I got my forge picked up today, pictures are before I had to disassemble and get it out of the building. the blower was mounted on a cement pedestal and fan motor mounts were mounted into the chimney of the building. I need to build a new mount for the blower and motor. it has a .5 horse motor with a flat belt design that Im going to see if I can reuse, but the belt looked pretty bad. sure I will have questions as work my way into this.

Pretty huge blower and firepot. 

bit too big I reckon, but if it works for you, im not judging

I think that, if the air can be throttled, it will be highly capable.  You could have a small fire to make leaves and such or crank it up and heat up and entire scroll or weld a big billet.  That forge will teach some fire management for sure.

I haven't had much time to mess with reassembling and rebuilding the motor and blower mount. It it does have a throttle on the air, a slide gate of some sort underneath the tub.  Im ordering a new belt,  I need that to make the blower and motor mountings. also need to figure out wiring on an  old single phase 110/220 motor with out any capacitors or diagrams want to make sure that can be used before building anything.  

I forgot about this post and am finally working on this again. I test ran it just for belt alignment. but need to build another sheave I didn't have a small enough  boring bar so just drilled it, of course it wobbles and kicks off the belt. o well.

it seems to be kind of a lazy air flow I was thinking shop vac type pressure and its not there. my rpm is the same as it was originally set up I did change the motor though may have to upsize the pulleys. here is some pictures of the build. 

Did you put a crown on the sheave? It makes a big difference tracking.

Frosty The Lucky.

1 degree per side is a good starting point for crowning.

 

As shopvac type pressures are generally too much for hobby blacksmithing; how did you choose that for a desiderata?

I dont know how much air flow it needs. everything I have read says I need at leaast 5" of pressure. I have this belt so Im probably going to use it at this speed and see if blacksmithing is something I want to stick with.

I'm surprised to see the ratio on the motor to blower.  looks like 1:1 or possibly a bit overdrive. fan at motor speed or above.  3600rpm or 1800?  seems like it would move a tremendous quantity of air.  

 

I’m with Moto, based on what we can see that sucker, I’d think, would make your forge look like an erupting volcano!

Haveyou pulled the fan case apart and checked out the impellar? Old sheave on the impellar axle properly fixed n place and not slipping?

Hows the tuyere and air grate? Is it occluded somehow?

And the guys are right a crown can help belt tracking tremendously on the sheaves. If yours are not crowned, you can even put a couple wraps of tape in the center of them to test, and to be honest, I’ve run stuff for years with that rigged type of fix before the tape wore down.

its a 3400 rpm motor built a new sheave and now its tracking a lot better. Im using an old tablesaw motor with the sheetmetal mounting system and that flexes and moves the belt around but its working right now. cleaned everything out and it flat out moves air sounds like a small leaf blower, had chunks blowing out of the hole. now im moving on to the next thing to work on I dont know what the air port into the forge is called to look it up ands see how to rebuild it

Glad you got it operating!

3400RPM is really humping, I’m going to guess the original motor was between 1200-1800: don’t know about original pulley ratios tho. Make sure you have a good blast gate or diverted to reduce the air flow, or a choke on the fan shroud inlet. Yes air pressure is important to get air up through the coals, but not that huge volume that sucker will provide. You will blow out the fire, or  decarburize your work, and go through fuel at an alarming rate.

Unfortunately the heavy wire mesh you used for a tuyere grate will probably burn through fairly quickly, I’ve had better luck with thicker plate with holes drilled/milled in it, or bars of material used to make a grate.

when I got it it had an 1800 on it with shot babbit bearings but when I measured pulleys and punched it into a calculator the fan was at around 3500 rpm. but it was in an old lineshaft building so who knows what rpm it was designed to originally run. it has a good blast gate that will shut the air completely off. Im going to cut a circle and start drilling. would I be better off with .250 stainless plate or .375 milld steel. when you say go through fuel fast do you mean 2lbs an hour or 20lbs an hour? coal here is 22.00 for 80 lbs of nut size.

What type of coal?

This was the only stuff available in the local area unless I want to ship a long ways

Bituminous---good.

alright I drilled a grate out its free hand so the holes are all over I will see if it works. if I crank the blower all the way up it try to blow it out of the hole. I think I will start shopping for a used 1800 rpm motor. I want to light it tomorrow so how much coal do I pile on it just a few inches? 

I can’t tell you exactly how much, there are so many factors in how you manage fire: how deep and wide you keep your fire, if you work your coal wet, turn your blower off between heats etc. The main thing tho to me isn’t just gobbling fuel, it’s burning up or overly scaling up your work, etc. I know this isn’t definitive, but any more air than is needed to heat your stock reasonably fast, in the appropriate sized fire, is too much air. Tha t means extra fuel consumed, extra scaling, possibly cooling your work with unconsumed air. 

We all posted at the same time. If you are blowing the grate out that’s a LOT of air.

The randomness of your air holes is no big deal, don’t sweat it.

Since you have a lathe reduce the diameter of your motor pulley or make a larger diameter for your blower axle, you don’t need to immediately jump to a lower rpm motor. If your current motor pulley is 4” turn it down to 3” try again. At 2”, or half what it is now, then it will run the equivalent of the 1800 rpm with you’re current pulley set up.

Is your fire pot/duck nest made of clay or packed ash? How deep is it? You want your fire at least as deep as the nest so your stock can slide straight through, plus some on top of that. How much depends on the stock size worked and what type of work you’re doing to it.

Have you run a coal forge before, or is this your virgin voyage?

If so, guys do you know if we have videos on the forum of managing a coal fire?

Might want to read through this thread.

.

I have never worked with coal before so begin trip my whole forge is som kind of cement it actually has gravel in it but it’s definettly been used this way

I have a blower in the shop forge that is a bit larger than that one, about 16" diameter ...  but it runs on a 1400 rpm motor and the pulley ratio is 2:1 ... so fan is at 700 rpm and it needs the gate to rain the air in all the time.

i fired it up today like you all figured I had way to much air. had flames 3' in the air even with the slide gate closed.. I cut in a gate valve on the down side of the blower and let it run to waste and that seemed to help a lot. I finally got some metal to at least orange but its going to take me some time and a ton of coal to get to were I can make this do what I want.. does a chimney help guide some of the heat away? it was cooking being close to it. and I need to build a diverter to keep the heat off my motor.