Member postings for Graham Williams 11

Just another question then. Was 6082, or same spec different identifier, not available or not readily available when the Viper was designed to 'take-on' the best engines of the day, presuming that's the Olivers and ETAs.

Cheers

GW

Thanks guys and thanks for the offer John. 6082 is readily available locally but as the Viper was/is a high performance engine (in its day) believed that the spec quoted was necessary over the 6082. will make a cheeky 'phone call to the local Aalco tomorrow on the off chance that they'll help but won't hold my breath. If it's no-go then 6082 will have to be used and fingers crossed it'll hold together.

Cheers

GW

Made the front housing out of the only piece of 6061 Alum ( plans indicate this spec) I had and started looking for more to make the c/case, backplate etc. Seems none of the suppliers to the model trade offer this spec and after searching online seems only the big boys list it. Haven't approached anyone yet to see if they'll supply but past experiences haven't been positive in the quantities I've wanted. Anyone know of someone who might oblige?

Cheers

GW

Is black, presume hot rolled, round steel bar generally or always of EN3B spec???

Cheers

GW

Good to have you back on the Forum. Any chance you'd like to comment on my gear cutting query under Velocette on here. Had lots of input and going to try a couple of things out but your input would be gratefully received.

Graham W

Chris.

Velo tat box sadly depleted as I sold every bit and bike I had a few years ago, regretted it ever since so got the MAC a couple of years ago, couldn't afford MSS/VM/VR and just buy bits when I see them at autojumbles.

Have you tried Ray Thurston, he's got loads of stuff and is on Facebook, Thames Valley member I think, his son Kevin runs KTT Services, easy to find on the web so might be able to help or even Martin Bratby who seems to have cornered the piston market.

Best of luck

Cheers

Graham W

Thanks John and Nigel. Decided to cut the teeth as before but with the correct handed helix and as a test before trying it on a bike (no takers on a Velo enthusiast to try it out for me LoL) I'm going to make a test rig with an old intermediate gear driving the mag gear (will have to provide some resistance somewhere) and see if I can detect any of the potential problems outlined. After that may well look at a hobber as the next project after refurbing an old Mills aero engine as I'm giving the locos a rest for now.

Graham

Got no worries about the use of a steel gear. Bikes fitted with manual a/r magnetos were fitted with steel gears as far as I remember ( based on the Clubman Viper my riding mate had) and the second hand BTH mag and wheel sourced by a local dealer that I fitted to my Viper.

The slight mismatch between module and DP was the worry as I'm no gear specialist just a t***t a**e and making the gear is keeping me away from her indoors who's decorating the kitchen.

Is there a Velo enthusiast out there who's desperate for a mag wheel that's willing to do an extended test, can let him/her have one cheap Lol.

Thanks for all your advice guys

Don't know when exactly that Velocette made the change to helical cut gears, it may well have been pre WW2 when the MAC was introduced, I believed the early ones (early 30's) had straight cut gears so that might give a reason for 20 degree pa.

Commercially available mag gears are steel as far as I know no-one has offered Alum gears and think the wear factor s a consideration, Tufnol doesn't seem to wear that badly, the gear usually strips mostly by the kick back when the starting drill is slightly off, that's my experience when Velos were my daily transport anyway, prompting change to manual a/r with steel gear which was the standard for bikes so equipped from the factory, perhaps anodising might toughen them up, just a thought.

Rod.

In the Velobanjoagent link posted above you can see what Velocette's thinking was at the time, i.e they believed it gave quieter running but that with more modern gear manufacturing methods the same result could be achieved. However having said that they didn't change the gears on any of the singles at all as far as I'm aware once having made the change to helical teeth from the early straight teeth gears. Very quirky bikes are Velocettes, I won't get into the 'famous' clutch as many Velo fans will well know LoL

Thanks Jason, just need to find out how to put a comment up with the pictures................. need the grandson here LoL

Thanks for the 'how to' so put a couple of photos of the one I made (incorrectly) today.

John. There are quite a few suppliers, Tank Classics, Grove as well as VOC (I'm a member) and they all go for around the same price + P&P and did exactly that for a friend's bike but I just wanted to make my own using my vert. mill, going the manual mag route and made a simple jig to set the mag shaft taper., taper is 11mm to 13mm over 11.5 mm length.EN3 sourced from local machine shop for the price of a pint and disregarding the electric used much cheaper to make and kept me entertained, the cutter cost me £12 delivered from China and trying it today it cuts well. CRT ? in Sheffield want around £90 for the correct cutter and Tap & Die want £120 so more than I wanted to lay out. Bit disconcerting that you suggest there will be a noise problem making it this way, had whines in the past from the timing gears on a Viper but the adjustment on the intermediate gear put that right (thank you Mr. Dodkin). Will have to give it some thought as to completing number 2 methinks.

Wonder what a small gear hobber will cost to make........... where is this going?

Rod. How do you put photo into the post, it's not working for me.

Made a gear today but the 'not' deliberate mistake gave me RH helix, 92 teeth cut, what fun, must pay more attention.. LoL

No Jason, I find RDG an ok supplier but when I last checked they only did 14 1/2 degree pa cutters

It is 20 degree pa, tried to include a photo but the method eludes me I'm afraid. Understand that 32dp is about 0.794 mod but if I work out the outside diameter on module it equates to 2.961" ((94x0.8) x 0.03937) but  the automatic advance retard unit with tufnol gear i'm looking to replace is 3.055" and have been told previously that the diameter should be 3.063" which is I assume what Velo used way back.

Couldn't find a 32DP cutter at a price I could afford but did find a 0.8mod cutter on ebay hence the question

Edited By Graham Williams 11 on 16/08/2019 12:10:09

What's the consensus on the use of a 0.8mod cutter using 32dp specs i.e. depth of tooth and outside diameter on a magneto drive gear for a Velo MAC, alloy engine, 92 teeth?

Cheers

Graham W

Thank you Neil. Can see that now you've pointed it out, severe brain fade on my part methinks LoL.

Cheers

GW

Harold Hall's Tool & Cutter Sharpening, workshop series number 38

Built Harold Hall's simple tool grinding jig a while back and now decided to make the end mill sharpening fixture, plans in his book. 14mm dia hole shown in the front support and an 8mm dia hole in the rear. Looking to start assembling the jig, made all the parts to book drawings and it looks from the outline book drawing and a picture I've just downloaded from the web that these 2 holes have been transposed front to back bearing support. Might be missing something but........... can anyone advise ?

Cheers

GW