New guy from Norway, planning a Bonelle grinder

[BizibilderParticipant @bizibilder]

I found that I had to redrill the threaded holes in the wheelhead arms in order to attach the guide block when building my Bonelle – It seems that there are various cumulative errors that eventually don't quite add up! I had real trouble trying to find out why the thing didn't fit!! Additionally I had the problem that my 2" square iron bar for the wheelhead block (C4) was metric i.e. 50 mm square (rather than 2" or 50.8mm) and had also been cleaned up on all four sides making the actual dimensions even less by a few thou all round. Not really surprising that it did not fit off the drawings.

So far this is the only part that has not fitted after being machined straight from the drawings. I am currently building the toolholder and have worked through the drawing in more or less the order that they are set-out.

The only modification I have done is with the bellows and their attachments. I will be using commercial rubber bellows and have designed and machined a set of attachments to allow the bellows to rotate as the front bar is rotated – otherwise the bellows would twist and prevent free movement of the bar.

Just to add – Don't alter the guide block.  Just reposition the threaded holes used to secure it.  You will have problems if you alter the block.  There are two positions for the leadscrew in the wheelhead guide (C8) that can be used and both will fit if you simply reposition the holes for the block.

Edited By Bizibilder on 03/04/2023 15:35:17

[BazParticipant @baz89810]

Welcome to the world of Model Engineering! You will find things don’t line up, bits are drawn wrong, 26 tpi threads are supposed to fit in 40 tpi holes, the list goes on. Although all these drawings, steam loco, traction engine and workshop tooling have been around for years the drawings are never updated, the pathetic excuse from all the sellers of castings and drawings is copyright issues, this is just a lame excuse, all that is needed is a sheet of corrections sent out with each set of drawings, please watch out for missing holes here, wrong size hole there etc. Rant over, I wish you luck with the Bonelle, not many finished ones exhibited unfortunately. Please keep us all updated on your progress.

[FulmenParticipant @fulmen]

Ok, you've calmed me down a bit. I just figured all the bugs world be fixed after all these years. It's an easy fix, I just had to make sure it wasn't one of my stupid mistakes.

I'll reposition the holes and reduce the height of the guide so it doesn't interfere with the mounting bolts. This is why I model everything in 3D before building.

[FulmenParticipant @fulmen]

BTW, I came across this yesterday: hexagonal paper bellows

Plain office paper covered in packing tape works like a charm, I just printed the template and scored the paper with a ball point pen. The pattern is easy to make, the width of the vertical lines is 3.46 (2*tan(60)) times the height.

[FulmenParticipant @fulmen]

What, you thought you got rid of me? Fat chance, I just don’t do much machining during the summer.

Here’s the progress so far:

[martin haysomParticipant @martinhaysom48469]

i too am building a bonelle. i have used a quorn type column so missed that alignment error. only by luck as i made the change because i think it looks better. i am also planning to use a small er collet spindle and rubber bellows possible car steering rack gaiters

[FulmenParticipant @fulmen]

Haven’t given up yet:

If I find a suitable motor I can start testing it as a tool post grinder, so that will be my next focus. IIRC the design calls for a 100W / 1500RPM motor, but that would only give a speed of around 1000m/min. The old Norton manual I’m reading in seems to recommend 2-3 times that depending on the application. Am I missing something?

I also need some wheels, would this be a sensible place to start?

https://www.aliexpress.com/item/1005004633960267.html

[noel shelleyParticipant @noelshelley55608]

You do not say what size wheels but at a guess I would look at the spindle running at 3 – 4000 rpm. I would build in a way to be able to balance the wheels and buy wheels fron a reputable supplier. not the one you mention ! A simple wheel balancer will pay dividends as the slightest vibration will spoil your work. Your spindle looks very short ? Noel.

[FulmenParticipant @fulmen]

Sorry, forgot to give the details. It’s for 4″ wheels with a 1.75:1 gearing on the pulleys. So 2500RPM give or take for a 1500RPM motor. But that’s only 800m/min (less than 3000sfm). Norton seems to recommend 4-6000sfm for most applications. Fine, it’s not 2-3 times but still…

https://www.airgraver.com/shaper/Tool%20Room%20Grinding.pdf

A wheel balancer sounds like a good idea. The bonelle documentation doesn’t really cover this bit, and I started this project without really considering it’s use as a toolpost grinder. So I haven’t prioritized learning how to actually use this yet.

The problem with reputable dealers is that they come with reputable prices. None of my affordable dealers seem to carry anything useful (Chronos and Arc Auro have some resin bound stuff). Recommendations are welcome.

 

[Wade BeattyParticipant @wadebeatty78296]

Fullmen,

Welcome from another Norwegian member.

i dont know if you have seen this but he makes many of his tools from aluminum.

http://www.metallmodellbau.de/MINI_BONELLE_1.php

http://www.metallmodellbau.de/Eigenbau-Universalspindel.php

 

Wade

[FulmenParticipant @fulmen]

Thanks, that’s useful.

[FulmenParticipant @fulmen]

Fall is upon us again. The boat is back on dry land and there isn’t much left of the bike season, so time to crawl into the machine shop again. So far I’ve almost completed the Wheelhead Assembly with the exception of the motor mount.

My initial plan was to machine the base from cast steel, I even managed to source a very large chunk of CI before I had a change of heart. There is just so much metal to remove. So I’m slowly gearing up to do some aluminum casting.

Here’s the pattern for the main base:

I’ve made a few test molds in green sand, and I think I’m starting to get the hang of it. I even managed to cast a few parts in pewter as I haven’t made the furnace yet.

 

I’m more or less finished with the modelling:

This project is a beast. I think my last parts count was 136, so I won’t lack anything to machine for the foreseeable future.

 

 

[John HinkleyParticipant @johnhinkley26699]

Some years ago, I built a Worden from a Hemingway kit.  I incorporated some improvements as I progressed.  (Not mine, I would like to add – these actually were beneficial and worked!)  Recently, having reduced my workshop machines to a mini lathe only, I have had an inclination to build another tool and cutter grinder.  Heaven knows why, I don’t think I’ll ever get much use out of it.  Anyway, I have been browsing the ‘net for ideas and the ubiquitous Universal Deckel copy kept turning up.  The price precluded a purchased, but the itch remained to be scratched.  Then a couple of weeks ago, I was idly playing a game of Solitaire on the iPad and an advert popped up.  At first, I cursed it, as usual, then noticed that there was a picture of the work holder part of a universal grinder at a remarkable price.  Following the lead led me to a site called Temu.  Along with myriad adverts for ladies fashions and all sorts of other gubbins that I didn’t know existed or wanted was this one for the work head shown below:

I’d seen them on eBay for £140 up, but this was less than £100 with free postage, so I signed up for an account and ordered it.  It duly arrived a couple of days later from a UK distribution centre (so no import duty) and it now resides in a drawer in the workshop, waiting to move up the to-do list.  I’ll need to order or make some collets, but if I build a version of the Quorn, Bonelle or even the Brooks, referred to earlier in the thread, it will save an awful lot of time and effort in the construction of that part of the machine, not to mention the ball handles!

I told my wife that it was a long term project and she said “I hope you live long enough to complete it!”

John

 

[FulmenParticipant @fulmen]

The ball handles on the Quorn is certainly an attractive feature, but it’s a lot of work for purely decorative features.

[mgnbukParticipant @mgnbuk]

………..if I build a version of the Quorn, Bonelle or even the Brooks, referred to earlier in the thread, it will save an awful lot of time and effort in the construction of that part of the machine, not to mention the ball handles!

Snap !

Many years ago I bought an incomplete part built Quorn – just the base castings, bed bars & threaded column. I got a list of the missing castings from MES at one of the Midlands shows, but didn’t get around to buying them before MES disappeared & discussions with Hemingways didn’t come up with a satisfactory solution (basically start again with a full kit of castings rather than just supply the bits I was missing). Then I saw one of these Chinese work heads on Ebay – IIRC I paid around £120 for mine after a seller discount was offered for one I had on watch, which was less than the cost of the castings. To mod it to fit the Quorn base I will have to bore out the bed bar through hole from 25mm to 25.4mm & it may need raising blocks under the base castings, but a lot less work than making the Quorn bits from scratch.

Only down side so far is that the one I bought uses Deckel collets rather than 5C that some versions of the workhead use – I got a couple from Warco, but they are a bit pricey. Maybe look to make an ER collet adapter at some point- but that is a long way down the road, as mine is also a long term project !

Nigel B.

[John HinkleyParticipant @johnhinkley26699]

Nigel B,

After some research, I found these individual collets on AliExpress.  I consider them affordable, even after adding on the postage, and you have the luxury of choosing which specific size(s) that you need.  I am assuming, as you have already purchased the workhead, that you have no bias against Far Eastern-manufactured items.  I have used AliExpress previously and come out of the experience with any scars, and this is the route that I will undoubtedly take when the time comes.

John

 

 

[mgnbukParticipant @mgnbuk]

Thanks for the tip, John.

I bought the Warco collets when they were on sale last year – just checked the invoice & they were £8.75 each with the 30% discount applied at the time. I got a 16mm & 3/4″ with a view to  using an ER extension collet chuck or making sleeves to get me going, but at £3.22 each for the AliExpress collets it would be worthwhile getting the popular sizes for convenience.

WRT to Far Eastern tooling, I guess overall I have had more positive experiences than negative.

Nigel B.

[FulmenParticipant @fulmen]

With the choice to go for aluminium frames I have freed up a very large chunk of ductile cast iron (meehanite) for the remaining parts. It machines very nice and isn’t as brittle as regular CI would be. So many of the parts that were specified as steel will be made from this unless it’s obviously a bad idea. Any parts that really should be steel, other than pins, screws, shafts and so on?

 

[FulmenParticipant @fulmen]

I’m starting to regret that choice already. OK, it machines like butter but I look like a coal miner after a few hours.

[John HinkleyParticipant @johnhinkley26699]

While browsing Aliexpress again this morning, I noticed that there is a “sale” on and the workhead to which I referred on 10th October is on offer from one supplier for £59 and another at £69.  I didn’t investigate further as I’ve already got one, so I don’t know if there will be Postage and VAT to that, (inevitably, I guess), but it’s still cheap.

John

Edit:  I was searching for the collets and ordered a few.  Some were discounted to £0.78 each, others at £5.08 each, so what I considered a fair deal.

 

[FulmenParticipant @fulmen]

If I just needed a grinder that would probably be the sensible choice. Luckily I have never claimed to be sensible.

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