Biax scrapers and their uses

I have a question that many will probably like to have answered. The Biax brand of motorized scraper is very popular but there are several different models. Can anyone offer a description of the different models and where or how they would be used?

Also if you are in the market for a used one, is there any specific thing that you should look for that would make buying a used one less risky? By that I mean are there any parts that regularly break or wear that would make a used model undesirable?


Charles

Different model nomenclature for different countries and different eras...

Without researching and off the top of my head.....

7ELM/BL40, the common current model scraper, 20mm max stroke..
BL10, a light weight current model... Having used one, really nice... the stroke only goes to 10mm max...
7ESM/BS40, heavy duty current model 20mm stroke..

HM10 current model, similar size to the BL10, used for half moon flaking.... Totally different but very simple mechanism to the power scrapers...

I am going to assume that a longer stroke is more useful on larger way surfaces?

Are the blade attachments proprietary for each mfg, or is there some kind of standard?

Charles

This is the copy of the manual that DAPRA used from about 1985 until the stopped printing it in i'm guessing 2000. There is a page showing the models.. and a description. The older models that were blue are obsolete as far as buying repair parts. The blue models were one speed and the newer green motor models had a vari-speed motor. Biax Scraper Literature - 1991 I am a rep for DAPRA and have been working with them from the early 1980's. Rich

I bought the BL10, and at times I wished I had a longer stroke. But I think if I had got the 7ELM (I think that was the other option at the time) I would be unhappy about the extra weight when I did not need the extra stroke. I think it depends on what you are doing. If you want to do surface plates, I think you will do better with the longer stroke. For "finishing" work, or working on small stuff, the BL10 is perfect (at least for me).

With that said, I have not actually scraped a machine yet. Done straight edges and a small surface plates with a hole in the middle.

And if are a woodworking, and have hand planes, they are perfect to practice on. You can not really screw them up, and you will improve there performance (a lot in some cases).

Vince

Thank you Rich, What about the blade attachment, is this a proprietary mount that only Biax uses?

You know I just realized that I am assuming that there is more than one mfg of power scrapers. Does anyone other than Biax make them?

Charles

I am probably using mine all wrong but I have never found a need for a longer then 10-12mm stroke... I find if I go longer the tool become uncontrollable, even 10mm is a struggle at times... Have the angle too low it does not want to cut, so you raise the angle and it wants to bite in and kick back.. So I generally stick to 10mm when roughing then quickly cut back to 8-6-4 as scraping proceeds... Usually stick around the 90mm radius tool to start with, then go down to 60 and less as it progresses...

Here is my tooling.... I do not have any of the long flexible biax blades, only the stiff insert types... I get by with them... I only recently have vastly increased my biax tooling... I only ever had the one medium length insert type that came with my Biax 7EL I purchased a few years back...

This year I purchased the 8E Flaker, it came with a vast array of tooling including the genuine Biax radius gauge..... The other shiny stainless steel radius gauge in the picture is one that is made locally (as in, in Australia) and is being trialled for use by the scraping students we have down here, and others that may wish to purchase one... It has no bevelled edge but I have found that feature not of any use to me... When I scrape I much prefer to use a stone as it knocks down all the high, high spots as well as cutting off the burrs, giving you a flatter surface and a better blueing print... Although this is just me, others may have a different preference..



I wonder if the idea of moving this thread to this forum could be entertained www.practicalmachinist.com/vb/general/biax-7el-assembly-repair-198462/

You really can make the tooling for your Biax by your own.
Make 10 or more holders, consider them as disposable and braze the carbide to its end.

Re what model:
Variable speed and variable stroke. I would not go below that. Also, I consider 10 mm stroke as good enought for 95% of all applications. And if not, it just takes a bit longer for roughing.

BTW:
I didn't realize that the new subforum exists. Thanks to all for their support.
I think I will move a few postings of mine (with a bit of re-writing) here.


Nick

I like using the 150 series blades for just about everything from roughing to finishing. I only use the 3/4" stroke on my 7ELM models (I have 6 of the 7 ELM, 1 7ESM that I call Burtha as she is the heavy model I use when I have deep scores and 1 light-weight model BL-10. The bades can be home made and for the prices they are selling them for one has to I guess. I have some info on that later. Charles there is another brand out there, but I have tested it at a couple of shops that have them and in my opinion are not worth the effort. It's a poor excuse of a copy called a Rentz, also made in Germany. I have seen 2 of them in all my years. The blade holder that RC uses is what was originally sold and I say to my students it's like using a jack hammer comparred to the flexible more forgiving 150 series blades. Jim or "Hickory" the host at the Kalamazoo class had one I had him mill thiner on his Bridgeport so it was about .030 thiner and he said it made a world of difference. In the Dapra Biax catalog one page shows "roughing", Finish and Point spotting. Plus a chart showing the stroke length, blade tip radius, finish, etc. I teach this in my classes. The older models and BL-10 Models stoke did not go out as far as the newer ones.

I use the 3/4" stoke if i have a BIG G&L 6" wide slide that's out a mile...over .004" or so... The secret to long stroke is to have a blade radius of 60 r to 90 r and not flatter as it is so easy to roll the unit over and scratch. As i get more points and more accuracy i shorten the stoke more and more..I usually have about a 1/4" stoke for 20 PPI (Points per inch) and 1/16 to 1/8" for 40 PPI.

I use the sharp edge ofthe Radius gage to de-fuzz Turcite and in my DVD I used it prior to stoning the burr's off. More on that later.
Rich

PS: If you click on my name top left and look inside my "profile" I have several pictures showing scraping.

CBlair said:

You know I just realized that I am assuming that there is more than one mfg of power scrapers. Does anyone other than Biax make them

Click to expand...

Renz- Airo is the only other brand that I know of. RENZ-Eiro Apparatebau und Vertrieb: RENZ Elektronik-Schaber A20

That's what I carry. I love mine to death. Rich K had seen one years ago, and didn't like it. The Renz is actually lighter and has a touch more power. I think its a Fein motor, is doesn't seem to slow down despite the load.

Its had that rectangular shaft forever, its always tracked very well. But having said that I work with some one that has the newer Biax, with the slide built in. That's a beautiful machine as well.

As far as tooling, it either clamps in, or its one or two holes in the shank. You can make or modify anything.

Regards Phil.

(On Edit) P.S Can I tell stories here? It ties in with other manufacturer of power scrapers.

I was on site here in Melbourne. Large company,(@ R.C, the company you are thinking of) and I bumped into this tech from Brisbane / Queensland.

This bloke had a habit of running his mouth off, to the point where you couldn't get a word is side ways.

First rule broken, there's not that much machine tool action in Brisbane.

Second rule broken, he proceeds to tell me about Turcite. But he pronounce it Tur-Site. Down here we say Tur-Kite.

Then he avails me with stories of going to Singapore to scrap in Tur-site.

I ask him what gun he slings, expecting him to be a Biax or Renz man. But he tells me Bosch.

I figure that makes sense, Bosch being German, that would be the one company in the world that might come up with a new power, machine tool scraper.

I get back to the workshop, I spent an hour and a half on Google trying to find it. With no luck.

So I get back on site next morning, and I ask him to show me this machine tool scraper. He has one of these. With a Stanley knife blade attached. W.T.F

machtool said:

He has one of these. With a Stanley knife blade attached. W.T.F

Click to expand...

Maybe he specialises "Dulux Rebuilds" and that's to scrape the paint off before the hammertone floods on?

If I get a 'can't refuse' deal on an early Biax, can they be attached to a speed controller to reduce the speed?

Is there a Chinese made scraper, a Biax clone maybe? Chiax..

Answering the OP's question, I've got an old Biax 4-EL that works ok, you need an external speed controller, but they are generally a bit cheaper than the later models.

Ray

Hi Mud, I crossposted with the answer before I saw your question... psychic?

...Synchronicity...

What controller do you use?

Mud said:

...Synchronicity...

What controller do you use?

Click to expand...

I use this one 240V 10A Deluxe Motor Speed Controller Kit - Jaycar Electronics it's a kit that you have to assemble yourself, but it does some smart things with the control that make it provide nice smooth power down to low speeds, Have a look around at some of the better drill speed controllers, try to avoid the cheap phase angle fired lamp dimmer types.

Ray

ES DYJAK a DAPRA Distributor used to sell over 200 Biax's a Year up in MI when the auto industry was booming. Now DAPRA's biggest distributor is in China....along with many of the GM Auto plants. :-( Rich

CBlair said:

Thank you Rich, What about the blade attachment, is this a proprietary mount that only Biax uses?
Charles

Click to expand...

Don't know if it can be called proprietary or not. The blades are 20mm wide with a slot for a 5mm clamping screw. I use 20x3mm ground flat stock to make blades from, braze 25x3x6mm carbide blanks on to the ends, then grind to shape.


Richard:- Do the DAPRA sold ones use Imperial blade sizes??

Nick Mueller said:

You really can make the tooling for your Biax by your own.
Make 10 or more holders, consider them as disposable and braze the carbide to its end.
Nick

Click to expand...

Yep I've made some blades for my 7/EL and I made a couple of shanks to use them as hand scrapers. The shortest of them is the one original blade I have.



I've found that if they are too flexible you get fretting marks in the scrapes.

I use one of these as a speed controller

M012 Power Control 110 - 240 V/AC, 1200 VA

The blades are made in Europe by BIAX who has plants in Switzerland and Germany and the blades are metic. Thats why in the catalog they are listed as a 10-150, 20-150, etc. 20 mm wide x 150 mm long. You know, the feel of the blade is a personal preference to the scraper. I prefer the longer blades. I never use the twisted blades as they are to stiff. If I am scraping a dovetail or V way I use the 150 blades and tip the scraper. I know some scrapers who hate the 150 series and can do a wonderful job with shorter 75 mm long blades. A few months ago someone emailed or maybe it was a PM..I can't find it now, but he was in the UK I think and asked me about selling him blades purchased from DAPRA as he said he got prices from Germany. I checked with DAPRA and the USA prices were 40% higher then of the German prices. I would love to compare price sheets if Nick or one of you other guys in the UK or Germany can get retail price sheets for the blades and scrapers... I have a PDF of the DAPRA Prices. I think sometimes DAPRA has some blade holders and handscrapers made here in the USA, as the blades made in Europe don't fit to good in the Scraper blade receiver or the 1/2 moon blades that clamp on. But the 10-150 blades come from Germany as they are stamped or etched saying that.

If you checked out the You Tube show Jan made, he is using a home made blade on his factory made holder. I am a Distributor of DAPRA and won't recommend you make your own blades, copy a Scraper, as I don't want to get in hot water if you get my drift. The blades Peter shows, looks like a new blade to me. :-)