PDA

View Full Version : Steadyrest



wannabe
15th Dec 2008, 01:57 PM
I'm in the process of building a steadyrest for the Hercus. I've never used a steadyrest with finger extender bolts before and have a question about them.

The original Hercus steadyrest has square heads on the finger extender bolts but I'm thinking that these bollts would only ever be done up finger tight. Am I right in assuming this or are there instances where they need to be tightened with a spanner? If not needed I think I'll just put knurled knobs on them. A lot easier than making up square headed ones.

pipeclay
15th Dec 2008, 03:01 PM
In general I would say you wouldnt require to have to put a spanner on your adjusting screw to tighten your fingers.
The relation between steadies and adjusting srews is usually size related the bigger the steady the biger the head of the adjuster,with larger lathes I have had times when I have used a spanner when adjusting particularly with large heavy jobs,but with the hercus you would normally be able to do most if not all adjustments by hand.
When you get around to making your fingers if possible try to fit rollers rather than just Brass or Bronze ends.

Penpal
15th Dec 2008, 06:18 PM
When you make your steady a source of cheap and good bearings are those used in inline or other skates. At Jamison one of the cheap tool dealers has them. Another source is my mate at fyshwick, give me a bell if i can help.

regards Peter.:2tsup:
PS You will be blown away by a Guy called Skiprat on the Pen Forum making Pens from old Stainless Bolts.

wannabe
15th Dec 2008, 10:34 PM
Sounds good Pipeclay. I think I'll just go with knurled knobs loctited on. If it doesn't work out I can always heat it up to get them off and make some square headed ones up. It would be easier to just get 50mm cap head screws but that's a trip to the other side of town to get them.
I initially designed this thing to use roller bearings but somewhere along the way I got sidetracked and ended up with steel fingers with hard brass tips silver soldered on. I've been looking at using the same fingers but with a skateboard ABEC 7 bearing on either side of the finger. That way the load should be balanced out a bit and hopefully not want to twist the finger under load. It should be fairly simple to rig the bearings up on these fingers and that way I have the option for either brass or bearing with only a minute or so to change over.

Hi Pete. Didn't realise there was a skateboard place at Jamo (or are you talking 'Trash n Treasure'). I'll have to go have a look. I was eyeing off a set of 8 ABEC 7 bearings on Ebay for $17 delivered.

blackfrancis
15th Dec 2008, 11:24 PM
Hi Peter

You may find that brass does not work. Brass is not a good bearing material and round brass bar is exceedingly bad. Brass from rolled plate may be better, it is much harder, but I've never tried it. The problem with brass is that it wears very fast. I used it for a home built steady and it wore so fast that my steady wouldn't stay properly adjusted for long enough to be of any use. Cast iron, bronze and gunmetal are all good bearing materials. Another material that could be worth a try is nylon, perhaps it would be less inclined to leave marks on your work, but I've never tried it for bearings. I have vague memories of steadies on cylindrical grinders using some sort of fiber material on the fingers, much like they use to make fiber gears, may have been something else but I'm pretty sure it wasn't metal.

Of course the ball bearings should be a winner.

Cheers
Steve

Woodlee
16th Dec 2008, 12:06 AM
There are different grades of brass ,hard and soft depending on the alloying material ratios
Got brass on both my steadies and it's been ok for years.
Free machining brass would be ok , phosphor bronze would be better .You need to use oil to lubricate the fingers ,but roller bearings would be the best.
The shafts that hold the fingers normally have a slot cut down one side so they don't rotate ,a flat down one side with a locking screw would work.

Kev.

wannabe
16th Dec 2008, 12:22 AM
I had concerns that the brass would wear. That's why I just silver soldered tips on the end. The brass I used is from an old door threshold strip, about 25 years old and very hard. Hopefully it will stand up to it but once I get the bearings set up I'd say that's what I'll use all the time anyway. Don't know why I made the brass tips when I always intended using bearings. Think it was a case of I had the brass, didn't have the bearings at the time. Anyway it's getting close to being finished and then I can give it a try to see how it goes. Just have to get these finger bolts sorted out, clean the thing up and paint it. The two worst thing till last, prepping and painting. I hate them.
It doesn't look anywhere near as good as the one you made Steve but it seems solid enough and should handle anything from 3mm to 115mm with brass fingers, 4mm to 80mm using bearings and the best part is to date I'd say it's cost me $15 - $20.

blackfrancis
16th Dec 2008, 09:38 AM
Sounds good Peter, nice large capacity and it's how well it works that counts, so who cares what it looks like. The brass I used was definitely soft, so given what Kev says all should be fine :)

You'll have to let us know how it all turns out

Cheers
Steve

Penpal
16th Dec 2008, 06:07 PM
Was in Fyshwick today and enquired re those bearings and they the number you used are an American source from China. Euro quality is 5.00 a bearink.

Yes I did mean Jammo and the dealer is the heavy set guy with tools and his family that have been going for many years, one time I bought a string of them, whenever I see bearings good and cheap I stock up for projects.

Right now I have a bunch if you want to use them now give me a call.

Regards Peter:2tsup:

wannabe
16th Dec 2008, 10:16 PM
ABEC (Annular Bearing Engineers Committee) is a yank rating. All skateboard bearings I've seen seem to use this rating. From what I have been reading it appears to be equivalent to a class 4 bearing. The ABEC 7 bearings are supposedly high precision and rated at 34,000 rpm. Don't think I'll ever get the things up to that speed but they should be good quality for use on the steadyrest.
I've ordered some bearings so I'm ok for them thanks. They've even got green seals to match the paintwork :D

Forgot to mention. I had a look at the stuff that Skiprat1 is making. Very impressive.

prozac
16th Dec 2008, 11:36 PM
ABEC (Annular Bearing Engineers Committee) is a yank rating. All skateboard bearings I've seen seem to use this rating. From what I have been reading it appears to be equivalent to a class 4 bearing. The ABEC 7 bearings are supposedly high precision and rated at 34,000 rpm. Don't think I'll ever get the things up to that speed but they should be good quality for use on the steadyrest.
I've ordered some bearings so I'm ok for them thanks. They've even got green seals to match the paintwork :D

Forgot to mention. I had a look at the stuff that Skiprat1 is making. Very impressive.

I thought that ABEC must have been a brand of some superiority. Something new learnt every day. Thanks Peter.

12teethperinch
17th Dec 2008, 07:32 AM
I have heard that on steady rests with bearings if a chip catches and gets rolled between the work and the bearing, the bearing race can crack. I suppose that it would need to be a very stiff rest with no flex in order for this to happen.
Darrell

Penpal
17th Dec 2008, 09:44 AM
Glad you are all fixed up.

Regards Peter:2tsup:

pipeclay
17th Dec 2008, 11:58 AM
In regards to the mention of chips damaging a roller ,Ive never had a problem with using a proper fixed steady roller in my experiences normal it will leave an indentation in the work piece.
In regards to fitting steadies with bearings yes I have had them break and severely throw a job out of true,(this was on a 125mm shaft 2.5 metres long though).
It is allways good practice to make up some sort of guarding for the steady rollers to try and eliminate swarf getting to them, I generally use cardboard or heavy plastic sheeting.

wannabe
17th Dec 2008, 12:19 PM
I've seen references to chips getting under the bearings but didn't realise they could break them. Most of the reading/homework I've done indicates as Pipeclay has said is that they use a piece of cardboard fixed to the steady with just the job poking through to stop swarf getting in. I don't think I'd like to be dodging pieces of flying bearing. That would definitely get the sphincter muscle flexing.

neksmerj
20th Dec 2008, 11:49 PM
In answer to a PM from Peter (Wannabe) painting of small items is best done with an air brush. I use a Paasche airbrush set model H with a No.5 tip. Air pressure is around 30 psi.

I've also used a small touch-up gun with equal success, however, they take at least half an hour to clean, what a pain in the bum. The air brush takes less than 10 minutes with only the nozzle and bottle to clean.

Peter, you mentioned you were going to use Taubman's Pesto green, on advice from Penpal Pete. I will be very interested to see just how close this colour dries compared to Hercus Crowhurst Green.

Ken