Custom Camshaft Cores

RacetruckRon said:

Do you have a drawing?  Even a rough one with a few dimensions and material requirements will make those conversations with machine shops go a lot smoother.

Another option is to put an RFQ up on Alibaba and have your blanks made by a shop in Asia.  I've done this a couple times on one off prototypes and have a couple shops in the Shenzen area I have had good luck with.

We don't have drawings but we did CAD up a camshaft just in case we needed it. We could very easily make a drawing out of that. How does the RFQ process on Alibaba work? that sounds interesting, I didn't know that was a thing. I am curious.

In reply to BuildItYourself :

I made a business account with a new email.  I highly recommend using an email address that sounds like a small business but has little to no traceability back to you.  Otherwise you will get a lot of social media attention from sales reps from Chinese Machine Shops.  From your Alibaba account it's "manage RFQ" and you can put up a RFQ like "Prototype steel camshaft blanks machined and heat treat" fill out the other details that the RFQ page wants. You can upload PDFs of drawings and step files. Draw everything in metric and use GD&T to control you features if you know how to use it correctly.  

You likely will get a lot of quotes back and will have to sort through them.  Discuss how you will pay and make sure shipping is in the quote.  A lot of places will want a wire transfer, I push back on this whenever I am using a new shop. I say I am more comfortable using Alibaba pay options for this first run and will be open to using the wire transfer in the future once good business relationship has been established.  This is kinda the key to the whole operation is that they think you are a small business and that you will work with them in the future on other projects.  If you have any questions let me know, I'll help any way I can if you go the Alibaba route.

This was my first set of parts I had made. This was $78 machined, anodized and shipped from Shenzhen to my door in Wisconsin back in 2019. Shipping and material are more expensive now even over there but still a good option for one off parts.

In reply to RacetruckRon :

Crap, I would not even turn on my CNC for $78. That is an insanely good price, especially that part on the bottom left ... that's a big chunk of aluminum. And anodized lol. 

I have heard of the Swedish outfit mentioned up on the thread. I would reach out to them. 

A lot of people make it sound simple, but it isn't. I have machined a couple of cams for a Honda K20 out of aluminum for testing purposes and if it wasn't for a friend it would have been quite expensive. 

Just to add about China , 

do not tell them what your part is for  , or lie about Which car it fits , 

too many stories about sending a sample , getting a finished part for review , and then seeing your part on Alibaba for sale to anyone.

its happened to me and other friends, 

Slippery said:

In reply to RacetruckRon :

A lot of people make it sound simple, but it isn't.

It's true. I do this kind of stuff, there's a lot more to it than has been mentioned.

Two foot long cores are going to be a bitch to machine, even more difficult to heat treat, and they will have to be ground at least twice. I don't know anything about the application, but if it's a reasonably modern roller profile they will likely have VVT, which is more work,  and depending on the grind you decide on, an inverse radius on one side of the lobe, which a lot of shops (like one that was already mentioned) are not equipped, and may not even know enough about to grind properly. 

Peabody said:

Slippery said:

In reply to RacetruckRon :

A lot of people make it sound simple, but it isn't.

It's true. I do this kind of stuff, there's a lot more to it than has been mentioned.

Two foot long cores are going to be a bitch to machine, even more difficult to heat treat, and they will have to be ground at least twice. I don't know anything about the application, but if it's a reasonably modern roller profile they will likely have VVT, which is more work,  and depending on the grind you decide on, an inverse radius on one side of the lobe, which a lot of shops (like one that was already mentioned) are not equipped, and may not even know enough about to grind properly. 

I believe the Swedish guys can do inverse radius.

Update on cams, WE GOT SCREWED! 

Turns out the shop that was allegedly machining our cores, wasn't! This dude had been lying to us for the past 5 months and now we're back to square zero. Lies after lies, "they are in the works", "they are coming along", "they are being shipped to heat treat this week", "they were shipped off two weeks ago", "looks like they are lost", and on and on and on. What a frustrating situation. We even called the heat treating company he had "sent" the machined cores to and, surprise surprise, they told us they have no records of any camshaft shipments from this guy or his company.

No idea what he got out of this whole deal, why do people lie like this? 

We're giving this alibaba RFQ thing a try, and a few other shops around our area, but no luck from any local spots so far.

Who knew getting someone to turn some metal would be so hard!

Its a difficult piece to make, very few shops have the capability. 

I hope Alibaba comes through for you, but my hopes are very low. 

Ask mke.

About 1/3 down on the first page

preach (dudeist priest) said:

Ask mke.

About 1/3 down on the first page

good looking out! I reached out to mke. Thanks man!

Try contacting the guys at Roush Competition Engines in Livonia. They do a surprising amount of custom work and might be interested. I've seen a lot of interesting things in their custom build room. No clue what cost is gonna be like.

Alternatively, it may be more straightforward to buy two sets of aftermarket 4v steel cam blanks and weld them together. If you grind the bearing lands and lobes post welding there should be very little issue with eccentricity if there is any residual post-weld.

Not sure if this has been mentioned, but any chance of using the pushrod cams as a starting point for cores to regrind?

In reply to BuildItYourself :

Do yourself a favor and go through that whole thread.

BuildItYourself said:

iammclovin804 said:

Is welding 4.6/5.4 cams together out of the question?

We thought about doing that, but the problem with the stock cams is that the lobes are pressed in, so if we cut and weld them, most shops won't touch them even for a re-grind because they can't guarantee they will ever be back to spec due to distortion and they also will never guarantee the lobes will be (and stay) in the right place

They are not pressed in.

The lobes are a slip fit over the tube.  A mandrel is then rammed through the tube to open it up to size.

I don't see why one couldn't just try to duplicate the process.  Or even use a light press fit and weld the lobes in place.

Sorry to hear about your luck!

The more professional route if you're looking for the turned blanks would be to put it up on Xometry.com or MFG.com.   A lot of the prototype world runs through those sites.  Xometry is the big player, but MFG.com is trying to play catch-up.  You can even specify USA-based suppliers. 

This is for general machining, though, so you will be expected to have a decent model & print with critical dimensions, or you'll be dealing with a lot of yokels.

Pete. (l33t FS) said:

BuildItYourself said:

iammclovin804 said:

Is welding 4.6/5.4 cams together out of the question?

We thought about doing that, but the problem with the stock cams is that the lobes are pressed in, so if we cut and weld them, most shops won't touch them even for a re-grind because they can't guarantee they will ever be back to spec due to distortion and they also will never guarantee the lobes will be (and stay) in the right place

They are not pressed in.

 

The lobes are a slip fit over the tube.  A mandrel is then rammed through the tube to open it up to size.

I don't see why one couldn't just try to duplicate the process.  Or even use a light press fit and weld the lobes in place.

The vw cams are made similar, but the shaft is chilled and allowed to heat back up capturing the lobes. We were told we couldn't do regrinds of these cams for that reason specifically by a very well known cam grinder.

Paul_VR6 (Forum Supporter) said:

Pete. (l33t FS) said:

BuildItYourself said:

iammclovin804 said:

Is welding 4.6/5.4 cams together out of the question?

We thought about doing that, but the problem with the stock cams is that the lobes are pressed in, so if we cut and weld them, most shops won't touch them even for a re-grind because they can't guarantee they will ever be back to spec due to distortion and they also will never guarantee the lobes will be (and stay) in the right place

They are not pressed in.

 

The lobes are a slip fit over the tube.  A mandrel is then rammed through the tube to open it up to size.

I don't see why one couldn't just try to duplicate the process.  Or even use a light press fit and weld the lobes in place.

The vw cams are made similar, but the shaft is chilled and allowed to heat back up capturing the lobes. We were told we couldn't do regrinds of these cams for that reason specifically by a very well known cam grinder.

Yeah, exactly.

We actually called a grinder to ask if we could do what Pete suggested but they said they wouldn't touch them.

So it's really not an option. We need a billet spool if we want this to work.

Pete. (l33t FS) said:

BuildItYourself said:

They are not pressed in.

 

The lobes are a slip fit over the tube.  A mandrel is then rammed through the tube to open it up to size.

I don't see why one couldn't just try to duplicate the process.  Or even use a light press fit and weld the lobes in place.

I think furnace brazing would be better than welding, from standpoint of labor and HAZ distortion.
A centerless ground steel/iron tube/rod with a jig to secure the 'lobes' in place.
Drill rod in various alloys and lngths cut to order is a commodity, not a special.
The blank lobes can be ordered as laser or waterjet cut from any material with a rough profile.
The precision center hole in the blank lobes can be machined by just about any shop.
Conventional cam grinding could yield a final finished functional camshaft.

Easy enough to do a Proof of Concept with just 1 or 2 lobes on a length of drill rod.
Investigate which metals/alloys are fit for duty, braze compatible.

BUT, that said:
There are a number of mature industrial power transmission coupling solutions that could join two cut down sections of existing camshafts. 
We are not talking about extreme torque or power levels or RPM here.
 

BuildItYourself said:

Paul_VR6 (Forum Supporter) said:

Pete. (l33t FS) said:

BuildItYourself said:

iammclovin804 said:

Is welding 4.6/5.4 cams together out of the question?

We thought about doing that, but the problem with the stock cams is that the lobes are pressed in, so if we cut and weld them, most shops won't touch them even for a re-grind because they can't guarantee they will ever be back to spec due to distortion and they also will never guarantee the lobes will be (and stay) in the right place

They are not pressed in.

 

The lobes are a slip fit over the tube.  A mandrel is then rammed through the tube to open it up to size.

I don't see why one couldn't just try to duplicate the process.  Or even use a light press fit and weld the lobes in place.

The vw cams are made similar, but the shaft is chilled and allowed to heat back up capturing the lobes. We were told we couldn't do regrinds of these cams for that reason specifically by a very well known cam grinder.

Yeah, exactly.

We actually called a grinder to ask if we could do what Pete suggested but they said they wouldn't touch them.

So it's really not an option. We need a billet spool if we want this to work.

Our lobes are weldable, but the shaft is some alloy that doesn't like it.

In reply to clshore :

Torque is not an issue so much as harmonics.

Duckworth came up with a remarkably obvious in hindsight solution for harmonics issues with the Cosworth DFV (I think), and this was an engine with one piece camshafts.  The cam drive drives a quill that splines into the camshaft at its middle.

I guess technically the cams are two piece  but the point is he had to engineer a way to have a center mount cam drive to beat a harmonics issue.

I wonder if Moldex Crankshafts might be able to refer you to someone?  Moldex makes custom billet crankshafts and have been around forever.  They're in the metro Detroit area.  

Also, Cam Research specializes in Ford camshafts.  Perhaps they can point you in the right direction?

Finally, LSM Systems Engineering in Waterford, MI notes they can make custom cams for anything.  I have no experience with any of these groups just places I've found.

We finally got quotes from a few shops to turn our spools, we've already talked with Bullet and they will be able to rough cut, heat treat and finish grind them to our specs.

I'm actually waiting for one last quote from LSM and then we'll make a call. I sent  them our drawings on Friday so hope they get back to me soon.

In case anyone is interested, most places have quoted a minimum of 8 cores, ranging from cheapest of $150 per spool (Chinese company through Alibaba) up to about $300 per core from the Swedish company AGAP.

All assuming 8620 steel. Actually, AGAP is quoting us 16NiCrS4, which they claim is equivalent to 8620. 

Besides the fact that I've never heard of or bought anything of these Chinese companies in Alibaba, I almost just want to order them to see how they come out. I am more curious than anything. Their lead time is about 20 days, and just browsing through their websites, some of them have a pretty serious operation going. They did require both drawings and 3D files, which is not something LSM or AGAP required, all they needed was the 2D. Not worried about it though, Xometry also requires 3D so I think it's more about their process and what they need to properly program their CNC machines.

I'll give another update once we get the final quote from LSM and decide which route to go. I'll of course post updates as we get the spools back and finally the finished product.

Moral of the story:

Get your own CNC machine and make everything yourself.