Howell v-2 four stroke gas engine.

[gus]

Just picked up on this thread and haven't read it all but wanted to put my thoughts in.
My last build was Jerry's V twin and I truly enjoyed it. It pushed my skill levels to the limits but the prints were excellent.
I struggle with cutting gears since I haven't figured out how to accurately center my fixtures on the rotary table. I cheated and bought pinion wire for the two main gear sizes. I know its cheating but I wanted it to run, which it does very well.
Had a struggle getting the valve timing right but finally got it.

Your work looks great (better than mine) have fun.

Hogan

Hi Hogan,

Please advise gear vendors website address.

 

[gus]

Long ago found this micro drill chuck on LMS but they cost a bomb.
Arceuro Trade gave me a best deal. With this device, I can hopefully drill the 0.020" Carb Jet Orifice. With the specified jet orifice, carb tuning will be fine whereas the 0.030 might be rough and narrow. However Will try out both orifice.

 

[gus]

48 Pitch Gear Cutters.

Found a UK based vendor--TracyTools who ship to Singapore and Oz. Hopefully by next week I will get good news on pricing,availability and delivery time. Substituting with Module 0.5 with be tough and the gear mesh center distance have to be worked out abd Gus is no gear application expert.

 

[Swifty]

Hi Gus, I looked at changing the V4 gears to module instead of DP, too many changes have to be made. I still have to order my 48DP cutters yet, I don't know why they are so much dearer than module.

Paul.

 

[nx06563]

Gus, I bought my pinion wire from SDP-SI.com which is "Stock Drive Products- Sterling Instrument".

I got a kick out of your comments on the carburetor build. When I finally got a good one I built another one just like the other one. Duh- now I had two of the same side carbs. Carbs and gears- not easy.

keep up the good work.

HOgan

 

[gus]

Gus, I bought my pinion wire from SDP-SI.com which is "Stock Drive Products- Sterling Instrument".

I got a kick out of your comments on the carburetor build. When I finally got a good one I built another one just like the other one. Duh- now I had two of the same side carbs. Carbs and gears- not easy.

keep up the good work.

HOgan

Hi Hogan,

Thanks. Will buy one size each to use as direct indexing to cut gears.

 

[gus]

Fuel Jet Needle

Gus can't buy these needles. Using hand stitching needles ruled out as 2-56 thread won't take on.Going for the next size thread also ruled out due to space limit.
Just figure out a way to grind the needle sharp points( may not be the best or workable) but rather than reinventing,may be best to hear from the maestros who has succeeded making Carb Fuel Jet Needles. There are many ways to skin a cat.

Howell V-2 Engine demands too many skills and experience to do. Certainly not for the chicken-hearted beginners(include Gus).

I have 4 Fuel Jet Needles to make.;D

 

[Cogsy]

Good timing Gus, I built the needle for my Peewee carb today. I used a hand sewing needle (1.2mm dia, 0.047") and a 2-56 thread. I'll be posting the details in my Peewee thread later but I can tell you that it is fairly easy to squeeze the needle into the thread size. I peck drilled 0.25mm at a time for about 9mm and didn't have an issue. Seemed like I could have gone much deeper if I'd needed, but do you really need 0.450" of thread? That works out to at least 20 turns of adjustment on the needle and normally we only use a few, 5 at most in my experience. If you trim the thread length down you won't have to drill as deep.

 

[mayhugh1]

Gus,
I started with a ss SHCS in the lathe and turned the tip using the cross slide and a very sharp tool. I then pressed the head of the screw into a brass turned knurled disk. I don't think I quite made the whole .2" for the tip, but i got close. I heard the tip about the needle only after I did mine or I probably would have tried it. - Terry

 

[gus]

Gus,
I started with a ss SHCS in the lathe and turned the tip using the cross slide and a very sharp tool. I then pressed the head of the screw into a brass turned knurled disk. I don't think I quite made the whole .2" for the tip, but i got close. I heard the tip about the needle only after I did mine or I probably would have tried it. - Terry

Hi Terry,

Thanks for kind advice.
Took calculated gamble. Set angle at 5 degrees and with a very sharp HSS tool ,did a rough cut on the needle point,followed with grinding at 30,000 rpm with wannabe Dremel Grinder bought from TokyuHands last year and ground the point.
The Japanese Sakai Mini Lathe was able to take thou by thou though cutter was slightly off center.Sure glad I spent a bit more to buy Japanese Quality Lathe.
I have two more needles to go. Singapore have a dry/hot/humid spell making it uncomfortable to work.



Took five blanks to make two good Needles.
Took an hour to mentally design and make adapter to hold mini grinder.Some time later will go into end mill sharpening with same contraption but must provide for relief .

 

[Swifty]

Gus, your gears should be a simple 2:1 ratio, what number of teeth do they call for on the drawing? I will have a look at how a mod.5 cutter would work out.

Paul.

 

[gus]

Gus, your gears should be a simple 2:1 ratio, what number of teeth do they call for on the drawing? I will have a look at how a mod.5 cutter would work out.

Paul.

Hi Paul,

Timing Gear Train 32T 16T

Spacer 21T

13T Oil pump

Thanks for the kind help.

Hot and humid. No wind. Can only work between 8----10am.
This weekend good fishing.

 

[Swifty]

Hi Gus, I would have to see a drawing of the gear train, I have only found half a sheet on the internet that shows some mods where the gears go. From that half sheet, it doesn't look like you can change from 48DP.

Follow my V4 build, as I have decided to make a hob again, this time for 48DP. At least I will only have to make 1 cutter to cover all the gears.

Paul.

 

[gus]

Hi Paul,

See attached. Will go metric and backup will be Imperial. Module 0.8 means bigger gear case.
Module 0.5 is slightly smaller than the 48 pitch. Will take gamble. If i failed then at least the people who planned to build same engine are informed.

Gus may end up with half dozen gear case fishing sinkers.

 

[Cogsy]

Just from a quick look and trying to get my head around it, it looks like quite a problem to change the gear sizes.

The 16 tooth gear appears centred in the crankcase, but making all your gears smaller means the oil pump will need to move closer to the centre to maintain mesh.

Then the 32 tooth gears and the mated first set of 21 tooth gears will all also move towards the centre. Then the final 21 tooth gears on the cams will move towards the centre, with the error accumulating through the gear train.

From what I can see, the cams will be deeper in the crankcase, needing longer cam followers, and also closer together as well. If you can't change the position of the cam followers then I imagine the valve timing is possibly going to be altered by having the cams offset to the centre of the followers. I guess you could allow for the cams getting closer as they move towards the centre, but the followers would need to be even longer and of course assuming you have the room to move them that much.

This is all theoretical and you're in a much better position to know the amount of changes you need to make, but I think I'd be doing the math and drawing it out on paper before you commit to cutting metal if I were you.

 

[gus]

Hi Al,
From Day One, i saw the problem and mentally plan to make it work with Module 0.8 or 0.5 Gears. Won't be easy. Will do a mock-up. The Gear meshing centtre distance will be another problem but the Model Engineer Magazine had an article to the gears together and pop centre.
If I succeed then it will helpful for others using Module 0.5 gears.Failure of which splash $$$ to buy 48 pitch Gear Cutters as backup.:rant:
Or go to SDP-SI to buy the gears buy I still have one problem the shaft pinion gear.
Gus caught between the frying pan and fire.:rant: No worries.Mate!!!

 

[mayhugh1]

Gus,
There is also the option of making your own form tools to cut your own involute gears. Its really not difficult, the cost is practically zero, and you have the skill and equipment to do it. The process is to make a cutter out of a pair of hardened buttons which is used to make the form tool, and then the form tool is used to make the gear. The form tool is essentially the same high dollar cutter you've been looking at in the catalogs. Here are two links explaining the process if you aren't already familiar with it. I made my own very small diameter cutter to make a tricky integral crankshaft gear for my radials. I was able to skip the button tool step because I could create the form tool on my CNC lathe, but when done the form tool cut nearly perfect teeth in steel on two crankshafts and two practice parts before it was loaned out and destroyed. - Terry

http://www.metalwebnews.com/howto/gear/gear1.html

http://bbs.homeshopmachinist.net/threads/41591-involute-shaft?highlight=involute+shaft

 

[Swifty]

Terry and Gus, that method of making cutters will give you nice back clearance on the shape, although the cutters will only suit a certain number of teeth, in the case of the V2, 3 cutters will be needed. Whereas, if you make a hob, it will cover all the range. That is the way I will go.

Paul.

 

[gus]

Terry and Gus, that method of making cutters will give you nice back clearance on the shape, although the cutters will only suit a certain number of teeth, in the case of the V2, 3 cutters will be needed. Whereas, if you make a hob, it will cover all the range. That is the way I will go.

Paul.

Hi Paul,

Big problem. I know nothing about hobbs,gear hobbing and hobbing machine.
Some months back I did have a dream/vision of building my own mini hobbing machine after surfing YouTube.(Ha ha Ha .Very ambitious).
Will be watching your every move to get educated on hobbing.
No worries .Mate. !!!

Will be able to work longer with M.I.C. S$37 Stand Fan. Soon after assembling the fan, the very first season wind came. S$37 gone!!!:rant:

Making routing notes/steps to turn/mill/fit throttle barrel.

 

[Cogsy]

I know nothing about hobbs,gear hobbing and hobbing machine.

This type of 'hob' isn't used on a hobbing machine but as a milling cutter. You make one cut and index your gear blank one tooth and cut again, then repeat for all the teeth (plus 3 from memory). Here's the link to a very good page explaining the process and how to build, and use, the straight hob - http://www.helicron.net/workshop/gearcutting/gear_cutter/.

The navigation bar on the right side of the page has links for calculating the cutter dimensions, explaining how it works, etc.

Have a read, it's interesting stuff.