Blower brush replacement

[evfreek]

Hi. I posted a query that was buried in the T-metal pipe thread. A week or so ago I built a quick side blast forge out of red clay bricks, a hole in a terrace flush with the ground, some homemade fireclay/kitty litter refractory patch, a disposable propane cylinder, and a leaf blower.

It worked great, for about two sessions. Although it ate a lot of charcoal, I was able to get a lot of metal heated up. Unfortunately :mad: the blower started running erratically. I found out that there was a short brush. The company who built the blower was acquired, and the acquiring company did not provide new brushes. Furthermore, the local hardware stores (tried about 5-6 of them) did not sell brushes. Even though a lot of people have posted on the Internet that Ace Hardware stocks brushes, the local Ace thought I was crazy :confused: for asking. A motor repair store quoted me $25 for a set, but they said hand fitting might bring it up to $60. Either way, they said it was worth it, since the blower was made in the good 'ol days, and it was not throwaway quality. Too much money :mad:. Best solution: get a heavy duty blower with an induction motor (no brushes). But (if you are a blacksmith), this will take a while since you need to buy it at the "blacksmith price", not new or even used price.

So, I saw on a newsgroup some advice to just use any old universal motor brush and file it to size. No surplus houses in the area carried any, but someone left a junk table saw on the side of the road. Some goof dragged it into my back yard and even though I told him to get rid of it, somehow the motor case ended up behind the side gate. Inside was two nearly new universal motor brushes . They had wires coming out of the top instead of the sides, but a reroute + epoxy fixed that. A little hacksawing and filing got it to fit. Saved the messy dust in an envelope to mix with heavy oil for hot punch lube. Should work. Meanwhile, I buttoned up the leaf blower and seated the brush by running for a few hours with a 12 V battery charger.

Let's see how long it lasts.

[Bear]

Hi ev,
Actually induction motors suck. You want a universal motor. The old brush motor is much more useful and generally better quality Than any new induction motor. One thing however you have to check the old time hardware stores not any of the newer ones and definitely not the chain stores when looking for something like a motor brush. they usually do carry them.


Sean

[irnsrgn]

McMaster-Carr

[BT]

I needed to replace the brushes in my old Buffalo blower about a year ago. Tried the local motor repair places. None had brushes big enough to fit. Checked the online supply houses. No luck there either. I found a company on the internet that would custom make the brushes, but they had a 3 set minimum. Finally someone told me to try the local vacuum sweeper repair place. They rummaged around through their stock and came up with a pair that was just about 1/64 to wide, but the thickness and length was exactly what I needed. A few minutes sanding down the width and I was back in business. The guy kept apologizing that he had to charge me 10 dollars for the set.

[ThomasPowers]

Leaf blowers put out too much air for a bloomery much less a forge. Chuck it and use a cheap blowdrier without the heat being on.

[evfreek]

Hi. I tried McMaster-Carr, but they only have coil spring brushes, not the side-wire clock spring types. Yes, I know I can modify them, but not for $15 a pair.

I should give the hair dryer a try. I am not sure that it has enough air to do the job. I have a small Lively type forge that uses a hair dryer. It is marginal. The biggest problem is that the hair dryer kept cutting out because of the over temperature switch. Made the whole setup feel cheap and flaky . I tried to take out the heating element, but upon careful study of the circuit, the heating element was used as a voltage divider to power the motor. The motor was only getting about 12 volts. So, I ended up getting a transformer out of an old stereo and powering it with lower voltage. That enabled me to get rid of the heating element. Many people have trouble with this and end up burning up their motor. By the way, that motor is really cheap. It is a toy permanent magnet motor, similar to the ones found in cheap cars. It will not take long for the shaft to seize up or funny grinding noises to come out. And, all this for painstakingly tracing out the circuit

The reason that I am using a leaf blower is that the tuyere is a simple piece of old 3/4 inch iron plumbing pipe jammed into a chain drilled hole in the top of a 16.4 oz disposable propane cylinder. The hole is sort of sloppy, so I wrapped some aluminum foil around it. The end of the leaf blower blows into the open bottom (after hacksawing a little parts tray off) of the propane cylinder. By moving the leaf blower backwards and forwards, the air can be adjusted. If set on the lowest level, about a 2" gap is good, and enough air will go out the pipe. I suspect that little modified (loud) hairdryer will end up leaking a lot of its flow out the gap between the business end and the open bottom of the propane cylinder. Of course, I can stuff an old sock in there, and that may be preferable to paying $15 for a brush that I will have to hack on , but now that the leaf blower is fixed, I can go back to forging.