V-Twin 100cc Design & Build

[Craig Booth 1Participant @craigbooth1]

Posted by JasonB on 17/08/2019 20:44:26:

It's coming along nicely Craig and just goes to show you can hold milling cutters in a drill chuck

Ignorance is bliss. I guess as a newbie I can get away with it..

I presume now that you've hinted that the milling bit should be held in a collet instead for better accurancy?

[JasonBModerator @jasonb]

It is not just accuracy, the main reason is that a drill chuck does not hold the cutter very securely particularly when side load is applied and there is a risk of it moving. If you are lucky it will just ride up and not cut but due to the angle of the helix that the flutes follow the cutter is being pulled down when cutting, it would be a shame if this happened to a part that you had previously put a lot of work into.

I think we have all done it to start with or for the odd little cut where it's a faff to change from chuck to collet, (well at least I have) but would be worth investing in a collet chuck such as ER25 or 32 depending on what machine you have.

J

[Craig Booth 1Participant @craigbooth1]

Posted by JasonB on 18/08/2019 06:53:34:

It is not just accuracy, the main reason is that a drill chuck does not hold the cutter very securely particularly when side load is applied and there is a risk of it moving. If you are lucky it will just ride up and not cut but due to the angle of the helix that the flutes follow the cutter is being pulled down when cutting, it would be a shame if this happened to a part that you had previously put a lot of work into.

I think we have all done it to start with or for the odd little cut where it's a faff to change from chuck to collet, (well at least I have) but would be worth investing in a collet chuck such as ER25 or 32 depending on what machine you have.

J

Thanks for the info Jason, that's something new i've learnt.

I do have a collet set that i use for the larger (16mm bit), but will look to use them for the smaller also.

[Mark Gould 1Participant @markgould1]

Craig,

Loving this build thread immensely. As an alternative to holding your milling cutters in a collet you can also buy end mill holders from Arc which have fixed sizes. I have 2 ready to go with cutters in them 6mm and 10mm, being 2 sizes I use often.

**LINK**

Mark

[LainchyParticipant @lainchy]

Just spotted this thread, and it's superb! Nice work! I'm a noob myself (Far MORE of a noob than you! Far far behind lol)

I did try a milling cutter in my B16 chuck, and found that it pushed it off the B16 taper (maybe I just hadn't pushed it home enough)

Cracking work though!

[Craig Booth 1Participant @craigbooth1]

Hi all, well its been a few months and I been concentrating on the plane rather than the engine, but now that winters here starting to get back into it.

Finished off one of the rocker supports.

and then started on the front crankcase housing.

lump of aluminium turned and bored to shape. Main bearing will be a press fit, front bearing a push fit.

on the vertical rotary table on the mill I cut clearance for the valve sleeve and octagonal face plate.

and drilled and tapped holes for the magnet sensor

drilled the holes for fixing

[Craig Booth 1Participant @craigbooth1]

and I couldn't resist putting it together and seeing what it looked like on the plane

[Craig Booth 1Participant @craigbooth1]

Today I anodized the cylinder head and made the valves sleeves from Colphos. Pretty happy with the results.

[Henry BrownParticipant @henrybrown95529]

Great job Craig, that will be some plane! Not spotted this before but will follow the future updates with interest…

[Craig Booth 1Participant @craigbooth1]

The last couple of days has been work on the tappet guides and sleeves. I had to redesign these as I made an error in making the space available for the cam lobes to small a diameter. This has meant that I have needed to make the tappets much larger diameter 8mm diameter to meet the minimum calculated in the "cam with draw" spreadsheet I have been using. The main guides from aluminium H30 and the sleeves Colphos. Guides then anodised.

[Craig Booth 1Participant @craigbooth1]

also made start on the first conrod (alu H15), with a needle bearing on big end. Small end will have a colphos bushing.

[Craig Booth 1Participant @craigbooth1]

Today was a mix of things. Finished off 2 of the rockers in Silversteel, later to be hardened, rocker pin also from silver steel with circlips.

Made 2 of the port plates from stainless steel. I'll be silver soldering a sleeve onto these which will project into the port with an O-ring for sealing and will also allow the tubing to be soldered on.

Made the rear cam shaft housing which houses a roller bearing and has an oil seal.

And anodised the front prop plate.

[EmgeeParticipant @emgee]

For some reason Craig stopped posting here on his build but the engine is now completed and has been test run.

See it at this link **LINK**

Sounds good and seems powerful by the stats provided.

Emgee

 

Edited By JasonB on 14/01/2021 12:11:51

[JasonBModerator @jasonb]

Very nicely done, look forward to seeing it in the aircraft though not sure I would want to risk all that work myself.

[Tony Wright 1Participant @tonywright1]

Now that is a superb looking engine A+++

[Craig Booth 1Participant @craigbooth1]

Hi all, apologies, with everything happening last year a lot of things changed and I didn't get around to posting here. To close off the post, the engine is now complete and i've had it running a few times. I'm pretty happy with the design and performance so far. Range at the moment is around 1300-5500rpm (on a 24×10 prop). I've now got it stripped down to check for any issues.

Hopefully if I can be confident in the performance I will get her up in the plane later this year. A few quick photos to close off.

 

But for now I am starting to dream up a single cylinder 50cc version using similar geometry

Edited By Craig Booth 1 on 16/01/2021 08:35:30

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