Small heat treat or ceramic oven and toolpost grinder

[clockworkcheval]

A year ago I got a good deal on a small EFCO 150 oven with inner space of 160x85x195 mm and temperature up to 1100 degrees Celsius. More than enough for hardening small tools and parts at around 800 degrees Celsius. I have a simple SOLO controller attached which basically has two modes 1) straight heating and shut-of at set temperature. This leads to overshoot of up to 50 degrees Celsius. The second mode is a nice PID control which causes no overshoot. After using it with succes for some time I tried to use it in PID mode to max capacity of 1100 degrees. This took a long time and afterwards I thought the oven was broken because in the follow-up it did massively overshoot 820 degrees up to 950 degrees.
The seller then explained to me, what is not very clear from the manual, that the SOLO control in PID mode is self-learning. Heating up to max was only possible with continuous full force heating - and that is what the oven remembered when I tried to use it at the much lower temperature of 820 degrees, thus the overshoot. He showed me the programming how to reset it and mentioned that on its own the controller would probably need about 5 cycles to nicely again get to around 800 degrees. So I quit higher temperature experiments.

 

[trlvn]

The world moves very quickly---I just ordered a toolpost grinder and diamond dresser from Little Machine Shop in USA. It isn't a toolpost grinder even though that's what they call it. It mounts to the topslide.

Is this the one you ordered?

https://littlemachineshop.com/products/product_view.php?ProductID=2001&category=
These are remarkably inexpensive! Apparently takes an 80mm wheel (a bit over 3 inches) and runs at 6,000 RPM. As long as it has half-decent bearings, I would think it would be pretty darn good for hobby use.

Craig

 

[Brian Rupnow]

Yes, that is the one.---Brian

 

[Brian Rupnow]

My heat treat oven shipped today out of Montreal. I bought it from a lady who was a potter and somehow ended up with two used heat treat furnaces. I will probably have to spend some money on controls for it, but the price was right at $200.00. It cost $92 to ship it from Montreal by UPS. Of course the Rupnow Paypal fund is seriously depleted, but I've sold enough engine plans to pretty well pay for a toolpost grinder from Little Machine Shop and a used heat treat furnace. There is something so righteous about spending money from small engine plans to pay for tooling to build more small engines. I will post a picture of it when it gets here.---Brian

 

[dsage]

If you find you need new controls you can get excellent PID temperature controllers from the usual places in China for about $40 or less. They work well to keep the temp withing one degree or so of the set point. I replaced the archaic control board in an oven a few years ago. The new control is about 2" square in the front panel by about 6" deep. You'll also need a solid state relay to switch the power.

 

[Gordon]

I just looked at my oven and I got the Mypin TA4-RNR controller for $21.99 and the SSR-25DA relay for $4.27 back in 2018. You can just use the controller which is now on the oven. The only problem is that it is not as accurate and slow to react. Let me know if you want my notes on how I wired it.

Gordon

 

[Brian Rupnow]

My heat treat oven arrived today. Isn't that the cutest little thing you've ever seen!!! The inside measures 4" x 8 1/2" x 8". And as you can see, it works. It doesn't have any controls on it---just plug it into a 110 volt circuit and it heats up. I'm going to want some kind of on/off switch and something that I can set a dial on for the temperature I want it to hold at. I'm not worried about gradually ramping up the temperature. I just want it to go to whatever heat I wanted and then cycle it off and on to hold that temperature. I don't need a timer on it but if that comes as part of a package I would use it. I'm doing something totally new here, so be gentle with me. Can someone recommend what I need please. Ontario supplier works best for me, but I can shop USA if I have to.---Brian

 

[Brian Rupnow]

Gordon---the Mypin controller is no longer available (per google search) The relay you mention is $32 American.

 

[Gordon]

I think that you want something like this:

https://www.ebay.com/itm/121152022581?hash=item1c35392835:g:j9IAAOSwsYNghb21
That is basically what I have except that it is a free standing pre wired unit. Ships from Canada.

I am sure that there are similar options.

You would have to drill a hole through the wall to insert the probe unless you can insert it in the front hole.

Gordon

 

[abby]

If you are making mehanite rings the heat treatment is to "set" the ring and the temperature is not so critical that a muffle is required.
A suitable gas torch is all that is needed.
Dan.

 

[Brian Rupnow]

Gordon---I've just purchased the item you showed in your previous post.---Brian

 

[L98fiero]

Can someone recommend what I need please. Ontario supplier works best for me, but I can shop USA if I have to.---Brian

Thermomart is on eBay and are located in Richmond Hill, they have some pretty good controllers, that will store a few different programs that can have numerous heating/cooling steps with hold times. They will have the control that you need, and they're close. Temperature Controller Sensor Smart Home Measuring Equipment

 

[Gordon]

Gordon---I've just purchased the item you showed in your previous post.---Brian

I am not too sure that taking the recommendation of someone who is wrong as often as I am is really a good idea.

 

[Brian Rupnow]

I measured up all of the equipment on my garage wall, to see where I could find a place for my heat treat oven. Once I found a place on the wall where the compressor tank, stick welder and hose reel and 220 volt power outlet was, I designed an angle iron frame to support the oven. I asked my good wife if she could check Marketplace and Kijiji (local buy and sell forums) for anybody giving away bed frames. I got one free, one for $5 and one for $10.00 I spent this morning dismantling them---(I love bed frames for building this kind of thing. The steel in them is absolutely horrible to machine or drill, but it it cuts and welds just fine). I have ordered a controller for the furnace, but I'm not 100% sure where it is going to be mounted on the furnace, so I will wait for it before I build the frame.

 

[clockworkcheval]

In general I'm weary of heat and fumes in my wood-walled shop, so my grandson Jacob at 14 yrs welded me a heattreatment trolley so I can work heat in the open. For silversteel and regular toolsteels the oil hardening temperature is around 800 degrees Celsius. My EFCO150 oven is on top with next to it an oilcan on a hotplate to heat the quencing oil at 50 degrees Celsius. In practice I re-arranged it a little bit to be able to move the part very quick from oven to oil. For tempering I use a cheap portable oven that can be set at max one hour at max 220 degrees Celsius - my wife did not appreciate my suggestion to use her regular oven for this purpose. In my efforts to handle High Speed Steel I use a Nabertherm L/12/S27 oven that gets up to 1200 degrees Celsius and for tempering at 560 degrees Celsius the EFCO150. For not too big assemblies I find the ovens also quite useful for pre-heating any silver soldering jobs.

 

[ajoeiam]

In general I'm weary of heat and fumes in my wood-walled shop, so my grandson Jacob at 14 yrs welded me a heattreatment trolley so I can work heat in the open.
snip

Kudos to your grandson.

Suggestion for him - - - - I understand his need for 'cool factor' re: wearing his hat cocked to one side.
Wearing it that way isn't really a problem - - - - until you're doing some overhead welding and you happen to get some slag that rolls off the hat and into the gap between the collar and the hat. The dancing at that point is quite a work of high art.
(Pull the blasted hat brim back - - - its what shields the neck area - - - - working garb isn't about cool - - - - - its about minimizing the pain of problems - - - - besides a decent welding burn in the back of the neck area takes a while to heal and is a real PITA!)

 

[clockworkcheval]

Point well made, sir. I will advise my grandson. His hat however is not cocked - you look at his rightear protection flap which together with a fullsize neckflap and a similar leftear protection flap should provide good protection while welding underhand.

 

[ajoeiam]

Point well made, sir. I will advise my grandson. His hat however is not cocked - you look at his rightear protection flap which together with a fullsize neckflap and a similar leftear protection flap should provide good protection while welding underhand.

hmmmmmm - - - looking again - - - - what I would want, if it were me welding, is something so that there are no possible openings at the back of the neck.

(The yellow material joins something from the head - - - maybe part of the denim material(??) but there is a join there - - - I'd want that denim to overlap the yellow stuff and that yellow stuff better be cotton or a hot bit makes for some very interesting times (I've twice melted coveralls (once including a work shirt and t-shirt somewhat onto my chest) - - - - - I only wear cotton overalls since. Refuse the 'modern fire proof fabrics! I ask the person offering them that my test is for them to put them on and then for me to use a cutting torch to start a fire on the fabric - - - - - any melting and I don't care what standard its to - - - - I just don't wear, but then they never have the guts to do the test - - - - - so I don't have to wear them anyway!!!! Just don't ever want the joy of scrapping fabric, including body hair, off of my skin - - - - again(!!) - - - - twice is enough, I get the problem!!!)

I had the joy of catching a large lump of slag that rolled to where it sat wedged against my drawers welding wedged quite mercilessly into a turntable on a gravel trailer. Couldn't even do any dancing - - - - and really not funny. No point in trying to get out of the wedge to deal with it either. The lump had cooled considerably and would have been quite 'handle-able' before I even got out so finished the welding first. Took a bloody long time to heal up too. Tend to check those kind of things since. Easy enough to laugh at the story after the fact but a 'no fun' event at the time

 

[Gordon]

After my dad retired he bought a welder and did some hobby type welding. One day he came in the house and told my mother "I know why Gordon always wears cotton socks instead of these synthetic ones, when sparks land on these synthetic socks they melt right into your foot"

 

[clockworkcheval]

The yellow stuff is the leather collar of the leather welding jacket. The cap is a fully wooden wintercap. But you are right, the overlap is the wrong way around. I will get Jacob (and myself) better caps with good neck protection.