. Even the crankcase barrel is offcenter. I have the feeling that I am doing something not right all the time. I will persevere but I suspect that this will be the first and last time I will work on a casting model.

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

 楼主| 发表于 2014-4-23 04:39:17 | 显示全部楼层
Continued work on the front crankcase housing. Turned the spigot and with the crackcase barrel being casted off centre it came out not uniform. Drilled and bored the crankshaft hole 12.7mm and then machined the bearing housing for a push fit. Then parted off the casting and cleaned it with the mill.
It's not pretty but hopefully functional.

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

 楼主| 发表于 2014-4-23 04:39:44 | 显示全部楼层
This morning I went to the garage and as the chuck was already off the spindle I decided to check the alignment of the tailstock to the headstock. So, out came the parallel test bar. Took readings and everything was OK. It must be the 3 jaw chuck that is the problem because if I ream a 10mm hole it always ends up 10.2mm. Oh well have to work around it.
Started work on the crankshaft bush for the front crankcase. Used a piece of bronze from the kit. Turned it 12.7mm and gave it a 1.6mm lip of 15.8mm diameter. Parted it off and cleaned it up. Put back in the chuck and drilled 9.8mm. Now I am not going to ream it because it would end up oversize so the solution was to bore it. only problem was that I do not have such a small boring bar. After rumaging trough the tools I found an small imperial internal threading tool which I do not use, ground it out further to make it even smaller and now I had a small boring tool. Worked like a charm. The hole was bored 10.05 mm.

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

 楼主| 发表于 2014-4-23 04:40:21 | 显示全部楼层
I then pushed the bush in the cranckcase body and tried it with a 10mm silver steel rod. Good fit. I haven't pressed the ball bearing in yet as I still have some work to do and I do not want to contaminate it with aluminium dust, but seems to work also with the bush.
Last photo is my improvised boring bar.

发动机建造

发动机建造

发动机建造

发动机建造

 楼主| 发表于 2014-4-23 04:40:59 | 显示全部楼层
Did not do much today. Not that I usually do a lot. Morning was spent at the annual get-together at the radio amateurs club.
This evening drilled and tapped (5mm) the hole for the oil drain plug and inserted the bearing. Trial fit with a 10mm silver steel rod was ok. Then I started work on the timing cover. Machined on the lathe the outside face and reversed it to machine the other side, but the tool bit was getting too close to the chuck jaws, so I stopped for today.
Next time I have to figure out how to continue work on the timing cover.

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

发动机建造

 楼主| 发表于 2014-4-23 04:41:17 | 显示全部楼层
This morning spent most of the time figuring out how to continue work on the timing cover. At first I was thinking of putting a spacer under the cover in the chuck to take it out some more but at the end discarded this idea as I thought it would would be dangerous if the part flew out of the chuck.
So at the end I ended up using the same method I used for the tappet guides; i.e. fixing the cover to another piece of aluminium and using the rotary table. I figured out that in just one setting I could first reduce the diameter of the cover, then reduce the thickness of the cover and at the end machine the edge recess.
I only managed to get it fixed to aluminium using two 4mm brass screws. Will continue next time.

发动机建造

发动机建造

发动机建造

发动机建造

您需要登录后才可以回帖 登录 | 注册

本版积分规则

辽公网安备 21100402204006号|科技网 ( 辽ICP备07501385号-1   

GMT+8, 2019-11-23 05:21

Powered by tech-domain X3.4 Licensed

© 2001-2017 Comsenz Inc.

快速回复 返回顶部 返回列表