Bonelle T&C Grinder

[stefang]

Hi folks...the dull cutters in my shop are getting more and more, so a friend of mine convinced me to build the Bonelle grinder. For those, who don't know, the Bonelle is a modified version of the famous Quorn grinder, with no need for castings, as it is completely machined from bar stock.

First, I redid all the drawings in a 3d Cad and converted it to metric.

As the drawings were nearly finished, I could order some steel and start on the base:


Cleaning up on the shaper:


Drilling and milling on the cnc:


Contouring the ends:



Boring out the holes for the bars, those for the front bar are oversized by 2mm, as they will be filled with moglice, to form a perfect sliding fit. (Moglice is a product of the german manufacturer Diamant, which is special designed to cast/mold bearing surfaces, see here: http://www.moglice.com/ .)


The bars are aligned in the baseparts with the help of gauge blocks and purpose made centering rings:



Then the moglice is injected with a syringe throug a small hole previous drilled. After 24 hours, the bar can be removed, and what you get, is a high precision bearing:


Here is a piece of cast iron cut to size for the front sliding base:


...and machined on the shaper:


..drilled, and bored, also oversize:


Once again, casting the bearing surface with moglice, this is, what the final preparated workpiece looks like, the hot glue seals the centering discs against the workpiece, so no moglice can escape:


Again, the bearing surface, it's a bit hard to photograph, in reallife it is absolute perfect and smooth:


Progress so far:


Machining the sheet metal parts for the sliding base:




Mounted to the sliding base:


And now, for the micrometer dial, I started with a piece of M.S. (Mystery Steel):


A few hours later:



Machining the tilting base:



Put together:


Here with the rotating base:

In the picture, I am measuring the planar runout of the rotating base, which is well below 1/100mm (its a 1/1000mm dial indicator)

Overview:


Then I went on for the rocking arm (Sorry, no machining pictures here...)



And finaly here is the motor, which will drive the grinding spindle. Its a Perske 3phase highspeed motor, which is ratet up to 23000rpm and is powered by a Siemens frequency converter.


Will keep you updatet...as long as i dont bore you 

greetings
Stefan

[ieezitin]

Stefan

I have never herd of moglice, wow what a product, thank you so much for introducing this product to me. May I also comment on the great use of the shaper in this project, sadly it’s a shame this wonderful machine tool is not used so much anymore and or people who know how to run it, and may I compliment you on such a nice bit of kit and machinery  through out your shop, whats the makers name of the shaper?.

I commend you on such an interesting build, be sure I will be watching.

Anthony

May I add that the use of the stick rule has fallen by the way too.  To me its apart of my body my  wife always complains it sits on my side of the bed.   

[cidrontmg]

Oh boy... That´s just lovely. The Gack doing nice chips! Would that friend perhaps be Mr. Joachim Steinke (http://www.metallmodellbau.de/)? He also did a (modified) splendid Bonelle t/c grinder. I have my fair share of dull cutters. I´ve been contemplating about a t/c grinder (buying, doing, not stealing though...), and come to the conclusion that I´ll just keep on buying new ones, and throw the dull ones away, with a bleeding heart...      
I´ll be following this with both eyes wide open.
 

[Rob.Wilson]

Great stuff Stefang 

I have the Bonelle TCG plans ,,,, one day i may make a start on it ,,, will be good to see how you go about building it 


Rob

[doubleboost]

Real quality work 
Keep the posts coming
John

[stefang]

Thanks for your comments, I will keep the pictures coming

Oh boy... That´s just lovely. The Gack doing nice chips! Would that friend perhaps be Mr. Joachim Steinke (http://www.metallmodellbau.de/)? He also did a (modified) splendid Bonelle t/c grinder.

The Gack is an awesome piece of machinery, I love it.

I know and adore Joachims work, it is just perfect, but the person, who convinced me, was JimmyBondi (He has pictures of his Bonelle over there at HMEM)

May I also comment on the great use of the shaper in this project, sadly it’s a shame this wonderful machine tool is not used so much anymore and or people who know how to run it

Yeah its sad, that this sort of machine is dying...replaced by CNC and EDM Machines..but they are a great value for the home engineer, as the tool costs are almost zero...AND the shaper is a wonderfull machine to watch..almost hypnotic.

whats the makers name of the shaper?.

Its a German made Gack HE-20, there is somewhere a Thread here on MadModder relating to it.

one day i may make a start on it

Go for it, Rob, it will last long enough

Todays (and yesterdays and before yesterdays..) work:

Beginning with the toolhead:

Machining a piece of cast iron to size:


The toolholder is hidden somewhere in this block of cast iron.. 


After a bit more shaping, boring and milling, the bearings were again cast with moglice, here a shot, short before injecting the moglice. The hotglue holds the centering discs in place and seals everything up (The moglice will go everywhere, if not done..)


My way of adjusting the "master"-shaft before casting:


After casting, a bit more shaping with the shaper.. 



...and profiling with the milling machine:


The almost finished toolholder, test fit:


greetings
Stefan

[Trion]

Very impressive build you have there, not to mention the über neat shaper!
May I ask where one can buy Moglice?

[arnoldb]

Excellent work Stefan 
Thank you very much for showing; a T&C grinder is pretty high on my to-build priority list, and I'll be following along closely 

I really like that Moglice stuff as well...  Is it relatively expensive & can it be used to replace Babbit bearings ?  Their site does not seem to give too much information - or I'm too uninformed to understand it 

Kind regards, Arnold

[kvom]

This is a very interesting project, and as well interesting as to the use of Moglice.  I think a couple of points could be added about it:

1) The accuracy/smoothness of the bearing is only as good as the shaft used to mold it.

2) The shaft is coated with a releasing agent so that the Moglice doesn't stick to it.

I am wondering how durable the bearing surface is, i.e., could it stand up to steam engine crankshafts?

[stefang]

1) The accuracy/smoothness of the bearing is only as good as the shaft used to mold it.

2) The shaft is coated with a releasing agent so that the Moglice doesn't stick to it.

I am wondering how durable the bearing surface is, i.e., could it stand up to steam engine crankshafts?

1 & 2: Full Acknowledge, but even with the releasing agent (A alkohol solved wax), it takes some force to release the parts, but when you have washed away the releasing wax, the parts move freely.

For the crankshaft, I don't know...this stuff comes out of the world of big machines, and I belive it is better used for slow rotating parts, other than small, fast moving, but, maybe I will try it out one day

Is it relatively expensive & can it be used to replace Babbit bearings ?

50gramms (42g resin and 8g hardener) cost 11eur here in Germany. For the replace of babbit bearings, you have to ask the diamant people, they will tell you, whats possible.

And now, for the bonelle grinder, more pictures:

Slitting the collet, that holds the dividing disk on the tool holder spindle:


Machining the dividing disk:



The postman hates me
http://gtwr.de/bonelle_58.jpg
Hot rolled steel for the upright slide.

Machined on the shaper, then bored out with a rough surface, to give the moglice a firm grip:


Slide with moglice applied:

Master shaft, thats molded is positioned by the slip gauges, the hot glue (and two aluminum rings) seals the end

Overall view:



The scale on the vertical axis:


Stefan

[Rob.Wilson]

Great stuff Stefang 

Do you need any milling cutters to practice on ,,,,,,,,,,,,,, i have a bucket full that need a sorting out 

Rob

[stefang]

Some progress

Machining the Bars, that will hold the grinding spindle, two at once, they are aligned to each other using two dowel pins:


Other setup to mill the longitual slot:


Making chips, using a 10mm roughing cutter, 5mm depth of cut:


Everything put together, using a piece of steel bar as a spindledummy:


There is light at the end of the tunnel

Stefan

[stefang]

Will there be any metal finishing applied to help deal with rust over the years or will you just attempt to keep it well oiled over the years and hope that is enough?

No Paint (dont like the look of painted stock material) and no oil (it will collect the grinding cust like a magnet...), so I will try something like a hard carwax, thats applied to all steel parts.

Good news, the spindle is finished:





The spindle can be mounted in two different orientations, depending on the work that has to be done.

The bearings are standard angular contact types with seals, and preloaded via 4 springs, almost the standard Quorn Design.

Stefan