Howell v-2 four stroke gas engine.

[Swifty]

Gus, as Cogsy said, a hob is just a cutter with the correct rack shape on it. It is relieved to produce cutting edges. The hob is used about half way up the cutter so that you have the same amount of teeth above as well as below the blank, although you do have to have a tooth lined up on centre. As you feed the blank into the cutter, it is cutting on a few teeth at the same time, as you index the blank around and cut the other teeth, a near enough tooth form is produced.

Paul.

 

[gus]

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.

Hi Al,

Thanks. Wasn't as complicated as I thought. I am having some bright ideas.
Still stuck at the Carb Department. One throttle barrel done and one more to go. Hard to believe 4 hours to drill two orifice,drill/tap M3,turn and mill. One catch, we left hand and right hand carb and throttle same too left& right hand.;D Snail pace.:wall:

 

[gus]

Gus, as Cogsy said, a hob is just a cutter with the correct rack shape on it. It is relieved to produce cutting edges. The hob is used about half way up the cutter so that you have the same amount of teeth above as well as below the blank, although you do have to have a tooth lined up on centre. As you feed the blank into the cutter, it is cutting on a few teeth at the same time, as you index the blank around and cut the other teeth, a near enough tooth form is produced.

Paul.

Thanks for the info.

Still stuck at the Carb Department and enjoying making parts to detail. Think I picked up the black magic art of drill 0.030'' orifice. Gentle teeny weeny slow shallow pecks and withdraw. First throttle barrel done with no micro drill breakage but did break a M2 Tap when my wife came and distracted me.
Was a cheapy OSG Hand Tap.
After the carb,the rest will be big parts. SW Monsoon trying to come in and thats good. Need the rain to flush out the remnant Red Algae Tide.
Fans are selling very well.
Trust weather at Mount Martha area remains good. My sister is doing OK in Sydney but faraway from the bad storms.
Take Care.

 

[gus]

DAY 36----38

CARB BARRELS

Couldn't wait for the micro feed drill chuck to come in from ArcEuroTrade. Took extra precaution with the drill bit feed. Shall depth feed and withdraw to drill and clear chips. Snail pace but all 4 orifice holes drilled w/o drill breakage. These micro drill bits demand respect/care/caution.
Milling the full throttle/idle stop slot and the butterfly vane was done with the DIY Rotary Table and Centre Support. No hiccups.No scrap. But some hand finish required. The RT made last year was more of an asset than tool. W/o the RT ,the slot and butterfly would be tough to do.
Still have 5 more parts to make and complete Carbs.

 

[crankshafter]

Hi Gus.
Have a look.
http://www.helicron.net/workshop/gearcutting/
http://www.metallmodellbau.de/GEAR-CUTTING.php

Best Reg.
CS

 

[gus]

Hi Gus.
Have a look.
http://www.helicron.net/workshop/gearcutting/
http://www.metallmodellbau.de/GEAR-CUTTING.php

Best Reg.
CS

Hi CS

Thanks for the kind help.

This info is J.I.T. aka Just In Time. Sometime next month will begin cutting the 48 Pitch Time Gear Train. Paul Swift is now DIYing his 48 Pitch HOB.
Meanwhile Gus is still busy in the Carb Department with so many mini parts to make. Trying to enjoy making this mini parts.

 

[gus]

Day 39

Throttle Barrel Split Hub.

Simple part but took 3 hours to plan routing, marking out,mill profile,drill/ream 3/16 hole,drill and tap M2 clamp screw and clean up. Very unproductive. 3 hours to make only one mini split hub.

Am sure Paul Swift will tell Gus ------------D.C.M.

I am now one barrel hub nearer. The carb throttle lever and Jet needle is next.

Howell V-2 is not for beginners,impatient and the faint hearted. Too many mini parts. Skill and patience stretched beyond limit.:rant:

 

[maintman]

when will you be making the crankshaft and end plates?

 

[gus]

when will you be making the crankshaft and end plates?

Hi Maintman.

Still at the Carb Department. Too many mini parts. Hopefully by end this week will complete and move on to another job piece. Most like the front bearing housing.crankshaft,con-rods etc. Taking my sweet time.

 

[maintman]

do you have a direct email address i want to sent you a picture.
thanks

 

[gus]

Day 40.

Throttle Lever and Twin Carb Linkage.

The two throttle levers took the whole morning to complete. The linkage and clevis took another two hours.
Drilling the holes on the 33 thou thick brass levers is best done firmly clamped down and drill bit reground to drill thin brass. Job piece is to thin and too delicate to cut the 200 thou radius profile with RT.. Did the old fashion way using a drill bit as mandrel and skimming bit by bit rotating and clamping job. Some hand finishing required. Will move on to the intake filter housings. Most likely another full day job.

 

[Cogsy]

Looking good Gus. I'm glad I didn't have to make 2 carbs - that's a fiddly job.

 

[gus]

Looking good Gus. I'm glad I didn't have to make 2 carbs - that's a fiddly job.

h


Hi Cogsy,

You are right. Just carb drives us mad and two carb --------left hand and right.
All in I scrapped 4 blanks and needles but no throttle barrels and levers.
Discovered I could turn the needles to and finish off with file and emery paper.

Going on to bigger parts which will a wee bitty less taxing.

Even soft soldering the throttle split hub and lever required a jig for alignment.Was a very simple jig. Got both levers soldered as left hand and right hand.

 

[gus]

Day 41

Filter Housing.

Filter Cover was easy and stress free to turn. Mounting holes marked and drilled spot on. With Starrett Height to scribe and precision center popping on cross and manual spot drill. Mounting holes were dead center on outer head mounting holes. Installing the filter housings on to H/D was a reward. Now taking a pee/tea break before working on the 1/8'' vent hole on the filter housing. This hole can kill the housing. 1/8 drill bit must be ground to drill the brass housing.
Both outerheads looks good with intake filter bolt-on.

 

[gus]

DAY 41 1/2

Filter Element---------Foam.
Found my darling wife's dish washing foam a good choice.Cutting this tidily and look good seems impossible.
No harm try the copper/brass shim cutter. Results turned out to be surprisingly good. Jerry Howell specified UreThane Foam. I have no idea on the foam found in my wife's kitchen.

 

[Cogsy]

Really looks the part Gus, maybe just try a bit for compatibilty with petrol before you install it - hate to see it melt all over the inside of your carbs!

 

[digiex-chris]

Speaking of stress free turning. I usually feel that way about a job. The complex milling job is the stress maker, and the lathe is the stress reliever. Do t know what it is about it.

 

[digiex-chris]

That foam looks a lot like what's in my Briggs and Stratton filters.

 

[gus]

That foam looks a lot like what's in my Briggs and Stratton filters.

Hi Cogsy & Chris.

Air Filter element--foam. Worked on Honda,Robin Petrol Engines and they use foam.Frankly speaking I have no idea of foam material. Some Ingersoll-Rand small aluminium compressors use same.
Have a backup. Run engine w/o element,since Howell V-2 will be run a few times and after that will be kept as display on my PC Desk or as humongous paper weight. By now I have five such paper weights.

We seem to have better control over lathe turning than over milling.
For today,will turn the breather and fuel cup..

Its May 1st ( May Day) No fishing .Will work. Week End fishing is on. The fishy mates are gearing up to fight the return match with the line breakers with some heavier lines,reels and rods. This is not fair??? Ha Ha 6-B Gray has ample stock of very fresh fishy catch. At least 3 fishy dinners weekly.Its true,I do get sick of fishy and will go out for a piece of ''PorterHouse'' or Tee Bone.Ha ha

 

[gus]

Day 42.
Completion of Twin Carbs


At last I see daylight. Carbs completed with ''O'' Rings installed. Would most likely run engine w/o the foam filter element.. Its weekend fishing again.