Crankpin Drilling Jigs

If you are making something new or have found something, announce it here.
User avatar
Paul Willis
Forum Team
Posts: 3033
Joined: Sun Jul 20, 2008 6:00 pm

Crankpin Drilling Jigs

Postby Paul Willis » Wed Sep 19, 2012 9:36 pm

paultownsend wrote:I wonder why no-one has yet produced a set of wheel-fettling jigs commercially? Come on entrepreneurs, I know you are there :)


Well, the subject of crankpin drilling jigs was raised at the Society's Committee meeting tonight by Terry Bendall, who always has an eye for how we can bring benefits to members.

Without making a firm commitment to go to production, we have agreed that we will research the manufacture of these jigs for the Society to sell to members. This will be in the same manner as the turnout filing jigs that have recently been produced for us, and will be to the same properly engineered standard by an external firm.

In the meantime we will be researching the best/most effective design to produce. If anyone has any suggestions on what would work best, then please do get in contact with any Committee member, or perhaps even start a new topic on the Forum to discuss the idea.

Cheers
Paul Willis
Deputy Chairman
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk

User avatar
Paul Townsend
Posts: 964
Joined: Mon Sep 14, 2009 6:09 pm

Re: Tim V's workbench

Postby Paul Townsend » Thu Sep 20, 2012 3:03 am

Flymo748 wrote:
paultownsend wrote:I wonder why no-one has yet produced a set of wheel-fettling jigs commercially? Come on entrepreneurs, I know you are there :)


Well, the subject of crankpin drilling jigs was raised at the Society's Committee meeting tonight by Terry Bendall, who always has an eye for how we can bring benefits to members.

Without making a firm commitment to go to production, we have agreed that we will research the manufacture of these jigs for the Society to sell to members. This will be in the same manner as the turnout filing jigs that have recently been produced for us, and will be to the same properly engineered standard by an external firm.

In the meantime we will be researching the best/most effective design to produce. If anyone has any suggestions on what would work best, then please do get in contact with any Committee member, or perhaps even start a new topic on the Forum to discuss the idea.

Cheers
Paul Willis
Deputy Chairman


Thank you Committee for taking this on.....such a fast response!

I don't feel I have enough experience of Cpin fettling to choose between the three designs already mentioned and it seems possible that other ideas will emerge. Each seem to have their merits.

I am confident that you bods will choose a good compromise between manufacturing tolerances, price and user precision as evidenced by other Society products.

What I do know is that there is a need for such a tool for modellers unable to make their own and as I have several locos to build where the drivers will need this attention so will be very happy to evaluate any prototypes in due course.

PS
Silly time to be on the Forum!.....b$5£&y new students arriving opposite and making whoopee.....the price I have to pay for a Victorian basement for my railway 8-{

Steve Carter
Posts: 643
Joined: Tue Nov 11, 2008 6:51 pm

Re: Crankpin Drilling Jigs

Postby Steve Carter » Thu Sep 20, 2012 2:45 pm

Well done Committee 
This is another example of how our Society is prepared to provide support to members.
I look forward to adding one of these useful jigs to my workbench in the not to distant future (hopefully).
Steve
Steve Carter

User avatar
Tim V
Posts: 2868
Joined: Tue Jul 29, 2008 4:40 pm

Re: Crankpin Drilling Jigs

Postby Tim V » Thu Sep 20, 2012 3:54 pm

An excellent idea. Long overdue.

Not everyone has access to, or the skills to use, decent facilities. I am loathe to mention how I do things at times.

A jig has to be flexible to cope with:

    Different throws

    Different wheel diameters

    Different axle diameters

Not a tall order.
Tim V
(Not all railways in Somerset went to Dorset)

User avatar
grovenor-2685
Forum Team
Posts: 3918
Joined: Sun Jun 29, 2008 8:02 pm

Re: Crankpin Drilling Jigs

Postby grovenor-2685 » Thu Sep 20, 2012 7:41 pm

Tim V wrote:An excellent idea. Long overdue.
Not everyone has access to, or the skills to use, decent facilities. I am loathe to mention how I do things at times.
A jig has to be flexible to cope with:
Different throws

That was discussed on the great 3F build off, here http://www.scalefour.org/forum/viewtopic.php?f=20&t=2019&start=50#p18358
No problem having a range of holes for common crank throws.
The size of hole needs some thought, presumably 14BA tapping, when a bigger hole is wanted it can always be enlarged.
Different wheel diameters

If the jig is to establish the throw relative to the wheel centre the diameter should not matter.
Different axle diameters

This bit may be a bit more awkward, if its to cater for industrials with 2 mm axles, rtr conversions with 2.5 mm and 3 mm axle and standard 1/8" axles then a set of interchangeable spigots, or one spigot with detachable sleeves seems to be indicated.

I've managed without so far but I'll buy one.
Regards
Keith
Regards
Keith
Grovenor Sidings

User avatar
steamraiser
Posts: 558
Joined: Thu Dec 31, 2009 4:49 pm

Re: Crankpin Drilling Jigs

Postby steamraiser » Thu Sep 20, 2012 9:14 pm

I would also be interested in a jig that aids in drilling crank pin holes consistantly the same distance from the axle centre.

Gordon A
Bristol.

User avatar
Paul Townsend
Posts: 964
Joined: Mon Sep 14, 2009 6:09 pm

Re: Crankpin Drilling Jigs

Postby Paul Townsend » Fri Sep 21, 2012 7:51 am

Tim V wrote:An excellent idea. Long overdue.

A jig has to be flexible to cope with:

    Different throws

    Different wheel diameters

    Different axle diameters



I hope that swappable spigots for at least 2mm, 3mm and 1/8" axles would be covered and wheel diameters from 3'6" to 8'.
I suspect the hardest bit for the designers will be various CP throws.

Terry Bendall
Forum Team
Posts: 2420
Joined: Sun Jul 27, 2008 7:46 am

Re: Crankpin Drilling Jigs

Postby Terry Bendall » Fri Sep 21, 2012 3:05 pm

The ideas and comments suggested so far are very useful and any other observations will be welcome. We have some ideas for a design and once a prototype has been developed we will ask one or two people to test drive it. Clearly the ability to cope with different axle diameters and crank pin throws will be essential and these will be catered for as far as is possible.

Terry Bendall

doktorstamp
Posts: 73
Joined: Sat Oct 02, 2010 9:07 am

Re: Crankpin Drilling Jigs

Postby doktorstamp » Fri Sep 21, 2012 4:23 pm

And possibly not forgetting the different number of spokes

regards

Nigel

Philip Hall
Posts: 1947
Joined: Mon Aug 10, 2009 7:49 pm

Re: Crankpin Drilling Jigs

Postby Philip Hall » Fri Sep 21, 2012 4:41 pm

The jig, of whatever design, would simply have two holes, one for the axle and one for the crankpin, possibly with differing pins in the axle hole to cater for variations. So long as the two are in line, where the spokes are, or how many there are, won't matter so long as the holes are aligned with the centre line of the boss.

Philip

User avatar
steamraiser
Posts: 558
Joined: Thu Dec 31, 2009 4:49 pm

Re: Crankpin Drilling Jigs

Postby steamraiser » Fri Sep 21, 2012 5:21 pm

Some thoughts:

I would hope that the design of the jig would be such to allow for drilling 4 to 10 wheels with out having to totally reset the jig each time - in other words consistancy!

My thoughts are along the lines of a two part jig.
The combined jig would be mounted to the drill with an off set equal to the crank pin throw.
The first part is attached to the drill base, and the second will carry the wheel.
This part should be easily and accurately secured to the first part of the jig. By making this part removeable it will make the fitting and removal of wheels easey.

By removing the second part and replacing the wheel, which is then fitted back to the first section, I am hoping that crank pin holes can be drilled in any number of wheels without any tweeking take place, resulting in all the crank pin holes being the same distance from the axle centre.

Ihope the above makes some sense.

Gordon A
Bristol
Heading for the hills!

User avatar
Steve Taylor
Posts: 62
Joined: Wed Sep 09, 2009 11:14 am

Re: Crankpin Drilling Jigs

Postby Steve Taylor » Mon Sep 24, 2012 8:01 am

I certainly would be interested in hearing more details of this. Its a problem that has put me off tackling some of the pile of kits and conversions in favour of doing the easy ones like diesels and units that just require pop in wheelsets.

User avatar
Horsetan
Posts: 1371
Joined: Tue Jul 29, 2008 9:24 am

Re: Crankpin Drilling Jigs

Postby Horsetan » Tue Sep 25, 2012 12:03 am

Seeing as I got involved in this thing in the first place, I'll sign up for one.
That would be an ecumenical matter.


Return to “New Products”

Who is online

Users browsing this forum: ClaudeBot and 0 guests