Member postings for Fulmen

With most alloys annealing is a matter of time and temperature, so the hotter you go the faster it anneals. If you don't want it soft as clay you should work your way up. I haven't found any reason for a quench either, except to limit the amount of heat you put into the part.

Some special CuNi-alloys can be age hardened, but that usually means holding the part at elevated temperatures for hours.

The detector could use one of the spark electrodes as common ground. Or more likely use the burner as the other electrode. The difference in temperature could in theory form a crude diode, this would make it possible to detect short circuits and leak currents.

I don't buy the hunting tooth theory, the two wheels aren't connected in any way.

My guess would be that they got two batches of cheap wheels and just mixed them together. If they're the same pitch the knurl should turn out the same. If they're the same diameter the knurl would be slightly asymmetric but I doubt it's noticeable.

I have to agree with Pete here. Any lube is better than no lube, within reason.

For high speeds and light loads oil seems to be best, grease for slow speeds and high loads. Then again oil should be applied regularly, so for sealed units without a sump I would choose grease.

BTW, I came across this yesterday: hexagonal paper bellows

https://www.youtube.com/watch?v=ldmCQayLieI

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.

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.

I'm a bit stumped now. I've been working on the wheelhead and something doesn't add up right:

The wheelhead guide (Drg 11, Det 1) does not line up with the jack screw (C10 Det1) and the square guide rod (C11, Det 2). I've double and triple checked the drawings and I can't find any mistakes. Also the guide collides with the mounting bolts for the wheelhead arm (C3 Det 1). I've checked both Don Williams original PDF and this metric one: http://www.mosoft.nl/slijpmachine/A0%20Bonelle%20TCG%20drawings%20Metric.pdf

Wow, this turned out better than I could have hoped for. Got a call today from a nice member of this forum that had ductile iron for me. He could even cut it to the rough shape for me.

Guess I'm all out of excuses now

Yikes! Start by pulling off the rear fan cowling, they are easily dented by rough handling. Mechanically these motors are nothing more than a spinning shaft with a bearing at each end. Simple enough to service if you can pull it apart.

Thanks, that's good advice. The drawings aren't checked for errors yet, and they will be "metrified" before construction. So plenty of time to add my own errors

Here's the spindle assembly all drawn up:

I did consider a castings kit, but I'm not really a model builder. Getting everything lined up right seems to be big part of the challenge and I kinda detest creative setups that could break a casting. Building it from scratch provides more leeway for solving things my own way.

While it was a hard sell I'm going for aluminum. My local dealer actually has 50mm square aluminum in stock, 6068 T6 IIRC. That should do nicely if I ever get the drawings done. I'm about 50 parts in so far...

2000C is slightly on the hot side of things My notes say 900-950°C, and it has worked very well for me in the past.

One source suggested the following mix: 50% charcoal, 35% coke, 10% barium carbonate, 3% calcium carbonate and 2% sodium carbonate. I've only used straight BBQ charcoal with 10-20% carbonates. As noted earlier the barium is probably not needed for our kind of work, any carbonate will work fine or at least better than none.

I don't know how Richard solved that, I was thinking of brass sleeves for the moving parts.

@SillyOldDuffer: Various carbonates are added as "activators", but I haven't found any good info on the reason for the different metals used. But I suspect it has to do with the temperature and rate of decomposition (into CO2 and the corresponding metal oxide). Barium carbonate breaks down more slowly than sodium or calcium carbonate so I suspect it's mostly needed for very thick casings on large parts. These can take days to form.

I actually have suitable barium salts, but never tried it due to it's toxicity. In my experience a 50/50 mix of sodium and calcium carbonate will work just fine.

IIRC Cherry Red was primarily ferrocyanides, forming a very thin nitrocarburizing case. While nitrides provide a very hard, wear resistant case they don't really provide the increased structural strength that carburizing does.

The way I understand "case hardening" describes any process where a hard outer "case" is applied to a part. The classic process is as Bill Davies said "pack carburizing" where carbon is added to low carbon steel by heating it in a closed box with charcoal. Other processes adds nitrogen (nitriding) or a combination of carbon and nitrogen ( carbonitriding) using either a molten salt bath or a controlled gas atmosphere.

A simple yet effective concoction is regular BBQ charcoal with say 5% of calcium carbonate (limestone) and/or sodium carbonate (washing soda). The carbonates provides a source for CO2 which combined with the charcoal forms carbon monoxide. This is the actual carrier that transports carbon into the part.

The deposition rate is slow. You can expect a case depth of 0,1mm per hour at the beginning, but this quickly drops as case depth increases.

@ Richard Millington: Have you ever regretted the choice or felt that a cast iron base would have made any real difference?

@Bizibilder & John Haine: Thank you that's very useful.

I'm working off the PDF by Don Williams, and I think I will model the original design first in Fusion 360 just to get a good reference. Besides I need the practice. The metric conversion doesn't look that hard, I haven't found any inherent geometry that can be screwed up. But it's nice to have something to follow, even if I choose to alter the design somewhat.

The real problem seems to be the materials for the base. Obviously cast iron is the top choice, but square stock is impossible to source here. Making it from round stock isn't too appealing either. There are some suppliers in the UK, but the shipping cost is pretty horrendous.

Has anybody seen a build with an aluminum frame? It would make it easier to stow away between use, and casting it myself isn't entirely out of the question.

Please don't hold your breath waiting for that, it's a loooong project and I'm just getting started.

I'm still in the process of modelling everything, and I also need to rework everything into metric units and dimensions. I'm also looking for suitable stock material which so far is pretty much unobtainium. I really would like to get cast iron for the base, but I'm also considering aluminum.

Greetings everybody. As the title says I'm not from the UK, but that shouldn't matter too much right? There is just no good forum for this in Norway (other than some Facebook (shudder) groups.

My reason for joining is that I'm planning a Bonelle/Quorn build, and there seems to be a fair bit of experience with them here.